Effects of hypothermia and shivering on standard PACU monitoring of patients.

Inadvertent postoperative hypothermia is common among patients in the postanesthesia care unit (PACU). Shivering traditionally is attributed to hypothermia, but it is not always thermoregulatory. The exact impact of hypothermia and shivering on standard PACU monitoring parameters of patients has not been sufficiently studied. The present study included 170 orthopedic surgical patients. On PACU arrival, we recorded the incidence of hypothermia and shivering, as well as heart rate, mean arterial blood pressure, and oxygen saturation of all subjects. Analysis of covariance was used to investigate the effects of hypothermia and shivering on these monitoring parameters. Among orthopedic patients, 73.5% of them had hypothermia and 24.7% experienced shivering, which was observed primarily in hypothermic patients. Mean arterial blood pressure was significantly higher in hypothermic patients, and heart rate was significantly higher in shivering patients, whereas oxygen saturation was not affected by hypothermia or shivering. Our data confirm that standard PACU monitoring parameters are affected partially by hypothermia and shivering. A low incidence of shivering in normothermic patients and a high incidence of shivering in younger patients are discussed. Limitations of this study are reported.