Flow requirements for the Bain breathing circuit during anaesthesia for caesarean section

We studied the relationship between arterial carbon dioxide tension (PaCO2) and fresh gas flow (FGF) during use of the Bain breathing circuit for Caesarean section anaesthesia. Thirty-one patients undergoing Caesarean section were anaesthetised using the Bain circuit with intermittent positive pressure ventilation. The PaCO2 were measured at FGF of 70 ml X kg-1 X min-1, 80 ml X kg-1 X min-1, and 100 ml X kg-1 X min-1. The FGF requirement to maintain a given PaCO2 during Caesarean section anaesthesia is the same as the requirements for nonpregnant subjects, despite the increase in carbon dioxide production associated with pregnancy. This is probably because the total FGF determined by body weight and given during Caesarean section anaesthesia is 15-20 per cent higher than nonpregnant levels, due to the weight gain associated with pregnancy. A FGF of 100 ml X kg-1 of pregnant weight/min maintains PaCO2 of 4.44 kPa predelivery, which is in the desirable range of PaCO2 during Caesarean section.     

Onset of vecuronium neuromuscular block is more rapid in patients undergoing Caesarean section

This investigation was carried out in ten patients undergoing elective Caesarean section and the results were compared with those of a control group of ten nonpregnant females of the same age group. The study investigated the onset of vecuronium neuromuscular block and the conditions of tracheal intubation when ketamine (1.5 mg.kg-1)-vecuronium 100 micrograms.kg-1) sequence was used for rapid-sequence induction of anaesthesia. The ulnar nerve was stimulated supra-maximally at the wrist with train-of-four stimuli every 20 sec, and the electromyographic response of the adductor pollicis muscle was displayed. The onset of 50% neuromuscular block as monitored by electromyography was shorter in the Caesarean group (80 +/- 30 sec) than in the control group (144 +/- 43 sec). The conditions of intubation at 50% block were adequate in both groups. Also, the onset of 90% block was shorter in the Caesarean group. The time of recovery to T1/control ratio of 25% was longer in the Caesarean group (46 +/- 10 min) than in the control patients (28 +/- 10 min). The results show that administration of vecuronium according to body weight results in a more rapid onset and delayed recovery of neuromuscular block in pregnant women undergoing Caesarean section than in the nonpregnant control patients.     

Comparison of blood pressure profiles with flunitrazepam/fentanyl/nitrous oxide vs cervical epidural anesthesia in surgery of the carotid artery

A study was carried out to compare the evolution of arterial blood pressure during carotid endarterectomy performed under either general anaesthesia (GA) or cervical epidural anaesthesia (CEA). 20 patients were randomly assigned to two equal groups. In the CEA group, 15 ml of 0.375% bupivacaine and 150 micrograms fentanyl were injected into the epidural space at C7-D1 level. In the GA group, patients were anaesthetized with 0.2 mg.kg-1 flunitrazepam and 5 micrograms.kg-1 fentanyl; intubation was carried out using 0.08 mg.kg-1 vecuronium, and the patients were ventilated with a mixture of nitrous oxide and oxygen (50% of each). Further injections, every 30 min, of 2 micrograms.kg-1 fentanyl were given to the patients in group GA. Blood pressure was monitored continuously, up to 4 h postoperatively, with a radial arterial catheter. Per- or postoperative hypertension was defined as a rise in systolic arterial blood pressure (Pasys) over 180 mmHg for greater than 3 min; this was treated with 20 mg nifedipine intranasally (group CEA) or 100 micrograms fentanyl with 0.5 mg flunitrazepam with or without nifedipine (group GA). Per- or postoperative hypotension was defined as a fall in Pasys below 100 mmHg and or a 30% fall in mean arterial blood pressure for greater than 3 min; this was treated, in both groups, with an intravenous bolus of 3 mg ephedrine. Patients in group CEA experienced more frequent episodes of peroperative hypertension (8/2; p less than 0.02) and postoperative hypotension (5/1) than group GA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Propofol infusion anaesthesia for Caesarean section

Two propofol infusion regimens and a standard general anaesthetic were compared in thirty Chinese women undergoing elective Caesarean section. After induction of anaesthesia with propofol 2 mg.kg-1, ten patients received propofol 6 mg.kg-1.hr-1 and nitrous oxide 50 per cent in oxygen while ten were given propofol 9 mg.kg-1.hr-1 with 100 per cent oxygen. The other ten patients received thiopentone 4 mg.kg-1 and nitrous oxide 50 per cent in oxygen with enflurane one per cent. Maternal recovery times and psychomotor performance were recorded. Neonates were assessed by Apgar scores, neurologic and adapative capacity scores (NACS) and umbilical cord blood gas analysis. Haemodynamic changes were similar immediately following induction but the low propofol infusion group had the best haemodynamic stability subsequently. Recovery times were fastest in the low-infusion group but there were no differences in later postbox testing. Neonatal Apgar scores and umbilical blood gas analysis were similar but NACS at two hours were poorer in the high infusion group. A propofol infusion coupled with nitrous oxide appears to be a satisfactory technique for Caesarean section.     

Haemodynamic effects of ketamine and thiopentone during anaesthetic induction for caesarean section

Ketamine (1 mg . kg-1) or thiopentone (4 mg . kg-1) was used to induce anaesthesia for Caesarean section in 62 normotensive patients. During induction of anaesthesia and before laryngoscopy, blood pressure did not change in either group (preinduction systolic blood pressure, 131 mmHg, and diastolic blood pressure, 75 mmHg). When laryngoscopy and intubation were performed, mean blood pressures of both patient groups increased 20-30 per cent. With ketamine (n = 30) heart rate was unchanged from the preinduction rate of 85 beats/min before laryngoscopy and increased significantly by 15 per cent during laryngoscopy and intubation. With thiopentone (n = 32), heart rate increased significantly to 20 per cent above the preinduction rate of 87 beats/min during induction and increased further (to 35 per cent above the preinduction rate) during laryngoscopy and intubation. The average maximal rate-pressure product calculated for the thiopentone group was over 18,000, which was significantly higher than the 15,000 calculated for the ketamine group. Neonatal outcome as assessed by Apgar score and umbilical blood gas analysis was good and did not differ significantly between groups.     

A case of pheochromocytoma in pregnancy]

A 29-year-old woman was referred to our hospital at the 34th week of her first pregnancy with a diagnosis of severe pregnancy-induced hypertension. A diagnosis of pheochromocytoma was made by elevated values of serum and urinary noradrenaline. Ultrasonography and computed tomography revealed a left adrenal tumor. Caesarean section combined with removal of the tumor at the 36th week of gestation was performed with a satisfactory result obtaining a healthy mother and an infant. Current management of patients with a pheochromocytoma during pregnancy is discussed.     

Manual displacement of the uterus during Caesarean section

Ninety ASA 1 and 2 pregnant women with term singleton pregnancies and no maternal and fetal complications, scheduled for elective or emergency Caesarean section, were randomly allocated to group LT (15 degrees left lateral table tilt, n = 45) and group MD (leftward manual displacement, n = 45). Subarachnoid block was established with a 25-gauge spinal needle at the L3-L4 interspace using 1.5 ml of 0.5% hyperbaric bupivacaine. A median sensory level of T6 was observed in both groups but the incidence of hypotension was markedly lower in group MD when compared to group LT (4.4% vs 40%; p < 0.001) with a significant reduction in mean (SD) ephedrine requirement (6 (0) vs 11.3 (4.9) mg; p < 0.001). The mean (SD) fall in systolic blood pressure was 28.8 (7.3) mmHg in group LT and 20 (12.7) mmHg in group MD. The time to maximum fall in systolic blood pressure was similar in both groups (4.5 min). We conclude that manual displacement of the uterus effectively reduces the incidence of hypotension and ephedrine requirements when compared to 15 degrees left lateral table tilt in parturients undergoing Caesarean section.     

Role of vitamin C on adrenocortical effects of etomidate]

This study was carried out to assess whether the adrenal inhibition induced by etomidate could be prevented by associating ascorbic acid with etomidate, as a protective effect of ascorbic acid administered three hours after etomidate has been described. Sixteen ASA 1 or 2 patients, less than 65 years old, free of endocrine disease, were included. At induction of anaesthesia, eight of them (group B) were given an infusion of ascorbic acid 1 g, in 500 ml of 5% glucose. Group A patients (n = 8) were given 500 ml of 5% glucose. Anaesthesia was induced with etomidate 0.3 mg.kg-1, fentanyl 0.005 mg.kg-1 and vecuronium 0.1 mg.kg-1. Maintenance was carried out using a continuous infusion of etomidate (0.1 mg.kg-1.h-1 for 10 min, followed by 0.01 to 0.02 mg.kg-1.h-1). Additional boluses of fentanyl or diazepam (10 mg) were administered when arterial blood pressure or heart rate were 20% greater than preanaesthetic values. The number of injections required was the same in both groups. Plasma cortisol concentrations were measured by radioimmunoassay (RIA) before anaesthesia (T0), 4 h (T4) and 24 h (T24) after the end of surgery. Blood ACTH levels were also assessed by RIA at T0 and T4. The adrenal insufficiency at T4 had completely ended at T24. In fact, the relative decrease in cortisol levels was greater in patients treated with ascorbic acid (T4/T0: 47.6 +/- 9% in group A vs 76.5 +/- 33% in group B, p less than 0.05); this was suggestive of a higher degree of adrenal inhibition in patients receiving ascorbic acid.(ABSTRACT TRUNCATED AT 250 WORDS)     

Disposition of propofol infusions for caesarean section

The disposition of propofol was studied in women undergoing elective Caesarean section. Indices of maternal recovery and neonatal assessment were correlated with venous concentrations of propofol. After induction of anaesthesia with propofol 2.0 mg.kg-1, ten patients received propofol 6 mg.kg-1.hr-1 with nitrous oxide 50 per cent in oxygen (low group) and nine were given propofol 9 mg.kg-1.hr-1 with oxygen 100 per cent (high group). Pharmacokinetic variables were similar between the groups. The mean +/- SD Vss = 2.38 +/- 1.16 L.kg-1, Cl = 39.2 +/- 9.75 ml.min-1.kg-1 and t1/2 beta = 126 +/- 68.7 min. At the time of delivery (8-16 min), the concentration of propofol ranged from 1.91-3.82 micrograms.ml-1 in the maternal vein (MV), 1.00-2.00 micrograms.ml-1 in the umbilical vein (UV) and 0.53-1.66 micrograms.ml-1 in the umbilical artery (UA). Neonates with high UV concentrations of propofol at delivery had lower neurologic and adaptive capacity scores 15 minutes later. The concentrations of propofol were similar between groups during the infusion but they declined at a faster rate in the low group postoperatively. Maternal recovery times did not depend on the total dose of propofol but the concentration of propofol at the time of eye opening was greater in the high group than the low group (1.74 +/- 0.51 vs 1.24 +/- 0.32 micrograms.ml-1, P less than 0.01). The rapid placental transfer of propofol during Caesarean section requires propofol infusions to be given cautiously, especially when induction to delivery times are long.     

Effects of ketamine on behavioral responses to somatic and visceral stimuli in rats]

The responses to colorectal distension as a visceral stimulus were observed and tail-flick test was performed in rats, after intraperitoneal administration of ketamine 30 mg.kg-1 (n = 6) or 100 mg.kg-1 (n = 5). After determining control colorectal distension and tail-flick values, both procedures were repeated every 10 minutes for one hour in both groups. The control thresholds for colorectal distension and tail-flick latencies were 20.8 +/- 1.0 mmHg and 4.5 +/- 0.3 sec (mean +/- SD), respectively in ketamine 30 mg.kg-1 group. They were 21.2 +/- 1.1 mmHg and 4.7 +/- 0.4 sec in ketamine 100 mg.kg-1 group. These baseline threshold and latency values in the two groups were not significantly different. Ten minutes after ketamine administration, the colorectal distension thresholds and tail-flick latencies were 43.7 +/- 7.2 mmHg and 6.4 +/- 0.9 sec, respectively in ketamine 30 mg.kg-1 group. They were 53.3 +/- 14.8 mmHg and 7.2 +/- 0.8 sec, respectively in ketamine 100 mg.kg-1 group. These values were significantly greater than the preketamine control values in both groups. The present study demonstrates that ketamine exerts apparent analgesic effects against both visceral and somatic stimuli. These results led us to consider that ketamine may be clinically useful to control visceral pain.     

Myocardial infarction and death after caesarean section in a woman with protein S deficiency and undiagnosed phaeochromocytoma

We describe the case of a 36-year-old woman, with a previous history of recurrent abortion due to protein S deficiency, undergoing an elective Caesarean section at 39-weeks gestation. During pregnancy no signs of hypertension or cardiovascular disease were reported, but at the end of the surgical procedure, the patient developed acute hypertension, leading to myocardial infarction, severe heart failure and death. The autopsy revealed a 2-cm undiagnosed phaeochromocytoma in the right adrenal gland. Clinical diagnostic features of phaeochromocytoma during pregnancy as well as the main therapeutic approaches suggested in the literature are discussed.     

Rachianesthésie pour césarienne : la vitesse d'injection a-t-elle une influence sur l'incidence de l'hypotension ?

OBJECTIVE: To study effect of injection rate on spinal blockade and haemodynamic of spinal bupivacaine for Caesarean section. STUDY DESIGN: Prospective and randomized. PATIENTS AND METHODS: Sixty ASA I-II patients scheduled for elective Caesarean section were randomized to receive either fast (20 seconds, group R, n=30) or slow (60 seconds, group L, n=30) spinal injection of 10 mg of hyperbaric bupivacaine 0.5% associated with 25 microg of fentanyl and 100 microg of morphine. Sensory and motor blockade and haemodynamic parameters were recorded. RESULTS: Profiles of sensory and motor block were similar in both groups. Variations of arterial blood pressure and total dose of ephedrine were not different between R and L groups. However, the number of patient with systolic blood pressure lower than 100 mmHg were significantly lower in L group than in R group (p=0.04). Incidences of adverse effects were similar in both groups. CONCLUSION: Result of the present study suggests that a slow rate of injection would induce lower incidence of hypotension induced by spinal bupivacaine for Caesarean section.     

Peroperative massive pulmonary embolism of tumoral origin. Value of extensive monitoring]

A case is reported of a 47-year-old female patient who suffered from massive tumour embolism during a nephrectomy for a renal carcinoma invading the inferior vena cava. Intraoperative monitoring consisted in direct blood pressure measurement (radial artery cannula), central haemodynamic monitoring (Swan-Ganz catheter), pulse oximetry and capnography. During the surgical manipulation of the suprahepatic vena cava, Petco2 suddenly decreased (from 25 mmHg to 14 mmHg), together with Spo2 (from 99% to 89%), and the mean pulmonary arterial pressure increased from 18 mmHg to 40 mmHg. The drop in arterial blood pressure to 50/30 mmHg, initiated an immediate sternotomy. After clamping the superior and inferior venae cavae, numerous tumour fragments were removed from the pulmonary artery. Cardiac activity restarted after internal cardiac massage, 1 mg adrenaline, 1 g calcium chloride and 150 mmol of molar sodium bicarbonate. The whole procedure lasted 30 min. Arterial blood pressure became stable at 110/50 mmHg, pulmonary arterial and wedge pressures at 20 and 5 mmHg. The Spo2 increased to 98%, and Petco2 to 25 mmHg. The nephrectomy was then carried out, the patient being given 5 micrograms.kg-1.min-1 dobutamine and 3 micrograms.kg-1.min-1 dopamine. At the end of surgery, systolic blood pressure was 120 mmHg, mean pulmonary arterial pressure 25 mmHg, and PaCO2 34 mmHg. The patient left the intensive care unit after twelve days. After one year of follow-up, no complication had occurred. The value of cardiopulmonary bypass in nephrectomy for renal carcinoma invading the vena cava, or the renal vein, is discussed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Caesarean section in a patient with a history of HELLP syndrome]

A 36-year-old woman underwent emergency caesarean section following the diagnosis of HELLP syndrome. Four years earlier, after having undergone the same procedure for HELLP syndrome, she had experienced hypovolemic shock, renal failure, and disseminated intravascular coagulopathy during the postoperative period. This time, the patient showed bleeding, elevation of liver enzymes (ALT, AST, LDH) and a reduction of antithrombin III activity in the 36th week of pregnancy. Anesthesia was induced by thiamylal 4 mg.kg-1 and suxamethonium 1 mg.kg-1 and after delivery maintained by oxygen-nitrous oxide-isoflurane, and all procedures were performed without any incident. No major complications such as intraperitoneal bleeding, renal failure, or disseminated intravascular coagulopathy occurred during the postoperative period. It is suggested that caesarean section should be carried out as soon as possible after the diagnosis of HELLP syndrome is confirmed.     

Effects of Diprivan on cerebral blood flow, intracranial pressure and cerebral metabolism in head injured patients

The effects of propofol on cerebral blood flow, intracranial pressure (ICP) and cerebral oxygen consumption (CMRO2) were assessed in ten severely head-injured patients undergoing surgery for limb fractures. The patients, aged between 15 and 40 years, were in deep coma, scored 6-7 on the Glasgow coma score. They were mechanically ventilated and sedated with 1 mg.h-1 phenoperidine. Anaesthesia was carried out with a 2 mg.kg-1 intravenous bolus of propofol, immediately followed by a 150 micrograms.kg-1.min-1 infusion, which lasted for a mean time of 41.4 +/- 7.3 min. Data were collected 5 min before any propofol was given, 15 min after the start of the infusion, and 15 min after its end. A radial artery cannula, a 7.5 Fr thermodilution flow-directed pulmonary arterial catheter, a cerebral intraventricular catheter and a catheter in the jugular venous bulb were used for this purpose. Carotid arterial injection of 133Xenon was used to determine regional cerebral blood flow (rCBF). Anaesthetic blood concentrations of propofol (3 to 5 micrograms.ml-1) were associated with a decrease in all the parameters studied: cerebral perfusion pressure, from 82 +/- 14 mmHg to 59 +/- 7 mmHg (p less than 0.001); rCBF, from 35 +/- 6 ml.100 g-1.min-1 to 26 +/- 5 ml.100 g-1.min-1 (p less than 0.01); ICP from 11.3 +/- 2.6 mmHg to 9.2 +/- 2.5 mmHg (p less than 0.001); CMRO2 from 1.63 +/- 0.38 mlO2 +/- 100 g-1.min-1 to 1.18 +/- 0.38 mlO2.100 g-1.min-1 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Uncommon calcification of a pheochromocytoma: a case report

A 62-year-old man with a 2-year history of hypertension was referred for evaluation of severe back pain, but his blood pressure was normal during his hospital stay. Plain radiography and excretory urography demonstrated central and eggshell-like calcification in the left suprarenal area. Computed tomographic scan confirmed similar shapes for the left adrenal calcifications. Laboratory examination revealed that the urinary normetanephrine was elevated. Left adrenal venography showed that the mass was in the middle to lower portion of the left adrenal gland. The most likely diagnosis was, calcified pheochromocytoma. The left adrenal tumor was removed surgically through a thoracolumbar incision on September 19, 1985. The blood pressure rose to 186/102 mmHg at the time of tumor manipulation. The tumor was a markedly hard mass, which was 3.5 x 3.5 x 3.0 cm and weighed 20 g. The histopathologic diagnosis was calcified pheochromocytoma. The patient remained symptomless after the operation.     

Ethylene glycol intoxication misdiagnosed as eclampsia

Ethylene glycol intoxication is one of the most serious acute poisonings with very uncertain prognosis with regard to both recovery and survival. A case report is presented in which a woman who was admitted for the termination of pregnancy by Caesarean section with a diagnosis of eclampsia turned out to be severely intoxicated by ethylene glycol.     

Atracurium with halothane and isoflurane in pediatric anesthesia

The study was carried out to assess the effects of atracurium neuromuscular blockade in children anaesthetized with N2O:O2: halothane vs N2O:O2: isoflurane. Thirty-two ASA I-II children, age 1-13 yr, undergoing elective surgery, were divided into two groups according to age and the mode of anaesthesia induction. Anaesthesia was induced in the younger children (group 1: 1-6 yr) with nitrous oxide and inspired halothane or isoflurane in oxygen via a face mask. Intravenous thiopental (6-7 mg/kg-1) was used to induce anaesthesia in older children (group 2: 7-13 yr). Each group of patients was randomly allocated to two groups each receiving halothane (group A: n = 8) or isoflurane (group I: n = 8). Halothane 0.8% end-tidal and isoflurane 1% end-tidal as anaesthesia maintenance. A bolus dose of atracurium 0.35 mg/kg-1 was administered. Premedication consisted of oral flunitrazepam (0.04 mg/kg-1) and bellafoline (0.02 mg/kg-1). Heart rate (by electrocardiography), arterial pressure (by auscultation) were monitored. Then end-expired carbon dioxide concentration was maintained at 30-40 mmHg. Neuromuscular transmission was evaluated by response to indirect stimulation (TOF) of the ulnar nerve at the wrist via surface electrodes. Conditions for endotracheal intubation were excellent in 25 of the children, good in 6 and poor in 1. The intubation was carried out within 112 s (group 1A), 130 s (group 1 I), 112 s (group 2A) and 135 s (group 2 I) following the administration of atracurium. The maximum twitch depression was recorded in the isoflurane groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

妊娠合并库欣综合征二例报告并文献复习

目的探讨罕见的妊娠合并库欣综合征病例的病因、临床表现、诊断和治疗。 方法回顾性分析2例我院收治的妊娠合并库欣综合征病例的临床资料，复习相关文献并予以讨论。例1：患者29岁，因"妊娠25周，四肢皮肤瘀点、瘀斑2个月，左小腿外伤半天"入住内分泌科。腹部超声检查发现左侧肾上腺区35 mm×29 mm低回声肿块。进一步完善各项检查后患者诊断为妊娠合并库欣综合征，并存在严重精神障碍。患者及家属要求手术治疗后终止妊娠。纠正低钾血症后转入泌尿外科行腹腔镜下左侧肾上腺肿瘤切除术，术中保留部分正常腺体。例2：患者28岁，因"妊娠22周，发现血糖升高1个月"入住我院内分泌科。腹部MRI检查发现左侧肾上腺区45 mm×59 mm占位。经进一步检查患者诊断为妊娠合并库欣综合征，并存在肝功能异常，考虑与患者皮质醇异常增高相关。患者及家属要求手术治疗后终止妊娠，遂转入泌尿外科行腹腔镜下左侧肾上腺肿瘤切除术。 结果2例手术均顺利完成。2例术后病理回报均为肾上腺皮质腺瘤。例1术后监测皮质醇水平低于正常，予小剂量糖皮质激素补充治疗。2例患者均术后2周引产终止妊娠。例1术后随访12个月，该患者术后小剂量糖皮质激素补充3个月后检查皮质醇恢复正常水平予停药，其后随访皮质醇均正常；患者精神障碍症状经过药物对症治疗后逐渐好转并恢复正常。例2术后已随访6个月，皮质醇及转氨酶术后均恢复正常。2例患者电解质及其他相关激素等随访检查均正常。 结论妊娠合并库欣综合征临床罕见，对孕妇及胎儿危害较大，需及时诊断。治疗时应综合评估孕妇及胎儿情况，选择合适的个体化治疗方案。     

Captopril reduces the dose requirement for sodium nitroprusside induced hypotension

The authors studied 12 patients who required deliberate hypotension for spinal fusion operations in order to investigate the efficacy of captopril for reducing dose requirement for sodium nitroprusside (SNP). Six patients, selected at random, were pretreated with captopril, 3 mg/kg po, and the remaining six patients served as controls. All patients received a similar anesthetic technique, consisting of thiopental 3 mg/kg, pancuronium 0.1 mg/kg, morphine 0.5 mg/kg, plus nitrous oxide 70% in oxygen. SNP was used to maintain mean arterial pressure (MAP) at 50-55 mmHg during deliberate hypotension lasting 140 +/- 13 minutes (mean +/- SE). Patients who received captopril required less SNP than untreated patients both early during hypotension (1.4 +/- 0.5 micrograms X kg-1 X min-1 vs. 4.8 +/- 0.8 micrograms X kg-1 X min-1, P less than 0.05), as well as late during hypotension (2.2 +/- 0.2 micrograms X kg-1 X min-1 vs. 5.6 +/- 0.6 micrograms X kg-1 X min-1, P less than 0.05). Whole blood cyanide was significantly lower in the patients pretreated with captopril than the untreated controls both early in the hypotensive period (2.7 +/- 0.6 mumol/l vs. 13 +/- 4 mumol/l, P less than 0.05) and also late in the hypotensive period (3.7 +/- 0.8 mumol/l vs. 30 +/- 10 mumol/l, P less than 0.05). MAP was reduced by captopril pretreatment both following induction of anesthesia (64 +/- 4 mmHg captopril vs. 80 +/- 4 mmHg control, P less than 0.05) and during surgery before deliberate hypotension (86 +/- 5 mmHg captopril vs. 100 +/- 4 control, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)