[The impact of early hypoxemia on the prognosis of patients undergone general anesthesia patients in intensive care unit].

OBJECTIVE: To form the strategy of prevention of postoperative pulmonary complication, investigate the incidence of early hypoxemia after general anesthesia for surgery in intensive care unit (ICU), and assess its impact on the prognosis of patients.

METHODS: Clinical data of patients who were directed transferred to ICU after general anesthesia for selective surgery during October 2011 to June 2012 were analyzed retrospectively. According to the oxygenation index (PaO2/FiO2) obtained in 1 hour after ICU admission, patients were divided into three groups, normal blood oxygen level (n=134, PaO2/FiO2>300 mm Hg, 1 mm Hg=0.133 kPa), mild hypoxia (n=88, PaO2/FiO2 200-300 mm Hg) and moderate to severe hypoxia (n=49, PaO2/FiO2≤200 mm Hg) groups. Duration of mechanical ventilation, ICU stay days, postoperative hospital stay days, and duration of oxygen therapy were compared among three groups.

RESULTS: Two hundred and seventy-one patients were included. There were no statistical differences in gender, age, duration of operation, type of operation, and postoperative extubation. The incidence rate of hypoxemia (PaO2/FiO2≤300 mm Hg) was 50.6%. Duration of mechanical ventilation was significantly prolonged in moderate to severe hypoxia group as compared with normal blood oxygen group [20.3 (13.0, 46.1) hours vs. 12.5 (6.0, 17.5) hours, D=40.803, P=0.005], the ratio of duration of mechanical ventilation longer than 24 hours was significantly higher in moderate to severe hypoxia group compared with normal blood oxygen and mild hypoxia groups (44.4% vs. 8.8%, 16.1%, χ(2)1=21.394, P2=0.000; χ(2)2=9.368, P2=0.002). The ICU stay was significantly longer in moderate to severe hypoxia group than normal blood oxygen and mild hypoxia groups [44.5 (21.5, 121.5) hours vs. 22.0 (18.0, 46.5) hours, 21.8 (19.0, 66.9) hours, D1=54.302, P1=0.000; D2=44.171, P2=0.005]. Compared with normal blood oxygen group, postoperative hospital stay days and duration of oxygen therapy were significantly longer in moderate to severe hypoxia group [postoperative length of stay: 15.0 (12.0, 21.5) days vs. 9.0 (12.0, 16.0) days, D=40.851, P=0.005; duration of oxygen therapy: 170.0 (97.5, 307.5) hours vs. 89.0 (47.8, 192.0) hours, D=45.049, P=0.002].

CONCLUSIONS: The incidence of hypoxemia postoperative patients after general anesthesia is high when transferred to ICU. PaO2/FiO2≤200 mm Hg was closely related to prolonged duration of mechanical ventilation, ICU stay days, postoperative hospital stay days, and duration of oxygen therapy.