RESTRAINT POSITION AND POSITIONAL ASPHYXIA

Study objective: To determine whether the ''hobble'' or ''hogtie'' res traint position results in clinically relevant respiratory dysfunction . Methods: This was an experimental, crossover, controlled trial at a university-based pulmonary function laboratory involving 15 healthy me n ages 18 through 40 years. Subjects were excluded for a positive urin e toxicology screen, body mass index (BMI) greater than 30 kg/m(2), or abnormal screening pulmonary function testing (PFT). Forced vital cap acity (NC), forced expiratory volume in 1 second (FEV1), and maximal v oluntary ventilation (MW) were obtained with subjects in the sitting, supine, prone, and restraint positions. After a 4-minute exercise peri od, subjects rested in the sitting position while pulse, oxygen satura tion, and arterial blood gases were monitored. The subjects repeated t he exercise, then were placed in the restraint position with similar m onitoring. Results: There was a small, statistically significant decli ne in the mean FVC (from 5.31+/-1.01 1 [101%+/-10.5% of predicted] to 4.60+/-.84 L [88%+/-8.8% of predicted]), mean FEV1 (from 4.3+/-.53 L [ 103%+/-8.4%] to 3.70+/-.45 L [89%+/-7.7%]), and mean MVV (from 165.5+/ -24.5 L/minute [111%+/-17.3%] to 131.1+/-20.7 L/minute [88% +/-16.6%]) , comparing sitting with restraint position (all, P<.001). There was n o evidence of hypoxia (mean oxygen tension [Po-2] less than 95 mm Hg o r co-oximetry less than 96%) in either position. The mean carbon dioxi de tension (Pco(2)) for both groups was not different after 15 minutes of rest in the sitting versus the restraint position. There was no si gnificant difference in heart rate recovery or oxygen saturation as me asured by co-oximetry and pulse oximetry. Conclusion: In our study pop ulation of healthy subjects, the restraint position resulted in a rest rictive pulmonary function pattern but did not result in clinically re levant changes in oxygenation or ventilation.