老年人瑞芬太尼、丙泊酚全麻维持中瑞芬太尼与丙泊酚的量效关系

Relationship of the dosage of remifentanil and propofol used in the maintain stage of general anesthesia in elderly selective surgery

目的探讨老年人瑞芬太尼、丙泊酚静脉复合全麻维持中不同瑞芬太尼、丙泊酚配伍剂量与全麻维持效果的关系。方法选择老年择期手术患者120例,均实施气管插管全麻,全麻诱导方法均相同。全麻维持分为恒速泵注不同剂量丙泊酚、调节瑞芬太尼用量控制并维持全麻中MAP比基础MAP降低5%左右(0~10%)部分(简称BR法)和恒速泵注不同剂量瑞芬太尼、调节丙泊酚用量控制并维持全麻中MAP比基础MAP降低5%左右部分(简称RB法)。BR法共30例,随机分为丙泊酚泵速1.0 mg/(kg·h)组(B_(1.0)组)、1.5 mg/(kg·h)组(B_(1.5)组)、2.0 mg/(kg·h)组(B_(2.0)组)、2.5 mg/(kg·h)组(B_(2.5)组)、3.0 mg/(kg·h)组(B_(3.0)组),每组6例。瑞芬太尼起始泵速均为30μg/(kg·h),如瑞芬太尼用量增加到60μg/(kg·h),MAP降低未达预设范围,丙泊酚用量增加0.5 mg/(kg·h),再调节瑞芬太尼用量,如此反复直至降压达到预设范围;如瑞芬太尼用量降到零,MAP仍低于预设范围,降低丙泊酚用量0.5 mg/(kg·h),再调节瑞芬太尼用量,如此反复直至降压达到预设范围。RB法共90例,随机分为瑞芬太尼泵速60μg/(kg·h)组(R_(60)组)、55μg/(kg·h)组(R_(55)组)、50μg/(kg·h)组(R_(50)组)、45μg/(kg·h)组(R_(45)组)、40μg/(kg·h)组(R40组)、30μg/(kg·h)组(R_(30)组),每组15例。丙泊酚起始泵速均为2 mg/(kg·h),调节丙泊酚用量在25 min内控制并维持全麻中MAP比基础MAP降低5%左右。全部11组控制性降压均在手术结束前5 min停止。结果 (1)BR法中B_(1.0)组有3例,B_(1.5)组、B_(2.0)组、B_(2.5)组各有2例能够按原计划丙泊酚用量完成全麻维持;有18例需增加或减少丙泊酚用量后再调节瑞芬太尼用量完成全麻维持,这其中还有3例丙泊酚用量大于3.0 mg/(kg·h)才能完成全麻维持;还有3例按照原计划丙泊酚用量用药,但需在输入多巴胺的同时输入瑞芬太尼完成全麻维持。(2)RB法各组均可较容易地把全麻维持中的MAP控制到比其基础MAP降低5%左右的范围,BIS值均维持在35~60,6组间维持MAP平稳指数比较差异无统计学意义,瑞芬太尼用量与丙泊酚用量呈负相关(r=-0.94,P<0.05),丙泊酚用量与睁眼时间呈正相关(r=0.95,P<0.05)。R_(30)组丙泊酚用量显著大于R_(60)组、R_(55)组、R_(50)组、R_(45)组(P均<0.05)。R_(60)组、R_(55)组、R_(50)组睁眼时间相对较短。(3)全麻维持效果评级:R_(55)组、R_(50)组达Ⅰ级,R_(60)组、R_(45)组达Ⅱ级,R40组达Ⅲ级,R_(30)组达Ⅳ级。结论 BR法很难把血压调控平稳,不适合老年人临床全麻使用;RB法较容易把血压调控平稳,其中以恒速泵注瑞芬太尼50μg/(kg·h)和55μg/(kg·h),调节丙泊酚用量控制并维持全麻中MAP比其基础MAP降低5%左右,全麻维持效果评级最好,清醒快,拔管无呛咳躁动发生,推荐临床使用。

Objective It is to investigate the relation of the dosage of remifentanil and propofol used in the maintain stage of general anesthesia in elderly selective surgery.Methods 120 old elderly undergoing selective surgery were selected.The methods of the general anesthesia induction were the same.The methods of the general anesthesia maintenance were BR and RB for short.The method BR was injecting different dosage of propofol at constant speed and adjusting the dosage of remifentanil to maintain the MAP about 5%lower than the basal MAP.The method RB was injecting different dosage of remifentanil at constant speed and adjusting the dosage of propofol to maintain the MAP about 5%lower than the basal MAP.The patients of the method BR were 30.According to the different dosage of propofol at constant speed,the 30 patients were divided into 5 groups randomly(n=6).The injection speeds of propofolare 1.0 mg/(kg·h)(group B 1.0),1.5 mg/(kg·h)(group B 1.5),2.0 mg/(kg·h)(group B 2.0),2.5 mg/(kg·h)(group B 2.5)and 3.0 mg/(kg·h)(group B 3.0).The initial dose of remifentanil was 30μg/(kg·h).If the dosages of remifentanil increase to 60μg/(kg·h),and the MAP could not reach the range of controlled hypotension,the dosage of propofol would increase 0.5 mg/(kg·h),then the dosage of remifentanil was adjusted again and again until the the MAP could reach the range of controlled hypotension.If the dosages of remifentanil reduce to 0μg/(kg·h),and the MAP was under the range of controlled hypotension,the dosage of propofol would reduce 0.5 mg/(kg·h),then the dosage of remifentanil was adjusted again and again until the MAP could reach the range of controlled hypertension.The patients of the method RB were 90.According to the different dosage of remifentanil at constant speed,the 90 patients were divided into 6 groups randomly(n=15).The injection speeds of remifentanil were 60μg/(kg·h)(group R 60),55μg/(kg·h)(group R 55),50μg/(kg·h)(group R 50),45μg/(kg·h)(group R 45),40μg/(kg·h)(group R 40)and 30μg/(kg·h)(group R 30).The initial dose of propofol was 2 mg/(kg·h).Adjust the dosage of propofol to maintain the MAP about 5%lower than the basal MAP in 25 min.The controlled hypotension of all the groups was stopped 5 min before the end of surgery.Results①There were 3 patients of group B 1.0,2 patients of group B 1.5,2 patients of group B 2.0 and 2 patients of group B 2.5.The total patients who were injected the dosage of propofol as planned to complete the general anesthesia maintenance were 9(about 30%).There were 18 patients whose blood pressures were higher or lower than the range of controlled hypotension.If the dosages of remifentanilis increased to 60μg/(kg·h),and the MAP could not reach the range of controlled hypotension,the dosage of propofol would be increased,then the dosage of remifentanil was adjusted again and again to complete the general anesthesia maintenance.Or if remifentanil was injected,and the MAP reduce too much,the dosage of propofol would be reduced,then the dosage of remifentanil was adjusted.Three of 18 patients were injected more than 3.0 mg/(kg·h)propofol to complete the general anesthesia maintenance.The other 3 patients were injected the dosage of propofol as planned.So blood pressure drops to lower degree as long as remifentanil was injected.Dopamine and remifentanil must be injected at the same time to complete the general anesthesia maintenance.②The MAP of the method RB was controlled to about 5%lower than the basal MAP.The BIS value was maintained 35-60.There was no significant differences among the stable index of MAP in general anesthesia maintain of six groups in demographic data.There was negative correction between remifentanil and propofol(r=-0.94,P<0.05).There was positive correction between propofol and eye-opening time(r=0.95,P<0.05).The dosage of propofol in group R 40 was significant more than the dosage of propofol in group R 60,R 55,R 50 and R 45(P<0.05).Eye-opening time in group R 60,R 55 and R 50 was shorter relatively.③The effect rating of general anesthesia maintain:The group R 55 and R 50 were levelⅠ;The group R 60 and R 45 were levelⅡ;The group R 40 was levelⅢ;The group R 30 was levelⅣ.Conclusion It is difficult to maintain blood pressure of method BR steadily.So it was not fit for the elderly.It is easy to maintain blood pressure of method RB steadily.Injecting 50μg/(kg·h)and 55μg/(kg·h)remifentanil at constant speed and adjusting the dosage of remifentanil could maintain the MAP about 5%lower than the basal MAP.The effect rating of general anesthesia maintain is the best.Patients were awaken quickly.There was no agitation and bucking in the period extubation.We recommend using this method in clinic.