Abstract 2: Cardiac Arrest During Aeromedical Transport: A 5-year Retrospective Case Review

Abstract

Objectives Air emergency medical services (AEMS) are regularly employed in many parts of the world to transport severely ill or injured patients rapidly to definitive care. Out-of-hospital cardiac arrest (OHCA) is a potentially catastrophic event that may occur among a subset of the most severely ill patients that are encountered. This study describes the pre-arrest characteristics, treatments applied, and short-term outcomes of patients with OHCA treated by AEMS. Methods All adult patients who experienced OHCA at a single, academic aeromedical transport service between 2013–2017 were included in this retrospective analysis. All cases during which an adult patient suffered cardiac arrest occurring from the time of AEMS arrival at the scene or sending facility to hand off at the receiving facility were included. Data including standard Utstein variables, treatments, and short-term outcome were extracted by the authors. Univariate descriptive statistics were computed using SPSS ver. 25. Results During the 5-year period, 92 cases of adult OHCA were identified among 16,779 transports. The median age of patients experiencing OHCA was 64.5 years [55.3, 63.3]. Among patients transported, the average transport time was 75.4 minutes [63.4, 87.3]. 60 OHCA cases (65.2%) were of medical etiology and 32 (34.8%) were traumatic. Scene calls were the origin for 51.1% of calls; the rest were interfacility transfers. 36/92 patients (39.1%) had multiple cardiac arrests under AEMS care, and OHCA occurred for the first time most often before take-off: 39.1% at the initial scene, 29.3% in transit or loading to aircraft, and in flight 31.5% of the time. 17.4% of the cohort had an initial shockable rhythm and 42.4% achieved return of spontaneous circulation (ROSC) by arrival at the destination facility; an additional 5.4% achieved ROSC and were not transported. Conclusions In this cohort, OHCA occurred in 92 adult patients over 5 years, with approximately two thirds medical and one third traumatic in nature. Initial rhythm was rarely shockable, but sustained ROSC was achieved in almost half the patients. Almost 4 in 10 patients had multiple cardiac arrests under AEMS care, and initial arrest was most likely to occur prior to air transport as opposed to in flight. A high proportion of patients achieving ROSC is possible, even with relatively low rates of shockable initial rhythm. This study suggests that while cardiac arrest in flight is rare, medical teams must be prepared to handle both medical and traumatic arrests as well as multiple arrests during the course of air transport.