中文摘要：

目的评价呼气末正压通气对阻塞性睡眠呼吸暂停综合征（OSAS）肥胖患者全麻术中呼吸功能的影响。方法择期行悬雍垂腭咽成形术的OSAS患者40例，性别不限，年龄26—57岁，ASAⅠ或Ⅱ级，按照体重将患者分为2组（n=20）：正常体重组（A组），BMI〈26kg／rn2；肥胖组（B组），BMI〉32kg／m2。静脉注射咪达唑仑、异丙酚、舒芬太尼和顺阿曲库铵麻醉诱导，气管插管后先行非呼气末正压通气60min，再行呼气末正压通气60min，PEEP为8cmH2O2维持PZTCO235—45mmHg和气道峰压〈28cmH2O。分别于气管插管后5min（T1）、60min（T2）和120min（T3）时记录胸肺顺应性（CL）和气道阻力（Raw）。于清醒状态未吸纯氧前（T0）和T1-3时，采集足背动脉血样进行血气分析，计算氧合指数（PaO2／FiO2）、呼吸指数（RI）和生理无效腔（VD／VT）。记录术后24h内不良反应的发生情况。结果与T0时比较，B组T1和T2时PaO2／FiO2降低，RI升高（P〈0．05）；与T1时比较，B组rr3时Pa02／FiO2、CL升高，RI降低（P〈0．05）；与A组比较，B组T1和T2时PaO2/FiO2和CL降低，T1-3时Raw，RI和VD/VT升高（P〈0．05）。两组患者术后24h内均未见心脑血管意外、气胸或肺水肿等不良反应的发生。结论呼气末正压通气（PEEP8cmH2O）可抑制OSAS肥胖患者全麻术中肺不张，改善气体交换和胸肺顺应性。

英文摘要：

Objective To investigate the effects of positive end expiratory pressure ventilation on respiratory function during general anesthesia in obese patients with obstructive sleep apnea syndrome （OSAS）. Methods Forty ASA Ⅰ or Ⅱpatients aged 26-57 yr undergoing elective uvulo-palato-pharyngoplasty （UPPP） were divided into 2 body weight groups （ n = 20 each） ： group A normal body weight patients- BMI 〈 26 kg/m2 and group B obese patients-BMI 〉 32 kg/m2 . Anesthesia was induced with midazolam, propofol and sufentanil. Tracheal intobation was facilitated with cis-atracurium. Anesthesia was maintained with 1.0% sevoflurane and continuotis infusion of propofol and remifentanil and intermittent iv boluses of cis-atracurium. All patients were mechanically ventilated, first without PEEP for 60 min followed by PEEP 8 cm H2O for 60 min. PET CO2 was maintained at 35-45 mm Hg and Peak airway pressure was maintained at 〈 28 cm H2O. Chest wall and lung compliance （CL） and airway resistance （Raw） were monitored and recorded at 5 min （T1）, 60 min （T2 ） and 120 min （T3） after tracheal intubation. Arterial blood samples were taken before induction of anesthesia when the patients were awake breathing ambient air （ baseline, To ） and at T1 -T3 . PaO2/FiO2, respiratory index （RI） （ PA-a O2/PaO2 ） and physiologic dead space fraction （VD/VT） were calculated. Results PEEP 8 cm H20 significantly increased PaO2/FiO2, CL and decreased RI at T3 as compared with those at T1 in group B, but there was no significant change in PaO2/FiO2, CL and RI when PEEP 8 cm H20 was applied at T3 as compared with those at T1 in group A. No adverse reaction occurred in the two groups. Conclusion In obese patients with OSAS, PEEP 8 cm H2O can effectively prevent atelectasis and improve gas exchange and compliance.