Medical Abstract Reviews

Albuterol by EMT-Bs

Silverman R, Richmond NJ, Kusick M, et al. Out-of-hospital administration of albuterol for asthma by basic life support providers. Acad Emerg Med 12(5):396–403, May 2005.

Abstract: Each year, approximately 40,000 patients with acute asthma are transported by the Fire Department of New York EMS. Out-of-hospital administration of bronchodilator therapy has, however, been restricted by scope of practice to advanced life support (ALS) providers. Since the rapid availability of ALS units cannot always be assured, some individuals with acute asthma may receive only basic life support (BLS) measures in the field. Objectives—To demonstrate that basic emergency medical technicians (EMT-Bs) are able to effectively administer nebulized albuterol to asthma patients in the out-of-hospital environment. Methods—This was a prospective, observational cohort study of 9-1-1 asthma calls received by the NYC EMS system for patients between the ages of 1–65 years. Baseline peak expiratory flow rate (PEFR) and other clinical measures were obtained prior to and following BLS administration of one or two treatments with nebulized albuterol. Results—Data were available for 3,351 patients over a one-year study period. Sixty percent of the patients received one out-of-hospital albuterol treatment; 40% received two. The PEFRs increased from 40.4% predicted (SD +/-21.0) to 54.8% predicted (SD +/-26.1), for a post-treatment improvement of 14.4% (95% CI, 13.8–15.1). Other clinical outcome measures, including dyspnea index, respiratory rate and use of accessory muscles, also showed improvement. Conclusion—This study demonstrates that EMT-Bs can effectively administer albuterol to acute asthma patients in the out-of-hospital environment.

Comment: Similar but smaller studies have also concluded that EMT-Bs can safely and effectively administer medications to carefully selected patient groups. In this study patients were limited to those who had previous diagnoses of asthma, were no older than 65 and were not in respiratory failure. Albuterol was clearly helpful. EMS systems should consider albuterol by EMT-Bs for these patients. The authors point out that a minority of EMS patients with asthma, both pediatric and adult, receive beta-agonist treatment (albuterol), and that this may help improve that.

Out-of-Hospital CPR

Wik L, Kramer-Johansen J, Myklebust H, et al. Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest. JAMA 293(3):299–304, Jan. 19, 2005.

Abstract: Cardiopulmonary resuscitation (CPR) guidelines recommend target values for compressions, ventilations and CPR-free intervals allowed for rhythm analysis and defibrillation. There is little information on adherence to these guidelines during advanced cardiac life support in the field. Objective—To measure the quality of out-of-hospital CPR performed by ambulance personnel, as measured by adherence to CPR guidelines. Design and setting—Case series of 176 adult patients with out-of-hospital cardiac arrest treated by paramedics and nurse anesthetists in Stockholm, Sweden; London, England; and Akershus, Norway, between March 2002–October 2003. The defibrillators recorded chest compressions via a sternal pad fitted with an accelerometer and ventilations by changes in thoracic impedance between the defibrillator pads, in addition to standard event and electrocardiographic recordings. Main outcome measure—Adherence to international guidelines for CPR.

Results—Chest compressions were not given 48% (95% CI, 45%–51%) of the time without spontaneous circulation; this percentage was 38% (95% CI, 36%–41%) when subtracting the time necessary for electrocardiographic analysis and defibrillation. Combining these data with a mean compression rate of 121/min. (95% CI, 118–124/min.) when compressions were given, resulted in a mean compression rate of 64/min. (95% CI, 61–67/min.). Mean compression depth was 34 mm (95% CI, 33–35 mm); 28% (95% CI, 24%–32%) of the compressions had a depth of 38–51 mm (guidelines recommendation); and the compression part of the duty cycle was 42% (95% CI, 41%–42%). A mean of 11 (95% CI, 11–12) ventilations were given per minute. Sixty-one patients (35%) had a return of spontaneous circulation, and five of six patients discharged alive from the hospital had normal neurological outcomes. Conclusion—In this study of CPR during out-of-hospital cardiac arrest, chest compressions were not delivered half of the time, and most compressions were too shallow. Electrocardiographic analysis and defibrillation accounted for only small parts of intervals without chest compressions.

Comment: This is one of several recent studies that come to the same conclusion: EMS and hospital personnel perform CPR poorly, and inadequate CPR may affect patient survival. The three main errors are: pausing CPR for too long during and after procedures, too slow a rate, and too shallow a compression depth. This is a surprising finding to many, since CPR is taught from the very beginning of EMS training, and EMS personnel have frequent opportunities to practice.

There are at least two reasons why this occurs. First, the amount of time spent on training is minimal. A few minutes of practice every two years is, according to all the educational research, insufficient. And second, precision in CPR is not emphasized. When have you ever seen “rate and depth of CPR” as an EMS system quality indicator? With the increasing awareness of the relationship between quality of CPR and patient survival, EMS systems should prioritize CPR in their quality improvement efforts.

IN vs. IM Naloxone

Kelly AM, Kerr D, Dietze P, et al. Randomized trial of intranasal versus intramuscular naloxone in prehospital treatment for suspected opioid overdose. Med J Australia 182(1):24–7, Jan. 3, 2005.

Abstract: Objective—To determine the effectiveness of intranasal (IN) naloxone compared with intramuscular (IM) naloxone for treatment of respiratory depression due to suspected opiate overdose in the prehospital setting. Design—Prospective, randomized, unblinded trial of either 2 mg naloxone injected intramuscularly or 2 mg naloxone delivered intranasally with a mucosal atomizer. Participants and setting—155 patients (71 IM and 84 IN) requiring treatment for suspected opiate overdose and attended by paramedics of the Metropolitan Ambulance Service (MAS) and Rural Ambulance Victoria (RAV) in Victoria. Main outcome measure—Response time to regain a respiratory rate greater than 10 per minute. Secondary outcome measures were the proportion of patients with respiratory rate greater than 10 per minute at eight minutes and/or a GCS score over 11 at eight minutes; the proportion requiring rescue naloxone; the rate of adverse events; and the proportion of the IN group for whom IN naloxone alone was sufficient treatment. Results—The IM group had more rapid response than the IN group, and were more likely to have more than 10 spontaneous respirations per minute within eight minutes (82% vs. 63%; P = 0.0173). There was no statistically significant difference between the IM and IN groups for needing rescue naloxone (13% IM group vs. 26% IN group, P = 0.0558). There were no major adverse events. For patients treated with IN naloxone, this was sufficient to reverse opiate toxicity in 74%. Conclusion—IN naloxone is effective in treating opiate-induced respiratory depression, but is not as effective as IM naloxone. IN delivery of naloxone could reduce the risk of needlestick injury to ambulance officers and, being relatively safe, making it more widely available, could increase access to lifesaving treatment in the community.

Comment: There’s been a lot of recent interest in intranasal naloxone. It has the obvious advantage of not using needles, therefore preventing needlestick injuries and blood exposure from the riskiest patients. This study shows that IN naloxone can be nearly as effective as IM. However, it appears that it will not replace IM naloxone, since about a quarter of patients given the medication IN required an additional IM dose. EMS systems may want to consider IN naloxone as the first treatment for selected opioid (heroin) overdoses, but will likely need to keep IM or IV naloxone available as a backup.