肺保护性通气对膝关节置换术中氧合功能及肺顺应性影响

 目的 探讨术中使用肺保护性通气对膝关节置换术中氧合功能及肺顺应性的影响。方法 择期行单膝关节置换术患者40例,随机分为两组,保护性通气组(V组)和常规机械通气组(C组),每组20例。麻醉诱导后两组患者的通气模式均为容量控制模式,氧浓度70%,氧流量2 L/min,吸呼比1∶2。V组诱导后全程采用肺保护性通气:潮气量(VT)=6 ml/kg,呼吸频率(RR)=16次/min,呼气末正压(PEEP)为5 cmH₂O, 每30 min给予1次手法肺复张(气道压维持在30 cmH₂O,持续30 s);C组采用常规模式进行通气:VT=10 ml/kg,RR=10次/min。分别于麻醉诱导后5 min(T₀)、手术开始时(T₁)、骨水泥置入后5 min(T₂)、手术结束即刻(T₃)、手术拔管后15 min(T₄)5个时间点记录患者的吸气平台压(Pplat),并在上述五个时间点采集患者桡动脉血,进行动脉血气分析,计算肺泡氧合指数(OI)和肺顺应性(CL)。结果 与T₀时刻比较,C组Pplat在T₂～T₃时刻明显升高(P<0.05),OI值C组在T₂～T₄时较T₀时刻明显降低(P<0.05),而V组仅在T₄时较T₀时刻明显降低(P<0.05);C组CL值在T₂～T₄时明显降低(P<0.05)。两组间比较,V组Pplat在T₂～T₃时明显低于C组,而OI值在T₂～T₄时,CL值在T₂、T₃时均明显高于C组(P<0.05)。结论 与常规机械通气相比,肺保护性通气能明显改善患者氧合功能,提高患者的肺顺应性,减轻膝关节置换手术中患者的肺损伤,具有一定的肺保护作用。

Effect of protective mechanical ventilation on lung compliance and oxygenation in patients undergoing total knee replacement surgery

Objective To investigate the effect of protective mechanical ventilation on lung compliance and oxygenation in patients undergoing total knee replacement surgery.Methods Forty patients undergoing total knee replacement surgery were randomly divided into two groups:protective mechanical ventilation group (Group V) and conventional ventilation group (Group C).All the patients were subjected to intermittent positive ventilation at an oxygen concentration of 70％,oxygen flow rate of 2 L/min and inhalation and exhalation ratio of 1:2.After induction,patients in Group V received protective mechanical ventilation,while those in Group C were under conventional ventilation.Pplat was monitored at the following time points:5 min after general anesthesia (T0),the start of surgery(T1),5min after bone cement inplantation (T2),the end of surgery (T3),and 15 min after extubation (T4).Moreover,arterial blood samples were collected for the oxygenation index (OI) and compliance of the lung (CL) at these five time points.Results Compared with T0,Pplat at T2 and T3 increased (P ＜ 0.05),but OI decreased at T2 to T4 (P ＜ 0.05) in Group C.In Group V,OI decreased at T4 only (P ＜ 0.05).Patients in Group V showed a lower Pplat at T2 and T3,and a higher OI and CL between T2 and T4 than in Group C (P ＜ 0.05).Conclusions Protective mechanical ventilation may contribute to lung compliance and oxygenation,thus protecting lung function of patients undergoing total knee replacement surgery.