Overhydration with Secondary Hyponatremia, Fort Benning, Georgia

摘要

Martin Army Community Hospital (MACH), Ft. Benning, Georgia requested an epidemiological consultation (EPICON) in July 1997 to investigate 5 cases (1 fatal) of hyponatremia in basic trainees. The EPICON team was tasked to examine the nature, magnitude, causes, and risk factors related to this problem, and to provide recommendations to prevent further cases. Ft. Benning hospital databases and medical surveillance sources were searched to define problem. Hospital databases were searched for cases of low serum sodium in association with physical activity seen in the emergency rooms and cases of hyponatremia at Ft. Benning for 1996-1997 were reviewed. Surveillance sources included Army Medical Surveillance Activity (AMSS) database and the Total Army Injury and Health Outcomes Database (TAIHOD) which were examined for heat injury and hyponatremia. Nine cases of hyponatremia and 2 cases of pneumonia with secondary hyponatremia were found in previously healthy individuals at Ft. Benning during 199697. All cases were associated with heat stress and many were associated with moderate to heavy physical activity. Where water consumption data were obtained, all were associated with large oral intake of water. The AMSS data revealed that between 1989-1996 there were an average of 16 cases of hyponatremia/yr. Forty percent of the hyponatremia cases were at Ft. Benning. The TAIHOD data demonstrated hyponatremia rates of 1/100,000 soldier-yrs from 1980-1988 with a gradual rise over the next four years to 12/100,000 soldier-yrs which has remained stable since 1990. Evidence gathered at Ft. Benning suggested that the hyponatremia cases may have been due to hypervolemic hyponatremia (overhydration). The team concluded that: (1) overhydration with secondary hyponatremia is a problem at Ft. Benning and in the Army, and (2) overhydration and hyponatremia resulted from success in enforcing fluid consumption policy to prevent heat injuries.