EFFECT OF GENERAL-ANESTHESIA ON PROLONGED INTRAESOPHAGEAL PH MONITORING

Investigation of gastro-oesophageal reflux often includes endoscopy, u sually under general anaesthesia, and pH monitoring. In most cases, th e pH probe is passed when the child is awake and is poorly tolerated. The effect of general anaesthesia on pH monitoring is unknown. The aim of the study was to determine if placing the probe in the anaesthetis ed child gives a representative pH study. Twenty children aged 4 month s to 13 years underwent oesophago-gastroduodenoscopy under general ana esthesia. A pH electrode was placed under direct vision in the distal oesophagus. pH monitoring was begun after completion of anaesthesia an d continued for 18-24 hours. The study was repeated within 14 days wit hout anaesthetic. The reproducibility of values of percent pH (4, numb er of reflux episodes/hour, reflux episodes lasting >5 min, and longes t reflux episode was 85%, 90%, 75%, and 75% respectively. These result s are comparable with those in adults and children in whom pH studies were performed on consecutive days (without anaesthetic) keeping all v ariables constant. Therefore pH data collected in a child within 24 ho urs of endoscopy under general anaesthesia are representative.