“Negative Pressure” Edema

Dorene A. OHara, M.D., M.S.E.

To the Editor

This is in response to the query by Garner regarding the etiology of pulmonary edema after six cases of appendectomy in young adult patients. They suggest that because of the time frame involved (gradual improvement over 48 hours), negative pressure pulmonary edema is unlikely. There is no mention of a history of coughing, bucking or laryngospasm just prior to or after extubation.

In more than one institution I have observed a few episodes of similar pulmonary edema, but not necessarily in appendectomy patients. However all patients have been young, strong, minimally premedicated, and capable of generating a large negative inspiratory pressure with what would seem a minimal coughing/breathholding episode after extubation. This has been followed by fulminant frothy pulmonary edema similar to that described in Garner’s letter. My experience in teaching institutions is that this tends to happen more in July, when new residents learn how to evaluate awakening and readiness for extubation, but these incidents happen to experienced anesthesiologists as well.

This phenomenon is well-known (1,2) to occur in young adults a well as others. It would be interesting if some specific additional predisposing factor were present due to the process of appendicitis itself. Infections are considered a predisposing factor for the development of pulmonary edema. (3) Perhaps they alter capillary permeability. However, the possibility also exists that the common factor is youth, and that appendicitis just happened to be present as well.

Dorene A. OHara, M.D., M.S.E. Assistant Professor of Anesthesia

University of Medicine & Dentistry of New Jersey New Brunswick, NJ


  1. Kamal RS, Agha S. Acute pulmonary oedema. A complication of upper airway obstruction. Anaesthesia 39-.464467,1984.
  2. Oswalt CE, Gates GA, Holmstrom FMG. Pulmonary edema as a complication of acute airway obstruction. JAMA 2M:1&33-1835,1977.
  3. Murray TR, Marshall BE. Cause and management of perioperative pulmonary edema. IN Paul C. Barash, Ed. American Society of Anesthesiologists, Vol. 15, Chapter 12. pp 149-163,1987.