Objective To evaluate the efficacy and the effects of sevoflurane induced hypotension on balance of cerebral oxygen supply and consumption and on cerebral energy metabolism. Methods Forty patients undergoing elective procedures were randomly divided into three groups. Group Ⅰ :sevoflurane induced hypotension ; group Ⅱ: sevoflurane maintained normal arterial tension ; group Ⅲ: nitroprusside induced hypotension . In groupⅠ and Ⅲ MAP was decreased to 50%-60% of baseline ,was kept for 40 min either by sevoflurane inhalation or by nitroprusside infusion. MAP ,HR,ECG were monitored continuously, and radial arterial blood samples and jugular blood samples were taken synchronously for measuring blood gas and blood lactate ,SOD and MAD levels. Results In group Ⅰ during induced hypotension Da jvO 2 showed reduction ,but in group Ⅲ Da jvO 2 increased significantly. There were no significant changes in blood lactate level and in the cerebral arteriovenous differences of MAD and SOD in three groups.Conclusions The sevoflurane induced hypotension has no adverse effect on cerebral oxygen balance and the cerebral perfusion . The cerebral energy metabolism is well maintained . Sevoflurane can safely applied to controlled hypotension during cerebral neurosystem.

0.05). In captopril group MAP, HR and plasma ET concentration remained unchanged during intubation, but the plasma NO concentration was increased at intubation (T2) or (T3) and NO/ET ratio increased significantly at T2 as compared with the baseline (T1 ) . In control group MAP, HR and plasma ET concentration were increased significantly during intubation (P

ve To assess the efficacy of chemolysis with collagenase injected into epidural space and the effects upon intervertebral disk and nerve roots. Methods Sixty-four healthy new Zealand rabbits of either sex, weighing 2.5-3.0kg were divided into four groups of sixteen each: group A, B, C and D. In group A and B herniation of disk was produced by injecting normal salin 0.1ml into the intervertebral disk after surgical resection of spine and posterior arch of L4_6, while in group C and D no herniation of disk was produced. In group A and C collagenase 300u( in normal saline 0.5ml) was injected into the epidural space at the level of L4-6, and in group B and D normal saline 0.5ml was injected into epidural space as control. Three animals from each group were sacrificed on the 7th, 15th, and 30th day after operation and intervertebral disk and nerve roots at the operation site were removed and fixed for light and electron microscopic examination. Sciatic nerve conduction velocity (NCV) was measured before operation and on 1st, 7th, 15th and 30th postoperative day. Results In group A the intervertebral disk was dissolved to some extent. In group B nerve roots were injured to different degree. In group A and C NCV was higher than normal on the 7th and 15th day after operation. Conclusions Collagenase may dissolve the herniated intervertebral disk but does not injure the nerve roots. It may increase NCV.

Objective To investigate the effects of captopril on intubation response and the mechanism. Methods Thirty ASA Ⅰ - Ⅱ patients aged 25-60 yr, weighing 45-70 kg, scheduled for elective surgery under general anesthesia with tracheal intubation and mechanical ventilation were randomly divided into 2 groups: captopril group ( n = 15) and control group ( n = 13) . Premedication consisted of intramuscular phenobarbital 0.2 g and atropine 0.5 mg. In captopril group, captopril 0.3-0.35 mg?kg-1 was injected intravenously 10 min before induction while in control group normal saline 10 ml was given instead. Anesthesia was induced with droperidol 0.05 mg?kg-1 , fentanyl 1 ?g?kg-1 , thiopentone 5-6 mg?kg-1 . Intubation was facilitated with succinylcholine 1.5 mg ? kg-1 . Laryngoscopy and tracheal intubation was successfully performed within 30 seconds. Mechanical ventilation was started and enflurane inhalation was begun and maintained at 2.1 % , SBP, DBF, HR, EGG and SpO2 were continuously monitored. Blood samples were taken from peripheral vein before induction (T0 ) , at intubation (T1 ), 1-1.5 min (T2) and 5 min (T3) after intubation for determination of plasma concentrations of angiotensin- Ⅰ (A 1 ), angiotensin- Ⅱ (A Ⅱ ), aldosterone (ALD), noradrenaline (NE), adrenaline (E), atrial natriuretic polypeptide (ANP) and thromboxane B2(TXB2) .Results (1) In captopril group SBP, DBF, HR, and heart rate-systolic BP product (RPP) remained unchanged at intubation, while in control group the parameters were significantly increased at T1 or T2 as compared with the baseline values ( P