Introduction-Performing cardiopulmonary resuscitation (CPR) in microgravity is challenging due to reciprocal motion between the patient and operator, requiring unique methods of stabilization for chest compressions. In this study, the Polaris Dawn mission crew evaluated optimal methods of CPR administration in the Dragon spacecraft during spaceflight as well as the impact of CPR tasks to the vehicle.Methods-CPR was simulated by compressing a CPR Adult Manikin Bellows Piston with Clicker against different surfaces of the vehicle. Crew members performed compressions at 3 different locations to select the optimal worksite. All 4 crew members then performed a 2-min round of compressions at the optimal worksite. Workload was measured using the Bedford workload and Borg rating of perceived exertion scales, where lower scores are desirable for both scales. Vehicle impacts were monitored with navigation and carbon dioxide sensors.Results-The outboard seat was selected as the optimal worksite. When performing a full 2 min of chest compressions at this location, average Bedford workload and Borg rating of perceived exertion scores among all 4 crew members were 4.75 and 16, respectively. All 4 crew members achieved the target-frequency range (mean, 1.8 Hz; range 1.7-1.9 Hz). Vehicle accelerations were observed in all axes, and cabin carbon dioxide increased to a peak level of >3.6 mm Hg, triggering a carbon dioxide caution limit.Conclusions-Outboard seat location provided the best ergonomics for administration of CPR on the Dragon spacecraft, although task performance had high difficulty ratings. CPR also was associated with elevated cabin carbon dioxide and vehicle accelerations, as measured by the navigation system.
Keywords: CPR; astronaut; cardiac arrest; chest compressions; microgravity; spaceflight.