Efficacy of Cardiopulmonary Resuscitation in the Field: Effect of the NATO Litter With and Without a Backboard

The use of a backboard during cardiopulmonary resuscitation (CPR) has been a recommendation since the introduction of CPR in 1960. However, during wartime or contingency scenarios, or aeromedical transport, backboards may not be available. Data regarding patient characteristics during wartime, humanitarian, and disaster missions all confirm that there will be large numbers of patients who suffer from a serious traumatic injury, are critically ill, or suffer a primary cardiac arrest. Currently the three USAF medical teams configured for rapid deployment with missions of caring for the most critically ill or injured do not carry CPR backboards. During recent exercises involving these teams, cardiopulmonary resuscitation was performed with the "patients" on a NATO litter without a backboard. Additionally, during aeromedical transport if a patient suffers a cardiac arrest, the standard practice is to move the patient off the NATO litter to the floor of the aircraft, where resuscitation is attempted. This movement results in a critical delay in the initiation of CPR; a factor known to increase mortality. A recent query from the USAF School of Aerospace Nursing regarding techniques for CPR in both the field and the aeromedical evacuation environment led to this proposal.

The aim of this study is to determine if there is a difference in the efficacy of CPR performed on the NATO litter with and without a backboard as indicated by (1) end-tidal carbon dioxide (ETCO₂) level, (2) coronary perfusion pressure (CPP), and (3) return of spontaneous circulation (ROSC). Two NATO litters (canvas and decontamination) will be evaluated. Using a randomized, three group experimental design 70 kg pigs will undergo four minutes of ventricular fibrillation followed by eight minutes of CPR using a mechanical compression device on one of three surfaces: (1) NATO litter (canvas) without a backboard, (2) NATO litter (decontamination) without a backboard, and (3) NATO litter (canvas) with backboard (control). Differences between the groups on ETCO₂, CPP, and ROSC will be tested with Repeated Measures ANOVA and Chi-Square analysis depending on the level of measurement.