Format

Send to

Choose Destination
Laryngoscope. 2004 May;114(5):883-6.

Middle ear pressure changes after nitrous oxide anesthesia and its effect on postoperative nausea and vomiting.

Author information

1
Department of Anesthesiology, Veteran's Administration, Western New York Healthcare Center, Buffalo, NY 14215, USA. nnader@buffalo.edu

Abstract

OBJECTIVES/HYPOTHESIS:

This study was designed to explore the relationship between changes in middle ear pressure associated with inhalational anesthesia and the incidence of postoperative nausea and vomiting (PONV).

STUDY DESIGN:

Prospective, randomized.

METHODS:

Middle ear compartment pressures were measured by tympanometry in 27 randomly assigned knee arthroscopy patients throughout the surgical procedure as well as into recovery.

RESULTS:

A positive correlation between the maximum positive pressure (MPP) and maximum negative pressure (MNP) gradient and PONV was demonstrated (P <.05). The incidence of PONV in the nitrous oxide (N2O) treatment group was 6 of 16 patients, whereas only 2 of 11 patients in the control group developed nausea, vomiting, and vertigo symptoms. Those patients that did not experience PONV demonstrated a median MPP of 155 with a median MNP of -52. The patients that experienced PONV exhibited a median MPP of 179 with a median MNP of -164. This demonstrates a significant increase in the incidence of PONV in the N2O treatment group.

CONCLUSIONS:

Barometric changes in the middle ear contribute to the incidence of PONV induced by N2O.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center