PostoPerative hypoxemia is a well-recognized and documented complication after general anesthesia and surgery when patients breathe room air during their initial recovery period. Although initial reports of postoperative hypoxemia were in patients after thoracic surgery, it has become an accepted potential hazard after general anesthesia for any surgical procedure. It is considered a significant contributing factor to the morbidity and mortality associated with anesthesia. Therapeutic oxygen administration immediately after hypoxemia recognition has been demonstrated to improve mean arterial oxygen saturation (Sa02) as measured by arterial blood gas analysis. At present, oxygen is routinely administered prophylac-tically to most postoperative patients. The modes of delivery to spontaneously breathing, nonintubated patients during their postanesthesia recovery room stay include nasal cannula, nasal catheter, face mask, or face tent. canadianneighborpharmacy.com
Mild desaturations have also been demonstrated during preoperative transfer of patients from the induction room to operating room during spontaneous room air breathing, as well as during transfer from the operating room to the recovery unit. This suggests that hypoxemia may be related to the effects of anesthesia as well as surgery. Most studies of postoperative hypoxemia have used intermittent saturation sampling or have been during continued room air breathing. Daley et al did utilize continuous pulse oximetry and found at least one hypoxemic episode in 41 percent of 177 patients postanesthesia care after oxygen supplementation had been discontinued, but no episodes during oxygen administration.
In the present study, a clinical survey of surgical patients was undertaken under routine conditions during their postanesthesia recovery room (PAR) stay to evaluate the incidence, degree, and duration of arterial oxygen desaturations as measured by continuous pulse oximetry during postoperative oxygen delivery by aerosol face tent.
With approval of the Pennsylvania State University College of Medicine Human Studies Committee, 100 awake, spontaneously breathing, nonintubated adult patients were studied following elective surgery with either general or regional anesthesia. Patients requiring postoperative intensive care unit admission or mechanical ventilation were excluded.
All patients who had received general anesthesia had been breathing 100 percent oxygen immediately prior to and immediately after extubation.