Background: The incidence of intraoperative hypothermia is still high despite the proposal of different preventive measures during thoracoscopic surgery. This randomized control study evaluated the effects of 30-minute prewarming combined with a forced-air warming system during surgery to prevent intraoperative hypothermia in patients undergoing video-assisted thoracic surgery under general anesthesia combined with erector spinae nerve block. Methods: Ninety-eight patients were randomly and equally allocated to prewarming or warming groups (n = 49 each). The primary outcome was the incidence of intraoperative hypothermia. Secondary outcomes were core temperature, irrigation and infused fluid, estimated blood loss, urine output, type of surgery, intraoperative anesthetic dosage, hemodynamics, recovery time, the incidence of postoperative shivering, thermal comfort, postoperative sufentanil consumption and pain intensity, patient satisfaction, and adverse events. Results: The incidence of intraoperative hypothermia was significantly lower in the prewarming group than the warming group (12.24% vs 32.65%, P = .015). Core temperature showed the highest decrease 30 minutes after surgery start in both groups; however, the rate was lower in the prewarming than in the warming group (0.31 ± 0.04°C vs 0.42 ± 0.06°C, P < .05). Compared with the warming group, higher core temperatures were recorded for patients in the prewarming group from T1 to T6 ( P < .05). Significantly fewer patients with mild hypothermia were in the prewarming group (5 vs 13, P = .037) and recovery time was significantly reduced in the prewarming group ( P < .05). Although the incidence of postoperative shivering was lower in the prewarming group, it was not statistically significant (6.12% vs 18.37%, P = .064). Likewise, the shivering severity was similar for both groups. Thermal comfort was significantly increased in the prewarming group, although patient satisfaction was comparable between the 2 groups ( P > .05). No adverse events occurred associated with the forced-air warming system. Both groups shared similar baseline demographics, type of surgery, total irrigation fluid, total infused fluid, estimated blood loss, urine output, intraoperative anesthetic dosage, hemodynamics, duration of anesthesia and operation time, postoperative sufentanil consumption, and pain intensity. Conclusion: In patients undergoing video-assisted thoracic surgery, prewarming for 30 minutes before the induction of anesthesia combined with a forced-air warming system may improve perioperative core temperature and the thermal comfort, although the incidence of p...

Background: Laparoscopic colorectal surgery may adversely affect respiration, circulation, and acid-base balance in elderly patients, owing to the relatively long duration of CO 2 absorption. We conducted this retrospective study to determine the safety and efficacy of warmed, humidified CO 2 pneumoperitoneum in elderly patients undergoing laparoscopic colorectal surgery. Methods: We enrolled 245 patients between January 2016 and August 2018. The experimental group (warming and humidification group [WH]) received warmed (37°C), humidified (98%) insufflation of CO 2 , and the control group (cold, dry CO 2 /control group [CD]) received standard CO 2 (19°C, 0%). All other aspects of patient care were standardized. Intraoperative hemodynamic data, arterial blood pH, and lactic acid levels were recorded. We also recorded intra-abdominal pressure, incidence of shivering 1 hour after surgery, satisfaction scores of patients and surgeons 24 hours after surgery, times to first flatus/defecation, first bowel movement, and tolerance of semiliquid food, discharge time, and incidence of vomiting, diarrhea, and surgical site infections. Results: Compared with the WH group, heart rate and mean arterial pressure were significantly higher from T3 to T8 ( P < .05), lactic acid levels were significantly higher from T4 to T9 ( P < .05), and recovery time in the post-anesthesia care unit (PACU) was significantly longer in the CD group ( P < .05). Patient and surgeon satisfaction scores were significantly higher in the WH group than the CD group ( P < .05). In addition, the times to first flatus/defecation and bowel movement were significantly longer in the CD group ( P < .05). No significant differences were noted between the groups in the time to tolerance of semiliquid food and time of discharge ( P > .05). The incidence of vomiting, diarrhea, and shivering was significantly lower in the WH group ( P < .05). The number of patients with a shivering grade of 0 was significantly higher in the WH group, whereas the number with a shivering grade of 3 was significantly higher in the CD group ( P < .05). Conclusion: Warmed, humidified insufflation of CO 2 in elderly patients undergoing laparoscopic colorectal surgery could stabilize hemodynamics, and reduce lactic acid levels, recovery time in the PACU, and the incidence of acute gastrointestinal injury-related symptoms.