瑞芬太尼控制性降压对颅内动脉瘤手术患者脑氧代谢的影响

目的研究瑞芬太尼控制性降压对颅内动脉瘤手术患者脑氧代谢的影响。方法择期行颅内动脉瘤手术患者36例，美国麻醉师协会麻醉分级Ⅰ-Ⅲ级，年龄31—60岁，随机分为对照组、瑞芬太尼组和硝普钠降压组。颅骨钻孔前开始进行控制性降压，对照组瑞芬太尼输注速率为0．1ug／（kg．min），不进行控制性降压；瑞芬太尼组瑞芬太尼输注速率每2min增加0．1ug／（kg．min）；硝普钠组静脉输注硝普钠0．5ug／（kg·min），然后每2min增加1ug／（kg·min），直到降至目标血压。瑞芬太尼组和硝普钠组平均动脉压降至麻醉诱导前基础值的70％，但不低于50mmHg。颅内动脉瘤夹闭5min后停止降压，瑞芬太尼组输注速率恢复至降压前水平，硝普钠组停止输注硝普钠；关闭颅骨后停止吸入七氟醚；术毕停止输注瑞芬太尼。记录控制性降压诱导时问和血压恢复时间；于麻醉诱导前、降压前即刻，降压达目标血压后5min、降压达目标血压后30min和停止降压后10min时，记录平均动脉压和心率；采集桡动脉和颈内静脉球部血样进行血气分析，计算动脉血氧含量、静脉血氧含量、脑氧摄取率和动脉-颈静脉乳酸含量差。结果瑞芬太尼组控制性降压诱导时问和血压恢复时间长于硝普钠组，但血压较硝普钠组稳定（P〈0．05）；与对照组比较，瑞芬太尼组脑氧摄取率和动脉-静脉乳酸含量差降低；硝普钠组脑氧摄取率和动脉-静脉乳酸含量差（P〈0．05）。结论颅内动脉瘤手术患者瑞芬太尼控制性降压效果满意，有利于维持脑氧代谢平衡。

Effects of remifentanil-induction controlled hypotension on cerebral oxygen metabolism in patients undergoing intracranial aneurysm

Objective To investigate the effects of remifentanil-induction controlled hypotension on the cerebral oxygen metabolism in patients undergoing intracranial aneurysm. Methods Thirty-six patients, with American Society of AnesthesioIogists Ⅰ-Ⅲ , from age 31 to age 60 with intracranial aneurysm, were randomly divided into control group, remifentanil group and sodium nitroprusside group. Controlled hypotension was started before sphenotresia. In control group the infusion of remifentanil was 0.1 ug/（kg.min）, while in remifentanil group the remifentanil infusion rate was increased 0.1 ug/（kg.min） every 2 minutes until the desirable blood pressure was achieved and in sodium nitroprusside group sodium nitroprusside infusion rate was 0.5ug/（kg.min） and was increased 1 ug/（kg.min） increment every 2 minutes until the desirable blood pressure was achieved. The average arterial pressure reduced to 70% of the baseline value but never below 50 mmHg. 5 minutes after intracranial aneurysm occlusion was performed the infusion rate of remifentanil in remifentanil group returned to the original level before controlled hypotension when sodium nitropusside was stopped. Controlled hypotension induction time and blood pressure recovery time were recorded. Arterial and jugular bulb venous blood samples were obtained before induction of anesthesia, immediately before induction of controlled hypotension, 5 and 30 min of controlled hypotension and 10 min after termination of controlled hypotension. The arterial and jugular bulb venous oxygen content and cerebral oxygen extraction rate （CERO2） and difference between arterial and jugular bulb venous blood lactate concentration （Da-jvL） were calculated. Results The controlled hypotension induction time and blood pressure recovery time were significantly longer in remifentanil group than in sodium nitroprusside group, while blood pressure was more stable during controlled hypotension in remifentanil group than that in sodium nitroprusside group. Compared with control group, CERO2 and Da-jvL significantly decreased in remifentanil group, while CERO2 and Da-jvL significantly increased in sodium nitroprusside group. Conclusion Remifentanil can effectively induce controlled hypotension and reduce cere- bral oxygen consumption in patients with intracranial aneurysm and help to maintain the cerebral oxygen metabolism.