急性等容血液稀释联合控制性降压对老年骨科手术患者血管外肺水及氧合的影响

摘要

Objective To investigate the effect of acute normovolemic hemodilution (ANH) combined with controlled hypotension (CH) on the extravascular lung water (EVLW) and oxygenation in elderly orthopaedic surgery patients.Methods Forty-five elderly orthopaedics surgery patients,23 males,22 females,aged 65-75 years old,ASA grade Ⅰ or Ⅱ,were randomly divided into 3 groups (n=15 each).Group A,served as control,received regular routine transfusion and intraoperative crystalloid fluids and colloidal liquid to add volume.Group B,namely ANH group,received normovolemic hemodilution till Hct reaching 30% after induction of anesthesia.Group C,ANH combined with CH group,received ANH with Hct reaching 30% after induction of anesthesia,and the patients were continuously pumped nitroglycerin combined with esmolol for controlled hypotension.The target mean arterial pressure controlled and cut by 30% below the basic value.We collected arterial blood for blood gas analysis at 5 points: before before induction of anesthesia (T1),immediately after ANH (T2),30 min after ANH (T3),30 min after CH (T4),immediately after surgery (T5).Meanwhile the MAP,HR,PaO2,SpO2,Hct,HCO3-,pH,cardiac index (CI),stroke volume variation (SVV),stroke volume index (SVI),extravascular lung water index (EVLWI) and intrathoracic blood volume index (ITBVI) were recorded.Blood loss,urine output after surgery and the operation time were also recorded.Results The volumes of autoblood removed had no significant difference between group B and group C,and no autoblood was removed in group A.The volume of blood loss in group C was significantly less than that in group A and group B (P<0.05).Six cases in group A,one case in group B and none in group C needed homologous allogeneic blood transfusion.Compared with T1,MAP,HR,CI,SVI and Hct were significantly decreased at T2-T5 (P<0.05),but all those are stable in the normal range.Compared with T1,SVV was significantly decreased at T2-T4 (P<0.05).Compared with T1,ITBVI,PaO2 and SpO2 were increased at T2-T5 (P<0.05),but all those are stable in the normal range.CI and SVI at T2 in group A was significantly lower than that in group B and C.Compared with group A and B,MAP at T4 in group C were significantly decreased and SVV at T4 in group C were significantly increased(P<0.05).Urine output,the operation time,EVLWI,HCO3-and pH in three groups had no significant difference.Conclusion Acute normovolemic hemodilution combined with controlled hypotension has an effect of saving blood in elderly patients,without any influence on the extravascular lung water and oxygenation,which can be used safely in elderly patients which they are monitored.%目的 研究急性等容血液稀释(ANH)联合控制性降压(CH)对老年骨科手术患者血管外肺水及氧合的影响.方法 选择择期行骨科手术的老年患者45例,男23例,女22例,年龄65~75岁,ASA Ⅰ或Ⅱ级.随机分为三组,每组15例:对照组(A组):术中常规输入晶体液和胶体液补充血容量;ANH组(B组):麻醉诱导平稳后,手术前进行ANH,目标Hct 30%;ANH联合CH组(C组):手术前进行ANH,持续泵注硝酸甘油,辅助艾司洛尔,将目标MAP控制在基础值的70%.分别于诱导前(T1)、血液稀释后即刻(T2)、血液稀释后30 min(T3)、CH达到目标MAP 30 min后(T4)、术毕(T5)采集动脉血样做血气分析,监测并记录MAP、HR、PaO2、SpO2、Hct、HCO3-、pH、心脏指数(CI)、每搏变异量(SVV)、每搏指数(SVI)、血管外肺水指数(EVLWI)及胸内血容量指数(ITBVI)的变化,并记录采血量、出血量、尿量及手术时间等.结果 B组和C组采血量差异无统计学意义,A组未做自体血采集.C组出血量明显低于A组和B组(P<0.05).A组有6例,B组有1例输注异体血,C组未输注异体血.与T1时比较,T2~T5时三组MAP、HR、CI、SVI和Hct明显降低(P<0.05),但均稳定在正常范围内.与T1时比较,T2~T4时三组SVV明显降低(P<0.05).与T1时比较,T2~T5时三组ITBVI、PaO2和SpO2明显升高(P<0.05),但均稳定在正常范围内.T2时A组CI、SVI明显低于B组和C组(P<0.05).与A组和B组比较,T4时C组MAP明显降低、SVV明显升高(P<0.05).三组患者尿量、手术时间、EVLWI、HCO3-和pH组间组内差异均无统计学意义.结论 急性等容血液稀释联合控制性降压用于老年骨科手术患者节约用血效果确切,对血管外肺水及氧合未产生不利影响,但联合应用时需加强监测.