Recession-Related Surge in Nursing Employment Just a Blip, Study Cautions

The worst economic recession in the post–World War II era has shed jobs across almost all industrial sectors, pushing the national unemployment rate close to 10%. Yet for one group in the slowing but still robust healthcare sector — hospital-based registered nurses (RNs) — the current economic downturn has led to a record employment spike, according to a study published online June 12 in Health Affairs.

However, this spike is only temporary, warns lead author Peter I. Buerhaus, PhD, RN, the Valere Potter Professor of Nursing at Vanderbilt University School of Nursing, Nashville, Tennessee. "We've eased the nursing shortage, but we haven't permanently ended it," Dr. Buerhaus told Medscape Nursing.

The history of such shortages, Dr. Buerhaus and the study coauthors write, is inversely related to the general health of the economy: RNs are in short supply during boom periods and are available to fill vacancies when the economy is spiraling down.

In 2001, 3 years after hospitals began reporting difficulty filling vacancies, RN shortages peaked. With vacancy rates reaching a national average of 13%, an estimated 126,000 full-time-equivalent (FTE) RN positions went unfilled, forcing "many hospitals to close nursing units and restrict operations."

The 2001 recession altered this trend. Faced with a bad economy and the prospect of reduced family income, nurses already in the workforce increased their hours, and those who had left it returned, in part to take advantage of the substantially higher RN wages that hospitals began offering in 2002. The exigencies of the recession, coupled with the lure of higher wages, worked like a magnet: During the next 2 years, hospital RN employment surged by 184,000 FTE RNs. "At the time, that was a world record — right off the charts," Dr. Buerhaus said.

But if hospital officials thought their nurse vacancy problems were solved, they were wrong. Once the economy recovered, the shortage problem reasserted itself. In fact, the annual growth in FTE RN employment between the economic boom years of 2004 and 2006 was −0.9%. It has taken this most recent recession, which some argue started as early as the final months of 2007, to reverse the nursing shortage problem yet again.

In 2007 and 2008, according to the study, hospital-based RN employment increased by an estimated 243,000 FTEs. As in the 2001 recession, bad economic times have pushed nurses back into the labor market, and for many of the same reasons as before. But the lure of higher wages is not among them; for the most part, said Dr. Buerhaus, hospitals did not increase RN wages in 2007 and 2008. That fact, he says, makes the dramatic surge in RN employment during this recession all that more surprising. "From our past studies, we knew the effect the recession would have. But we were completely stunned by the size of the increase. Looking back, there's simply no 2-year period of growth in the hospital employment sector that rivals this one."

For nurses fresh out of school, the influx of new hires has not always worked to their benefit. "Their ability to find the job of their dreams in the hospital down the street from where they live has probably changed," Cheryl Peterson, MSN, RN, director of Nursing Practice and Policy at the American Nursing Association, told Medscape Nursing. "We've also found that employers can be a little more selective these days, holding out for someone with more experience rather than hiring a recent graduate or someone with limited experience."

Despite the trend toward older, more experienced hires, however, younger nurses are by no means absent from the workforce. In 2008, for example, the number of FTE RNs aged 23 to 25 years — 130,000 — was the highest it has been in more than 2 decades, according to the study. In addition, in 2008 there was a large jump in the number of younger FTE nurses with children younger than 6 years, compared with in 2007 — a phenomenon the authors say is related to families' efforts to boost their incomes during hard economic times. Overall, in 2008, employment of RNs younger than 35 years increased by a dramatic 74,000, with most ending up in hospital-based jobs.

Getting a Handle on Looming Shortages

Given the oddly cyclical nature of nurse employment, however, few if any in the nursing community are sanguine about the recent employment surge. "We can't be lulled into thinking that the problem of a shortage is over," said Ms. Peterson.

Similar to past shortages, Dr. Buerhaus said, future ones will be driven by the interaction of supply and demand. On the demand side, he and his coauthors lean heavily on projections outlined by the federal Health Resources and Services Administration (HRSA). Noting that "changing demographics constitute a key determinant of projected demand for FTE RNs," HRSA points to the "much greater per capita healthcare needs" of an aging baby boom generation, the leading edge of which will approach age 65 years starting around 2010.

Dr. Buerhaus and coauthors also consider something likely to drive demand that HRSA does not — the prospect that healthcare reform will expand coverage to more citizens, thereby placing even greater pressure on the nursing workforce.

On the supply side of the equation, the authors say, the waves of baby boomer RNs retiring during the next decade will be significant. So too will be the prospective size of the successive cohorts that will replace them. Will these cohorts be large enough to keep the workforce from shrinking, and yet too small "to meet the projected demand"? If so, the authors say, a much older RN workforce than ever before may be left to do the heavy lifting.

Action Plan for Policymakers

The authors conclude by proposing a series of action steps for policymakers. They want to strengthen the current workforce and, in particular, to "improve the ergonomic environment of the clinical workplace" for older nurses. They want to improve communication skills, especially for RNs educated in other countries — a group that has not only helped to fuel the current surge but also is likely to play a significant role in future supply scenarios. Perhaps most notably, they want to see steps taken to expand the numbers of 2 "underrepresented" groups in nursing — men and Hispanics.

Representatives of each group are sympathetic, although they cite challenges.

"We're up against the historical image of men as doctors and women as nurses," Demetrius J. Porsche, DNS, RN, dean of the Louisiana State University Health Center School of Nursing and president of the American Assembly for Men in Nursing, told Medscape Nursing. Among the barriers to full participation that Dr. Porsche sees are unsupportive families, school counselors who "don't understand that nursing is an autonomous profession, not just a handmaiden to doctors," and too few public images of men in the profession. Each year, Dr. Porsche explained, the American Assembly for Men in Nursing presents a series of awards aimed at enhancing the status of men in nursing, including one for the best workplace and another for the best nursing school/college.

"The push for men in nursing is a diversity issue," he said. "The profession should be open and welcoming not only to all races and ethnicities but to both genders."

Anyone recruiting Hispanics to nursing also faces barriers, said Norma Martinez-Rogers, PhD, RN, FAAN, associate clinical professor in the Department of Family Nursing at the University of Texas Health Science Center, San Antonio, and president of the National Association of Hispanic Nurses.

The biggest barrier, Dr. Martinez-Rogers told Medscape Nursing, is money. Despite some funding, she said, "many Hispanic students end up having to pay back big loans." Then there's the work issue, she added. Used to holding down part-time jobs to make ends meet before entering nursing school, too many Hispanic students try, at their peril, to duplicate that work schedule once enrolled. "Nursing school is all about the application of the content that you're learning, which is very time consuming," Dr. Martinez-Rogers said. "Students can hold down part-time jobs, but they risk having to repeat a course."

Hoping for more funding and support for what she characterizes as "not a brand-new problem," Dr. Martinez-Rogers has been talking to the Congressional Hispanic Caucus about renewed efforts to bring more Hispanics into nursing. One step would be to work with universities — her own included — that have the potential, because of their location, to enroll significant numbers of Hispanic nursing students. Once enrolled, she said, such students need to be mentored while in school and encouraged after they graduate. Her own university has what she described as a "student-driven" mentorship program; for its part, the National Association of Hispanic Nurses is working to develop its own national mentorship program.

Dr. Buerhaus thinks that expanding the capacity of educational programs — for Hispanics, men, and anyone else interested in becoming a nurse — is key. So, too, he said, is turning out the "right" nurses: "Beyond all the rhetoric, we need the future nurse to be really, really sharp in the areas of both quality and safety."

The ANA's Cheryl Peterson agrees, but added that nursing education "can't change on a dime" and that employers must also do their part by giving the freshly minted nurse the necessary "space to learn."

Source : http://www.medscape.com/viewarticle/704668?sssdmh=dm1.488649&src=nldne

Administration of PRN Range Opioid Analgesic Orders for Acute Pain

Abstract

The use of "as needed" or "pro re nata" (PRN) range opioid analgesic orders is a common clinical practice in the management of acute pain, designed to provide flexibility in dosing to meet an individual's unique needs. Range orders enable necessary adjustments in doses based on individual response to treatment. However, PRN range opioid orders have recently come under scrutiny as a source of confusion and as a medication management safety issue. How nurses administer range orders may vary based on their interpretation of the intent of an order, inadequate knowledge of analgesic titration, or exaggerated concerns about opioid safety. The purpose of this study was to investigate nurses' opinions of the appropriate implementation of range orders. Six hundred two nurses from one large academic medical center and one multihospital system completed an online survey using theoretic clinical vignettes to examine their opinions of appropriate analgesic administration practices. The majority of participants chose appropriate responses to the vignettes; however, there was a great deal of variability in responses. Those who had attended pain management courses were more likely to have a higher percentage of appropriate responses than those who had not attended courses. Years in practice and educational level were not significantly related to percentage of appropriate responses; however, there was a trend for nurses with a master's degree to have a higher percentage than nurses with other educational preparation. Consideration of opioid pharmacokinetics can provide logic to develop a new paradigm where range orders are replaced with orders that provide more explicit instructions to titrate an opioid to the most effective dose.

Introduction

Opioids are commonly used to manage moderate to severe acute pain. The amount of opioid required to manage pain is known to vary widely owing to inter- and intraindividual responses to pain and the available opioid analgesics. The use of "as needed" or "pro re nata" (PRN) range opioid analgesic orders is an age-old conventional practice in the management of acute pain, designed to provide flexibility and safety in dosing to meet an individual's unique needs. However, pain is often undertreated because physicians underprescribe opioid analgesics (order inappropriately low doses or prolonged dosing intervals) and nurses administer inadequate doses (give the lowest doses in a provided dose range despite indications that a higher dose is necessary) (Pasero, Portenoy, & McCaffery, 1999).

In 2001, the Joint Commission (JC) incorporated pain management standards into their survey and accreditation process as a means to stimulate improvements in the quality of pain care in the U.S. (Dahl & Gordon, 2002). Simultaneously, a series of national consensus meetings led by the Institute of Medicine fueled the development of a set of national patient safety goals (Chassin, Galvin, & National Roundtable on Healthcare Quality, 1998). Among these goals is a heightened focus on improved communication among caregivers and medication safety, including the use of opioids. The JC Medication Management standard (MM 3.20) states that medication orders are to be written clearly and transcribed accurately and that hospitals are responsible for taking steps to reduce the potential for error or misinterpretation. An important element of compliance with this standard is "there is a documented diagnosis, condition, or indication-for-use for each medication ordered," emphasizing the need for clear understanding and communication between staff (Joint Commission, 2007).

Following the release of the pain management standards and development of national patient safety goals, JC surveyors began inquiring into institutional policy and procedures surrounding the use of PRN range opioid orders. During accreditation reviews, surveyors encouraged detailing in range orders, such as the designation of specific dose or route of analgesia based on pain intensity ratings. The slogan of pain as the "fifth vital sign," originally developed to increase visibility of pain assessment in the clinical arena (APS, 1995), became misconstrued by some as an edict to treat to a target pain rating. With the encouragement of JC surveyors, many institutions developed policies that led to the development of PRN orders based solely on patient report of pain intensity indexed with a numeric scale. An example of this type of order is: "one tablet oxycodone 5 mg orally (PO) for pain less than or equal to 4/10 (scale 0-10); two tablets oxycodone 5 mg PO for pain 5 to 7/10; morphine 2 mg intravenous (IV) for pain 7-8/10; morphine 4 mg IV for pain greater than 8/10." Regrettably, this approach was soon linked to increased rates of significant adverse events (Taylor et al 2003, Vila et al 2005). In one setting (Vila et al., 2005), the incidence of opioid oversedation episodes per 100,000 inpatient hospital days increased from 11 before implementation of a numeric pain rating treatment algorithm to 24.5, a more than twofold increase (p < .001). Although practice guidelines recommend that the choice of analgesic be based on the severity of pain, the route and amount of medication must always be individualized (APS, 2003).

In response to questions and concerns by clinicians about the course of range order policies, the American Society for Pain Management Nursing, in collaboration with the American Pain Society (APS), developed a national consensus statement to support and clarify the use of PRN opioid analgesic range orders (Gordon, et al., 2004). To date, the APS nursing special interest group E-mail listserve, whose members have a special interest or specialize primarily in pain management nursing, (http://mailman.listserve.com/listmanager/listinfo/apsnursingsig) continues to reverberate with ongoing debate and questions about range order competencies and policies. There are at least two sources of common confusion for nurses about a PRN range order. The first is which dose to administer from within a range. The second is the total time interval during which the maximum dose may be administered. In other words, what dose is safe, effective, and within the prescribed parameters? Considerations for dosing have previously been described (Gordon et al., 2004) and include patient and drug characteristics, such as the patient's prior drug exposure, prior responses to analgesics, age, organ function, pain severity, anticipated pain duration, comorbid conditions, and concomitant drug use. The "total time interval" dilemma has also been described (Pasero, Manworren, & McCaffery, 2007). Some nurses may believe the time interval is defined by the time of the first dose, whereas other nurses may interpret the time period as starting from the most recent dose. The latter is referred to as the "rolling-clock" time interval (Pasero, Manworren, & McCaffery, 2007), whereby the time interval ordered serves as the limiting and pivotal guidepost; the maximum cumulative dose should not be exceeded in any block of the ordered time interval.

Management of acute pain, including the administration and titration of range opioid analgesic orders and patient monitoring, is a critical nursing responsibility. Identification of beliefs that result in variable administration of PRN range orders may further facilitate national recommendations about how to construct range orders that will improve patient safety and outcomes in pain management. The purpose of the present study was to document nurses' opinions of the appropriate implementation of a range order. The research questions were:

1. How much agreement is there among nurses about the administration (timing and dosing) of analgesics ordered with a PRN range order?
   
   
2. Do respondent characteristics (such as education, years of nursing experience, pain course attendance) affect knowledge and/or comfort in titration and vignette responses?
   
   
3. What factors do nurses consider when selecting a dose to administer from a range order?

Methods

The study was conducted at one 471-bed academic medical center in the Midwestern U.S. and a multihospital system with five operating units (2,102 total beds) located in a mid-Atlantic state. The study protocol was reviewed and given exemption status by the Institutional Review Boards at both sites. Data were collected from participants using a self-administered internet-based questionnaire that took approximately 10-15 minutes to complete. Risks were considered to be minimal, because data were aggregated via a security-protected public online survey service (http://www.vovici.com/). The internet protocol (IP) addresses were analyzed only in aggregate for the two participating sites; no connection was made between individuals and a computer's IP address or compliance. Participation in the study was voluntary. Respondent confidentiality was ensured throughout all stages of the study. No identifying information including age or gender was collected. All 611 licensed nurses at one site were individually contacted via e-mail with an invitation to participate in the study and were provided a link to enter the web-based survey. Because the second site did not provide individual nurses with email accounts, all nursing staff, totaling 3,323, were invited to participate via a notice posted on the health system home web page.

The questionnaire was developed by the authors and pretested among five staff nurses who completed the questions and then discussed the clarity of the specific items with the authors. The final 15-item questionnaire included items on the following: level of nursing education and practice experience; usual patient population and practice setting; special training, course, or certification in pain management; knowledge/comfort level of opioid titration; patient vignettes for determining timing and dose titration of IV and PO opioids; and the three most important factors to consider when selecting a dose to administer from within a range order. The vignettes are described in the Results section of this article.

Data Analysis

Descriptive statistics were run for respondent characteristics and answers to the vignettes. Each answer to the vignettes was then coded as appropriate (preferred) (given 1 point) or not appropriate (not preferred) (given 0 points). The majority of vignettes were constructed to elicit a response of the soonest next dose based on peak effect of the route administered or the amount of a next dose based on a percentage upward titration. Answers were deemed to be appropriate or preferred if the choice was a dose administered at the time or just after peak effect of the previous opioid dose or if the answer was a dose that had previously been effective or represented a 50%-100% dose titration of a previously ineffective dose. Because of the difficulty in constructing a brief vignette with one correct answer, all but one question had two to three answers that were scored as appropriate. A total score was calculated for each respondent by totaling the number of appropriate answers. In final analysis, the authors could not agree on the preferred response(s) for the dose question in the second vignette and decided to delete that item from the total score analysis (see Titration discussion). Therefore, total scores could range from 0 to 6. Comparisons of responses were used to determine if there were associations between respondent characteristics and responses to clinical vignettes using chi-squared and t tests.

Results

Respondent Characteristics

A total of 602 participants completed the on-line survey in July and August 2007. Response rate was 222 (36%) for the site with individual E-mails and 378 (11%) for the site with only a web page invitation; two respondents did not identify their site. Table 1 summarizes the respondents' characteristics. The largest number of participants was baccalaureate-prepared RNs (56%). The largest percentage (27%) had more than 25 years of experience in nursing. Most (90%) worked with adult patients, with 22% identifying themselves as working with pediatric patients. Medical, surgical, and intensive care units were the most frequent responses for current practice settings. Forty-three percent had previous special training or had attended a course in pain management; however, only nine (2%) held certification in pain management by the American Nurses Credentialing Center.

Although both sites had a policy or written protocol for PRN opioid range orders, when asked if they were aware of one at their facility, slightly fewer than one-half said "yes." Forty-one percent were unsure of the existence of a policy. Nurses were also asked to rate on a 0-10 scale (0 = extremely uncomfortable; 10 = extremely comfortable) their knowledge/comfort level on how to titrate opioids. Titrate was defined as "to determine the effective dose by giving graduated increases or decreases in the amount of a drug." The mean rating was 5.98 (standard deviation [SD] 2.66); however, there was a large amount of variability in responses.

Timing and Titration

Four vignettes were included in the survey ( Table 2 ) for the administration of IV and PO opioid analgesics regarding timing and/or titration of opioids. The first described a situation in which a patient had a fourfold PRN range order for IV morphine (2 to 8 mg every 2 h). Following a first dose of 2 mg at 14:00, respondents were asked to choose how soon another dose could be given. The appropriate answers were 14:15 or 14:30. Sixty-eight percent of the respondents chose one of these answers ( Table 2 ). Twenty-three percent, however, chose to wait the entire 2-hour time period before giving another dose. Respondents were then asked what dose should be given assuming there was no change in pain rating, pain was still severe, and there were no side effects. Seventy-two percent chose 3 mg or 4 mg, which were the preferred answers ( Table 2 ).

The patient described in the second vignette had the same range order (2 to 8 mg IV morphine every 2 h PRN) and had received 2 mg at 12:00 and 3 mg at 13:30 with no relief from either dose. This was followed by a 6 mg dose at 14:00. Sixty-five percent of the respondents chose to wait until 15:30 or 16:00 (which was the appropriate answers) before giving a next dose ( Table 2 ). Twenty-nine percent would have given a dose as early as 14:15 or 14:30. Although a rolling-clock time interval approach would indicate that there is still another 2 mg available in the range order maximum, a 2 mg dose at 14:15 or 14:30 was not preferred, because it was considered to be a previously ineffective dose. At the time of the next dose the patient was described as having reported satisfactory relief with the previous dose of 6 mg, but the pain has returned. The patient is drowsy and arousable, but drifts off to sleep during conversation. Respondents were asked what dose of morphine they would next administer. Nearly one-half (49%) of the respondents chose 4, 5, or 6 mg ( Table 2 ), however, 25% chose none (see Titration discussion). Of note, this item was not included in the total score, owing to author disagreement regarding interpretation of the meaning of the phrase "drowsy and arousable, but drifts off to sleep during conversation."

The third vignette asked participants what they would do if they thought the next dose given to a patient should be less than what was ordered. The order stated "morphine 4 to 8 mg IV every 2 h PRN." The patient had received several doses of 4 mg 2 h apart with "good" pain relief and "no" side effects. Just over one-half (56%) of the respondents said they would call an MD to get an order change, which was the preferred response; however, 22% said they would increase the time between doses (which was considered to be inappropriate), and 22% would give some amount less than what was ordered (which was considered to be inappropriate) ( Table 2 ).

The final vignette presented an order for an oral opioid (oxycodone 5 to 20 mg every 4 h PRN). The patient received 5 mg at 08:00, 10 mg at 09:00, and 5 mg at 11:00. Nurses' opinions were again elicited for the soonest time the next dose could be given and the amount of the next dose if the patient has no change in pain rating and is still in severe pain with no side effects. Fifty-two percent of the respondents chose to give the next dose at 12:00 (preferred) ( Table 2 ). Many (23%) chose to wait a full 4 hours after the last dose, which was given at 11:00, before giving the next dose. Appropriate doses (15 to 20 mg) were chosen by 54% of respondents ( Table 2 ).

If respondents selected an appropriate answer for all vignettes they were given a total score of 6. The average total score for all respondents was 3.64 (SD 1.11). (As mentioned, the dose question in the second vignette was not scored.)

Relationship of Respondent Characteristics and Comfort in Titration and Vignette Responses

Increased comfort level with titration was associated with increased years of experience in nursing (Figure 1).

Figure 1.

Years of experience and comfort in titrating opioids (0 =extremely uncomfortable to 10 = extremely comfortable). *Nurses with <5>25 years of experience (p < .05).

Those with <5>25. Special training or course attendance was also associated with higher titration comfort levels. Respondents that had special training or attended a pain course had significantly higher confidence levels, (6.71 [SD 2.47]) than those who did not (5.43 [SD 2.68]); t = 5.88; p < .001. Comfort level with titration was not associated with total score for preferred answers.

Interestingly, there were no significant differences in total score of appropriate responses by years of experience or education level (Figure 2).

Figure 2.

Years of experience and total score for preferred answers (6 = maximum score, meaning all vignettes were answered with an appropriate or preferred response).

All groups had similar scores. Although not significant, there was a trend for respondents with a master's degree to score higher than other groups. Associate and baccalaureate degree graduates were very similar, and those with licensed/vocational and doctoral preparation tended to score slightly lower. There were no differences in scores between respondents who had previous special training or attended a course in pain management and those who did not. Only nine people were certified in pain management, so comparisons were not meaningful.

Factors to Consider in Opioid Administration

The four factors that were most often chosen as the most important to consider when selecting an opioid dose to administer from a range order were, in order of frequency: sedation level, pain intensity rating, respiratory rate, and the patient's prior response to dosing (Figure 3).

(Enlarge Image)

Figure 3. Respondents were asked to mark the three most important factors to consider when selecting a dose to administer from a range order. Discussion Timing A variable pattern of PRN range order administration is often observed in clinical practice. A range order such as "oxycodone 5 to 20 mg as needed every 4 h" might be administered over 24 hours using incremental doses and varying dosing intervals within any defined 4-hour time period. Although acute pain may vary widely between rest and activity, one must question if a patient's analgesic needs and responses to doses vary in a manner that would require two- to fourfold variations in dosages within a short time period of several days, or if variable patterns of administration more accurately reflect nurses wide range of comfort and opinions of order limits and knowledge of opioid titration. The results of the present study would seem to confirm the latter. It has been suggested (Pasero, Manworren, & McCaffery, 2007) that range orders could be designed similar to IV patient-controlled analgesia (PCA) to afford patients access to rapid administration when needed and minimize delays that can lead to worsened pain. Time to peak effect varies between opioids, ranging from 1 to 5 minutes for IV fentanyl, to 15 to 30 minutes for morphine and hydromorphone. With IV PCA therapy, the time interval or lockout period is set at 5 to 10 minutes for all opioids, allowing rapid maximum, yet safe, usage, because 80% of peak effect characteristically occurs within the first 5 minutes of bolus administration (Upton & Macintyre, 1997). The recommended hourly limit with IV PCA is three to five times the projected hourly requirement (APS, 2003). Thus it would seem rational to construct a PRN range IV opioid analgesic order in a manner that allows a nurse to repeat at least the same bolus dose at least every 15 minutes. Likewise, it would be reasonable to allow PRN doses of short-acting oral opioids as frequently as every hour. Onset of action of a short-acting oral opioid typically occurs within 45 minutes, with peak drug effect in 1 to 2 hours. It is therefore theoretically safe to provide a second dose at peak effect of a first dose of a short-acting opioid, provided the patient has unrelieved moderate to severe pain and there are minimal side effects. Although the use of a "rolling-clock" time interval approach clarifies the timing of PRN orders and facilitates a more consistent interpretation of cumulative dosing, it may hamper needed titration. For example, given an order of oxycodone 5 to 20 mg every 4 h PRN, a patient who has received a dose of 10 mg that resulted in inadequate pain relief would need to wait a full 4 hours before receiving an appropriate increased dose of 15 mg. Although the rolling-clock method provides nurses with a more literal interpretation than alternative time-interval approaches, it is less focused on the pharmacokinetics and pharmacodynamics of the analgesic being administered. Titration Titrate means to determine the effective dose by giving graduated increases or decreases in the amount of the drug. The APS suggests that repeat IV boluses can be used to titrate to a plasma concentration that provides effective pain relief, e.g., morphine 0.03 mg/kg (e.g., approximately 2 mg in a 150-pound individual), or the equivalent dose of a similar opioid every 10 minutes until there is a 50% reduction in pain or the patient reports satisfactory relief (APS, 2003). The total loading dose required can then be considered to be an effective dose for analgesia and made available as a PRN IV bolus dose for subsequent doses (Harris, Kumar, & Rajagopal, 2003). Alternatively, it has been suggested that subsequent doses be increased if at the time of peak effect the patient has minimal pain relief with minimal or no side effects (Mercadante, 2007). Based on pharmacologic observations (Hanks, DeConno, Cherny, Hanna, Kalso, & McQuay, 2001), the next dose can be increased by 50% to 100% for moderate to severe pain and by 25% for more minor adjustments (Pasero et al., 1999). Similarly, oral opioid doses could be titrated as soon as every hour and the total dose required for pain control could then be made available as the PRN dose, or several graduated increased doses could be used to find the most effective dose. This would require a more lengthy order set or use of a pre-established protocol, as described elsewhere (Pasero et al., 2007). For example a one-time order reads: "Give 10 mg PO oxycodone now; if after 1 h pain is unrelieved and there are no side effects give 20 mg PO oxycodone; if 1 hour later pain continues to be unrelieved and there are no side effects give a third dose of 30 mg PO oxycodone." However, multiple orders would be required for slower titration for conditions of unrelieved pain in the presence of side effects and to also stipulate that the dose that was found to be effective is then the only available PRN dose. Beyond understanding the pharmacokinetics of opioid analgesics, titration and use of range orders requires nurses to properly evaluate patient status before administration of an opioid dose. The second vignette in the present survey demonstrated the complexity of decision making when a nurse implements an opioid range order and the need to understand how to lower a dose or titrate down. Recall that the patient in the vignette was given a 6 mg dose and reported "satisfactory" pain relief with a reduction of severe pain to moderate pain. The decision to administer an equal or larger subsequent dose should be an easy one in patients who experience a return of severe pain, provided there are no or minimal side effects. However, the patient in this vignette was described as being excessively sedated and "drifting off to sleep during conversation" at the time of the subsequent dose (which, as noted, resulted in significant author debate and exclusion from the total score). A reasonable and safe action in such a situation is to hold opioid analgesia and any other sedating agents (chosen by 25% of respondents), promptly inform the physician of the patient's status, request an order for nonsedating analgesia, and investigate the possible cause of the excessive sedation. Reducing the dose by 25% to 50% and waiting to administer it until the patient is less sedated are also appropriate actions. Thirty percent chose to administer a dose in this dose reduction range (3, 4, or 5 mg), whereas 24% chose to repeat the previous dose of 6 mg which, although effective for pain, had resulted in a significant side effect. Nurse monitoring of sedation level is frequently cited as an essential function when caring for patients receiving opioids (Pasero and McCaffery 2002, Pasero et al 1999). Indeed, sedation level was cited most often by just over one-half (56.6%) of the respondents when they were asked to choose the three most common factors to consider when selecting an opioid dose. However, this means that nearly one-half of the respondents did not appreciate the importance of sedation assessment and underscores the need for reinforcement of this aspect of safe opioid administration. Relevance of Findings Although one-half to two-thirds of the nurses chose what we considered to be reasonably appropriate responses, the other one-third to one-half chose answers indicating that they err on the side of conservative administration of PRN opioid orders even in the presence of severe pain and minimal or no side effects. This may be explained by being less knowledgeable or comfortable with how to titrate opioids, or by variability in how nurses interpret the time interval. Nearly one-fourth of all of the nurses consistently chose responses that would delay or underdose a patient. Alarmingly, 21% of nurses indicated they would give a dose less than what was ordered without first calling a physician. These findings are of concern on at least two levels. First, this indicates that some nurses may not always follow the basic nursing principle that requires them to contact the prescriber when, for whatever reason, the nurse is unable to follow an order. Second, the decision to give less than allowed by the range order could result in loss of stabilized pain control; recall that the patient described in the third vignette had good pain relief and no side effects from 4 mg of IV morphine every 2 hours. The present findings are similar to those of another study that showed 38% of the nurse respondents thought patients should experience pain before giving a subsequent dose and should not be maintained in a "pain-free" state (Howell, Butler, Vincent, Watt-Watson, & Stearns, 2000). We could find nothing in the literature that described nurses' independent decisions to give less opioid than prescribed in a range order; however, research has shown that nurses will often administer less opioid than allowable when the opioid is prescribed as a PRN dose (Pasero et al 2007, Titler et al 2003). Surveys have consistently shown that nurses tend to select lower PRN doses or withhold analgesics even when a patient's condition warrants the need for more analgesia (McCaffery, Pasero, & Ferrell, 2007). In a study of pain assessment and analgesic administration in elders, Titler et al. (2003) found that the patients in their sample received 25% of the minimum parenteral morphine equivalent of opioid prescribed and that eight patients received no analgesic whatsoever despite having PRN orders for analgesics and demonstrating behaviors indicative of moderate to severe pain. Boer et al. (1997) studied the administration of analgesics that were prescribed in scheduled doses to 150 postoperative patients and found that naproxen and acetaminophen plus codeine were often administered as prescribed. However, patients in the study almost never received the total prescription of parenteral morphine. Nurses cited fears of addiction and respiratory depression and a preference for nonopioid analgesics as reasons for failing to administer the scheduled morphine doses. These findings indicate that nurses should be reminded that the flexibility in dosing made possible by a range order does not include adjusting the dose limits of the order. They should be encouraged to always communicate with other members of the health care team when they think it is necessary to administer more or less opioid than is prescribed. Limitations There are a number of limitations to this study. The survey involved a convenience and voluntary sample of nurses who may not be representative of all nurses. Recruitment was different in the two sites based on E-mail availability. Those who have internet access and/or use E-mail may represent a different group from nurses who do not. A major limitation is the difficulty of using simple vignettes to mirror the complex reality of a patient condition and the comprehensive assessment and decision making nurses perform. No psychometrics analysis was performed in the construction of the nurse survey. Finally, although the authors determined appropriate answers based on onset, peak, and duration of IV and PO short-acting opioids, there were no absolute right or wrong answers. Summary Although the use of PRN range opioid analgesic orders has long been a familiar strategy in the inpatient setting, the safety of this practice has recently been called into question owing to concerns about the literal clarity of the orders and the competency of both prescribers and nurses who administer the opioids. Policies and practices that construct range orders in a manner that ties a specific dose or route to a pain-intensity rating raise serious concerns about potential harm. This study demonstrates nurses' variable opinions and likely practices related to selecting a dose from within a range and their decisions on how to space doses within a designated time period. For institutions, the findings of this study underscore the importance of conducting a multidisciplinary examination of range order practices and the need to increase efforts to educate prescribers in how to write appropriate range orders and nurses in how to implement them to provide effective and safe analgesia. A closer examination of opioid pharmacokinetics can provide logic to develop a new paradigm where range orders are replaced with titration orders. Clear understanding and communication between staff involved in the medication administration process is essential. Nurses should work together with colleagues in pharmacy and medicine to develop and study the safety of alternative ways of constructing orders that would more clearly guide titration of an opioid to meet a patient's need.Benedetti et al., 1998, ISMP (2002) Source : http://www.medscape.com/viewarticle/580915

Pacemaker and Automatic Internal Cardiac Defibrillator

Basic Concepts

Introduction

Pacemakers and implantable cardioverter defibrillators (ICDs) have been in use for more than 20 years. With expanding indications and an ever-growing elder population, emergency physicians must be familiar with emergent indications for their application, discontinuation, and complications arising from a patients’ existing device. This article introduces the common problems encountered with pacemakers and ICDs, and rescue techniques that may aid in treating such complications.

Pacemaker and ICD basics

Permanent pacemakers are implanted devices that provide electrical stimuli, thereby causing cardiac contraction when intrinsic myocardial electrical activity is inappropriately slow or absent. These devices sense intrinsic cardiac electric potentials and, if too infrequent or absent, they transmit impulses to the heart to stimulate myocardial contraction.

An ICD is a specialized device designed to directly treat a cardiac tachydysrhythmias. If a patient has a ventricular ICD and the device senses a ventricular rate that exceeds the programmed cut threshold, the device performs antitachycardia pacing. With antitachycardia pacing, the device fires a preset number of rapid pulses in succession in an attempt to terminate the ventricular tachycardia. If unsuccessful, the device will perform a cardioversion/defibrillation.

Newer-generation ICDs are also equipped with an intrinsic bradycardia demand pacing system, and some, if required, are a combination of an ICD and a pacemaker. It is important to be aware that some of the older models (more than 10 years old) may lack this function.

Pacemaker and ICD anatomy

Pacing systems consist of a pulse generator and pacing leads. With permanent systems, endocardial leads are inserted transvenously and advanced to the right ventricle and/or atrium where they are implanted into the myocardial tissue. The pulse generator is placed subcutaneously or submuscularly in the chest wall.

Pulse generators contain a battery as well as sensing, timing and output circuits. The battery (most commonly lithium-iodide) typically has a life span of 5-10 years.

During pacemaker placement, signal amplitude and width are set high enough to reliably achieve myocardial capture, yet low enough to maximize battery life.

Temporary systems use an external pulse generator with leads placed either transcutaneously or transvenously. Transcutaneous leads are the easiest and most convenient to use for rapid application of temporary pacing and is the method of choice during ED resuscitation. Once the patient is stabilized or central venous access is gained, transvenous leads provide the most reliable pacing mechanism and are a good transition to permanent systems.

For transvenous temporary pacing, semirigid catheters are inserted through a central venous access. ECG monitoring (specifically V₁) is used to track catheter positioning. For example, P-wave morphology is initially inverted and becomes upright as the catheter is in line with the SA node. QRS morphology is also initially inverted, transitioning to isoelectric and then upright as the tip is placed in the apex. An injury pattern resembling ST elevation ensures that the catheter tip is in proper positioning for pacing. Semifloating or flexible balloon-tipped catheters can be used in emergencies since they can be positioned without such monitoring.

Transcutaneous pacing is discussed in detail in a separate article (see External Pacemakers).

Pulse generators can be set to fixed-rate (asynchronous) or demand (synchronous) modes. In the asynchronous mode, impulses are produced at a set rate independent of intrinsic cardiac activity. This mode carries a small but inherent danger of producing lethal dysrhythmias should the impulse coincide with the vulnerable period of the T wave. In the synchronous mode, the sensing circuit searches for an intrinsic depolarization potential. If this is absent, a pacing response is generated. This mode closely mimics intrinsic myocardial electric activity.

Pacing Codes

The Heart Rhythm Society and the British Pacing and Electrophysiology Group (BPEG) have developed a code to describe various pacing modes.

Table 1.Pacemaker Code Used to Describe Various Pacing Modes

Table

1st Letter	2nd Letter	3rd Letter	4th Letter	5th Letter
Chamber Paced	Chamber Sensed	Response to Sensing	Programmability and Rate Modulation	Antitachyarrhythmia Function
A	A	T	P	P (pacing)
V	V	I	M	S (shock)
D	D	D	C	D (dual: pacing + shock)
	O	O	R
			O

1st Letter	2nd Letter	3rd Letter	4th Letter	5th Letter
Chamber Paced	Chamber Sensed	Response to Sensing	Programmability and Rate Modulation	Antitachyarrhythmia Function
A	A	T	P	P (pacing)
V	V	I	M	S (shock)
D	D	D	C	D (dual: pacing + shock)
	O	O	R
			O

Abbreviations: A, atrium; V, ventricle; D, dual (both chambers); O, none; T, triggered; I, inhibited; D, double (atrial triggered and ventricular inhibited); P, simple programmability; M, multiprogrammable; C, communicating (telemetry); R, rate adaptive.

Pacing code explanation:

A typical pacing code consists of 3-5 letters.

• The first letter indicates the chamber(s) paced.
  • A: Atrial pacing
  • V: Ventricular pacing
  • D: Dual-chamber (atrial and ventricular) pacing
• The second letter indicates the chamber in which electrical activity is sensed.
  • A, V, or D
  • O is used when pacemaker discharge is not dependent on sensing electrical activity.
• The third letter refers to the response to a sensed electric signal.
  • T: Triggering of pacing function
  • I: Inhibition of pacing function
  • D: Dual response (ie, any spontaneous atrial andventricular activity will inhibit atrial and ventricular pacing and lone atrial activity will trigger a paced ventricular response)
  • O: No response to an underlying electric signal (usually related to the absence of associated sensing function)
• The fourth letter represents programmability and rate modulation.
  • P: Simple programmable
  • M: Multiprogrammability
  • C: Communication
  • R: Rate-response ("physiologic") pacing
  • O: No programmability or rate modulation
• The fifth letter represents presence of antitachyarrhythmia function.
  • P: Pacing (antitachyarrhythmia)
  • S: Shock
  • D: Dual (pacing + shock)

Although the first 3 letters are used most commonly, a 5 position code is currently in use. The first position denotes the chamber(s) paced; the second position denotes the chamber(s) sensed; the third position denotes the action(s) performed; the fourth position denotes rate response; finally, the fifth position denotes antitachyarrhythmia function.

More modern pacemakers have multiple functions. The simplest settings are VVI and AAT. The VVI mode senses and paces the ventricle and is inhibited by a sensed ventricular event. Alternatively, the AAT mode senses and paces in the atrium, and each sensed event triggers the generator to fire within the P wave.

The most common setting, DDD mode denotes that both chambers are capable of being sensed and paced. This requires two functioning leads, one in the atrium and the other in the ventricle. In the ECG, each QRS is preceded by 2 spikes, The first indicating the atrial depolarization and the second indicating the initiation of the QRS complex. Given that one of the leads is in the right ventricle, a left bundle-branch pattern may be evident on ECG. Note that a 2-wired system does not necessarily need to be in DDD mode, since the atrial or ventricular leads can be programmed off. Additionally, single tripolar lead systems are available that can sense atrial impulses and either sense or pace the ventricle. Thus, this system provides for atrial tracking without the capability for atrial pacing and can be used in patients with atrioventricular block and normal sinus node function.

Pacemaker programming can be performed noninvasively by an electrophysiology technician or cardiologist. Because of the myriad of pacemaker types, patients should carry a card with them providing information about their particular model. This information is crucial when communicating with the cardiologist about a pacer problem. However, most pacemaker generators have an x-ray code that can be seen on a standard chest radiograph. The markings, along with the shape of the generator, may assist with deciphering the manufacturer of the generator and pacemaker battery.

For further information or locations of technicians for pacemaker devices, the device company can be contacted at the 24-hour help line telephone numbers below.¹

• Guidant (Boston Scientific) - 800-CARDIAC (800-227-3422)
• Medtronic - 800-MEDTRONIC (800-633-8766)
• St. Jude Medical - 800-722-3774

Pacemaker and ICD Indications

Pacemaker indications

Absolute indications for pacemaker placement include the following:

• Sick sinus syndrome
• Symptomatic sinus bradycardia
• Tachy-brady syndrome
• Atrial fibrillation with sinus node dysfunction
• Complete atrioventricular block (third-degree block)
• Chronotropic incompetence (inability to increase the heart rate to match a level of exercise)
• Prolonged QT syndrome
• Cardiac resynchronization therapy with biventricular pacing

Relative indications include the following:

• Cardiomyopathy (hypertrophic or dilated)
• Severe refractory neurocardiogenic syncope

Temporary emergency pacing is indicated for therapy of significant and hemodynamically unstable bradydysrhythmias and for prevention of bradycardia-dependent malignant dysrhythmias. Examples include refractory symptomatic sinus node dysfunction, complete heart block, alternating bundle-branch block, new bi-fascicular block, and bradycardia-dependent ventricular tachycardia. Examples of indications for prophylactic temporary pacing include insertion of a pulmonary artery catheter in a patient with an underlying left bundle-branch block, use of medications that may cause or exacerbate hemodynamically significant bradycardia, prophylaxis during the perioperative period surrounding cardiac valvular surgery, Lyme disease or other infections (Chagas disease) that cause interval changes, and prolonged PR intervals.

ICD indications²

(For further reading and a detailed list of indications, see ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities.³ )

Indications for ICDs include the following:

• Survivors of cardiac arrest due to ventricular fibrillation (VF) or hemodynamically unstable sustained ventricular tachycardia (VT) after evaluation to define the cause of the event and to exclude any completely reversible causes
• Structural heart disease and spontaneous sustained VT (stable or unstable)
• Syncope of undetermined origin with clinically relevant, hemodynamically significant sustained VT or VF induced at electrophysiological study
• Patients with left ventricular ejection fraction (LVEF) <35%>
• Nonischemic dilated cardiomyopathy with LVEF ≤35% and NYHA functional Class II or III
• Left ventricular (LV) dysfunction due to prior MI, ≥40 days post-MI, with LVEF <30%,>
• Nonsustained VT due to prior MI, LVEF <40%,>
• Unexplained syncope, significant LV dysfunction, and nonischemic dilated cardiomyopathy
• Sustained VT and normal or near-normal ventricular function
• Hypertrophic cardiomyopathy who have 1 or more major risk factors for sudden cardiac death (SCD)

Initially, ICDs were used for secondary prevention in patients who had documented life-threatening ventricular arrhythmias and survivors of cardiac arrest. A meta-analysis of 3 large trials, principally, Antiarrhythmics vs Implantable Defibrillator (AVID) study,⁴ the Cardiac Arrest Study Hamburg (CASH),⁵ and the Canadian Implantable Defibrillator Study (CIDS),⁶ showed patients in the ICD group had significant reduction in all-cause death and death from arrhythmia. Further analysis of the CIDS trial with an 11-year follow-up revealed that the benefit of ICD over amiodarone increased with time.⁷

Recent trials suggest ICDs are beneficial for primary prevention of sudden cardiac death. Multiple trials have demonstrated that primary prevention in post-MI patients with reduced ejection fraction, nonsustained VT, and inducible nonsuppressible VT in electrophysiological testing with ICD over conventional medical therapy saved lives.^8,9 Further studies have shown that primary prevention using ICDs in other patient subset groups is also beneficial.^{10,11,12,13,14}

For further detailed discussion and evidence supporting ICDs, see Implantable Cardioverter-Defibrillators.

Magnet Inhibition

Placing a magnet over a permanent pacemaker closes an internal reed switch to inhibit sensing. This temporarily "reprograms" the pacer into asynchronous mode. It does not turn the pacemaker off. Each pacemaker type has a unique asynchronous rate for beginning-of-life (BOL), elective replacement indicator (ERI), and end-of-life (EOL). Therefore, application of a magnet can determine if the pacer's battery needs to be replaced. Further interrogation or manipulating of the device should be performed by an individual skilled in the technique.

Although many different branded pacemaker/ICD magnets are available, emergency physicians should be aware that in general any pacemaker/ICD magnet can be used to inhibit the device.

It is worth mentioning that, when a magnet is applied to an ICD, it can temporarily turn off defibrillation therapy without altering its backup bradycardia pacing, this is further described later in the article .

Pacemaker Malfunctions and Complications

Major pacemaker malfunctions include the following:

• Failure to output
• Failure to capture
• Failure to sense
• Pacemaker-mediated tachycardia
• Runaway pacemaker
• Pacemaker syndrome
• Twiddler's syndrome

Failure to output

Failure to output occurs when no pacing spike is present despite an indication to pace. This may be due to battery failure, lead fracture, fractured lead insulation, oversensing (inhibiting pacer output), poor lead connection at the takeoff from the pacer, and "cross-talk" (ie, a phenomenon occurring when atrial output is sensed by a ventricular lead in a dual-chamber pacer).

Management of pacer output complications includes medications to increase the intrinsic heart rate and placement of a temporary pacer. A chest radiograph is warranted to check pacer leads and to evaluate for possible lead fracture, which occurs most commonly at the clavicle/first rib. The patient's pacer identification card should be obtained and his/her electrophysiologist/cardiologist consulted.

Failure to capture

Failure to capture occurs when a pacing spike is not followed by an atrial or a ventricular complex. This may be due to lead fracture, lead dislodgement, fractured lead insulation, an elevated pacing threshold, myocardial infarction at the lead tip, drugs (eg, flecainide), metabolic abnormalities (eg, hyperkalemia, acidosis, alkalosis), cardiac perforation, poor lead connection at the takeoff from the generator, and improper amplitude or pulse-width settings. Fibrosis at the endocardial surface where leads were implanted may also occur in the weeks following pacemaker implantation. The fibrosis may create an electrical resistance barrier preventing ventricular depolarization.

Managing pacer capture complications is similar to treating output complications, with extra consideration given to treating metabolic abnormalities and potential myocardial infarction. Temporary pacing is used to stabilize the patient until an electrophysiology technician or cardiologist can further evaluate the pacemaker.

Oversensing

Oversensing occurs when a pacer incorrectly senses noncardiac electrical activity and is inhibited from pacing. This may result in a heart rate lower than the preset rate. This form of output failure may be due to muscular activity (particularly the diaphragm or pectoralis muscles), electromagnetic interference (MRIs), or fractured lead insulation. Oversensing is one condition that is diagnosable and treatable with magnet application. As mentioned before, magnet application will convert the pacemaker to asynchronous mode, and it will then operate at the preset rate.

Of note, recently, it has been reported that cellular phones held within 10 cm of the pulse generator may elicit this response.

Individual ICD manufacturers also have recommendations for unsafe devices that may interact with the ICD. (For example, Safe and Unsafe devices - Medtronic Brochure for Patients¹⁵ )

Undersensing

Undersensing occurs when a pacer incorrectly misses intrinsic depolarization and paces despite intrinsic activity. The pacemaker is more or less operating in asynchronous mode. This may be due to poor lead positioning, lead dislodgment, magnet application, low battery, or myocardial infarction. Management is similar to that for other types of failures.

Pacemaker-mediated tachycardia

A premature ventricular contraction (PVC) in a dual-chamber pacemaker may precipitate a pacemaker-mediated tachycardia. If a premature ventricular contraction (PVC) is transmitted in a retrograde manner through the AV node, it may, in turn, depolarize the atria. This atrial depolarization is detected by the atrial sensor, which then stimulates the ventricular leads to fire, hence creating an endless loop. Although the maximum rate is limited by the pacemaker’s programmed upper limit, the possibility of developing ischemia exists in susceptible patients. This is another opportunity to use a magnet to diagnose and treat the arrhythmia. The magnet will place the pacemaker into asynchronous mode and sensing will be deactivated, thus preventing continuation of the reentrant dysrhythmia.

Runaway pacemaker

A malfunction of the pacemaker generator resulting in a life-threatening rapid tachycardia (up to 400 bpm) is known as runaway pacemaker. The generator may malfunction from various causes, although most commonly it is a battery failure or external damage. This rare medical emergency requires immediate action. An external magnet may induce slower pacing, but it is possible that the device will not respond to magnet application and more aggressive measures may be necessary. If a patient becomes unstable, treatment involves making an incision in the chest wall over the pacemaker and severing the pacemaker leads from the generator. Note that the patient may require temporary packing as a result.

Pacemaker syndrome

Pacemaker syndrome is a phenomenon where a patient feels symptomatically worse after pacemaker placement and presents with progressively worsening symptoms of congestive heart failure (CHF). This is mainly due to the loss of atrioventricular synchrony whereby the pathway is reversed and now has a ventricular origin. The atrial contribution to the preload is lost and cardiac output as well as blood pressure fall. Immediate treatment is mainly supportive, whereas long-term treatment involves altering the pacemaker to restore atrial-ventricular synchrony. For example, this may require changing the pacemaker from single-chamber to dual-chamber pacing.

For further reading, see Pacemaker Syndrome.

Twiddler's syndrome

Some patients will persistently disturb and manipulate the pacemaker generator resulting in malfunction. A chest radiograph may reveal twisting or coiling, or lead fracture, dislodgement, or migration. This situation will require surgical correction with further patient education and counseling.

Pacemaker complications

Pacemaker complications include malfunction due to mechanical factors such as pneumothorax, pericarditis, infection, skin erosion, hematoma, lead dislodgment, and venous thrombosis (also see Pacemaker Malfunction). Treatment depends on the etiology. Pneumothoraces may require medical observation, needle aspiration, or even chest tube placement. Erosion of the pacer through the skin, while rare, requires device replacement and systemic antibiotics. Hematomas may be treated with direct pressure and observation, rarely requiring surgical drainage. Lead dislodgment generally occurs within 2 days of device implantation pacer and may be seen on chest radiography. Free-floating ventricular leads may trigger malignant arrhythmias. Device-associated venous thrombosis is rare, but generally presents as unilateral arm edema. Treatment includes extremity elevation and anticoagulation.

Advanced life support protocols, including defibrillation may safely be performed for patients with pacemakers in place. Sternal paddles are placed at a safe distance (10 cm) from the pulse generator. Temporary pacing may become necessary in cases of myocardial infarction, as the current pacemaker discharge settings may be insufficient to stimulate ventricular contraction.

ICD Complications

Major implantable cardioverter defibrillator (ICD) complications are similar to those found in pacemakers and include operative failures, sensing and/or pacing failures, inappropriate cardioversion, ineffective cardioversion/defibrillation, and device deactivation.

Operative failures are identical to those found in regular pacemakers.

ICD sensing problems similar to those seen with pacers may also occur. An example of appropriate failure to treat is when a device has a cut-off rate of 180 bpm. If ventricular tachycardia occurs at 160 bpm, the device, appropriately, fails to cardiovert the patient since the rate of the dysrhythmia is below the programmed threshold.

Inappropriate cardioversion is the most frequent ICD-associated complication. This should be considered when a patient presents in atrial fibrillation or reports multiple shocks in rapid succession without preceding symptoms. Other causes include T wave oversensing, lead fracture, lead insulation breakage, electrocautery, MRI, and electromagnetic interference.

Magnet use inhibits further ICD discharge. It does not, however, inhibit bradycardiac pacing. In some devices, application of a magnet produces a soft beep for each QRS complex. If the magnet is left on for approximately 30 seconds, the ICD is disabled and a continuous tone is generated. To reactivate the device, the magnet must be lifted off the area of the generator and then replaced. After 30 seconds, the beep returns for every QRS complex.

• Indications for ICD deactivation
  • End-of-life care (after a discussion with the patient and family)
  • Inappropriate shocks
  • During resuscitation
  • With transcutaneous pacing (external pacing can cause an ICD to fire)
  • During procedures such as central lines or surgery with electrocautery

Failure to deliver a shock may be caused by failure to sense, lead fracture, electromagnetic interference, and inadvertent ICD deactivation. Management includes external defibrillation or cardioversion and antidysrhythmic medications.

Ineffective cardioversion may result from inadequate energy output, rise in defibrillation threshold (possibly due to antiarrhythmic medications such as amiodarone, flecainide, phenytoin), myocardial infarction at the lead site, lead fracture, insulation breakage, and dislodgment of the leads or cardioversion patches. The latter is occasionally still seen in patients with ICDs implanted during open chest surgery prior to 1993.

Many ICDs deliver a programmed set of therapies per dysrhythmic episode. The number of therapies per episode is manufacturer specific. If a delivered therapy does not terminate the arrhythmia, the device proceeds to the next programmed therapy. For example, a total of 6 attempts at defibrillation are attempted per episode of ventricular fibrillation. The device attempts defibrillation and then reevaluates the cardiac rhythm. If the arrhythmia persists, it delivers therapy number two and so on, until all 6 attempts have been delivered. Once this occurs, the device does not deliver therapy until a new episode is declared. Note that as mentioned earlier in this article, initial therapy for ventricular tachycardia may be anti-tachycardia pacing (also known as overdrive pacing) rather than simple cardioversion.

ICDs do not prevent all sudden deaths, and acknowledging that cardiac arrest is not necessarily an ICD malfunction is important. The device may have properly delivered the required shocks for the triggering rhythm but was ineffective in resolving it.

Resuscitation

If a patient enters a life-threatening cardiac arrhythmia, advanced cardiac life support (ACLS) protocols should be initiated immediately. Although an implantable cardiac defibrillator (ICD) will attempt defibrillation, chest compressions should be continued. Note that some of the current may enter the rescuer, and, besides some mild discomfort, there has never been a reported case of rescuer injury from this.¹ Ventricular tachycardia and ventricular fibrillation refractory to ICD defibrillation will require external defibrillation and/or antiarrhythmic medications as dictated by ACLS protocols. If external defibrillation is required, attempt to keep the generator at least 10 cm away and out of the shock wave. Defibrillation that affects the generator may cause total device failure. However, do not withhold therapy for fear of damaging the ICD.

If rescuers are uncomfortable with ICD discharge during resuscitations, it is indicated to deactivate the ICD with a magnet, as described in Magnet Inhibition.

Central venous catheters

Pacemaker or ICD leads placed in the venous system often have surrounding thrombosis with 20% of patients having complete occlusion at 2 years.¹⁶ If the metal guidewire contacts the lead system during central line placement, there may be enough noisy artifact to trigger an inappropriate shock. Consideration should be given to either avoid a metal guidewire or deactivate the ICD during central line placement. Although the contralateral subclavian or internal jugular vein can be cannulated with care, the femoral vein access is a much safer option.

Admission and Difficulties Surrounding a Safe Discharge

One of the most difficult decisions after a patient presents to the ED complaining of an ICD discharge is to determine if the discharge was appropriate. Whenever possible, the device should be investigated. Unless the shock and rhythm that preceded it was witnessed, it is not possible to determine shock appropriateness without investigation. Reasons for admission may include the following: device investigation to determine whether there is an eminent battery failure (multiple shocks will deplete battery life); addition of antiarrhythmic medications; treatment of myocardial infarction, which may be linked to the initial discharge; treatment of patient discomfort; and to give psychological support (up to 35% of people develop anxiety disorder following ICD placement).¹⁷

Summary

The goal of this article is to orient the reader to the basic function and use of pacemakers/ICDs and important complications of such devices, thus allowing the ED clinician to better understand and troubleshoot the causes of pacemaker/ICD failure and initiate appropriate therapy. The patient's electrophysiologist/cardiologist can also be an invaluable resource in these cases and should be contacted early during the emergency department evaluation.

Multimedia

(Enlarge Image)

Media file 1: Intermittent periods of ventricular capture.

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Media file 2: Complete heart block.

(Enlarge Image)

Media file 3: 100% ventricular paced rhythm.

Keywords

pacemakers, defibrillator, internal defibrillator, automatic internal cardiac defibrillator, cardiac contraction, cardiac tachydysrhythmia, implantable cardioverter-defibrillators, ICD, ICDs, AICD, AICDs.

References

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Source : http://emedicine.medscape.com/article/780825-overview?src=emed_whatnew_nl_0#ICDindication

Serious Parenteral Medication Errors Common in Intensive Care Units

Parenteral medication errors at the administration stage are common in intensive care units and may result in permanent harm or death, according to a multinational study published online March 12 in the British Medical Journal.

"The combination of complexity and the potential for great harm makes medicine, especially intensive care, even more fraught with risk than other high complexity areas such as aviation," explain Andreas Valentin, MD, from the Department of Emergency Medicine, Medical University of Vienna and the Rudolfstiftung Hospital, Medical Department II in Vienna, Austria, and colleagues. "Although patients' safety is increasingly recognized as an essential component in the practice of intensive care medicine, the complexity of processes and medical conditions dealt with makes the practice of this specialty vulnerable and prone to error."

The frequency of medication errors at the prescription and administration stages was previously reported in the first multinational sentinel events evaluation (SEE 1). Because these errors are associated with a high potential for serious harm, this current study, the second multinational sentinel events evaluation study (SEE 2) was designed to evaluate the frequency, characteristics, and contributing factors of parenteral medication errors at the administration stage in intensive care units. In addition, the effect of parenteral medication errors and the outcome of patients exposed to these errors were assessed.

SEE 2 was a prospective, observational, 24-hour, cross-sectional study involving 113 intensive care units from 27 countries. A total of 1328 adult patients participated in the study, in which hospital staff self-reported medication errors in a single questionnaire for each participant.

"A medication error at the administration stage was defined as an error of omission or commission in the context of parenteral drug administration that harmed or could have harmed a patient," Dr. Valentin and colleagues write. "We exclusively addressed medication errors that were attributable to five types of error during the stage of administration: wrong dose, wrong drug, wrong route, wrong time, missed medication." These errors were further classified according to the method of drug administration and the class of drug administered.

The total prevalence of parenteral medication errors at the administration stage in intensive care units was found to be 74.5 errors per 100 patient days (95% confidence interval [CI], 69.5 – 79.4). In addition, while 71% of errors resulted in no change in the patient's health status, 0.9% of the total study population experienced permanent harm or death as a result of errors in the administration of parenteral drugs in intensive care units.

Overall, 67% of the participants experienced no errors, 19% experienced 1 error, and 14% experienced more than 1 error. Nineteen percent of the intensive care units did not report any medication errors. Errors were most frequently associated with the wrong time of administration (n = 386) followed by missed medication (n = 259), wrong dose (n = 118), wrong drug (n = 61), and wrong route (n = 37). Medication errors at the administration stage were most likely to occur during routine situations (69%) and during intravenous bolus administration (9%). Furthermore, the administration of antimicrobial drugs and those in the class of sedation or analgesia were most frequently associated with errors.

Workload, stress, and fatigue were reported as the most frequent contributing factors to medication errors (32%). Other contributing factors included changes in drug names; written or oral miscommunication; lack of experience, knowledge, or supervision; violation of protocol; shift change; and equipment failure. More than half of the errors (53%) that resulted in permanent harm or death occurred in situations in which trainees were involved.

"One of the most important steps in improving patients' safety is to understand how and why errors occur," the authors emphasize. Several contributing factors to medication errors were identified in this study, but a causal relationship could not be confirmed due to the study's observational design. "Univariate and multivariate analyses showed that more severely ill patients, who receive a higher level of care with the corresponding increased use of parenteral medication, are more likely to experience a medication error. This finding directly reflects the complexity of care and thus the increased opportunity for error," Dr. Valentin and colleagues write.

A limitation of this study was that certain elements that influence the occurrence of errors were unable to be evaluated due to the 24-hour observational study design. These elements include variations in culture, communication, data collection, and organizational structure. Furthermore, because hospital staff members were self-reporting the occurrence of errors, there was a risk of underreporting. The nature of the study design could have also led to overreporting due to possible duplications in the questionnaire.

"Our results suggest that the implementation of several achievable measures might enhance the safe process of parenteral drug administration in intensive care units," the authors conclude. These include the standard verification of perfusors and infusion pumps at every nursing shift change, the use of a critical incident reporting system, a lower ratio of patients to nurses, improved supervision of trainees, as well as enhanced technical measures such as aided recall, clear drug identification, and proper design of infusion pumps.

Source : http://www.medscape.com/viewarticle/589596

Home-Based Care Administered by Skilled Nurses Comparable to Standard Care for Obstructive Sleep Apnea

Home-based treatment administered by highly skilled nurses is noninferior to and less costly than standard hospital-based, physician-directed care for the management of symptomatic, moderate to severe obstructive sleep apnea (OSA), according to a study published in the March 15 issue of the American Journal of Respiratory and Critical Care Medicine.

In addition, there is no significant difference between both methods of care with regard to objective sleepiness, general and disease-specific quality-of-life measures, neurocognition, patient satisfaction, or adherence to continuous positive airway pressure (CPAP) after 3 months.

With the rise in obesity, the prevalence of OSA has increased throughout developed countries and will likely rise among developing countries as well because of their increasing acceptance of Western lifestyles, according to the study. Furthermore, the number of sleep centers and physician specialists is not adequate to meet the growing need.

"[Thus], more cost-effective clinical pathways of investigation and treatment are required to match the increased demand for services that is resulting from increasing public awareness of OSA," explain Nick A. Antic, PhD, MBBS, FRACP, from the Adelaide Institute for Sleep Health, Repatriation General Hospital in Daw Park, and the Department of Medicine, Flinders University in Bedford Park, South Australia, and colleagues. "The present study was designed as a randomized controlled study in which a package of care incorporating...newer management strategies including simplified home diagnosis, CPAP titration with an autoadjusting positive airway pressure device to set a fixed CPAP pressure, and overall care supervised by a specialist nurse was compared with the more traditional physician-directed, in-laboratory polysomnography (PSG), hospital-based program of care."

A total of 195 symptomatic patients with moderate to severe OSA from 3 Australian sleep medicine service centers were randomly assigned to receive either the simplified, nurse-led model of care or the traditional, physician-directed model of care. The primary endpoint of the study was the change in Epworth Sleepiness Scale (ESS) score after 3 months of CPAP therapy. The ESS score among the patients who received the nurse-led model of care was 4.02, and the ESS score among the patients who received the traditional physician-directed care was 4.15 (difference, −0.13; 95% confidence interval [CI], −1.52 to 1.25).

Nurse-Lead Management Noninferior

"We found that the mean change in ESS score for nurse-led management was not inferior to the mean change in ESS score for specialist-led service because the lower limit of the two-sided 95% confidence interval for the mean difference did not include −2, the margin of noninferiority," state Dr. Antic and colleagues.

In addition, there was no significant difference between the 2 models of care with respect to the other outcomes measured, which include the Short Form 36 Health Survey, Functional Outcomes of Sleep Questionnaire, executive neurocognitive function, objective CPAP adherence, Maintenance of Wakefulness Test after 3 months of therapy, and general patient satisfaction with investigation and treatment.

However, there was a significant decrease in the cost associated with the simplified, nurse-led model of care vs the traditional, physician-directed model of care. Specifically, nurse-led management cost $1111 Australian (A$1111) per patient less than physician-directed care (95% CI, A$1084 – A$1137). "Hence the within-study analysis suggests that a nurse-led model of care saves considerable resources without compromising effects in patients diagnosed by oximetry as having a high likelihood of moderate to severe [OSA,] and consequently is cost-effective in these patients," write the researchers.

One possible limitation of this study is the fact that the results may not be replicated without the specific combination of diagnostic and therapeutic equipment used. Moreover, several conditions contributed to the effectiveness of the simplified model of care in this study. These include awareness of the pretest probability of OSA among the patient referrals, availability of a highly experienced nursing staff in the management of OSA, access to a tertiary sleep laboratory as a back-up for the interpretation and quality control of oximetry data and autoadjusting positive airway pressure (APAP) data, and availability of input from a sleep physician.

Physician Consult Allowed

Twelve percent of the patents in the simplified model of care group received physician consults because of unsatisfactory progress. "We believed it important for the specialist nurse to be able to cross-consult under circumstances in which they were uncertain about the management of the patient," explain Dr. Antic and colleagues. "[Thus, there is] the need for this simplified model of care to be ideally conducted either within a tertiary sleep medicine service or with patient access to same. We do not recommend that the simplified management approach occur autonomously."

Nevertheless, the researchers emphasize that there is the possibility that the use of this simplified model of care could be used in existing sleep medicine clinics to reduce the PSG and physician waiting time by approximately 20% to 25%.

"This overall package of care involving simplified OSA diagnosis, APAP titration in the home, and the expansion of the sleep medicine workforce using skilled CPAP nurses working under protocol (with the backup of sleep medicine services if needed) has the potential to add significantly to the field of sleep medicine and improve access to care for those with OSA," the authors conclude.

This study was supported by the National Health and Medical Research Council of Australia. Dr. Antic has received financial support for research in terms of equipment from Respironics and ResMed and from Masimo. Another author has received grants totaling $2.5 million from the Respironics Sleep and Respiratory Foundation for an investigator-initiated multicenter trial. Equipment grants are also pending for the Respironics Foundation and ResMed for the same trials. The authors also received $20,000 from Fisher and Paykel for the same study in 2008.

Am J Respir Crit Care Med. 2009;179:501–508.

Source : http://www.medscape.com/viewarticle/589440