Negative Pressure Edema Seen as Likely Cause

Scott A. Lang, M.D., FRCPC

More on Pulmonary Edema

Editor’s Note: In the Spring issue, there was a letter to the Editor describing an unusual series of cases of postoperative pulmonary edema following appendectomies. Two follow-up letters appeared in the Summer issue and two more are published here.

To the Editor

Negative pressure pulmonary edema should not be discounted as a cause of the pulmonary edema seen in the patients described by Dr. Garner (APSF Newsletter, Spring 1993). Negative pressure pulmonary edema remains a diagnosis of exclusion as there are no confirmatory diagnostic tests.(1) However, the clinical scenario Dr. Garner describes is exactly the one I would consider highly suspicious of negative pressure pulmonary edema.

Patients who develop negative pressure pulmonary edema are often young healthy adult males.’ The period of airway obstruction can be extremely short (less than 60 seconds) and may be unrecognized when the patient is transferred to the Recovery Room. The presentation is often dramatic with pink frothy sputum. Aspiration can never be ruled out as a contributory factor, and it is known that regurgitation is more likely in the presence of a partially obstructed airway.’

I recently had a similar case of bona fide negative pressure pulmonary edema in a 24-year-old, otherwise healthy male, following an appendectomy. He presented dramatically in the Recovery Room after developing complete but transient airway obstruction (less than two minutes) on transfer from the Operating Room to the Recovery Room. He required continuous positive airway pressure and supplemental oxygen in the Intensive Care Unit for 48 hours.

In summary, airway obstruction (partial or complete), negative pressure pulmonary edema and aspiration are common variables in the development of pulmonary edema in the population of patients described by Dr. Garner.’

Scott A. Lang, M.D., FRCPC Assistant Professor

Department I Anaesthesia University of Saskatchewan Royal University Hospital

Saskatchewan, Canada S7N OXO

References

  1. Lang SA, Duncan PC, Shephard DAE, Ha HC. Pulmonary Edema Associated with Airway Obstruction. Canadian journal of Anaesthesia 1990; 37: 210-8.
  2. Calkin M et.al. Risk Factors for Negative Pressure Pulmonary Edema. Anaesthesia Analgesia 1993; 76: S32.
  3. Illing L et.al. Gastroesophageal Reflex During Anaesthesia. Canadian journal of Anaesthesia 1992; 39:466-70.