The effects of positional restraint on heart rate and oxygen saturation

To study the effects of positional restraint on heart rate and oxygen saturation during recovery, a crossover experimental design with prospective control trials was used in a two-phase study. In phase 1, serial resting oxygen saturations (RO1) measured on 18 volunteers were compared with those measured in the seated unrestrained (SU1) and the hogtie (HT) positions after submaximal cycle exercise. Additionally, serial heart rates were compared postexercise on subjects in the SU1 and HT positions. In phase 2, resting oxygen saturations (RO2) were compared with those measured in the seated unrestrained (SU2) position and an alternate maximal restraint (MR) position after a simulated pursuit and struggle scenario. No statistical differences were found between SU1 and HT recovery heart rates in phase 1. Small oxygen saturation differences (1%) were found in both phase 1 and phase 2 between resting (RO1 and RO2) positions and those measured in the seated unrestrained (SUI), hogtie (HT), and maximal restraint (MR) positions. Oxygen saturations taken during a 5-min period in each of the three situations in phase 1 (RO1, SU1, and HT) were averaged, yielding 97.8, 98.0, and 97.6%, respectively. In phase 2, mean oxygen saturations were 98.0, 97.4, and 96.8% for RO2, SU2, and MR, respectively. In our study population, the use of hogtie and an alternate maximal restraint method did not result in any clinical restrictions in heart rate or oxygen saturation recoveries.