Delaying Suspension Syndrome Onset in Aerially Suspended Victims Through Leg Raising

Suspension syndrome (SS) develops when venous blood pools in extremities of passively suspended individuals, resulting in presyncopal symptoms and potential unconsciousness or death independent of additional injuries. We investigated use of leg raising to delay onset of SS, as it can decrease venous pooling and increase cardiac return and systemic perfusion.

Participants were suspended in rock climbing harnesses at an indoor climbing wall in a legs-dangling control position or a legs-raised interventional position to compare physiological outcomes between groups. Participants were suspended for a maximum of 45 min. Onset of 2 or more symptoms of SS, such as vertigo, lightheadedness, or nausea, halted suspension immediately. We recorded each participant's heart rate, blood pressure, oxygen saturation, lower leg oxygen saturation, pain rating, and presyncope scores presuspension, midsuspension, and postsuspension, as well as total time suspended.

There were 24 participants. There was a significant difference in total time suspended between groups (43.05±6.7 min vs 33.35±9.02 min, p=0.007). There was a significant difference in heart rate between groups overall (p=0.012), and between groups, specifically at the midsuspension time interval (80±11 bpm vs 100±17 bpm, p=0.003). Pain rating was significantly different between groups (p=0.05). Differences in blood pressure, oxygen saturation, lower leg oxygen saturation, and presyncope scores were not significant.

Leg raising lengthened the time individuals tolerated passive suspension and delayed symptom onset.