Effects of Preoperative Warming of Patients on Postoperative Hypothermia and Shivering

Effects of Preoperative Warming of Patients on Postoperative Hypothermia and Shivering.

The investigators want to evaluate the effect of prewarming on the rate of postoperative hypothermia and shivering and to compare sublingual versus tympanic temperature assessment during the perioperative period in patients.

Patients will be randomly assigned to 4 groups with different duration of prewarming. Body temperature will be recorded regularly by sublingual and tympanic (by thermocouple) measurement. Incidence of hypothermia (temp. < 36°C) and shivering will be assessed postoperatively.

Inadvertent perioperative hypothermia causes many serious complications. Therefore, prevention from, detection and therapy of hypothermia is essential. The appropriate methods of temperature assessment are still under debate as well as the effect and necessary duration of active prewarming of patients to avoid postoperative hypothermia and shivering.

The aim of our study is to evaluate the effect of prewarming on the rate of postoperative hypothermia and shivering and to compare sublingual versus tympanic temperature assessment during the perioperative period in patients undergoing elective minor surgery.

The investigators plan to include patients scheduled for routine minor surgery of approximately 1h duration. Patients will be randomly assigned to 4 groups with different duration of active prewarming. Body temperature will be recorded regularly by sublingual and tympanic (by thermocouple) measurement. Incidence of hypothermia (temp. < 36°C) and shivering will be assessed postoperatively.

Inclusion Criteria:

• Patients scheduled for minor surgery (planned duration approximately <1h).
• Age 18-75yrs,
• ASA I-II physical status

Exclusion Criteria:

• Emergency surgery,
• pregnant patients,
• patients not able to give informed consent,
• duration of surgery >2h,
• necessary postoperative mechanical ventilation