Objective To investigate pharmacokinetics of propofol administered by target-controlled infusion (TCI) in patients with liver failure. Methods Nine ASA Ⅳ patients with liver failure aged 32-53 years,weighing 60-81 kg,who would undergo liver transplantation,were enrolled in this study,and nine ASA Ⅰ-Ⅱ patients aged 22-59 years,weighing 46-70 kg,who would undergo selective upper abdominal surgery,were as control group. In the two groups,propofol was administered for 60 min by TCI via Graseby 3500 infusion pump incorporated with Stelpump software,while the target plasma propofol concentration was set at 2.5 ?g/ml. Arterial blood samples were taken immediately before and at 2,5,10,20,30,40,50,60,62.5,65,70,75,80,85,90 min after the start of propofol infusion,and the plasma concentrations of propofol were measured by using gas chromatography-mass spectrometry. The data obtained were analyzed by DAS pharmacokinetic software. Results The central volume of distribution (Vc),apparent volume of distribution (Vp) and total clearance (CL) were significantly larger in liver transplantation group than those in control group (P

Objective To evaluate the neurotoxic effects of intrathecal (IT) different concentrations of ethanesulfonic acid ropivacaine on spinal cord in rats. Methods Sixty healthy Wistar rats of both sexes weighing 210-220 g in which IT catheters were successfully placed according to Yaksh et al. were randomly divided into 5 groups (n= 12 each). The animals received 0.9% NaCl solution 0.4 ml (group C); 0.224%, 0.447%,0.671%, 0.894% ethanesulfonic acid ropivacaine 0.4 ml (group R1-4 ). The onset time and duration of the block were recorded. The animals were killed on 7th day after IT administration. The L4,5 segment of the spinal cord were removed for neuropathologic examination with electron microscope. The spinal cord injury was scored.Neurotoxicity was defined as the spinal cord injury score ≥ 2 and the spinal neurotoxicity was recorded. Results Onset time was shorter and duration of the block was prolonged with increasing concentrations of ethanesulfonic acid ropivacaine. The incidence of the spinal neurotoxicity was 0, 0, 17%, 42% and 100% in group C, R1, R2, R3 and R4 respectively. The incidence of the spinal neurotoxicity was gradually increased with increasing concentrations of ethanesulfonic acid ropivacaine. Conclusion IT ethanesulfonic acid ropivacaine can produce neurotoxicity to the spinal cord and it depends on the concentration.

OBJECTIVETo study the effect of urapidil combined with phentolamine in the management of hypertension during extracorporeal circulation.

METHODSNinety patients undergoing aortic and mitral valve replacement were randomly divided into 3 equal groups to receive treatment with phentolamine (group A), urapidil (group B), or both (group C) during extracorporeal circulation. The mean arterial pressure (MAP) before and after drug administration, time interval of two administrations, spontaneous recovery of heart beat after aorta unclamping, ventricular arrhythmia, changes of ST-segment 1 min after the recovery of heart beat, ante-parallel cycle time, aorta clamping time, post-parallel cycle time, dopamine dose after cardiac resuscitation, and perioperative changes of plasma TNF-α and IL-6 levels were recorded.

RESULTSThere was no significant difference in MAP between the 3 groups before or after hypotensive drug administration (P>0.05). The time interval of two hypotensive drug administrations was longer in group C than in groups A and B (P<0.05). The incidence of spontaneous recovery of heart beat after aorta unclamping, incidence of ventricular arrhythmia, changes of ST-segment 1 min after the recovery of heart beat, ante-parallel cycle time, aorta clamping time, and post-parallel cycle time were all comparable between the 3 groups. The dose of dopamine administered after cardiac resuscitation was significantly larger in group B than in groups A or group C (P<0.05). The plasma levels of TNF-α and IL-6 were significantly increased after CPB and after the operation in all the groups, but were lowed in group C than in groups A and B at the end of CPB and at 2 h and 12 after the operation.

CONCLUSIONSUrapidil combined with phentolamine can control hypertension during extracorporeal circulation without causing hypotension.

Extracorporeal Circulation ; Heart Rate ; Humans ; Hypertension ; prevention & control ; Interleukin-6 ; blood ; Phentolamine ; therapeutic use ; Piperazines ; therapeutic use ; Tumor Necrosis Factor-alpha ; blood