Hyperventilation-Induced Hypocapnia in an Aviator.

BACKGROUND: Physiological episodes are a top safety concern for aviators across the United States military. While many cases and a variety of causes for physiological episodes have been described, few cases, if any, have been reported of hyperventilation-induced hypocapnia and transient loss of consciousness.CASE REPORT: Here we describe a case of an aviator who experienced tingling extremities, confusion, and loss of consciousness during a flight. The aviator incorrectly believed he was experiencing hypoxia and continued to take multiple steps to troubleshoot the wrong underlying problem for his symptoms. Evaluation after landing suggested this was instead a stress-induced hyperventilation that resulted in symptomatic hypocapnia.DISCUSSION: We report this case to add to the body of literature in understanding this phenomenon as well as to provide aviators, physiologists, and flight surgeons with practical suggestions for recognizing hyperventilation-induced hypocapnia and awareness of how to remedy this situation when they recognize it.Kramer KEP, Anderson EE. Hyperventilation-induced hypocapnia in an aviator. Aerosp Med Hum Perform. 2022; 93(5):470-471.

Offspring sex ratio of male active duty U.S. Navy submariners, 2001-2015.

The natural human sex ratio at birth (male:female) slightly favors males, and altered sex ratios might be indicative of exposure to reproductive hazards. In the U.S. Navy submarine community, there is a widespread belief that submariners are more likely to father females, but corroborating scientific evidence is limited. To assess this, Department of Defense Birth and Infant Health Research program data were used to identify 7,087 singleton infants whose fathers were considered submariners. Chi-square tests and unconditional logistic regression models were used to compare the offspring sex ratio of male submariners with 2 other active duty populations and the U.S. population. The offspring sex ratio of male submariners was 1.048, which did not substantially differ from the sex ratio of each comparison population. Furthermore, this study found no meaningful variation in offspring sex ratio by length of submarine or military service or by rating.