Michael Shuster

Effect of fire department first-responder automated defibrillation

STUDY OBJECTIVE To examine the effect of fire department first-responder defibrillation on time to defibrillation in a mid-sized community with two tiers of emergency medical services (EMS) ambulance response. DESIGN Retrospective cohort. SETTING The study area was the region of Hamilton-Wentworth, which has more than 445,000 inhabitants and covers 1,136 km2 (438 square miles). TYPE OF PARTICIPANTS We studied 297 victims of out-of-hospital cardiac arrest presenting to the EMS system between May 1, 1990, and April 30, 1991. MEASUREMENTS AND MAIN RESULTS The mean defibrillation interval was decreased from 11.96 minutes to 8.50 minutes (P < .001) by the introduction of fire first-responder defibrillation. Survival was significantly greater with bystander-witnessed arrest, initial rhythm of ventricular fibrillation, and presence of a pulse on arrival in the emergency department. CONCLUSION In our EMS system, fire first-responders were able to provide defibrillation in significantly shorter times than ambulance attendants. Other EMS systems should review their response times and consider instituting first-responder defibrillation as one means of reducing defibrillation intervals.

Patterns of death among avalanche fatalities: a 21-year review

Background: Avalanches are a significant cause of winter recreational fatalities in mountain regions. The purpose of this study was to determine the relative contributions of trauma and asphyxia to avalanche deaths. Methods: We reviewed all avalanche fatalities between 1984 and 2005 that had been investigated by the offices of the British Columbia Coroners Service and the Chief Medical Examiner of Alberta. In addition, we searched the database of the Canadian Avalanche Centre for fatal avalanche details. We calculated injury severity scores for all victims who underwent autopsy. Results: There were 204 avalanche fatalities with mortality information over the 21-year study period. Of these, 117 victims underwent autopsy, and 87 underwent forensic external examination. Asphyxia caused 154 (75%) deaths. Trauma caused 48 (24%) deaths, with the rate of death from trauma ranging from 9% (4/44) for snowmobilers to 42% (5/12) for ice climbers. In addition, 13% (12/92) of the asphyxia victims who underwent autopsy had major trauma, defined as an injury severity score of greater than 15. Only 48% (23/48) of victims for whom trauma was the primary cause of death had been completely buried. Interpretation: Asphyxia and severe trauma caused most avalanche fatalities in western Canada. The relative rates differed between snowmobilers and those engaged in other mountain activities. Our findings should guide recommendations for safety devices, safety measures and resuscitation.

Prereduction radiographs in clinically evident anterior shoulder dislocation

The main study objective was to determine if experienced emergency physicians can accurately identify a subgroup of patients with anterior shoulder dislocation for whom prereduction radiographs do not alter patient management. Our prospective study evaluated 97 patients who presented to 2 ski-hill clinics and to our rural emergency department with possible shoulder dislocation between November 1996 and May 1997. Emergency physicians were certain of shoulder dislocation by clinical examination alone in 40 of 59 cases (67.8%) of possible dislocation. All 40 cases were found to have a dislocation (100%; 95% Cl, 91.19% to 100%), and the prereduction radiograph did not affect management of the injury. Prereduction radiographs added 29.6 +/- 12.68 minutes to treatment. We conclude that shoulder dislocation is often readily apparent from history and physical examination. When the experienced emergency physician is certain of the diagnosis of anterior shoulder dislocation, prereduction radiography delays treatment and does not alter management.

Prospective evaluation of a guideline for the selective elimination of pre-reduction radiographs in clinically obvious anterior shoulder dislocation

OBJECTIVE Research has demonstrated that experienced emergency physicians can identify a subgroup of patients with shoulder dislocation for whom pre-reduction radiographs do not alter patient management. Based on that research, a treatment guideline for the selective elimination of pre-reduction radiographs in clinically evident cases of anterior shoulder dislocation was developed and implemented. The primary objective of this study was to prospectively determine whether the treatment guideline safely eliminates unnecessary radiographs. METHODS We enrolled a convenience sample of patients who presented to our rural emergency department with possible shoulder dislocation between November 2000 and April 2001. Physicians scored their level of clinical diagnostic certainty on a 10-cm visual analogue scale prior to viewing pre-reduction radiographs (if obtained). Data were collected on clinical scoring and evaluation, compliance with the guideline, and outcomes. RESULTS A total of 63 patients were enrolled, ranging in age from 17 to 79 years (mean = 33); 87.3% were male. Emergency physicians were certain of shoulder dislocation in 59 (93.7%) patients (95% CI, 84.5%-98.2%) and complied with the treatment guideline in 52 patients (82.5%). Most deviations from the treatment guideline involved the elimination of post-reduction radiographs (which the guideline recommends for all patients). The treatment guideline eliminated 56 (88.9%, 95% CI, 78.4%-95.4%) pre-reduction radiographs, as compared to the standard practice of obtaining pre-reduction films for all cases of suspected shoulder dislocation (p < 0.0001) CONCLUSIONS Experienced emergency physicians are frequently certain of the diagnosis of anterior shoulder dislocation on clinical grounds alone and can comfortably and safely use this guideline for the selective elimination of pre-reduction radiographs. Compliance with the guideline substantially decreases pre-reduction radiographs. Validation of the guideline in other settings is warranted.

Effects of Prehospital Care on Outcome in Patients With Cardiac Illness

STUDY OBJECTIVE To compare outcomes of patients with acute cardiac illness transported by ambulance for whom prehospital care was provided by emergency medical technician-paramedics (EMT-Ps) or EMTs trained in defibrillation (EMT-Ds). DESIGN A prospective chart review carried out over 3.5 years. SETTING The Hamilton-Wentworth region of Ontario, Canada, which covers 1,136 km2 and includes five receiving hospitals. PARTICIPANTS We prospectively identified 8,720 potentially eligible patients from approximately 30,000 who presented to the ambulance service. We reviewed hospital charts to confirm eligibility. The group of 8,720 patients yielded 3,066 patients with acute cardiac illness who met all other eligibility requirements. We excluded patients in cardiac arrest. RESULTS Incidence of myocardial infarction (MI), length of hospital stay, and mortality were evaluated. Analysis was performed with chi 2 tests for association, linear regression, and logistic regression. Of the eligible patients who received prehospital EMS care, 783 sustained MIs. The proportions of people discharged alive with the diagnosis of MI did not differ between crew types (P = .16). Average hospital stay was 13 days in both groups for patients with the discharge diagnosis of MI; hospital stay ranged from 9 (EMT-D) to 11 days (EMT-P) for any patient with a discharge diagnosis other than MI. These values were statistically similar. The odds ratio of having had an MI after treatment by an EMT-D crew was 1.02 (95% confidence interval, .86 to 1.21) compared with that for treatment by an EMT-P crew. CONCLUSIONS In an urban setting with short (less than 10 minutes) average transport times, the availability of prehospital paramedic care does not affect occurrence of MI, length of hospital stay, or mortality of patients presenting to the EMS system with cardiac illness.

Reliability of prehospital rating scales for case severity and status change

The purpose of this report is to determine the reliability and sensibility of the currently available prehospital rating scales by a prospective evaluation of ambulance call reports using generalizability methodology. Sequential samples of emergency call data from the Hamilton Base Hospital Paramedic program database were used to sample calls randomly for a two-phase study. Phase I and II used blinded ambulance call report forms presented to six rates during three sessions in each phase. Generalizability (reliability) coefficients were then generated to determine the degree of reliability for the scales in both phases of the study. The generalizability coefficients for all scales are substantial or excellent using the standards commonly applied to agreement statistics. The conclusion of the study is that all ambulance officers can use the prehospital scales reliably. The reliability of these general measures is one of the parameters that will allow us to evaluate where basic and advanced prehospital care have an impact on overall patient outcome.

Update on cardiopulmonary resuscitation and emergency cardiovascular care guidelines

PURPOSE The key changes included in the 2005 cardiopulmonary resuscitation (CPR) and emergency cardiac care (ECC) guidelines are reviewed. Advances since publication of the current guidelines are also discussed. SUMMARY The 2005 CPR and ECC guidelines include several key changes from the previous version published in 2000. The new guidelines place an increased emphasis on chest compressions and recommend a compression:ventilation (C:V) ratio of 30:2. Current knowledge on defibrillation has also been incorporated by recommending that Emergency Medical Service (EMS) rescuers give two minutes of CPR before defibrillation when the response interval is greater than four to five minutes and EMS responders did not witness the arrest. Another major change is the recommendation for a single shock to be administered followed immediately by CPR with no check of the cardiac rhythm until two minutes of CPR has been performed postdefibrillation. The 2005 guidelines recommend that an automated external defibrillator should be implemented in public locations where there is a relatively high likelihood of witnessed cardiac arrest. In addition, the most recent guidelines highlight the shift from primary-rhythm-based therapies and resuscitation to a focus on neurologic outcomes. CONCLUSION Several evidence-based changes were included in the 2005 CPR and ECC guidelines, including a C:V ratio of 30:2 and mitigation of hands-off time, early defibrillation, administration of a single shock versus a three-shock sequence, use of public-access defibrillators, and a shift from primary-rhythm-based therapies to a focus on neurologic outcomes.

Focused abdominal ultrasound for blunt trauma in an emergency department without advanced imaging or on-site surgical capability

OBJECTIVES To determine whether focused abdominal sonogram for trauma (FAST) in a rural hospital provides information that prompts immediate transfer to a tertiary care facility for patients with blunt abdominal trauma who would otherwise be discharged or held for observation. METHODS Prior to the study, participating emergency physicians underwent a minimum of 30 hours of ultrasound training. All patients who presented with blunt abdominal trauma to our rural hospital between Mar. 1, 2002, and Apr. 30, 2003, were eligible for study. Following a history and physical examination, the emergency physician documented his or her disposition decision. A FAST was then performed, and the disposition reconsidered in light of the FAST results. RESULTS Sixty-seven FAST exams were performed on 65 patients. Three examinations (4.5%) were true-positive (95% confidence interval [CI] 0.9%-12.5%); 60 (89.6%) were true-negative (95% CI 79.7%-95.7%), 4 (6%) were false-negative (95% CI 1.7%-14.6%) and none (0%) were false-positive (95% CI 0%-5.4%). These values reflect sensitivity, specificity, negative predictive value and positive predictive values of 43%, 100%, 94% and 100% respectively. FAST results did not alter the decision to transfer any patient (0%: 95% CI 0.0%-5.4%), although one positive FAST may have led to an expedited transfer. One of 38 patients who was discharged after a negative FAST study returned 24 hours later because of worsening symptoms, and was ultimately found to have splenic and pancreatic injuries. CONCLUSIONS This study failed to demonstrate that FAST improves disposition decisions for patients with blunt abdominal trauma who are evaluated in a hospital without advanced imaging or on-site surgical capability. However, the study is not sufficiently powered to rule out a role for FAST in these circumstances, and our data suggest that up to 5.4% of transfer decisions could be influenced by FAST. Rural emergency physicians should not allow a negative FAST study to override a clinical indication for transfer to a trauma centre; however, positive FAST studies can be used to accelerate transfer for definitive treatment.

Prospective evaluation of clinical assessment in the diagnosis and treatment of clavicle fracture: Are radiographs really necessary?

INTRODUCTION Current recommended treatment for middle-third clavicle fractures is limited to the use of ice, analgesics, a sling, and rest. Radiography for these fractures would be superfluous if physicians could accurately identify them by clinical examination alone. The primary purpose of this study was to determine whether emergency physicians can accurately diagnose clavicle fractures, and whether they can differentiate middle-third fractures from medial- or lateral-third fractures by clinical assessment alone. METHODS We enrolled a convenience sample of patients who presented to our rural emergency department with possible clavicle fracture between Nov. 1, 2001, and Apr. 30, 2002. Prior to viewing radiographs, physicians scored their clinical certainty of diagnosis on a 10-cm visual analogue scale. When certain of fracture, physicians determined the location of the fracture, the nature of the fracture and their hypothetical comfort in treating the injury without radiography. RESULTS In 51 of 77 enrolled patients (66%; 95% confidence interval [CI], 54.6%-76.6%), treating physicians were certain of the diagnosis of clavicle fracture prior to radiography. In these 51 cases, radiography revealed a fracture in 50 cases (98.0%; 95%CI, 89.6%-99.9%). The physicians were 100% accurate for 4 fractures clinically identified as lateral-third fractures (95% CI, 39.7%-100%) and for 41 fractures identified as middle-third fractures (95% CI, 91.4%-100%). They were correct on only 1 of 5 injuries (20%; 95% CI: 1%-72%) they clinically identified as medial-third fractures. Despite high clinical accuracy with middle-third fractures, they stated in 27 of 42 cases (64%; 95%CI, 48.0%-78.5%) that they would have been uncomfortable treating the patient without a radiograph. CONCLUSIONS This study provides evidence that experienced emergency physicians are highly accurate when they are clinically certain of clavicle fracture. Further, when emergency physicians do clinically diagnose clavicle fracture, they can accurately identify the patient subgroup that will be responsive to conservative treatment. Routine radiography of obvious middle-third clavicle fractures does not appear to improve diagnostic accuracy or treatment decisions.