Cardiorespiratory consequences to hobble restraint

Mechanical restraints in agitated, violent psychiatric patients are still sometimes in use in the initial phase of emergency treatment, especially when patients are taken to hospital by law enforcement. Sudden death has occurred in persons in hobble restraint. Cardiopulmonary response to prone or upright hobble restraint for three minutes was investigated in six male volunteers in randomised crossover trial.

No change was observed in the investigated cardiopulmonary parameters after hobble restraint in the upright position. After hobble restraint in the prone position, mean forced vital capacity decreased by 39.6%, mean forced exspiratory volume by 41%, mean end-tidal carbon dioxide increased by 14.7%, mean heart rate decreased by 21.3%, mean systolic blood pressure decreased by 32.3%, mean diastolic blood pressure decreased by 26.1% and mean cardiac output decreased by 37.4% (P for all reported changes < 0.01).

Hobble restraint in the prone position leads to a dramatic impairment of hemodynamics and respiration. Upright position and frequent control of vital parameters are necessary to prevent a possibly fatal outcome in persons in hobble restraint.