Evaluation of the ventilatory effects on human subjects in prolonged hip-flexed/head-down restraint position.

BACKGROUND: The restraint chair is a tool used by law enforcement and correction personnel to control aggressive, agitated individuals. When initiating its use, subjects are often placed in a hip-flexed/head-down (HFHD) position to remove handcuffs. Usually, this period of time is less than two minutes but can become more prolonged in particularly agitated patients. Some have proposed this positioning limits ventilation and can result in asphyxia. The aim of this study is to evaluate if a prolonged HFHD restraint position causes significant ventilatory compromise. METHODS: Subjects exercised on a stationary bicycle until they reached 85% of their predicted maximal heart rate. They were then handcuffed with their hands behind their back and placed into a HFHD seated position for five minutes. The primary outcome measurement was maximal voluntary ventilation (MVV). This was measured at baseline, after initial placement into the HFHD position, and after five minutes of being in the position while still maintaining the HFHD position. Baseline measurements were compared with final measurements for statistically significant differences. RESULTS: We analyzed data for 15 subjects. Subjects had a mean MVV of 165.3 L/min at baseline, 157.8 L/min after initially being placed into the HFHD position, and a mean of 138.7 L/min after 5 min in the position. The mean baseline % predicted MVV was 115%; after 5 min in the HFHD position the mean was 96%. This 19% absolute difference was statistically significant (p = 0.001). CONCLUSIONS: In healthy seated male subjects with recent exertion, up to five minutes in a HFHD position results in a small decrease in MVV compared with baseline MVV levels. Even with this decrease, mean MVV levels were still 96% of predicted after five minutes. Though a measurable decrease was found, there was no clinically significant change that would support that this positioning would lead to asphyxia over a five-minute time period.

Review of the medical and legal literature on restraint chairs.

Use of restraint chairs by law enforcement for violent individuals has generated controversy and a source of litigation because of reported injuries and deaths of restrained subjects. The purpose of this study is to review the available medical and legal literature and to allow the development of evidence-based, best practice recommendations to inform the further development of restraint chair policies. This is a structured literature review of four databases, two medical and two legal. The medical review focus was on the restraint chair with additional review of materials regarding other restraint methods and options. The legal review focused on litigation cases involving the restraint chair. The review of the medical literature revealed 21 peer-reviewed studies investigating the physiological or psychological effects of using a restraint chair on humans or primates. Of these studies, 20 were performed on primates. The single human study revealed no clinically significant effects from the restraint chair on test subjects. The legal literature review revealed very few cases where the restraint chair was either a major or minor focus. The overall issues relating to the restraint chair cases involved deviations from set protocols and rarely involved issues with the chair itself. The available medical literature reveals that the restraint chair poses little to no medical risk. Additionally, when used appropriately, the restraint chair alone carries little legal liability. With proper monitoring and adherence to set protocols, the restraint chair is a safe and appropriate device for use in restraining violent individuals.