Wetterslev J, Hansen E G, Kamp-Jensen M, Roikjaer O, Kanstrup I L
Department of Anaesthesiology and Intensive Care, Herlev University Hospital, Denmark.
Acta Anaesthesiol Scand. 2000 Jan;44(1):9-16. doi: 10.1034/j.1399-6576.2000.440103.x.
The incidence of late postoperative hypoxaemia and complications after upper abdominal surgery is 20-50% among cardiopulmonary healthy patients. Atelectasis development during anaesthesia and surgery is the main hypothesis to explain postoperative hypoxaemia. This study tested the predictive value of PaO2<19 kPa during combined general and thoracic epidural anaesthesia and the preoperative functional residual capacity (FRC) reduction in the 30 degree head tilt-down position for the development of late prolonged postoperative hypoxaemia, PaO2<8.5 kPa for a minimum of 3 out of 4 days, and other complications. Forty patients without cardiopulmonary morbidity, assessed by ECG, spirometry, FRC and diffusion capacity preoperatively, underwent upper abdominal surgery. PaO2 during anaesthesia and preoperative FRC reduction were compared to known risk factors for the development of hypoxaemia and complications: age, pack-years of smoking and duration of operation. The effect of optimizing pulmonary compliance with peroperative positive end-expiratory pressure (PEEP) on postoperative hypoxaemia and complications was evaluated in a blinded and randomized manner.
Late prolonged postoperative hypoxaemia and other complications were found in 37% and 38% of the patients, respectively. Patients with PaO2>19 kPa during anaesthesia with F(I)O2=0.33 exhibited a risk, irrespective of PEEP status, of suffering late prolonged hypoxaemia of 0% (0;23) and patients with PaO2<19 kPa a risk of 52% (32;71), P<0.005. Having smoked more than 20 pack-years was associated with a 47% (19;75) higher incidence of postoperative complications than having smoked less than 20 pack-years, P<0.006.
PaO2 during anaesthesia and smoked pack-years provide new tools evaluating patients undergoing upper abdominal surgery in order to predict the patients who develop late postoperative hypoxaemia and complications.
在心肺功能正常的患者中，上腹部手术后迟发性低氧血症和并发症的发生率为20% - 50%。麻醉和手术期间肺不张的形成是解释术后低氧血症的主要假说。本研究测试了在全身麻醉联合胸段硬膜外麻醉期间动脉血氧分压（PaO₂）<19 kPa以及术前功能残气量（FRC）在头低30度位时降低对迟发性术后持续性低氧血症（定义为PaO₂<8.5 kPa至少持续4天中的3天）及其他并发症发生的预测价值。40例术前经心电图、肺功能测定、FRC和弥散功能评估无心肺疾病的患者接受了上腹部手术。将麻醉期间的PaO₂和术前FRC降低情况与已知的低氧血症和并发症发生风险因素进行比较：年龄、吸烟包年数和手术持续时间。以盲法和随机方式评估术中应用呼气末正压通气（PEEP）优化肺顺应性对术后低氧血症和并发症的影响。
分别有37%和38%的患者发生了迟发性术后持续性低氧血症和其他并发症。在吸入氧浓度（F(I)O₂）=0.33的麻醉期间，PaO₂>19 kPa的患者，无论PEEP状态如何，发生迟发性持续性低氧血症的风险为0%（0；23），而PaO₂<19 kPa的患者风险为52%（32；71），P<0.005。吸烟超过20包年的患者术后并发症发生率比吸烟少于20包年的患者高47%（19；75），P<0.006。
麻醉期间的PaO₂和吸烟包年数为评估接受上腹部手术的患者提供了新的工具，以便预测发生术后迟发性低氧血症和并发症的患者。
