摘要目的 评价术侧肺小潮气量间歇正压通气(IPPV,1 ml/kg)对老年食管癌根治术患者单肺通气期间低氧血症的预防作用.方法 择期食管癌切除术患者60例,年龄65～75岁,性别不限,体重指数18.5～24.0 kg/m2,ASA分级Ⅰ或Ⅱ级,采用随机数字表法分为2组(n=30):常规组和IPPV组.常规组单肺通气时潮气量6～8ml/kg,频率15次/min,吸呼比1∶2,吸人氧浓度70％.IPPV组单肺通气时术侧肺潮气量1 ml/kg,频率15次/min,吸入氧浓度70％,通气侧肺与常规组一致.于麻醉诱导前(T0)、双肺通气10 min (T1)、单肺通气15 min(T2)、30 min(T3)、45 min(T4)和单肺通气结束后10 min(T5)时采集桡动脉血样,进行血气分析,记录PaO2、肺泡-动脉血氧分压差,计算呼吸指数(RI)及氧合指数(OI).记录单肺通气期间PaO2＜60mmHg、RI＞1.0和OI＜200 mmHg发生情况.结果 与常规组比较,IPPV组T4时RI降低,PaO2和OI升高,PaO2＜60mmHg、RI＞1.0、OI＜200 mmHg发生率降低(P＜0.05).结论 单肺通气时术侧肺1 ml/kg IPPV可预防老年食管癌根治术患者单肺通气期间低氧血症的发生.

abstractsObjective To evaluate the efficacy of intermittent positive pressure ventilation (IPPV,1 ml/kg) of the operated lungs in preventing hypoxemia during one-lung ventilation (OLV) in elderly patients undergoing radical resection of esophageal cancer.Methods Sixty American Society of Anesthsiologists physical status Ⅰ or Ⅱ patients of both sexes,aged 65-75 yr,with body mass index of 18.5-24.0 kg/m2,were divided into 2 groups (n =30 each) using a random number table method:convention group and IPPV group.In convention group,ventilator settings were adjusted with the tidal volume of 6-8 ml/kg,respiratory rate of 15 breaths/min,inspiratory/expiratory ratio of 1 ∶ 2,and fraction of inspired oxygen 70％ during OLV.In IPPV group,ventilator settings were adjusted with the tidal volume of 1 ml/kg,respiratory rate of 15 breaths/min,and fraction of inspired oxygen 70％ on the operated side during OLV,and the ventilator settings on the other side were consistent with those previously described in convention group.Before anesthesia induction (T0),at 10 min of two-lung ventilation (T1),at 15,30 and 45 min of OLV (T2,4) and at 10 min after the end of OLV (T5),blood samples were collected from the radial artery for blood gas analysis.The partial pressure of arterial oxygen (PaO2) and alveolar to arterial partial pressure of oxygen were recorded.Respiratory index (RI) and oxygenation index (OI) were calculated.The occurrence of PaO2 ＜ 60 mmHg,RI＞ 1.0 and OI＜ 200 mmHg was recorded during OLV.Results Compared with convention group,the RI was significantly decreased at T4,the PaO2 and OI were increased,and the incidence of PaO2＜60 mmHg,RI＞ 1.0 and OI ＜ 200 mmHg was decreased in IPPV group (P＜ 0.05).Conclusion IPPV (1 ml/kg) of the operated lungs can prevent the occurrence of hypoxemia during OLV in elderly patients undergoing radical resection of esophageal cancer.