亚临床水平控制性低血压对脊柱手术病人脑氧代谢的影响

目的研究硝普钠(SNP)诱导的亚临床水平控制性低血压对脊柱手术病人脑氧代谢的影响。方法 60例ASAⅠ～Ⅱ级择期在全麻下行腰椎减压植骨内固定手术的成年病人,随机分为正常血压组(C组)、临床水平控制性低血压组(D1组)、亚临床水平控制性低血压组(D2组)。C组不予处理,D1组和D2组均在手术开始后持续输注SNP,使平均动脉压(MAP)在30min内达目标血压(D1组:7.33～8.00kPa,D2组:6.00～6.67kPa)。分别在控制性降压前10min、达目标血压时、达目标血压后60min、开始复压时、手术结束时、术后24h、术后48h等时间点采血,检测并计算颈内静脉球血氧饱和度(SjvO2)、脑动脉-静脉血氧含量差(Da-jvO2)、脑氧摄取率(CERO2)及动-静脉血乳酸浓度差(LAC(jv-a))等的变化,观察控制性降压对脑氧代谢的影响。结果与C组相比,应用临床水平控制性低血压及亚临床水平控制性低血压后,病人SjvO2、Da-jvO2、CERO2、LAC(jv-a)均无明显变化(P>0.05)。结论应用SNP诱导的亚临床水平控制性低血压对病人的脑氧代谢无明显影响。

EFFECTS OF SUB-CLINICAL CONTROLLED HYPOTENSION ON CEREBRAL OXYGEN METABOLISM IN PATIENTS UNDERGOING SPINAL SURGERY

Objective To investigate the cerebral oxygen metabolism in patients undergoing spinal surgery under sub-clinical controlled hypotension using sodium nitroprusside(SNP).Methods Sixty adult patients(ASAⅠ-Ⅱ)undergoing lumbar decompression and bone graft fixation operation under general anesthesia were randomized to normal-blood-pressure group(group C),clinical-controlled-hypotension group(group D1)and sub-clinical-controlled-hypotension group(group D2).No special management was offered to group C.For those in groups D1 and D2,SNP was infused continuously from the beginning of operation to reach the mean arterial pressure(MAP)at target blood pressure(BP)(D1:7.33-8.00 kPa,D2:6.00-6.67 kPa)in 30min.Blood samples were collected at 10 min before depressurization,the time reaching target BP,60 min after reaching target BP,the time to recover BP,upon completion of surgery,24 and 48 hours after surgery.The blood samples were sent for detecting and calculating internal jugular venous oxyhemoglobin saturation(SjvO2),cerebral arterial-venous oxygen content difference(Da-jvO2),cerebral oxygen extraction rate(CERO2)and arterial-venous blood lactate concentration difference(LAC(jv-a)).The influence of controlled hypotension on cerebral oxygen metabolism was investigated.Results Compared with group C,the changes ofSjvO2,Da-jvO2,CERO2 and LAC(jv-a)in groups D1 and D2 were not significant(P>0.05).Conclusion Sub-clinical controlled hypotension induced by SNP has no significant influence on cerebral oxygen metabolism.