灌注指数对兔伤害性刺激反应的评价及该指数与肾脏血流量变化的关系

Perfusion index in evaluation of response to nociceptive stimuli in rabbits and its relationship with renal blood flow

目的观察末梢灌注指数(PI)对兔伤害性刺激反应的监测效果,同时评价丙泊酚和酚妥拉明抑制伤害性反应的有效性。方法15只新西兰白兔,分为丙泊酚组(6只)和酚妥拉明组(9只)。麻醉后行机械通气,建立外周末梢PI监测,超声测定肾脏血流量,记录伤害性刺激前、后兔的血压、心率、PI和肾脏血流量的变化。分别予不同剂量的丙泊酚(0、0.5、1.0、1.5 mg/kg)和酚妥拉明(0、0.5、1.0 mg/kg)进行药物处理,然后施加相同的刺激,观察两种药物对PI和肾脏血流量的影响。结果存在伤害性刺激时,伴随着平均动脉压(MAP)的升高和肾脏血流量的减少,PI明显降低,与MAP呈负相关(r=-0.286,P<0.01),而与肾脏血流量测定值中的最大峰值速度(PS,r=0.198,P=0.013)及最大流速平均值(TAMAX,r=0.212,P=0.008)呈正相关。将各组数据与基础值取差值后,PI的变化(ΔPI)与对应的MAP的变化(ΔMAP,r=-0.635)、平均流速(TAMEAN)的变化(ΔTAMEAN,r=0.551)、平均流量的变化(r=0.524)、PS的变化(ΔPS,r=0.480)、舒张末期速度(ED)的变化(ΔED,r=0.537)、流速最低点(MD)的变化(ΔMD,r=0.502)及TAMAX的变化(ΔTAMAX,r=0.522)等均存在明显相关性(P值均<0.01)。丙泊酚和酚妥拉明都能不同程度地抑制伤害性刺激产生的MAP升高、PI降低和肾脏血流量减少,且当丙泊酚剂量为1.5 mg/kg时,各时间点的MAP均显著低于其他剂量(P值均<0.01)。结论PI能有效监测兔对伤害性刺激的反应程度,并可用其估计伤害性刺激对兔内脏血流灌注的影响,也可用于评价药物对伤害性刺激的抑制效果。丙泊酚的抗伤害效果较酚妥拉明更为明显,其原因还有待进一步研究。

Objective To investigate the application of perfusion index（PI） in monitoring the response to nociceptive stimuli,and to assess the inhibitory effects of propofol and phentolamine against response to nociceptive stimuli.Methods Fifteen New Zealand White rabbits were randomly divided into 2 groups： phentolamine（0,0.5,1.0 mg/kg） group and propofol（0,0.5,1.0,1.5 mg/kg） group.The rabbits were ventilated mechanically after anesthesia,and peripheral PI monitoring was established.The arterial blood pressure,heart rate,perfusion index and renal blood flow were observed in the rabbits before and after stimulation.Ultrasonography was used to examine the renal blood flow.Results The skin nociceptive stimuli induced an increase in mean arterial blood pressure and decreases in renal blood flow and PI.PI was negatively correlated with the mean arterial blood pressure（r=-0.286,P〈0.01） and positively correlated with peak systole（PS,r=0.198,P=0.013） and time averaged maximum velocity（TAMAX,r=0.212,P=0.008）.The variation of PI was correlated with the variations of mean arterial blood pressure（r=-0.635）,time averaged mean velocity（TAMEAN,r=0.551）,PS（r=0.480）,end diastole（ED,r=0.537）,minimum diastole（MD,r=0.502） and TAMAX（r=0.522）.Both phentolamine and propofol effectively inhibited the blood pressure increase and decreases of renal blood flow and PI caused by sympathetic exciting.Propofol at 1.5 mg/kg（iv） resulted in significantly lower mean blood pressures compared with it at other doses（P〈0.01）.Conclusion PI can effectively monitor the response of rabbits to nociceptive stimuli,and it may also be used for assessing the change of visceral blood flow and the anti-nociceptive effects of anesthetics and other drugs.The reason why propoful is more effective than phentolamine in inhibiting response to nociception needs more studies.（Shanghai Med J,2010,33： 119-122）