Rapid insertion of a military unit into a high terrestrial altitude environment causes a cascade of physiological responses in unacclimatized personnel. This cascade is triggered by hypobaric hypoxia and often develops into pathologic conditions requiring intervention by medical personnel. The pathology induced is usually manifested in distinct symptom syndromes such as acute mountain sickness (AMS), high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE).

These syndromes are specific to high terrestrial altitude, in contrast to other environmentally related medical conditions such as sunburn, dehydration and cold injury which are common in high mountains, but also are seen frequently in other environments. The impact of these altitude illness syndromes on individual soldiers is variable, ranging from mild, self-limited discomfort to death. The impact on an operational unit can be equally variable, ranging from degraded efficiency of a minor portion of the unit’s manpower to loss of enough personnel to compromise the unit’s mission.

To accomplish the primary medical support mission of conserving fighting strength, medical officers and other military medical personnel must have sufficient knowledge of altitude medical problems to 1) advise the commander about the potential tactical impact of altitude exposure on unit personnel and operations, 2) recommend measures to prevent altitude-related problems, and 3) diagnose and treat altituderelated and other medical problems when they occur. Such expertise is not widespread in either the civilian or military medical community. Mountain medicine is seldom taught during formal medical training, and most of the skills and experience in this area have been accumulated by individuals with a personal interest in climbing and mountaineering.

Similarly, much of the research on high-altitude medical problems has also centered around recreational altitude exposure. The civilian experience provides an incomplete model, at best, for medical problems occurring during military operations in high-mountain regions because it does not take into account the obligate nature of factors related to a military unit’s specific mission. Civilians who engage in mountain recreation are a self-selected group, with equipment designed specifically for the mountain environment and with wide latitude as to the circumstances of their high altitude exposure. On the other hand, soldiers are deployed to mountain areas on the basis of their unit’s military function and the tactical situation, rather than their own interests and desires.

Foreword

Table of Contents

Acknowledgments

Introduction

Human Physiologic Responses to High Altitude

Barometric Pressure and Oxygen Availability

Hypobaric Hypoxia and Altitude Acclimatization

Acclimatization and Military Operations

Medical Problems in High-Mountain Areas

Medical Problems Related to Sustained Hypoxia

Acute Mountain Sickness

High Altitude Pulmonary Edema

High Altitude Cerebral Edema

High Altitude Peripheral Edema

High Altitude Retinal Hemorrhage

Thromboembolic Events

Subacute Mountain Sickness

Immune Suppression and Poor Wound Healing

Medical Problems Unrelated to Hypoxia

Cold Injuries

Solar Radiation Injuries

High Altitude Pharyngitis and Bronchitis

Lightning Injuries

Carbon Monoxide Poisoning