下腔静脉内径呼吸变异指数超声测量在全身麻醉高龄患者围术期容量负荷的评估价值

Value of respiratory variation index of inferior vena cava internal diameter by ultrasound measurement for perioperative volume load in elderly patients with general anesthesia

目的探讨高龄择期外科手术患者采用经胸多普勒超声定量检测下腔静脉内径呼吸变异指数(RVI_(IVC))在全身麻醉围术期容量评估中的应用价值。方法选择行下肢手术的高龄患者66例,其中男性36例,女性30例;年龄76~85岁,平均年龄79.6岁。根据麻醉诱导前中心静脉压(CVP)将患者分为低容量组[21例,CVP≤0.49 kPa(5 cmH_(2)O)]、正常容量组[30例,0.49 kPa<CVP<1.18 kPa(12 cmH_(2)O)]和高容量组(15例,CVP≥1.18 kPa)。通过监测平均动脉压(MAP)和CVP数值指导静脉补液,遂行麻醉诱导。检测术前30 min、术中1 h、手术结束前30 min、拔管前10 min和拔管后30 min的RVI_(IVC)和氧合指数,比较不同组间的RVI_(IVC);同时记录低血压发生率,比较低血压患者与正常血压患者各时间点的RVI_(IVC)值。结果术前30 min时,正常容量组RVI_(IVC)(45.5%±6.3%)较高容量组(38.8%±6.6%)高,但低于低容量组(62.7%±9.8%)(F=6.648,P<0.05);但3组其他各时间点RVI_(IVC)比较,差异无统计学意义(F=1.203、0.826、0.802、0.726,P>0.05)。3组各观察时间点氧合指数比较,差异均无统计学意义(F=0.622、0.703、0.614、0.660、0.921,P>0.05)。经Pearson检验发现,术前30 min的RVI_(IVC)与术中MAP和CVP呈负相关(r=-0.725、-0.776,P<0.05)。66例患者共发生低血压7例(10.6%),低血压组术中1 h的RVI_(IVC)明显高于正常血压组(47.8%±10.2%vs 41.3%±7.6%;t=6.569,P<0.05),其他时间点RVI_(IVC)比较,差异无统计学意义(P>0.05)。结论高龄手术患者术前30 min的RVI_(IVC)可能是评估术前血容量负荷的敏感性指标,而术中1 h的RVI_(IVC)可能是预测术中及术后苏醒期低血压风险的敏感性指标。

Objective To explore the value of quantitative measurement of respiratory variation index of inferior vena cava internal diameter(RVI_(IVC))parameters by transthoracic Doppler ultrasound for systemic volume evaluation in elderly patients undergoing elective surgery with general anesthesia.Methods A total of 66 elderly patients performed lower extremity operation were enrolled,which included 36 males and 30 females,aged 76-85 years old with mean age of 79.6 years old.By central venous pressure(CVP)before induction of anesthesia,patients were divided into 3 groups:low volume group[n=21,CVP≤0.49 kPa(5 cmH_(2)O)],normal volume group[n=30,0.49 kPa<CVP<1.18 kPa(12 cmH_(2)O)]and high volume group(n=15,CVP≥1.18 kPa).The mean arterial pressure(MAP)and CVP values were monitored to guide intravenous fluids and induct anesthesia.The RVI_(IVC)and oxygenation index at 30-minute before operation,1-hour intra-operation,30-minute before operation terminal,10-minute before extubation and 30-minute after extubation were measured and RVI_(IVC)were compared in different groups.The hypotension incidence was recorded,and RVI_(IVC)value at each time point between hypotension patients and normal blood pressure patients were compared.Results At 30-minute before operation,RVI_(IVC)value of normal volume group(45.5%±6.3%)was significantly higher than that of high volume group(38.8%±6.6%),but lower than low volume group(62.7%±9.8%)(F=6.648,P<0.05).There was no statistically significant difference in RVI_(IVC)at other time points in 3 groups(F=1.203,0.826,0.802,0.726,P>0.05).There was no statistically significant difference in oxygenation index at each time point in 3 groups(F=0.622,0.703,0.614,0.660,0.921,P>0.05).The RVI_(IVC)at 30-minute before operation was negatively correlated with intraoperative value of MAP and CVP(Pearson test,r=-0.725,-0.776,P<0.05).Hypotension were occurred in 7 cases(10.6%).The intraoperative 1-hour RVI_(IVC)of hypotension group was significantly higher than that of normal blood pressure group(47.8%±10.2%vs 41.3%±7.6%;t=6.569,P<0.05).There was no significant difference in RVI IVC at other time points in 3 groups(P>0.05).Conclusion It is demonstrated that RVI_(IVC)of 30-minute before operation in elderly patients may be sensitive index to evaluate preoperative blood volume load,and RVI_(IVC)of intraoperative 1-hour may be sensitive index for predicting the risk of hypotension at operation and postoperative recovery.