The effect of prophylactic rewarming on postoperative nausea and vomiting among patients undergoing laparoscopic hysterectomy: a prospective randomized clinical study

Abstract

Background: Postoperative nausea and vomiting (PONV) is a common complication from general anesthesia that impacts on postoperative recovery.

Objective: To evaluate prophylactic rewarming following general anesthesia, so as to decrease the incidence of PONV among patients undergoing laparoscopic hysterectomy.

Design and setting: Prospective randomized clinical study at a hospital in China.

Methods: Sixty-two patients were randomly assigned into two groups. The forced air warming (FAW) group received pre-warmed Ringer's solution with FAW until the end of surgery. The control group received Ringer's solution without FAW. The pre-warmed Ringer's solution was stored in a cabinet set at 40 °C. The FAW tube was placed beside the patient's shoulder with a temperature of 43 °C.

Results: Sixty patients completed the study. The FAW group showed significant differences versus the controls regarding temperature. At 6, 24 and 48 hours postoperatively, the incidences of PONV were 53.3%, 6.7% and 3.3% in the FAW group versus 63.3%, 30% and 3.3% in the controls. VAS scores were significantly lower in the FAW group than in the controls at 24 hours (P= 0.035). Forty-item questionnaire total scores in the FAW group were significantly higher than in the controls. The physical independence and pain scores at 24 hours and emotional support and pain scores at 48 hours in the FAW group were higher than in the controls (P < 0.05). There was no difference in hemodynamics or demographics between the two groups (P > 0.05).

Conclusions: Prophylactic rewarming relieved PONV and improved the quality of postoperative recovery.

Chinese clinical trial register (chictr): ChiCTR-IOR-17012901.

Figure 1. Changes to nasal temperature in the two groups. X axis encompasses the baseline of intubation and intubation after 30 minutes, 60 minutes and 90 minutes. Y axis represents the magnitude of the decline in temperature during the operation. All values are presented as means ± standard deviation (SD). Forced air warming (FAW) group versus control group at ΔT30 *P = 0.013, at ΔT60 **P = 0.001 and at ΔT90 ***P = 0.000, respectively.

Figure 2. Perioperative hemodynamics. a. Mean arterial pressure (MAP) trends in the two groups. b. Heart rate trends in the two groups. Values are expressed as means ± standard deviation (SD). X axis encompasses the baseline intubation and 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes and 60 minutes after induction of anesthesia. There were no significant differences between the two groups.