Richard C. Wuerz

Effects of prehospital medications on mortality and length of stay in congestive heart failure

HYPOTHESIS Prehospital medications for congestive heart failure should affect hospital outcomes (survival and length of stay). STUDY DESIGN In a retrospective case series, hospital outcomes were compared for patients treated with prehospital nitroglycerin, furosemide, and/or morphine (252) versus those given no medications (241). SETTING A rural/suburban emergency medical services system (population 140,000) served by three paramedic units. PARTICIPANTS Four hundred ninety-three consecutive cases of congestive heart failure or pulmonary edema were identified by hospital discharge diagnosis from a data base of 8,315 paramedic transports with known outcome. INTERVENTIONS Oxygen was given by protocol to 489 patients. Other medications were given by order of on-line physician medical command. RESULTS Overall mortality was 10.9% (54 of 493). Treated and untreated patients were comparable in age, sex, cardiac rhythms, prior use of cardiac medications, and response and scene times; mortality was reduced in treated versus untreated patients (odds ratio for improved survival, 2.51; 95% confidence interval, 1.37 to 4.55; P less than .01). Positive treatment effect was greatest for 58 nonhypotensive, critical patients (odds ratio for survival, 10.25; P less than .01). No single drug combination was unique in terms of treatment benefit. Patients treated in the field received medications 36 minutes earlier than patients first treated in the emergency department. No survival benefit was evidence for noncritical, nonhypotensive patients, and patients with final diagnoses of asthma, chronic obstructive pulmonary disease, pneumonia, or bronchitis had a higher than expected mortality if erroneously treated for congestive heart failure. Differences in hospital length of stay were not significant for any group. CONCLUSION Prehospital medications improve survival in congestive heart failure, especially in critical patients. More than one combination of medications seems effective, and early treatment is associated with improved survival. However, these medications appear to increase mortality in patients misdiagnosed in the field. Factors used in paramedica and medical command assessments require further study.

Safety of prehospital nitroglycerin

STUDY OBJECTIVE To define changes in vital signs and cardiac rhythm in prehospital patients given sublingual nitroglycerin. DESIGN A five-month prospective observational study with nitroglycerin administration as the independent variable. SETTING Five independent advanced life support services. TYPE OF PARTICIPANT Three hundred prehospital patients who were given nitroglycerin by advanced life support personnel for presumed myocardial ischemia or congestive heart failure; excluded were those without repeat vital signs or ECG monitoring and those given additional medications. INTERVENTION Nitroglycerin was administered by regional emergency medical services protocols or by the order of an on-line medical command physician. RESULTS Four study patients (1.3%) had adverse effects: One became asystolic and apneic for two minutes, two experienced profound bradycardia with hypotension, and one became hypotensive while tachycardic. All recovered. The 95% confidence interval for adverse effects was 0.5% to 3.4%. Mean fall in systolic blood pressure for the other 296 patients was 14 mm Hg for one dose (confidence interval, 11 to 16 mm Hg) and 8 mm Hg (confidence interval, 2 to 13 mm Hg) for a second dose. Heart rate changed minimally with nitroglycerin administration. The blood pressure drop was linearly correlated with initial systolic pressure (r = -.44; P < .001) but not correlated with number of prior doses of nitroglycerin, initial heart rate, advanced life support time interval, age, or sex. CONCLUSION Nitroglycerin seems to be a relatively safe advanced life support drug; however, a few patients experience serious adverse effects. Most of the adverse effects we observed were bradycardic-hypotensive reactions, which appeared to be unpredictable by pretreatment characteristics. Emergency personnel should have an increased awareness of this danger when considering the use of prehospital nitroglycerin.

On-line Medical Direction: A Prospective Study

OBJECTIVES To determine the frequency with which physician, on-line medical direction (OLMD) [direct medical control] of prehospital care results in orders, to describe the nature of these orders, and to measure OLMD time intervals. METHODS Blinded, prospective study. SETTING A university hospital base-station resource center. PARTICIPANTS Ten emergency physicians, 50 advanced life support providers. INTERVENTIONS Prehospital treatment was directed by both standing orders and OLMD physician orders. Independent observers recorded event times and the characteristics of OLMD. RESULTS Physician orders were given in 47 (19%) of the 245 study cases, and covered a variety of interventions, including many already authorized by standing orders. Mean OLMD radio time was four minutes (245 +/- 216 seconds [sec]), and time from beginning of OLMD to hospital arrival averaged 12 minutes (718 +/- 439 sec). Mean transport time in this system was 13 minutes. CONCLUSION Despite detailed standing orders, OLMD results in orders for clinical interventions in 19% of cases. On-line medical direction requires about four minutes of physician time per call. This constituted about one-third of the potential field treatment time interval in this system. Thus, OLMD appears to play an important role in providing quality prehospital care.

Attending supervision of nonemergency medicine residents in a university hospital ED

There have been a limited number of studies assessing the impact of attending physician supervision of residents in the emergency department (ED). The objective of this study is to describe the changes in patient care when attending emergency physicians (AEPs) supervise nonemergency medicine residents in a university hospital ED. This was a prospective study including 1,000 patients, 32 second- and third-year nonemergency medicine residents and eight AEPs. The AEPs classified changes in care for each case as major, minor, or none, according to a 40-item data sheet list. There were 153 major changes and 353 minor changes by the AEP. The most common major changes were ordering laboratory or x-ray tests that showed a clinically significant abnormality, and eliciting important physical exam findings. Potentially limb- or life-threatening errors were averted by the AEP in 17 patients. Supervision of nonemergency medicine residents in the ED resulted in frequent and clinically important changes in patient care.

Medical command errors in an urban advanced life support system

STUDY OBJECTIVE The aim of this study was to assist in focusing educational efforts for command physicians by identifying the most common types of errors made by on-line medical command. DESIGN Retrospective survey of prehospital advanced life support (ALS) trip sheets. SETTING An urban ALS paramedic service with on-line physician medical command rotating on a monthly basis among three hospitals. PARTICIPANTS From September 1988 through December 1990, all ALS run sheets were reviewed as part of an ongoing quality assurance program. Cases were identified as deviating from regional emergency medical services protocols as judged by agreement of three physician reviewers. Cases were excluded if all three reviewers did not agree that the command rendered was inappropriate. INTERVENTIONS Command errors were identified from the prehospital ALS run sheets and categorized. RESULTS One hundred ninety-four command errors in 167 cases were identified from 3,839 runs (4.4% of all runs). Six types of errors accounted for 80% of the total errors, with the most common error (34%) being failure to address the possibility of hypoglycemia with altered level of consciousness. Error rate decreased from 7.9% to 2.6% of total runs during the study period. CONCLUSION To reduce the medical command error rate, physician education should be directed at the six problem areas identified. Ongoing quality assurance review of medical command may result in a decrease of the command error rate.

Comparison of Interventions in Prehospital Care by Standing Orders Versus Interventions Ordered by Direct [On-line] Medical Command

OBJECTIVE The aim of this study was to compare the patient care measures provided by paramedics according to standing orders versus measures ordered by direct [on-line] medical command in order to determine the types and frequency of medical command orders. DESIGN Prospective identification of patient care measures done as part of a prehospital quality assurance program. SETTING An urban paramedic service in the northeast United States with direct medical command from three local hospitals. PARTICIPANTS One thousand eight paramedic reports from October 1992 through March 1993. INTERVENTIONS All patient care interventions recorded as done by standing orders or by direct medical command orders. Errors in patient care were determined by the same criteria as in the prior two studies of the same system. RESULTS Direct medical command gave orders in 143/1,008 (14.2%) cases. Paramedics performed 2,453/2,624 (93.5%) of the total patient care interventions using standing orders. In 61 cases (6.1%), medical command ordered a potentially beneficial intervention not specified by standing orders or not done by the paramedic. 21/171 (12.3%) command orders were for additional doses of epinephrine or atropine in cardiac arrest cases (where the initial doses had been given under standing orders), and 59/171 (34.5%) were for interventions already mandated or permitted by standing orders. The paramedic error rate was 0.6%, and the medical command error rate was 1.8% (unchanged form the prior study of the same standing-orders system). CONCLUSION Direct medical command gave orders in 14% of cases in this standing-orders system, but 35% of command orders only reiterated the standing orders. More selective and reduced uses of on-line command could be done in this system with no change in the types or numbers of patient care interventions performed.

Whole-bowel irrigation as adjunctive treatment for sustained-release theophylline overdose

STUDY OBJECTIVE To determine a therapeutic benefit for whole-bowel irrigation (with polyethylene glycol-electrolyte lavage solution) as adjunctive treatment to multiple doses of activated charcoal following an overdose of sustained-release theophylline. DESIGN Randomized crossover study. Three treatment arms were separated by one-week intervals. SETTING Animal care facility housing. TYPE OF PARTICIPANTS Eight female mongrel dogs. INTERVENTIONS Unanesthetized dogs were given approximately 75 mg/kg of sustained-release theophylline. In treatment arm 1, 1 g/kg activated charcoal was administered by nasogastric tube at two hours after ingestion followed by 0.5-g/kg doses at five and eight hours. During treatment arm 2, beginning two hours after theophylline ingestion, 25 mL/kg whole-bowel irrigation solution was administered every 45 minutes for four doses followed by activated charcoal. In treatment arm 3, the first dose of activated charcoal was given ten minutes before beginning the whole-bowel irrigation protocol. MEASUREMENTS AND MAIN RESULTS Serum theophylline levels were measured at zero, two, four, five, eight, 12, 16, and 24 hours after ingestion. Mean serum theophylline levels, area under the curve (P = .13), and terminal half-lives (P = .69) for each treatment group were not statistically different. This negative study had an 81% power to detect a 50% reduction in the area under the curve by whole-bowel irrigation treatment. CONCLUSION In this model, whole-bowel irrigation did not add to the therapeutic benefits of activated charcoal.

Evaluation of a Prehospital Chest Pain Protocol

STUDY OBJECTIVES To evaluate the diagnostic accuracy and outcomes for patients treated by use of a prehospital chest pain protocol (CPP). DESIGN Consecutive case series for 1 year (1993) of prehospital nontrauma advanced life support (ALS) cases including hospital outcomes. SETTING Nonurban two-tiered emergency medical services system. PARTICIPANTS Patients treated under the prehospital CPP or with hospital diagnoses of ischemic heart disease (IHD; ICD-9 between 410 and 414). Patients with cardiac arrest or dysrhythmias were excluded. INTERVENTIONS Patients were given, by standing orders, ECG monitoring, i.v. access, and sublingual nitroglycerin. Further therapy was guided by on-line medical direction. RESULTS Of 3,122 ALS nontrauma patients, 620 (20%) were treated with the CPP. All patients underwent ECG monitoring, i.v. access was started in 83%, and 61% received nitroglycerin. Only 55% of patients completed the entire CPP; patients who failed to complete the CPP had the same prevalence of IHD as those who completed it. When compared with hospital diagnosis of IHD, the CPP had a sensitivity of 69% (95% confidence interval [CI], 64% to 74%), a specificity of 87% (95% CI, 86% to 88%), and a positive predictive value of 42%. The positive likelihood ratio of CPP for IHD was 5.31, and the negative likelihood ratio was .36. The hospital mortality rate for all patients was 2.2%; for those with IHD, it was 1.6%. CONCLUSION This prehospital ALS CPP had good diagnostic accuracy, but only half of patients completed it, and the hospital mortality rate was low. These data challenge the efficacy of the CPP.

Adverse Events during Interfacility Transfers by Ground Advanced Life Support Services

OBJECTIVE To identify risk factors for adverse events that occur during interfacility transfers by advanced life support (ALS). DESIGN A four-year, retrospective, case series. SETTING Three ALS units in a rural/suburban emergency medical services (EMS) system. PARTICIPANTS 351 transports to or from twelve acute care facilities; two patients records could not be located. INTERVENTIONS Patients were classified by illness/injury, transporting staff, and ongoing therapy; these were correlated with frequency of ALS intervention and patient deterioration. RESULTS During the study period, the number of transfers as a percentage of total calls (1.1%-5.2%) rose consistently. There were 11 illness/injury categories; the largest was cardiac (44%, 154 patients). Hospital staff accompanied the patient in 15% (52). Advanced life support (ALS) therapy was required in 4.9% (17): one monitored cardiac arrest was defibrillated successfully, 13 patients required unanticipated medication therapy, and three were noted to have clinical deterioration en route. The upper 95% confidence limit for cardiac arrest is 12.9/1,000 transfers or 20.8/1,000 hours. Patient deterioration and the need for ALS intervention were associated with the presence of medication infusions (p < .05), but not with hospital staff (p > .40). CONCLUSIONS Interfacility transfers of a heterogeneous group of patients in this series involve a low risk of cardiac arrest. Patients with medication infusions are at higher risk of deterioration and more frequently require ALS intervention en route. The presence of hospital staff had no measurable effect. These findings have implications for the development of ALS transfer protocols.

Two cases of Munchausen's syndrome presenting as acute respiratory distress

We present two cases of factitious disorder that presented as acute respiratory distress. The presentation was extreme to the point that the patients were intubated. Both patients were employed in an ancillary health care profession.