Effect of general anesthesia and major versus minor surgery on late postoperative episodic and constant hypoxemia.

STUDY OBJECTIVE

To evaluate the relative contribution of general anesthesia alone and in combination with the surgical procedure to the pathogenesis of late postoperative hypoxemia.

DESIGN

Open, controlled study.

SETTING

University hospital.

PATIENTS

60 patients undergoing major abdominal surgery and 16 patients undergoing middle ear surgery, both with comparable general anesthesia.

MEASUREMENTS AND MAIN RESULTS

Patients were monitored with continuous pulse oximetry on one preoperative night and the second postoperative night. Significant episodic or constant hypoxemia did not occur on the second postoperative night following middle ear surgery and general anesthesia, but severe episodic and constant hypoxemia did occur on the second postoperative after major abdominal surgery and general anesthesia.

CONCLUSIONS

General anesthesia in itself is not an important factor in the development of late postoperative constant and episodic hypoxemia, which instead may be related to the magnitude of trauma and/or opioid administration.