Continuous monitoring of oesophageal pH during general anaesthesia with laryngeal mask airway in children

Abstract

We studied the incidence of gastro-oesophageal reflux (GOR) during general anaesthesia with the laryngeal mask airway (LMA) in a paediatric population with two ventilatory regimes: spontaneous breathing and controlled mechanical ventilation (CMV). Thirty children between 6 months and 15 years, ASA I-II, for routine surgery, were randomly assigned in two groups: spontaneous ventilation (n=14), and CMV (n=16). A pH probe was situated in the central third of the oesophagus. Some 66% of the patients breathing spontaneously had GOR episodes vs. 92% of the patients with CMV (P < 0,01). Reflux took place mainly after LMA removal (21% vs. 68%; P < 0,01) and in the Postanaesthetic Care Unit (PACU) (29% vs. 43%; P < 0,05). There was a high incidence of GOR during general anaesthesia and in the PACU in paediatric patients anaesthetized with the LMA. GOR episodes were significantly more evident in the CMV group, mainly after LMA removal, but without clinical significance.