Effects of different fractions of inspired O 2 during general anesthesia induction on perioperative pulmonary function in patients undergoing gynecological laparoscopic surgery / 中华麻醉学杂志

ABSTRACT

Objective:To compare the effects of different fractions of inspired O 2 (FiO 2) during general anesthesia induction on perioperative pulmonary function in patients undergoing gynecological laparoscopic surgery. Methods:A total of 100 patients, aged 30-64 yr, with body mass index<30 kg/m 2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, scheduled for elective total laparoscopic hysterectomy, were divided into 4 groups ( n=25 each) using a random number table method: group A, group B, group C and group D. In A, B, C and D groups, FiO 2 was 40%, 60%, 80% and 100%, respectively.Immediately after the establishment of electrocardiogram monitoring after entering the operation room (T 0), immediately after tracheal intubation (T 1), immediately after creation of pneumoperitoneum (T 2), at 30 min of pneumoperitoneum (T 3), immediately before tracheal intubation (T 4) and at 15 min after tracheal intubation (T 5), ventral (ROIⅠ), middle ventral (ROIⅡ), middle dorsal (ROIⅢ) and dorsal (ROI Ⅳ) lung ventilation were recorded using electrical impedance tomography.The impedance ratio (IR) was calculated and the safety time without ventilation was recorded.Blood samples were collected from the radial artery at T 0-2 and T 5 for blood gas analysis, arterial oxygen partial pressure (PaO 2) and arterial carbon dioxide partial pressure (PaCO 2) were recorded, and oxygenation index (OI) was calculated.The occurrence of pulmonary complications within 3 days after operation was recorded. Results:Compared with group D, the ventilation in ROIⅠ and ROIⅡwas significantly increased, the ventilation in ROIⅢ and ROIⅣ was decreased, and IR was increased at T 1 and T 2 in A, B and C groups, PaO 2 and OI were decreased at T 1, and the safety time without ventilation was prolonged in A and B groups, and PaO 2 was decreased, OI was increased at T 1 ( P<0.05), and no significant was change in the safety time without ventilation in group C ( P>0.05). There was no significant difference in the incidence of pneumoperitoneum among the 4 groups ( P>0.05). Conclusion:During general anesthesia induction, 80% FiO 2 has the least effect on lung function in the patients undergoing gynecological laparoscopic surgery.