Ambulance collisions in an urban environment.

INTRODUCTION: Decisions to send an ambulance with or without lights and siren are made every day. While travel with lights and siren is presumed to have relatively more risk associated with it than travel without, little epidemiologic analysis has been conducted to compare the two modes of travel or to characterize collisions in general. OBJECTIVE: To characterize ambulance collisions and assess the risk of traveling with lights and siren in an urban 9-1-1 environment. METHODS: Retrospective analysis of all consecutive ambulance collisions of the Paramedic Division of the San Francisco Department of Public Health during a 27-month period. RESULTS: The overall collision rate for lights and siren (LS) travel was higher than that for non-lights and siren travel, although the difference was not statistically significant (45.9 collisions per 100,000 LS patient travels, 95% confidence limits 29.7, 62.1, versus 27.0/100,000 for non-LS travel, 95% confidence limits 18.3, 35.7). However, the rates of resulting injuries displayed a statistically significant difference (22.2 injuries per 100,000 LS patient travel, 95% confidence limits 11.0, 33.5, versus 1.5/100,000 for non-LS travel, 95% confidence limits -0.6, 3.5). While the majority of collisions (60.0%) occurred during patient-related travel, 35.6% occurred while the ambulance was available awaiting assignment, and 4.4% in a hospital parking lot. The majority of collisions were due to inattention, failure of on-coming traffic to yield, or unsafe parking; unsafe speed was an infrequent cause. Most crashes occurred during daylight, in dry weather, and involved another vehicle. CONCLUSION: There is some elevated risk for collision and added injury during lights and siren travel compared to travel without LS. The causes for these collisions suggest that interventions designed to improve driver skills and increase citizen awareness of an approaching ambulance could help reduce the number of collisions.

A randomized clinical trial of high-dose epinephrine and norepinephrine vs standard-dose epinephrine in prehospital cardiac arrest.

OBJECTIVE: To determine the relative efficacy of high- vs standard-dose catecholamines in initial treatment of prehospital cardiac arrest. DESIGN: Randomized, prospective, double-blind clinical trial. SETTING: Prehospital emergency medical system of a major US city. PATIENTS: All adults in nontraumatic cardiac arrest, treated by paramedics, who would receive epinephrine according to American Heart Association advanced cardiac life support guidelines. INTERVENTIONS: High-dose epinephrine (HDE, 15 mg), high-dose norepinephrine bitartrate (NE, 11 mg), or standard-dose epinephrine (SDE, 1 mg) was blindly substituted for advanced cardiac life support doses of epinephrine. MAIN OUTCOME MEASURES: Restoration of spontaneous circulation in the field, admission to hospital, hospital discharge, and Cerebral Performance Category score. RESULTS: Of 2694 patients with cardiac arrests during the study period, resuscitation was attempted on 1062 patients. Of this total, 816 patients met study criteria and were enrolled. In the entire cardiac arrest population, 63% of the survivors were among the 11% of patients who were defibrillated by first responders. The three drug treatment groups were similar for all independent variables. Thirteen percent of patients receiving HDE regained a pulse in the field vs 8% of those receiving SDE (P = .01), and 18% of HDE patients were admitted to the hospital vs 10% of SDE patients who were admitted to the hospital (P = .02). Similar trends for NE were not significant. There were 18 survivors; 1.7% of HDE patients and 2.6% of NE patients were discharged from the hospital compared with 1.2% of SDE patients, but this was not significant (P = .37; beta = .38). There was a nonsignificant trend for Cerebral Performance Category scores to be worse for HDE (3.2) and NE patients (3.7) than for SDE patients (2.3) (P = .10; beta = .31). No significant complications were identified. High-dose epinephrine did not produce longer hospital or critical care unit stays. CONCLUSIONS: High-dose epinephrine significantly improves the rate of return of spontaneous circulation and hospital admission in patients who are in prehospital cardiac arrest without increasing complications. However, the increase in hospital discharge rate is not statistically significant, and no significant trend could be determined for neurological outcome. No benefit of NE compared with HDE was identified. Further study is needed to determine the optimal role of epinephrine in prehospital cardiac arrest.

Modeling emergency department operations using advanced computer simulation systems.

We developed a computer simulation model of emergency department operations using simulation software. This model uses multiple levels of preemptive patient priority; assigns each patient to an individual nurse and physician; incorporates all standard tests, procedures, and consultations; and allows patient service processes to proceed simultaneously, sequentially, repetitively, or a combination of these. Selected input data, including the number of physicians, nurses, and treatment beds, and the blood test turnaround time, then were varied systematically to determine their simulated effect on patient throughput time, selected queue sizes, and rates of resource utilization. Patient throughput time varied directly with laboratory service times and inversely with the number of physician or nurse servers. Resource utilization rates varied inversely with resource availability, and patient waiting time and patient throughput time varied indirectly with the level of patient acuity. The simulation can be animated on a computer monitor, showing simulated patients, specimens, and staff members moving throughout the ED. Computer simulation is a potentially useful tool that can help predict the results of changes in the ED system without actually altering it and may have implications for planning, optimizing resources, and improving the efficiency and quality of care.

The use of transthoracic electrical bioimpedance in assessing thoracic fluid status in emergency department patients.

Baseline transthoracic electrical bioimpedance (Z) was measured in 26 seriously ill emergency department (ED) patients in order to determine the usefulness of this noninvasive method of assessing thoracic fluid (TF) status. Patients were divided, on the basis of clinical and radiographic information, into three groups: group A (11 patients), with clinically normal TF status; group B (12 patients), with elevated TF status; and group C (3 patients), with decreased TF status. The mean Z values measured in each group were: 26.5 ohms in group A, 21.8 ohms in group B, and 37.4 ohms in group C (differences significant at P less than .02). Using a cutoff Z value of 24.0 ohms would have predicted group B individuals with a sensitivity of 92% and a specificity of 79%. In eleven patients, impedance measurement would have added information that confirmed diagnostic suspicions or suggested the diagnosis earlier than would otherwise have occurred. In five patients, real-time changes in Z were potentially useful in guiding and monitoring the results of therapeutic interventions or changes in clinical condition. This study demonstrates that Z measurement and real-time monitoring can be a useful and noninvasive means of assessing TF status in ED patients. However, it may be most helpful in those patients whose TF status is changing or unstable.

C4 complement allotypes in juvenile dermatomyositis.

Twenty probands with juvenile dermatomyositis and their relatives were studied to determine the inherited segregation patterns of class I, II, and III HLA region markers including C4A, C4B, Bf, and C2 complement polymorphisms. The extended haplotype B8, DR3, C4A*Q0, C4B*1, C2*C, and Bf*S was present in 13 of the 20 probands. Three other probands also carried a haplotype with a null allele for C4A and two further probands carried a null allele for C4B; only two probands had no detectable C4 null allele. These data confirm previous studies showing high frequencies of B8 and DR3 in patients with juvenile dermatomyositis, but show that there is a higher association with null alleles of C4. This suggests that the C4 genes are either themselves the disease-susceptibility genes or are in very strong linkage disequilibrium with such genes.

Treatment of mild exacerbations of recurrent alcoholic pancreatitis in an emergency department observation unit.

Patients with mild exacerbations of recurrent alcoholic pancreatitis are occasionally treated in the emergency department observation unit with parenteral hydration and analgesia in hopes of avoiding hospitalization. To determine whether such treatment is efficacious and cost-effective, we reviewed 27 consecutive admissions to the emergency department observation unit for exacerbation of previously documented recurrent alcoholic pancreatitis. For comparison, we studied 27 randomly selected, matched patients admitted directly to the hospital. Of the 27 admitted to the observation unit, 14 (52%) improved sufficiently for discharge in less than 24 hours (group A; mean duration of observation, 14.4 hours); the other 13 (48%) required continued hospitalization (group B; average length of stay, 7.5 days). The group admitted directly to the hospital (group C) had a mean stay of 5.8 days (difference not significant). Of a variety of parameters compared, only serum amylase values differed significantly between the three groups. A serum amylase cutoff of 300 U/dl would have correctly identified all patients in group A (sensitivity 100%), though with a relatively low specificity (60%). We conclude that there may be a subset of patients with mild exacerbation of recurrent alcoholic pancreatitis, identifiable by a low serum amylase level, who would benefit from a trial of management in an emergency department observation unit.

Recreational waterslide injuries.

Recreational waterslide facilities are a growing phenomenon in the United States, and injuries associated with their use are beginning to appear. Although there have been fatalities, the vast majority of injuries are minor, and occur over a large denominator of slide rides. The overall incidence of injuries is low, though the incidence varies from one facility to another. If safety practices and design features are implemented, waterslide use may become safer. Epidemiologic data will be required to clearly identify the optimal features of injury prevention.

Time study of patient movement through the emergency department: sources of delay in relation to patient acuity.

A continuous observation time study was used to track 1,568 patients through various stages of emergency department care in order to identify sources of delay. Patients initially were assigned to one of four categories of decreasing acuity, and flow profiles were compared for each category. Patients with lowest acuity level experienced long delays in moving through the ED, although the actual evaluation and treatment time was brief. Urinalyses, procedures, radiographs, and blood tests had an increasing impact on treatment times (45 minutes, 63 minutes, 65 minutes, and 126 minutes, respectively, compared to 31 minutes with no tests or procedures). Patients of increasing acuity moved more quickly, but with a longer evaluation and treatment time. The most critical patients moved most quickly but with a brief evaluation and treatment time due to a rapid disposition from the ED or death. This relationship suggests an emergency care system that is oriented toward the efficient care of high-acuity patients but that is less effective for low-acuity patients. This occurs despite the fact that low-acuity patients comprise the vast majority of the ED census, and represent a group for whom delay is a frequent source of patient dissatisfaction.

Patient compliance in filling prescriptions after discharge from the emergency department.

Frequently, emergency department treatment consists of prescriptions given to a patient at discharge on the assumption that they will be filled promptly and the medications begun as directed. Although the plan depends on the validity of this assumption, many patients may be unable (or unwilling) to fill their prescriptions. This study was undertaken to determine the prevalence of and reasons for noncompliance in filling prescriptions among patients discharged from the emergency department and to determine if differences in compliance exist among various socioeconomic groups. Ninety-six consecutive patients who had been given prescriptions at discharge from the emergency department were contacted by telephone the following day to determine if their prescriptions had been filled and if not, the reasons for not filling them. Patients were stratified by payor classification groups as follows: insured by third-party payor (53 patients), covered by Medicaid (19 patients), noninsured "self-paying", (14 patients), covered by Medicare (four patients), and unknown payor status, (six patients). The percentages in each group who had not filled their prescriptions by follow-up the next day were as follows: insured, 21%; Medicaid, 21%; self-paying, 21%; Medicare, 25%; unknown, 50%. Differences between groups were not significant. The following reasons were given for not having filled prescriptions: insufficient funds, 36%; lack of transportation or assistance, 14%; negligence, 32%; and miscellaneous, 18%. Of the prescriptions not filled, 45% were for analgesics or muscle relaxants, 41% were for antibiotics, and 14% were for miscellaneous medications.(ABSTRACT TRUNCATED AT 250 WORDS)

Reliability of home observation for victims of mild closed-head injury.

Victims of mild closed-head injury who do not require hospitalization frequently are observed at home. The efficacy of home observation for such cases and the extent to which after-care management plans are executed in this setting, however, are unknown. We studied 47 consecutive victims of mild closed-head injury discharged from the emergency department for home observation under the care of a responsible individual with a set of written after-care instructions for management. The instructions were reinforced verbally by ED staff before discharge. Followup was performed within 24 hours by telephone, and a questionnaire was sent. Three patterns emerged. Nine patients (19%), Group A, denied having received written after-care instructions despite documentation to the contrary in the medical record. Seventeen patients (36%), Group B, received the instructions alone and were told to convey them to the individual responsible for performing the home management. In the remaining 21 cases (45%), Group C, the instructions were given directly to the individual responsible for providing the home management. Although the after-care management plan specified observing or awakening the patient every two hours, this was done in only two patients (22%) in Group A and in four patients (24%) in Group B (NS). Fourteen patients (67%) in Group C, by comparison, were observed correctly as specified by the after-care instructions (P less than .02). No one in Group A could recall more than two of the eight items in the after-care management plan, and only three individuals (18%) in Group B (NS), could recall more than two items.(ABSTRACT TRUNCATED AT 250 WORDS)

Left mainstem bronchus intubation.

We report a case of a 78-year-old woman, previously in good health, who was endotracheally intubated and brought to the emergency department following sudden cardiac arrest. Physical examination revealed absent breath sounds over the right hemithorax, and a portable chest radiograph demonstrated left mainstem bronchus intubation. Although right mainstem bronchus intubation is a common complication of endotracheal intubation, left mainstem bronchus intubation is rare.

Administration of intravenous alcohol for prevention of withdrawal in alcoholic burn patients.

We studied the effects of intravenous alcohol infusions on 22 alcoholic burn patients admitted to our burn center. The relationship of infusion rates to blood alcohol levels was studied over a 3 to 8 day period of administration, and daily blood test results in liver function were followed. No patients had signs of withdrawal either during the infusion period or after the discontinuation of alcohol therapy. Our data suggest that the intravenous infusion of ethanol at rates of 0.02 to 0.06 g/kg per hour provides low but measurable blood alcohol levels (2 to 8 mg/100 ml), avoids sedation and toxic effects, and prevents the appearance of withdrawal symptoms in severely alcoholic burn patients.