不同吸入氧浓度对腹腔镜结直肠癌根治术老年患者氧合的影响

Effects of Different Inspired Oxygen Concentrations on Oxygenation in Elderly Patients Undergoing Laparoscopic Radical Resection of Colorectal Cancer

目的评价使用不同吸入氧浓度(Fraction of inspired oxygen,FiO_(2))机械通气对腹腔镜结直肠癌根治术老年患者氧合的影响。方法择期全身麻醉下行腹腔镜结直肠癌根治术患者40例,年龄65~75岁,ASA分级Ⅰ或Ⅱ级,BMI<28 kg/m^(2),采用随机数字表法分为两组(n=20):L组FiO_(2)=40%和H组FiO_(2)=60%。全身麻醉插管后分别维持不同的吸入氧浓度至术后拔管。分别于麻醉诱导前(T0)、气腹建立60 min(T1)和拔管后30 min(T2)取动脉血进行血气分析计算氧合指数(Oxygenation index,OI)及肺泡动脉血氧分压差[Alveolar-arterial oxygen difference,P(A-a)O_(2)]。结果两组患者OI在二氧化碳气腹后均降低,H组变化更明显;气腹建立后60 min,L组患者氧合指数明显高于H组患者,差异有统计学意义(P<0.05);H组患者在T1时间点的P(A-a)O_(2)明显高于L组(P<0.05)。结论60%的吸入氧浓度相较40%的吸入氧浓度能够使氧合指数下降,肺泡动脉血氧分压差升高。40%的吸入氧浓度能够提供良好的氧储备,且不增加术中低氧血症的发生率。在保证术中氧合情况下,应尽量选择低浓度氧气机械通气。

Objective Evaluate the effect of mechanical ventilation with different Fraction of inspired oxygen(FiO_(2))concentration on oxygenation in elderly patients undergoing laparoscopic radical resection of colorectal cancer.Method Forty patients underwent elective laparoscopic radical resection of colorectal cancer under general anesthesia,Patients aged 65-75 years,ASA gradeⅠorⅡ,BMI<28 kg/m^(2),were randomly divided into two groups(n=20)using a random number table:group L FiO_(2)=40%and group H FiO_(2)=60%.After intubation under general anesthesia,different inhalation oxygen concentrations were maintained until postoperative extubation.Arterial blood was collected before induction of anesthesia(T0),60 min after pneumoperitoneum establishment(T1),and30 min after extubation(T2)for blood gas analysis and calculation of Oxygenation index(OI)and Alveolar arterial oxygen difference(P(A-a)O_(2)).Results The OI of the two groups decreased in different degrees after CO_(2)pneumoperitoneum,and the change was more obvious in group H;At 60 min after pneumoperitoneum establishment,oxygenation index of group L was significantly higher than that of group H,and the difference was statistically significant(P<0.05);P(A-a)O_(2)in group H at T1 was significantly higher than that in group L(P<0.05).Conclusion Compared with 40%inspired oxygen concentration,60%inspired oxygen concentration can reduce the OI and increase the P(A-a)O_(2).Inhalation of 40%oxygen provides a good oxygen reserve and does not increase the incidence of intraoperative hypoxemia.In order to ensure oxygenation during operation,we should choose low concentration oxygen ventilation.