2.2. Anesthesia Protocol
bradycardia, mg·kgThe, hypotension, COA, shivering
COLD
Each patient’s core BT was measured before anesthesia induction using an infrared tympanic membrane (TM) thermometer (ThermoScan IRT 4520, Braun, Melsungen, Germany), and the highest temperature among the three measurements was considered. A thermometer was used in the patient’s right ear. After removing the earwax, the BT of the TM core was measured using an otoscope. After anesthesia induction, a nasopharyngeal temperature probe (Temperature Probe 400 series; General Electric, Helsinki, Finland) was inserted through the nostril at an appropriate location of 9.5 to 10 cm in depth. The core BT was checked every 10 min until the end of the surgery.In both groups, anesthesia was induced by a continuous infusion of 6 mg·kgThe ambient temperature of the operating room was maintained at 20–22 °C, and the corresponding relative humidity was 50–60%. Warmed intravenous and irrigating fluids and cold, dried peritoneal insufflation gas (COA MAP of less than 60 mmHg was considered hypotension, and an HR of <50 beats/min was considered bradycardia. A total of 250 mL of lactated Ringer’s solution was administered to treat hypotension, and, if hypotension was not corrected, 10 mg of ephedrine was administered. Atropine (0.5 mg) was administered for the treatment of bradycardia. Patients treated with ephedrine or atropine were excluded from this study.Each patient was administered analgesics using a PCA pump containing morphine (60 mg), ketorolac (150 mg), and ramosetron (0.6 mg) at a total volume of 100 mL of saline. This device was set to deliver a basal infusion of 2 mL·hrAs soon as the patients arrived at the PACU, their core BT was measured thrice using an infrared tympanic thermometer; the highest value was used as the core BT. An attending anesthesiologist observed shivering every 5 min until 15 min after the patient arrived at the PACU and every 10 min until the patient was discharged. A forced-air warming blanket (Bair Hugger Blanket, Augustine Medical, Inc., Eden Prairie, MN, USA) was used to deliver forced air at 42 °C when the core BT was below 36 °C. By resetting the warming blanket to 38 °C when the core BT reached 36 °C or higher, forced air was administered to the patient.The incidence and severity of PS were assessed during patients’ stay in the PACU. The seriousness of PS was assessed using a bedside shivering assessment scale, which rated shivering as none (grade 0), no shivering noted on palpation of the masseter, neck, or chest wall; mild (grade 1), shivering localised to the neck and thorax only; moderate (grade 2), shivering involved the gross movement of the upper extremities (in addition to neck and thorax); and severe (grade 3), shivering involved gross movements of the trunk and upper and lower extremities [