Effects of laryngeal mask ventilation combined with continuous nerve block analgesia on postoperative lung infection in elderly patients undergoing the lower extremity orthopedics surgery

Abstract

Objective To investigate effects of laryngeal mask ventilation combined with continuous nerve block analgesia versus the endotracheal intubation under general anesthesia on postoperative lung infection in elderly patients undergoing orthopedic surgery, so as to provide a theoretical basis for a reasonable anesthesia method. Methods A total of 180 elderly patients undergoing lower extremity orthopedic surgery at our hospital from January 2016 to December 2016 were enrolled and randomly divided into two groups.The control group(n=90)were treated with endotracheal intubation under general anesthesia and intravenous analgesia after the operation, and the observation group(n=90)received the ultrasound-guided continuous nerve block analgesia in spontaneous respiration with laryngeal mask ventilation.The anesthetic dosage, awakening time, visual analogue scale(VAS)scores, and incidence of lung infections at 7 days after surgery were compared between the two groups.Pathogenic strains causing lung infections were isolated and identified. Results The anesthetic dosage was lower in the observation group than in the control group(P<0.05). The awaking time was shorter in the observation group than in the control group[(22.4±4.4)min vs.(34.1±8.5)min, P<0.05]. The VAS scores under postoperative exercise were lower in the observation group than in the control group(P<0.05). The adverse reaction rate after surgery was lower in the observation group than in control group(3.3% or 3/90 cases vs.41.1% or 37/90 cases, P<0.05). The incidence of lung infections at 7 days after surgery was lower in the observation group than in the control group(3.3% or 3/90 cases vs.11.1% or 10/90 cases, P<0.05). Ten pathogenic strains were isolated from control group, of which 9 strains were gram-negative bacteria, accounting for 90.0%.Three pathogenic strains were isolated from the observation group, of which 2 strains were gram-negative bacteria, accounting for 66.7%. Conclusions Laryngeal mask ventilation combined with continuous nerve block analgesia can reduce the anesthetic dosage, shorten the awaking time, provide a better analgesic effect and decrease the incidence of lung infections in elderly patients undergoing lower extremity orthopedics.The main pathogenic bacteria are gram-negative bacteria. Key words: Autonomic nerve block; Pneumonia; Anesthesia and analgesia