Ventilatory and metabolic demands during aggressive physical restraint in healthy adults

We investigated ventilatory and metabolic demands in healthy adults when placed in the prone maximal restraint position (PMRP), i.e., hogtie restraint. Maximal voluntary ventilation (MVV) was measured in seated subjects (n=30), in the PMRP, and when prone with up to 90.1 or 102.3 kg of weight on the back. MVV with the heaviest weight was 70% of the seated MVV (122 +/- 28 and 156 +/- 38 L/min, respectively; p < 0.001). Also, subjects (n=27) were placed in the PMRP and struggled vigorously for 60 sec. During the restrained struggle, ventilatory function (V-E/ MVV) was 44% of MVV in the resting PMRP. While prone with up to 90.1 or 102.3 kg on the back, the decrease in MVV was of no clinical importance in these subjects. Also, while maximally struggling in the PMRP, V-E was still adequate to supply the ventilatory needs.