On-scene physician assessment of thromboembolic etiology in out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OOHCA) treatment produces dismal recovery rates. Newer, directed therapies such as thrombolysis may be best considered if possible etiologies can be assessed immediately. We conducted a prospective, pilot, feasibility study of on-scene physician assessments in non-traumatic OOHCA. Physicians responded to the scene and reported likelihood of thromboembolic etiology based on detailed history and physical assessments. Included were 136/148 OOHCAs during the 6-month study period; median age was 69.5 years and 72% were men. Physicians judged 103/136 (76%) of arrests to be of thromboembolic etiology and would have recommended thrombolytic bolus in 83/136 (61%). Among 19 instances of physician-reported contraindications, 17 (90%) were not true contraindications. Median age was lower in the group recommended for thrombolysis. Thromboembolic etiology as judged by on-scene physicians was common and physicians recommended thrombolytic bolus commonly. Contraindications were highly overestimated. These data may be useful in the consideration of innovative, directed therapies such as thrombolysis in attempts to improve outcomes from OOHCA.