Case Series of Arterial Gas Embolism Incidents in U.S. Navy Pressurized Submarine Escape Training From 2018 to 2019

The goal of Pressurized Submarine Escape Training (PSET) is to prepare future submariners for the physical and mental challenges of escaping a disabled submarine and promote proper handling of the Beaufort Ltd Mk 11 Submarine Escape and Immersion Equipment suit. Training participants are only permitted to enter PSET after strict health screening protocols have been met to optimize trainees’ safety. Before PSET, trainees are given detailed, one-on-one instruction on proper ascent mechanics by specially trained Navy Dive instructors. Since the reinstatement of PSET by the U.S. Navy, four incidents of arterial gas embolism (AGE) have occurred in submarine trainees with a 10-year period (2009-2019). Of these four incidents, three were observed within a couple months of each other from 2018 to 2019. A comprehensive review of AGE history, epidemiology, dive physiology, pathophysiology, and management was completed. Prompted by the recent incidents relative to the low reported incidence rate of AGE in historical PSET training, reported potential risk factors were compared with better understand potential etiologies of AGE in already medically screened individuals. Risks and benefits of PSET were listed, compared, and analyzed. The relative safety and cost effectiveness of this rigorous form of training was reconfirmed.