Effect of trans-nasal humidified rapid insufflation ventilatory exchange on reflux and micro-aspiration during induction of general anesthesia in patients undergoing laparoscopic cholecystectomy / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) on reflux and micro-aspiration during induction of general anesthesia in the patients undergoing laparoscopic cholecystectomy.Methods:A total of 60 patients, regardless of gender, aged 18-60 yr, with body mass index of 18-28 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ, scheduled for elective laparoscopic cholecystectomy, were divided into 2 groups ( n=30 each) using a random number table method: routine mask ventilation group (group C) and trans-nasal humidified rapid insufflation ventilatory exchange group (group H). Patients in group C were pre-oxygenated with a mask for 5 min, oxygen flow of 6 L/min and FiO 2 100%, after the induction of anesthesia, the pressure mask was used to artificially assist positive pressure ventilation for 2 min when the patient′s consciousness disappeared, and 2 min later endotracheal intubation was performed.Patients in group H were pre-oxygenated with THRIVE for 5 min, oxygen flow of 30 L/min and FiO 2 100%.The oxygen flow was increased to 50 L/min during anesthesia induction.After anesthesia induction, the oxygen flow was increased to 70 L/min when the patient′s consciousness disappeared, and chin lift and/or jaw thrust was used during apnoea to maintain an open airway, the patient′s mouth was kept closed during the whole process, and 2 min later endotracheal intubation was performed.Ultrasound was used to measure the cross-sectional area (CSA) of the gastric antrum and to monitor the occurrence of gastric insufflation, and the incidence of CSA greater than >3.4 cm 2 was recorded on admission to the operating room and immediately after tracheal intubation.Supraglottic and subglottic secretions were collected at the time of tracheal intubation using visual laryngoscopy after exposing the glottis, and the pepsin content was determined using enzyme-linked immunosorbent assay to assess reflux (content of pepsin in supraglottic secretion >216 ng/ml) and micro-aspiration (content of pepsinin subglottic secretion >200 ng/ml), and arterial blood gas analysis was simultaneously performed.The apnoea time was recorded, and P ETCO 2 at the first mechanical ventilation after tracheal intubation were recorded. Results:Compared with group C, PaO 2 was significantly increased and CSA was decreased immediately after tracheal intubation, and the incidence of CSA greater than >3.4 cm 2 immediately after tracheal intubation was decreased, and the incidence of gastric insufflation, reflux and micro-spiration was decreased, apnoea time was prolonged, and P ETCO 2 at first mechanical ventilation was increased in group H ( P<0.05). Conclusions:THRIVE applied during induction of general anesthesia can reduce the occurrence of reflux and micro-aspiration while ensuring oxygenation in the patients undergoing laparoscopic cholecystectomy.