An Autopsy Report of Hypoplastic Coronary Artery Disease Incidentally Identified in a Young Man

Hypoplastic coronary artery disease (HCAD) is a rare congenital abnormality characterized by underdevelopment of one or more major branches of the coronary arteries, which may lead to myocardial infarction and sudden death. We report a case of HCAD that was incidentally detected during autopsy in a 25-year-old male soldier who died during underwater escape training. On macroscopic examination, the right coronary artery measured 1 mm in diameter, which was significantly smaller than that of other coronary arteries. We observed no anomalies in addition to HCAD. Death was attributed to drowning, which was consistent with autopsy findings and the circumstances of death. Although extremely rare, if sudden cardiac death is suspected in children and young adults, it must be confirmed through careful evaluation.

Pulmonary barotrauma with cerebral arterial gas embolism from a depth of 0.75−1.2 metres of fresh water or less: A case report

During underwater vehicle escape training with compressed air, a fit 26-year-old soldier suffered pulmonary barotrauma with cerebral arterial gas embolism after surfacing from a depth of 0.75–1.2 metres of freshwater or less. She presented with an altered level of consciousness. Rapid neurological examination noted slurred speech, a sensory deficit and right hemiparesis. Eleven hours after the accident, hyperbaric oxygen treatment was initiated using US Navy Treatment Table 6. The soldier almost completely recovered after repeated hyperbaric oxygen treatment. Given the very shallow depth this is an unusual case with only two similar case reports published previously.

Dynamic Bayesian Network-Based Escape Probability Estimation for Coach Fire Accidents

Coach emergency escape research is an effective measure to reduce casualties under serious vehicle fire accidents. A novel experiment method employing a wireless transducer was implemented and the head rotation speed, rotation moment and rotation duration were collected as the input variables for the classification and regression tree (CART) model. Based on this model, the classification result explicitly pointed out that the exit searching efficiency was evolving. By ignoring the last three unimportant factors from the Analytic Hierarchy Process (AHP), the ultimate Dynamic Bayesian Network (DBN) was built with the temporal part of the CART output and the time-independent part of the vehicle characteristics. Simulation showed that the most efficient exit searching period is the middle escape stage, which is 10 seconds after the emergency signal is triggered, and the escape probability clearly increases with the efficient exit searching. Furthermore, receiving emergency escape training contributes to a significant escape probability improvement of more than 10%. Compared with different failure modes, the emergency hammer layout and door reliability have a more significant influence on the escape probability improvement than aisle condition. Based on the simulation results, the escape probability will significantly drop below 0.55 if the emergency hammers, door, and aisle are all in a failure state.

Evaluation of the Helicopter Emergency Breathing Apparatus on Egress Performance

BACKGROUND: Emergency helicopter landing at sea is dangerous. Specialized training, known as helicopter underwater escape training (HUET), prepares occupants to quickly exit the helicopter, which often inverts and sinks. In most jurisdictions, helicopter occupants are equipped with a helicopter underwater egress breathing apparatus (HUEBA) to provide sufficient air for escape. HUET trainees report that the HUEBA is easy to use, but it is well known that learners are often overconfident in their judgement of learning. To better understand how the HUEBA affects HUET sequence performance, we investigated whether using the HUEBA influences the sequence movement time and number of errors.METHODS: Twelve participants (7 men and 5 women, mean age 25.33 9.57 SD) with no prior experience with HUET performed consecutive trials of the HUET sequence, 5 with the HUEBA and 5 without the HUEBA. Video of each trial recorded the total movement time and enabled movement time analyses of each component of the sequence: crossing arms, tucking the head, pushing the window, inserting the regulator, and releasing the seatbelt. These recordings were also used to score performance errors according to a checklist.RESULTS: Analyses revealed that using a HUEBA increased the total movement time and time to release the seatbelt by 0.36 and 0.39 s, respectively, in comparison to without the HUEBA.DISCUSSION: Our study illustrates that using the HUEBA during the HUET sequence increases total movement time and time to release the seatbelt. However, this difference is marginal and unlikely to have practical significance during underwater escape.King M, Sanli E, Mugford K, Martina S, Brown R, Carnahan H. Evaluation of the helicopter emergency breathing apparatus on egress performance. Aerosp Med Hum Perform. 2020; 91(12):962965.

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

ABSTRACT 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.

Investigating Coercion, Abuse, and Manipulation: Recognizing the Legacy of the Cold War

In this manuscript, the authors examine the Cold War roots of the movement to study groups that engage in undue influence. In particular, the authors consider the transitions of some scholars directly from Cold War brainwashing research to the study of these groups and also the activities of researchers who did not directly address groups but established enduring foundations in this field. The authors also consider expert testimony in both the Hearst trial and a government program, the Survival, Evasion, Resistance, and Escape training program, which brought together disparate scholars to address these ideas. The authors then examine the influence of developments in social psychology on approaches to Cold War brainwashing and its connection to the later literature about groups that may use undue influence. The paper concludes with a review of strengths and limitations from this literature that remain in the study of these groups.

Identifying Predictors of Pressurized Submarine Escape Training (PSET) Attrition

Pressurized Submarine Escape Training (PSET) physically prepares submariners to safely escape a submarine at depth. Failure to complete PSET is not a submarine service disqualification. Serious medical incidents are rare, but the safety record tradeoff has been low throughput. From 2009 to 2015, only 34% of students screened completed PSET. Students may be medically screened out of the training altogether (disqualified), or dropout during the physical training (attrite). Training records from 12,122 U.S. Navy students were used to identify factors contributing to training disqualification and attrition. Multivariate logistic regression model predictors included demographic and screening items. Association to PSET disqualification included cold/congestion/cough (ORadj 12.34), limited duty status (ORadj 4.29), Physical Readiness Test failure (ORadj 3.37), pneumonia or bronchitis in last 2 years (ORadj 3.17) and nervousness or anxiety in tight spaces (ORadj 2.37). Basic Enlisted Submarine School students were more likely to be disqualified and attrite than other submariner groups, and black/African American (ORadj 1.53) students were more likely to attrite than white students. Only cold/congestion/cough (ORadj 1.52), trouble swimming (ORadj 1.53), and screening during cold/flu season (ORadj 1.28), were associated with training attrition. Recommendations to modify screening requirements are listed in conclusions.