术中两种不同吸入氧浓度对术后肺内分流量的影响

Effects of different concentrations of intraoperative inspired oxygen on intrapulmonary shunt at the end of surgery

目的比较术中30%FiO 2与60%FiO 2对全身麻醉(简称全麻)机械通气患者术后肺内分流量(Qs/Qt)的影响。方法选取2019年4月—2020年9月于复旦大学附属华东医院在全麻下行神经外科手术的患者120例,采用分层区组随机将患者分为30%FiO 2组和60%FiO 2组,每组60例。所有患者全麻诱导后行机械通气,分别吸入30%和60%浓度的氧气。比较两组患者一般资料和术中情况(麻醉时长、手术时长,术中丙泊酚、舒芬太尼、瑞芬太尼用量,术中晶体液量、胶体液量、出血量、尿量)。分别于麻醉诱导前和手术结束前5 min行动脉血气分析,计算估计动静脉混合指数(EVA)和氧合指数(PaO 2/FiO 2)。记录术后肺部并发症(PPC)发生率,以及术后第1天格拉斯哥昏迷量表(GCS)评分和呕吐发生率。结果最终纳入114例患者,30%FiO 2组56例、60%FiO 2组58例。两组间患者的性别构成、年龄、受教育年限、BMI、高血压病史、糖尿病病史、心脏病病史、吸烟史及术前血红蛋白水平的差异均无统计学意义(P值均>0.05)。两组间麻醉时长、手术时长,以及术中丙泊酚用量、舒芬太尼用量、瑞芬太尼用量、晶体液量、胶体液量、出血量、尿量的差异均无统计学意义(P值均>0.05)。两组间术前EVA和PaO 2/FiO 2,以及术毕PaO 2/FiO 2的差异均无统计学意义(P值均>0.05);30%FiO 2组术毕EVA显著低于60%FiO 2组(P<0.001)。两组间患者PPC发生率、术后GCS评分和术后呕吐发生率的差异均无统计学意义(P值均>0.05)。结论与60%FiO 2相比,术中30%FiO 2可显著降低全麻机械通气患者术后Qs/Qt。

Objective To compare the effects of 30%and 60%fraction of inspired oxygen(FiO 2)during mechanical ventilation on intrapulmonary shunt at the end of surgery.Methods We recruited 120 patients who underwent elective neurosurgery under general anesthesia at Huadong Hospital Affiliated to Fudan University from April 2019 to September 2020.Stratified block randomization was used to assign patients to two groups:30%FiO 2 group and 60%FiO 2 group,with 60 patients in each group.After induction of general anesthesia,all patients received mechanical ventilation and inhaled oxygen with concentrations of 30%and 60%respectively.Demographic characteristics and intraoperative conditions,such as anesthesia duration,surgery duration,doses of propofol,sufentanil and remifentanil,crystalloid fluid volume,colloid fluid volume,blood loss,and urine output,were compared between the two groups.Arterial blood gas analysis was performed before anesthesia induction and 5 min before the end of surgery to calculate the estimated venous admixture(EVA)and oxygenation index(PaO 2/FiO 2).The incidence of postoperative pulmonary complications(PPC),Glasgow Coma Scale(GCS)scores,and vomiting rate on the first day after surgery were recorded.Results A total of 114 patients completed the trial,with 56 patients in the 30%FiO 2 group and 58 patients in the 60%FiO 2 group.There were no statistically significant differences between the two groups in terms of gender composition,age,years of education,BMI,history of hypertension,history of diabetes,history of heart disease,smoking history,or preoperative hemoglobin levels(all P>0.05).There were also no significant differences between the two groups in the anesthesia duration,surgery duration,intraoperative s propofol dosage,sufentanil dosage,remifentanil dosage,crystalloid or colloid fluid volume,blood loss,or urine output(all P>0.05).No significant difference was found in preoperative EVA,preoperative or postoperative PaO 2/FiO 2 between the two groups(all P>0.05).However,postoperative EVA in the 30%FiO 2 group was significantly lower than that in the 60%FiO 2 group(P<0.001).Furthermore,there were no statistically significant differences in the incidence of PPC,GCS scores,or vomiting rate between the two groups postoperatively(all P>0.05).Conclusion 30%FiO 2 can significantly reduce intrapulmonary shunt at the end of surgery as compared with 60%FiO 2 for patients receiving mechanical ventilation under general anesthesia.