Gastroesophageal Reflux and Aspiration of Gastric Contents

Abstract

In Response: We would like to reply to Dr. Brock-Utne’s letter concerning our Review Article (1). The statement concerning the effect of ranitidine and other drugs on the lower esophageal sphincter (LES) was taken from Reference 27 (2). The weight of evidence does not support the view of Dr. Brock-Utne that ranitidine increases LES pressure for the following reasons. First, one of the studies showing that ranitidine increases LES pressure involved only 6 subjects (3); hence caution is required in accepting this work. Second, the possibility of false positive results with ranitidine on the LES may be related to normal variations in LES pressure in the interdigestive states (4). LES pressure rises from phase one to phase three of the interdigestive states. This fact was not taken into account in the methodology of the study cited by the author (3). Third, ranitidine and cimetidine are H2-receptor antagonists and thus would be expected to have similar effects. Cimetidine does not increase LES pressure (4,7,8), and the majority of studies have found also that ranitidine does not increase LES pressure (4,5,6). General anesthesia for pregnant patients is becoming increasingly uncommon. Pregnancy is associated with increases in heart rate (9), and in our institution it would be very unusual for anesthesiologists to use atropine before induction of general anesthesia. We agree that protective airway reflexes are impaired by many sedative agents, a concept that is well known, and we did not think that it was necessary to cite the historical articles of the 1970s enumerated by Dr. Brock-Utne (10,11). The main objective of this section was to characterize the components of these reflexes and describe the effect of drugs from more recent studies (12–14). Dr. Brock-Utne recommends that a nasogastric tube be removed before a rapid sequence induction. We are unable to support his view for the following reasons. First, and most importantly, there is good evidence that the nasogastric tube does not impair effective application of cricoid pressure (15,16). Second, the nasogastric tube provides a passageway for the drainage of gastric contents. Thus removal of the nasogastric tube is not only unnecessary but it may increase the risk of esophageal perforation in the event of retching during a rapid sequence induction. Alexander Ng, FRCA Graham Smith, MD, FRCA