CAEP/ACMU 2000 Scientific Abstracts: 22-25

CAEP Abstracts

CJEM 2001;2(3):169-187

022 Incidence, Mortality Rates and Advanced Life Support Treatment of Prehospital Acute Pulmonary Edema: A Retrospective Cohort.
Mawhinney SW, Su WY, Morrison LJ. Division of Prehospital Care, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, and Toronto Ambulance Service, Toronto, Ont.

OBJECTIVE: To describe the prehospital incidence, mortality and Advanced Life Support (ALS) treatment of presumed acute pulmonary edema (APE) in a system with an annual ALS volume of 51,225 patient carries.
METHODS: A retrospective chart review of all retrievable ALS ambulance call reports (ACRs) for one month was performed. Agreement of ACR extraction, data abstraction and double data entry was evaluated using a kappa statistic, ANOVA or percent error. The inclusion criteria were: bilateral crackles/rales, pink frothy sputum, or both on prehospital physical examination. Patients were excluded if crackles/rales resolved with basic airway maneuvers. Descriptive frequencies were reported. RESULTS: The 5026 ACRs retrieved represented 99.3% of the total monthly calls. In this sample, 238 met inclusion criteria, 6 ACRs were excluded. The ACR extraction kappa was 0.97. The two data abstractors performed consistently (p = 0.40). The percent error for double data entry was 0.7%. The incidence of prehospital APE was 4.6%. One hundred and two patients were hemodynamically unstable defined as BP <90 (24) and presence of chest pain (78). One hundred and four (44.4%) patients received ALS interventions and 22 patients were intubated. Ninety-four patients (40%) were given medications and 85 received nitroglycerin. Only 15 patients received the standard regimen of nitroglycerin, morphine and furosemide. The prehospital mortality was 0%. CONCLUSIONS: Approximately 1 in 20 prehospital patients have (presumptive) APE. Almost half of these patients received prehospital interventions, yet the treatment is varied and rarely complies with the standard regimen. The in-field mortality is low.
Key words: emergency medical services, pulmonary edema, congestive heart failure

023 Evaluation of the Myocardial Ischemia Subgroup in the Vasopressin Epinephrine Cardiac Arrest (VECA) Trial.
Stiell IG, Hebert P, Wells G, Clement C, Vandemheen K, Tang A, Higginson L, Dreyer J, Weitzman B. Clinical Epidemiology Unit, University of Ottawa, Ottawa.

OBJECTIVES: We previously reported the overall results of the Vasopressin Epinephrine Cardiac Arrest (VECA) clinical trial. This work rigorously reviews the a priori subgroup of patients with myocardial ischemia.
METHODS: This randomized controlled trial was conducted in the EDs, CCUs, and wards of 3 teaching hospitals. Adults who suffered cardiac arrest and required epinephrine according to AHA ACLS protocols were randomly allocated to receive one dose of either vasopressin 40 units or epinephrine 1 mg. Primary outcomes were survival to hospital discharge and to one hour and neurological function according to a modified Mini-Mental Status exam (MMSE). For the current review, two investigators blindly assessed all clinical records including ECGs and autopsy reports to determine whether the initiating cause of arrest could be attributed to myocardial ischemia or infarction. Analyses included the chi-square test with calculation of 95% CIs for the absolute increase in survival (AIS). RESULTS: Overall, 65 of 200 VECA patients were judged to be in the myocardial ischemia subgroup. The 32 vasopressin and the 33 epinephrine patients were similar for all characteristics including age (72.6 vs. 70.0 years), ED location (21.9% vs. 21.2%), witnessed (90.6% vs. 90.9%), rhythm VF/VT (34.4% vs. 27.3%), time collapse-CPR (1.7 vs. 1.6 min), and atropine given (78.1% vs. 75.8%). Comparing vasopressin to epinephrine, survival was not different for discharge (15.6% vs. 15.2%; p = 0.96; 95% CI for AIS ­18.9% to 19.9%), for one hour (28.1% vs. 36.4%; p = 0.48; 95% CI for AIS ­16.3% to 32.8%), or any return of pulse (53.1% vs. 66.7%; p = 0.27). The status of survivors was not different for mean MMSE scores (34.8 vs. 36.2; p = 0.51). CONCLUSIONS: The VECA Trial was unable to demonstrate benefit from vasopressin for any in-hospital cardiac arrest patients, including those suffering myocardial ischemia/infarction.
Key words: ardiac arrest, epinephrine, vasopressin

024 Epidemiology and Survival for Prehospital Cardiac Arrest in an Advanced Life Support System: The Calgary Experience.
De Maio VJ, Millard W, Gant PT, Burgwin DH, Curry G. City of Calgary Emergency Medical Services Department and University of Calgary, Calgary, Alta.

OBJECTIVES: Canadian accounts of the state of prehospital cardiac arrest in an advanced life support (ALS) system remain limited. Calgary, Alberta, is currently Canada's fastest growing centre boasting one of the largest land areas of any city in North America and Canada's first paramedic program. The objective of this study was to establish cardiac arrest incidence and survival rates to serve as a baseline for future prospective studies and comparison for other Canadian ALS programs.
METHODS: This observational cohort study included all adult, cardiac etiology, prehospital cardiac arrest cases where resuscitation was attempted. The system provided an ALS level of care, firefighter defibrillation, and a "medical priority dispatch" program that includes post-dispatch CPR instructions. EMS managers abstracted cardiac arrest data elements on a prospective basis directly into a database developed using the Utstein template. Descriptive statistics were used to characterize patient, EMS system, and survival data. RESULTS: From 1993 to 1996, 940 eligible cases were treated. Patients were primarily male (69%) with a mean age of 64 years. Of these, 48% were bystander-witnessed, 13% EMS-witnessed, 34% received citizen CPR, and 57% had an initial rhythm of VF/VT. The ALS response interval from call received to vehicle stopped was 8 minutes or less for 82% of cases with a mean response interval of 5.7 minutes. Survival to hospital discharge was 12% overall, 21% for VF/VT patients, 19% for bystander-witnessed VF/VT, and 32% for all EMS-witnessed cases. CONCLUSION: Although survival from prehospital cardiac arrest remains universally low, survival in this community is relatively good relative to other published ALS reports. We found an impressive citizen CPR rate that rivals the best results found in the current literature and supports community efforts toward making Calgary a "Heart Safe City."
Key words:cardiac arrest, resuscitation, emergency medical services

025 Pre-Hospital Oral Glucose Versus Glucagon for Symptomatic Hypoglycaemia: A Before and After Outcome Comparison of Blood Glucose and Glasgow Coma Scale.
Kloompas M, Mazza C. Division of Prehospital Care, Sunnybrook & Women's Health Sciences Centre, University of Toronto and Toronto Ambulance Service, Toronto, Ont.

OBJECTIVES: To compare the effect of prehospital administration of oral glucose versus subcutaneous (SC) glucagon for the treatment of symptomatic hypoglycemia on blood glucose and Glasgow Coma Scale (GCS).
METHODS: Prospective, observational trial of two consecutive cohorts of patients with confirmed hypoglycemia (blood glucose <4.0 mmol/L). For an initial six month period, (control group CG) paramedics (EMT-D) treated 407 hypoglycemic patients with up to 20 g of D-glucose gel orally by protocol. The following 6-month period, (treatment group TG) the same protocol was followed to treat 379 patients with 1.0 mg glucagon (SC) substituted for oral glucose.
RESULTS: Patients had similar demographics in both groups for age, gender, prevalence of IDDM and initial glucose level (CG 2.2 ± 0.68 mmol/L, TG 2.3 ± 0.71 mmol/L). The TG had a lower median initial GCS than the CG (median 11 vs. 12, p = 0.001). Patients treated with glucagon had higher blood glucose levels at 10 minutes after treatment (TG 3.7 ± 1.6 vs. CG 2.7 ± 1.3 mmol/L, p < 0.001) and at 20 minutes after treatment (TG 4.3 ± 1.6 versus CG 3.2 ± 1.5 mmol/L, p = 0.002). The change in median GCS scores was better with glucagon (median GCS change 12 to 14 for glucose gel versus 11 to 15 for glucagon, p < 0.01). Patients treated with glucagon were also more likely to show subjective clinical improvement on a validated ordinal scale (TG: 232 improved (74%) vs. CG: 120 improved (41%), p < 0.001) EMS time interval comparisons were similar for both groups (CG 25.1 ± 10.4 min, TG 24.2 ± 9.2 min for scene time and CG 7.0 ± 5.1 min, TG 7.4 ± 5.3 min for transport time).
CONCLUSIONS: Prehospital administration of subcutaneous glucagon for confirmed hypoglycemia significantly increased the blood glucose at 10 and 20 minutes post administration and improved the Glasgow Coma Scale.
Key words: diabetes mellitus, hypoglycemia, glucagons