The researchers examined whether nasogastric intubation causes gastroesophageal reflux in patients undergoing elective laparotomy.
The findings of the study were reported in the November issue of Surgery.
No previous studies have found a significant effect on the incidence of gastroesophageal reflux or on lower esophageal sphincter pressure in healthy volunteers.
In the prospective randomized case-control study, 15 consenting patients, admitted electively for bowel surgery, were randomized into 2 groups.
Group 1 underwent nasogastric intubation after induction of anesthesia, and Group 2 did not.
All patients had manometry and pH probes placed with the aid of endoscopic vision at the lower esophageal sphincter and distal esophagus, respectively.
Nasogastric tubes, where present, were left on free drainage, and sphincter pressures and pH were recorded continuously during a 24-hour period.
The researchers found that the mean number of reflux episodes (defined as pH < 4) in the nasogastric tube group was 137, compared with a median of 8 episodes in the group managed without nasogastric tubes.
|Mean number of reflux episodes lasting over 5 min:|
With nasogastric tube: 13
Without tube: 0.13
The median duration of the longest episode of reflux was 132 minutes in Group 1 and 1 minute in Group 2.
A mean of 13 episodes of reflux lasted longer than 5 minutes in Group 1, with pH less than 4 for 37% of the 24 hours.
This was in contrast to Group 2, where a mean of 0.13 episodes lasted longer than 5 minutes and pH less than 4 for 0.2% of total time.
The mean lower esophageal sphincter pressures were found to be lower in Group 1.
Author Brian J. Manning, of Cork University Hospital, said on behalf of the group, "These findings demonstrate that patients undergoing elective laparotomy with routine nasogastric tube placement have significant gastroesophageal reflux in the perioperative period.
"They also have a reduced ability to clear refluxed acid from the distal esophagus."
"Due to the associated risk of postoperative pulmonary complications, we recommend that nasogastric intubation be performed on a selective rather than routine basis," he concluded.