CAEP/ACMU 2000 Scientific Abstracts:1-3

CAEP Abstracts

CJEM 2001;2(3):169-187

001 Tissue Plasminogen Activator in Cardiac Arrest with Pulseless Electrical Activity: A Randomized Placebo-Controlled Trial.
Abu-Laban RB, Christenson JM, Innes GD, van Beek CA, Wanger KP, McKnight RD, MacPhail IA, Puskaric J, Sadowski RP, Singer J, Schechter MT, Wood VM. University of British Columbia, Vancouver, BC.

OBJECTIVES: Acute coronary or pulmonary thrombosis causes numerous cardiac arrests, and survival after thrombolysis during CPR has been reported. We sought to determine if a rapid infusion of tissue plasminogen activator (tPA) would benefit selected pulseless electrical activity (PEA) cardiac arrest patients.
METHODS: Prehospital or ED adult cardiac arrest patients with at least one minute of PEA (rate >20/min) who remained pulseless after intubation, 500 cc IV saline, and 1 mg IV epinephrine were eligible. Patients with reversible causes of PEA or contraindications to thrombolysis were excluded. Subjects were randomized to receive tPA (100 mg IV over 15 minutes) or an equal volume of placebo in a double-blind fashion. Standard resuscitation measures were then continued for a minimum of 15 minutes.
RESULTS: From February 1998 to September 1999, 1583 cardiac arrests were treated and 233 patients enrolled (117 tPA, 116 placebo). Baseline characteristics and survival predictors were similar in the two treatment groups. There was one survivor to hospital discharge in the tPA group (0.9%, 95% CI 0.0% to 4.7%) and none in the placebo group (0%, 95% CI 0.0% to 3.1%), p = NS. The survivor had a fully functional recovery. The proportion of return of spontaneous circulation (ROSC) was 21.4% in the tPA group and 23.3% in the placebo group (difference ­1.9%, 95% CI ­12.6% to +8.8%), p = NS.
CONCLUSIONS: This study was designed with 80% power to detect an increase in survival to hospital discharge from a 1% estimated baseline to 10.3% with treatment. We found no evidence for a treatment effect of this magnitude. It remains undetermined whether selected subgroups may benefit from thrombolysis during CPR.
Key words: pulseless electrical activity, cardiac arrest, resuscitation, tissue plasminogen activator

002 Fibrinolytic Therapy in Acute Myocardial Infarction: Time to Treatment in Canada.
Davies C, Christenson J, Matheson S, Campbell A, Cox J. Vancouver General Hospital, Vancouver, BC.

OBJECTIVES: To provide a current description of the time components in the treatment of acute myocardial infarction in Canada.
METHODS: Data from the FASTRAK™ II observational database was analyzed. The database has documented time intervals in 4,749 patients treated in 111 contributing institutions across Canada in 1998.
RESULTS: The mean time from onset of symptoms to admission to hospital was 153 minutes (2.55 hours). Only 8.2% of patients received fibrinolysis in less than one hour after onset of symptoms. Time from arrival at hospital to acquisition of first 12-lead ECG was 14 min. Mean time from diagnostic ECG to decision to treat was 31 min, and time from decision to treat to administration of fibrinolytic therapy was 14 min. The overall average time from arrival at hospital to administration of fibrinolysis was 56 min. Analysis of time intervals showed that 31.6% of patients had therapy in less than 30 min, 16.6% had therapy within 30­40 min, 22.5% of patients had received therapy by 40­60 min and 29.3% of patients did not have therapy for more than 60 minutes.
CONCLUSIONS: In Canada in 1998, time from onset of symptoms to hospital presentation precludes early fibrinolytic administration in many cases. Time intervals from arrival in the emergency department to administration of fibrinolytic therapy is longer than published and accepted standards. Strategies to alter health seeking behaviour and to minimize in-hospital delays are needed.
Key words:myocardial infarction, thrombolysis

003 Locations of Cardiac Arrest in a Large Urban Centre.
Millard W, De Maio VJ, Gant PT, Yahn S. City of Calgary Emergency Medical Services Department, Calgary Fire Department and University of Calgary, Calgary, Alta.

OBJECTIVES: Identification of the location of out-of-hospital cardiac arrest is necessary to optimize the placement of automated external defibrillators (AEDs) within the community. This study determined the locations of cardiac arrest, and developed a placement strategy for Public Access Defibrillation (PAD) to maximize future AED accessibility.
METHODS: This retrospective cohort study included all adult, nontraumatic, out-of-hospital cardiac arrests within an advanced life support (ALS) system. The city population was over 750,000 with a land area amongst the largest of any city in North America. Chart review revealed the location of arrest, which was then categorized by location type.
RESULTS: From 1992 to 1996, there were 1,410 consecutive cardiac arrests. Of these, 82% occurred in private residences or outside as follows: 58% occurred in private homes, 10% in apartment buildings, and 14% in the street or within a vehicle. There was no apparent tendency for these arrests to cluster in particular locations (e.g., older neighbourhoods) or high population areas. The remaining 18% of cardiac arrests occurred in public venues: 5% in nursing homes, 5% in large (>250 people) public buildings, most often hotels, airport and fitness facilities, and 8% in smaller (<250 people) public buildings, most commonly golf courses, doctor/dentist offices and restaurants or bars.
CONCLUSIONS: Although relatively few cardiac arrests occur in public locations, current PAD programs have focussed on these higher density areas as a strategy for providing greater coverage with fewer AED placements. The visible placement of AEDs where people work, shop and recreate will likely increase public awareness of the recognition and management of cardiac arrest. However, the vast majority of cardiac arrests occur in private locations and responsible PAD programs must continue to explore other feasible methods of optimizing rapid access to defibrillation.
Key words:public access defibrillation, cardiac arrest, resuscitation