Continuous monitoring of arterial oxygen saturation with pulse oximetry during transfer to the recovery room.

The incidence of hypoxemia in the immediate postoperative period was determined using a pulse oximeter for continuous monitoring of arterial oxygen saturation (SaO2) in 95 ASA class I or II adult patients breathing room air during their transfer from the operating room to the recovery room. Hypoxemia was defined as 90% SaO2 (arterial oxygen partial pressure (PaO2) approximately equal to 58 mm Hg). Severe hypoxemia was defined as 85% SaO2 (PaO2 approximately equal to 50 mm Hg). Hypoxemia occurred in 33 (35%) patients; severe hypoxemia occurred in 11 (12%). Postoperative hypoxemia did not correlate significantly with anesthetic agent, age, duration of anesthesia, or level of consciousness. There was a statistically significant correlation (P less than 0.05) between hypoxemia and obesity. All three patients with a history of mild asthma became severely hypoxemic even though none had perioperative evidence of obstructive disease, also a statistically significant (P less than 0.003) finding.