WILDERNESS MEDICINE Suspension Trauma By Alexis Corcoran, MD, on behalf of the SAEM Wilderness Medicine Interest Group
“Climb if you will, but remember that courage and strength are nought without prudence…do nothing in haste; look well to each step, and from the beginning think what may be the end.” —Edward Whymper Background
Suspension trauma, also called harness hang syndrome or orthostatic intolerance, results from hanging in a motionless vertical position suspended by a harness for a prolonged period. Any hobby or occupation that requires the use of a harness could potentially result in suspension trauma, so rock climbers, ice climbers, spelunkers, hunters in elevated stands, parachutists, other avid adventurists, electricians, and construction/high rise workers are at risk of life-threatening or fatal suspension sequelae. A large fall leading to extremity fracture(s), a head injury from falling debris, or any other medical problem or mechanism that leads to impaired awareness, decreased consciousness, or impaired mobility can lead to hanging suspended vertically and immobile in the harness. Suspension trauma is a true emergency, as it can cause death in as little as 10 minutes, though, if it occurs, death typically takes place between 15 and 40 minutes. This article will review current literature surrounding suspension trauma, rescue, and management. SAEM PULSE | SEPTEMBER-OCTOBER 2021
Harness Introduction
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Harnesses connect outdoor enthusiasts or high-rise workers to an anchor point with a rope as they ascend or descend a wall or structure. Different types of harnesses are used for different activities, as each call for different features, styles, and capacities to hold gear. Climbing harnesses focus their support on the waist and legs, while high rise/construction harnesses focus their support on the waist, legs, shoulders, and chest. The following two figures highlight the main features and differences between these two categories of harnesses, while Table 1 identifies more distinguishing features between harness types.
Figure 1: Basic Climbing Harness Features • The waistbelt is the wide opening at the top that tightens above the waist. Padding depends on harness type. • Leg loops can, but don’t always, adjust around each leg for comfort. These keep the person upright during a fall and help disperse weight when hanging. Padding depends on harness type. • The belay loop attaches to the carabiner and belay device for the belayer. • Tie-in-points (aka hard points) are a redundant system where a rope runs through for the climber. This is the point of connection for fall arrest. • Elastic risers adjust the distance between the waistbelt and leg loops.
Pathophysiology
There is debate of the pathophysiology of harness hang syndrome; however, the most accepted mechanism is a failure of the passive venous pump system. In normal physiologic states, blood pooling dependently is forced
back towards the heart with flexion/ movement of the lower extremities and one-way valves within the venous system. When someone is hanging motionless in a harness, their femoral veins may have decreased flow due to external pressure from the harness
