The influence of surgical sites on early postoperative hypoxemia in adultsundergoing elective surgery

To determine the influence of the surgical sites on early postoperative hyp oxemia, we studied postoperative hypoxemia in 994 patients, ASA physical st atus I or II, aged 18-68 yr, scheduled for various types of elective surger y. Patients were divided into three groups on the basis of the surgical sit es: Group 1 = elective superficial plastic surgery (n = 288); Group 2 = upp er abdominal surgery (n = 452); and Group 3 = thoracoabdominal surgery (n = 254). Anesthesia was maintained with 1%-2% enflurane and 67% nitrous oxide in oxygen; thiopental or fentanyl was given TV as required. Spo(2) levels were recorded while patients breathed room air shortly after arrival in the recovery room (0 min) and 5, 10, 15, 20, 30, 40, 50, 60, 120, and 180 min thereafter. The results showed that during the early postoperative period, the degree of arterial desaturation and the incidences of hypoxemia (Spo(2) 86%-90%) and severe hypoxemia (Spo(2) 85%) were closely related to the ope rative sites and were greatest for thoracoabdominal operations, less for th e upper abdominal operation, and least for the peripheral surgery. The inci dence of hypoxemia and severe hypoxemia in the recovery room was 7% and 0.7 %, respectively, in Group 1, 38% and 3% in Group 2, and 52% and 20% in Grou p 3. Mild airway obstruction and hypothermia in the postanesthesia recovery unit (PAR) were the predictive factors of early postoperative hypoxemia. W e conclude that during the early postoperative period, there were significa nt differences in Spo(2) levels and incidences of hypoxemia and severe hypo xemia among the three groups. Implications: We found that the severity of a rterial desaturation and the incidence of hypoxemia during the early postop erative period are closely related to the surgical sites and are strongest for thoracoabdominal surgery, less for upper abdominal surgery, and least f or peripheral surgery.