Nasogastric intubation causes gastroesophageal reflux in patients undergoing elective laparotomy

Background. The routine use of nasogastric tubes in patients undergoing ele ctive abdominal operation is associated with an increased incidence of post operative fever, atelectasis, and pneumonia. Previous studies have shown th at nasogastric tubes have no significant effect on the incidence of gastroe sophageal reflux or on lower esophageal sphincter pressure in healthy volun teers. We hypothesized that nasogastric intubation in patients undergoing l aparotomy reduces lower esophageal sphincter pressure and promotes gastroes ophageal reflux in the perioperative period. Methods. A prospective randomized case control study was undertaken in whic h 15 consenting patients, admitted electively for bowel surgery, were rando mized into 2 groups. Group 1 underwent nasogastric intubation after inducti on of anesthesia, and Group 2 did not. All patients had manometry and pH pr obes placed with the aid of endoscopic vision at the lower esophageal sphin cter and distal esophagus, respectively. Nasogastric tubes, where present, were left on free drainage, and sphincter pressures and pH were recorded co ntinuously during a 24-hour period. Data were analyzed with 1-way analysis of variance. Results. The mean number of reflux episodes (defined as pH < 4) in the naso gastric tube group was 137 compared with a median of 8 episodes in the grou p managed without nasogastric tubes (P = .006). The median duration of the longest episode of reflux was 132 minutes in Group 1 and 1 minute in Group 2 (P = .001). A mean of 13.3 episodes of reflux lasted longer than 5 minute s in Group 1, with pH less than 4 for 37.4% of the 24 hours. This was in co ntrast to Group 2 where a mean of 0.13 episodes lasted longer than 5 minute s (P = .001) and pH less than 4 for 0.2% of total time (P = .001). The mean lower esophageal sphincter pressures were lower in Group 1. Conclusions. These findings demonstrate that patients undergoing elective l aparotomy with routine nasogastric tube placement have significant gastroes ophageal reflux in the perioperative period and a reduced ability to clear refluxed acid from the distal esophagus. Due to the associated risk of post operative pulmonary complications, we recommend that nasogastric intubation be performed on a selective rather than routine basis.