七氟醚和异氟醚对肝硬化患者肝切除术后肝功能的影响

目的 比较七氟醚和异氟醚对肝硬化患者行肝切除术后肝功能变化的影响.方法 将40名年龄为40～70岁的肝硬化(Child-Pugh A级),择期行肝癌肝叶切除术的患者随机分为七氟醚组和异氟醚组.两组患者均以咪唑安定0.1mg/kg体重、舒芬太尼0.4μg/kg体重、哌库溴铵1mg/kg体重诱导,分别予七氟醚或异氟醚辅以舒芬太尼维持麻醉.分别于术前、术后1、3、7d抽取非输液侧上肢静脉血测谷草转氨酶、谷丙转氨酶、总胆红素、碱性磷酸酶、胆碱酯酶、白蛋白、凝血酶原时间和血小板计数.结果 两组患者血清谷草转氨酶、谷丙转氨酶和碱性磷酸酶较术前明显升高,术后3d达峰,且其增高值在异氟醚组明显高于七氟醚组;术后无患者出现肝衰竭或肝损伤的临床表现.结论 在肝硬化患者的麻醉中,异氟醚对肝功能的影响可能强于七氟醚.     

Effects of sevoflurane anesthesia combined with epidural block on renal function in the elderly: comparison with isoflurane

Purpose. Renal function declines with age, but little is known about the renal effects of the inhaled anesthetic sevoflurane in the elderly. We therefore compared the renal effects of sevoflurane and isoflurane anesthesia in elderly patients. Methods. Thirteen patients aged ≥70 years undergoing gastrectomy with epidural anesthesia combined with general anesthesia were randomly assigned to receive either sevoflurane (n = 7) or isoflurane (n = 6). Dopamine (3–5 μg·kg⁻¹·min⁻¹) was administered to all patients. Blood and urine samples were collected before, during, and after anesthesia. Serum and urinary inorganic fluoride was measured, and renal function tests were performed. Results. Serum inorganic fluoride was significantly elevated in both groups. The production of inorganic fluoride was significantly greater in the sevoflurane group, but the level did not exceed 50 μmol·l⁻¹ in any patient. No abnormalities were observed in blood urea nitrogen (BUN), serum creatinine, or urine volume in either group. The albumin excretion index increased during anesthesia and decreased after anesthesia in both groups. Creatinine clearance was unchanged in the sevoflurane group but fluctuated during and after anesthesia in the isoflurane group. α₁-Microglobulin (MG), β₂-MG, and urinary N-acetyl-β-d-glucosaminidase (NAG) excretion increased up to 3 h after anesthesia, and α₁-MG and β₂-MG excretion increased on postanesthesia day 3. Conclusion. In both groups, glomerular and tubular function were transiently affected, but no abnormalities were found in routine laboratory tests, suggesting that neither isoflurane nor sevoflurane in combination with dopamine and epidural anesthesia seriously affects renal function in the elderly. Received for publication on October 23, 1998; accepted on October 27, 1999     

Perioperative stress response in elderly patients for elective gastrectomy--the comparison between isoflurane anesthesia and sevoflurane anesthesia both combined with epidural anesthesia

The difference in stress responses between isoflurane anesthesia (I group) and sevoflurane anesthesia (S group) was studied. Twelve patients for elective gastrectomy were divided into two groups: S group, 7 patients, 78 +/- 4.3 years of age, and I group, 5 patients, 77.4 +/- 6.9 years of age. Anesthesia was induced by fentanyl, midazolam and sevoflurane or isoflurane with 100% oxygen. After laryngeal mask air way was inserted under spontaneous ventilation, anesthesia was maintained with air (3 l.min-1), oxygen (2 l.min-1), sevoflurane or isoflurane and epidural block. Vecuronium bromide was given during surgery when needed. The demographic data were not different between the two groups. During operation, it was confirmed that the responses of sympathetic nervous system (epinephrine, norepinephrine) and pituitary-adrenocortical system (ACTH, cortisol) were maintained in both groups. After operation plasma norepinephrine levels increased in both groups. Although the responses of I group tended to be stronger than that of S group, there was no significant difference between the two groups.     

七氟烷麻醉对肝切除术患者术后炎症应激反应程度与肝功能的影响

目的探讨七氟烷麻醉对肝切除术患者术后炎症应激反应程度与肝功能的影响。方法选择2014年7月~2015年7月期间我院收治的肝硬化并择期行肝右叶切除术患者60例为研究对象。将研究对象随机分为试验组,采用七氟烷麻醉,30例;对照组,采用丙泊酚麻醉,30例。观察炎症应激反应因子TNF-α、IL-6和IL-10水平;肝功能指标ALT、TBil、AST和ALB;统计并发症发生率。采用SPSS20.0软件进行统计学分析。结果 (1)术后1 d、3 d、7 d,两组患者TNF-α、IL-6及IL-10水平均较术前显著升高(P0.05),且试验组TNF-α、IL-6及IL-10水平显著低于对照组(P0.05)。(2)术后1、3、7 d,两组患者AST、ALT和TBi L均较术前显著升高(P0.05),且试验组AST、ALT和TBi L水平低于对照组(P0.05),两组患者ALB术前术后均无差异(P0.05)。(3)两组患者术后并发症比较无统计学差异(P0.05)。结论七氟烷麻醉抑制了患者术后炎症应激反应因子的分泌,促进了患者术后肝功能恢复,不能明显降低患者术后并发症的发生,效果优于丙泊酚。     

七氟醚、异氟醚或丙泊酚全身麻醉复合硬膜外阻滞对肝脏切除术后肝肾功能的影响

目的探讨低流量七氟醚、异氟醚或丙泊酚全麻复合硬膜外阻滞在相同脑电双频指数下三种麻醉方法对术后肝肾功能的影响。方法选择45例ASAI或II级,肝脏右叶部分切除病人,随机均分为七氟醚组(S组)、异氟醚组(I组)和丙泊酚组(P组),每组病人均复合硬膜外阻滞。三组病人分别吸入七氟醚、异氟醚或丙泊酚靶控输注(TCI)维持麻醉,维持BIS50±5。记录术前、术后第1、3、5天肝脏功能、肾脏功能指标。结果三组病人术后第1、3、5天肝脏酶显著增高,在术后第1天达到高峰,总胆红素术后第3天达高峰,白蛋白术后第1天显著降低,术后第3天和第5天与术前比较差异无统计学意义。三组病人均无肝功能衰竭。术后肾脏功能指标肌酐、尿素氮组内、组间比较差异均无统计学意义。结论应用全身麻醉复合硬膜外阻滞进行肝脏部分切除手术,七氟醚、异氟醚或丙泊酚对肝脏术后肝功能改变无明显区别,术后肾脏功能无明显变化。     

The effect of isoflurane or propofol anaesthesia on liver injury after partial hepatectomy in cirrhotic patients

This study compared the effect of isoflurane or propofol anaesthesia on postoperative hepatocellular injury, liver function and pro‐inflammatory cytokine concentrations in 60 cirrhotic patients, after partial hepatectomy using Pringle’s manoeuvre. In the isoflurane group postoperatively, both mean (SD) aspartate aminotransferase (day 1: 197 (123) U.l^?1 vs 261 (143) U.l^?1; p = 0.01; day 3: 465 (258) U.l^?1 vs 578 (311) U.l^?1; p = 0.02) and alanine aminotransferase (day 1: 575 (312) U.l^?1 vs 714 (434) U.l^?1; p = 0.04 and day 3: 776 (443) U.l^?1 vs 898 (746) U.l^?1; p = 0.03) were significantly lower compared with the propofol group. Mean (SD) postoperative white cell count was significantly lower with isoflurane than propofol (day 1: 12 (4) × 10³.mm^?1 vs 16 (4) × 10³.mm^?1; p = 0.01 and day 3: 10 (6) × 10³.mm^?1; vs 14 (4); p = 0.01). Tumour necrosis factor‐α (day 1) and interleukin‐1 (days 1 and 3) concentrations were significantly lower with isoflurane. Compared with propofol, isoflurane is associated with an attenuated postoperative inflammatory response and less postoperative hepatocellular injury in patients having this procedure.     

Clinical comparison of sevoflurane and isoflurane when administered with nitrous oxide for surgical procedures of intermediate duration

The purpose of this study was to compare the haemodynamic effects and emergence times of anaesthesia with sevoflurane with those of isoflurane when the agents were administered with nitrous oxide to adult inpatients (ASA I and II) undergoing surgery of at least an hour in duration. Fifty patients were randomly assigned to receive either 0.65 minimum alveolar concentration (MAC) (1.3%) sevoflurane or 0.65 MAC (0.8%) isoflurane together with 60% nitrous oxide following induction with thiopentone, fentanyl, and succinylcholine. Systemic blood pressure and heart rate trends were similar for both groups for the duration of anaesthesia. However, differences in systolic blood pressure measurements were noted at one minute after incision (99 ± 3 mmHg, mean ± SE, in the sevoflurane group compared with 109 ± 4 mmHg for isoflurane), and at emergence (125 ± 3 mmHg for sevoflurane, 134 ± 3 mmHg for isoflurane), and in diastolic blood pressure measurements at five minutes after intubation (64 ± 2 mmHg for sevoflurane, 73 ± 3 mmHg for isoflurane). Recovery of response to command was more rapid after discontinuation of sevofluranenitrous oxide (9.9 ± 1.1 min) than after isoflurane-nitrous oxide (13.9 ± 1.3 min). Despite earlier emergence, patients who had received sevoflurane did not request postoperative analgesia sooner. We conclude that the purported advantages of sevoflurane, namely haemodynamic stability and rapid emergence, can be expected even when the agent is administered at 0.65 MAC (1.3%) in nitrous oxide to a typical adult surgical population undergoing procedures of intermediate duration (2.3 ± 0.2 hr).     

Cost comparison of sevoflurane with isoflurane anesthesia in arthroscopic menisectomy surgery

PURPOSE: To determine the "real world" cost of sevoflurane compared with isoflurane in balanced general anesthesia for daycare arthroscopic menisectomy, we prospectively investigated perioperative drug requirement and expense as well as recovery time. METHODS: Following intravenous induction, 40 consenting adult patients randomly received either sevoflurane- or isoflurane-based anesthesia with a standardized gas inflow rate of 3 l x min. Recovery was assessed in the postanesthetic recovery room (PARR) in a double-blind manner at 15 min intervals using the Aldrete scoring system until patients met discharge criteria. RESULTS: Patient demographics, anesthetic duration, volatile potency and adjunct drug requirements were similar in the two groups. Total perioperative drug cost per patient was CAN$38.10+/-10.13 (mean +/- SD) for the sevoflurane group and $23.87+/-6.59 for the isoflurane group (P<0.01). Although the nonvolatile drug cost was comparable between the two groups, the volatile drug cost per patient was $19.40+/-8.80 for sevoflurane and $4.50+/-1.90 for isoflurane (P<0.01). This four-fold sevoflurane-to-isoflurane cost difference was the product of two ratios, both based on the volume of liquid anesthetic: the ratio of consumption, 2.1; and the ratio of institutional price, 2.1. Intraoperative hemodynamic response, time until discharge from the PARR and incidences of postoperative nausea and vomiting did not significantly differ between the two groups. CONCLUSIONS: When used to maintain equipotent balanced general anesthesia for daycare arthroscopic menisectomy, volatile consumption and cost were greater for sevoflurane compared with isoflurane. Nonvolatile perioperative drug cost and recovery times were similar, however, in the two groups.     

Immediate anesthesia recovery and psychomotor function of patient after prolonged anesthesia with desflurane, sevoflurane or isoflurane

OBJECTIVE: To compare the anesthetic maintenance and early postoperative recovery and psychomotor function in patients who have been anesthestized with desflurane, sevoflurane or isoflurane during prolonged open urological surgery. PATIENTS AND METHODS: Seventy-five patients were randomly assigned to receive desflurane, sevoflurane or isoflurane with N2O 60% for anesthetic maintenance. The concentration of each drug was adjusted to maintain arterial pressure and heart rate +/- 20% of baseline. After the operation the anesthetics were discontinued and times until eye opening, spontaneous breathing, extubation and orientation were recorded. In the post-anesthesia recovery ward we applied the Newman-Trieger and Aldrete tests and recorded instances of nausea and vomiting and need for analgesia during the first 24 hours after surgery. RESULTS: The groups were similar with regard to demographic features, anesthetic maintenance, duration of anesthesia and relative doses of the anesthetics used. Recovery times in the operating room were significantly shorter (p < 0.05) after anesthesia with desflurane and sevoflurane than with isoflurane, with no significant differences between the desflurane and sevoflurane groups (duration of anesthesia 198 +/- 90, 171 +/- 67 and 191 +/- 79; eye opening 7.6 +/- 3.7, 7.8 +/- 3.0 and 11.9 +/- 4.5; time until extubation 7.8 +/- 3.0, 8.3 +/- 3.0 and 11.0 +/- 3.5 for desflurane, sevoflurane and isoflurane, respectively; all data in minutes). Recovery in the post-anesthetic recovery ward was similar for all three groups. CONCLUSIONS: Anesthetic maintenance was comparable with all three drugs. Desflurane and sevoflurane demonstrated advantages over isoflurane during recovery from anesthesia in the operating theater. No significant differences were found in psychomotor recovery, nausea and/or vomiting or requirements for postoperative analgesia.     

Effects of sevoflurane and isoflurane anesthesia on arterial ketone body ratio and liver function

BACKGROUND: The purpose of this study was to compare the effect on arterial ketone body ratio (AKBR), which indicates hepatic mitochondrial energy charge in relation to hepatic blood flow, and liver function test (serum levels of liver enzymes) between sevoflurane and isoflurane anesthesia. METHODS: Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBil), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GTP), and lactate dehydrogenase (LDH) were measured before and 1,2,3,7, and 14 days after anesthesia in each of 60 patients receiving either sevoflurane or isoflurane anesthesia for neurosurgery (tumor resection). In 13 patients of both groups, arterial concentrations of acetoacetate and 3-hydroxybutyrate were also measured before, during and after (up to 12 h) anesthesia and the AKBR was calculated. RESULTS: AST, ALT and GTP increased, peaking 7 days after anesthesia, especially in the isoflurane group. There was a significantly greater number of patients with abnormal AST and ALT values in the isoflurane group than in the sevoflurane group. The increase of TBil had its peak 1 day after anesthesia in both groups. AKBR decreased after anesthesia induction and recovered to the control value 12 h after anesthesia in both groups. There was no difference between the two anesthetic groups in AKBR. CONCLUSION: Isoflurane induced an elevation of serum levels of liver enzymes more frequently than did sevoflurane 3 to 14 days after anesthesia, while AKBR until 12 h after anesthesia did not show any significant difference between sevoflurane and isoflurane anesthesia.     

Liver function after sevoflurane or isoflurane anaesthesia in neurosurgical patients

Purpose

Although both sevoflurane and isoflurane are thought to be less hepatotoxic than halothane or enflurane, recent case reports have described liver injury after sevoflurane or isoflurane anaesthesia. There are no studies comparing liver function after sevoflurane or isoflurane anaesthesia. The purpose of this study was to compare serum liver enzyme concentrations in patients receiving either sevoflurane or isoflurane anaesthesia prospectively.

Methods

Ninety patients scheduled for elective neurosurgery were studied. Serum concentrations of aspartame aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBil), alkaline phosphatase (ALP), γ- glutamyl transpeptidase (GTP), and lactate dehydrogenase (LDH) were measured before and, 1, 2, 3, 7, and 14 days after either sevoflurane (45 patients) or isoflurane (45 patients) anaesthesia.

Results

AST ALT and GTP increased peaking seven days after anaesthesia, especially in the isoflurane group. The numbers of patients with abnormal values in AST and ALT were not different in the isoflurane from that in the sevoflurane group. The increase in TBil peaked one day after anaesthesia in both groups.

Conclusion

Even in a small number of patients, isoflurane induced an elevation of serum levels of liver enzymes more frequently than did sevoflurane three to 14 days after anaesthesia.     

Nitrous oxide induces paradoxical electroencephalographic changes after tracheal intubation during isoflurane and sevoflurane anesthesia

In this randomized, double-blind, controlled study, we tested the hypothesis that nitrous oxide (N2O) affects bispectral index (BIS) and 95% spectral edge frequency (SEF95) in response to tracheal intubation during anesthesia with isoflurane and sevoflurane. In protocol 1, we randomly allocated 90 ASA physical status I patients to 6 groups (n = 15 each). Anesthesia was induced with isoflurane or sevoflurane with 0%, 33%, or 66% N2O. The concentration of isoflurane and sevoflurane was gradually increased and end-tidal concentrations were maintained at 1.1% and 1.7%, respectively. Tracheal intubation was performed 12 min after induction of anesthesia. BIS was significantly increased 1 min after tracheal intubation compared before laryngoscopy in patients receiving only isoflurane or sevoflurane (P = 0.001 and 0.007, respectively). In patients receiving 66% N2O-isoflurane or 66% N2O-sevoflurane, both BIS and SEF95 were significantly decreased after tracheal intubation and significantly lower than in those patients receiving only isoflurane or sevoflurane, respectively (P < 0.01 for both). In protocol 2, 3 microg/kg of IV fentanyl completely abolished the decrease of BIS and SEF95 after tracheal intubation during anesthesia with 66% N2O-isoflurane and 66% N2O-sevoflurane (n = 10). We conclude that 66% N2O induced a paradoxical decrease of BIS in response to tracheal intubation during anesthesia with isoflurane and sevoflurane.     

中老年腹股沟疝局麻与硬膜外麻醉手术的比较

目的比较中老年人在局麻与硬膜外麻醉下行腹股沟疝修补术的疗效、住院时间、平均费用、恢复正常生活的时间及手术并发症等.方法采用随机对照方法,将223例病人分为局麻组(男,113人)和硬膜外阻滞麻组(男110人).结果局麻组病人平均手术时间(44min)、住院时间(2.1d)、恢复正常生活时间(5.4d)和手术并发症等均明显小于硬膜外阻滞组(P＜0.01～0.05).结论中老年人局麻下进行疝修补,可明显减少手术费用,术后并发症的发生率,是一安全而有效的方法,值得推广.     

Recovery of cognitive function after remifentanil-propofol anesthesia: a comparison with desflurane and sevoflurane anesthesia

We compared the recovery characteristics of remifentanil, desflurane, and sevoflurane when used for anesthesia in elective operative procedures. Sixty ASA physical status I and II patients, aged 18-65 yr, were randomly assigned to receive remifentanil-propofol, desflurane-N2O, or sevoflurane-N2O anesthesia. Before the induction of anesthesia, the patients of the desflurane and sevoflurane groups received fentanyl 2 microg/kg. In all groups, anesthesia was induced with propofol and maintained either with remifentanil 0.25 microg x kg(-1) x min(-1), desflurane, or sevoflurane 0.85 MAC with 65% nitrous oxide in oxygen. Anesthetics were titrated to achieve an adequate level of surgical anesthesia and to maintain mean arterial pressure within 20% of baseline values. Early recovery times and a modified Aldrete Recovery Score > 9 were recorded. Trieger Dot Test and Digit Substitution Test (DSST) were performed the day before surgery and in the postanesthesia care unit to evaluate intermediate recovery. The remifentanil-propofol group had a significantly faster emergence than desflurane or sevoflurane, with no difference between both inhaled anesthetics. Thirty min after anesthesia administration, patients in the remifentanil-propofol and in the desflurane groups gave significantly more correct responses in the DSST compared with sevoflurane (remifentanil 87%, desflurane 83%, sevoflurane 56%), the impairment in the sevoflurane patients corresponding to the effects of a blood alcohol level of approximately 0.1% and, thus, being of clinical importance. Ninety minutes after anesthesia administration, no significant difference could be demonstrated among the groups in the DSST scores. Emergence and return of cognitive function was significantly faster after remifentanil-propofol compared with desflurane and sevoflurane up to 60 min after anesthesia administration. IMPLICATIONS: We compared awakening and intermediate recovery times after remifentanil-propofol anesthesia to desflurane-N2O and sevoflurane-N2O anesthesia. Emergence and return of cognitive function was significantly faster after remifentanil-propofol compared with desflurane and sevoflurane up to 60 min after anesthesia administration.     

A comparison between sevoflurane and propofol when combined with continuous epidural blockade in adult patients

Purpose. The effects of sevoflurane and propofol, in combination with continuous epidural blockade, on blood pressure control and time of recovery from anesthesia were compared. Methods. Adult patients were allocated to either a sevoflurane (n=54) or a propofol (n=64) group. Anesthesia was induced with either inhalation of 5% sevoflurane or intravenous administration of 2 mg·kg⁻¹ propofol. After an injection of vecuronium, the trachea was intubated and anesthesia was maintained with continuous epidural blockade, air/oxygen, and sevoflurane or propofol. The systolic arterial pressure was maintained within ±30% of that obtained on the ward. Results. The number of cases requiring a change in the dose of either anesthetics or vasoactive agents was not different between the groups. However, the arterial pressure and heart rate were more stable in the propofol group than in the sevoflurane group (P<0.05). The length of time before tracheal extubation was shorter in the sevoflurane group (10.4±5.2 min, mean±SD) than the propofol group (15.0±11.2 min,P<0.05). Conclusion. Propofol anesthesia, in combination with continuous epidural blockade, results in more stable intraoperative hemodynamics than sevoflurane anesthesia, but requries a longer recovery time and results in larger interindividual variability than sevoflurane anesthesia.     

腹部手术患者吸入七氟醚与异氟醚麻醉恢复的比较

目的比较腹部手术患者吸入七氟醚与异氟醚麻醉恢复的情况。方法全麻下行开腹手术患者40例,随机分为2组（n=20）：七氟醚组（S组）及异氟醚组（Ⅰ组）。麻醉诱导后行气管插管,机械通气。诱导后吸入纯氧,氧流量2 L/min,30min后调整为1 L/min。手术开始前,调整吸入麻醉药的呼气末浓度为1.0 MAC。麻醉维持：吸入七氟醚或异氟醚,间断静脉注射罗库溴铵和芬太尼,维持血压和心率波动幅度不超过基础值30%。缝皮结束时,停止吸入七氟醚或异氟醚,纯氧流量调整为5 L/min。记录睁眼时间（停止吸入麻醉药到睁眼的时间）、拔除气管导管时间（停止吸入麻醉药到拔除气管导管的时间）、Aldrete评分达到9分时间（从停止吸入麻醉药计时）及麻醉后恢复室（PACU）停留时间。记录吸入麻醉药用量。结果与Ⅰ组比较,S组睁眼时间、拔除气管导管时间、Aldrete评分达到9分时间及PACU停留时间缩短（P〈0.05）,吸入麻醉药的总用量和单位时间用量差异无统计学意义（P〉0.05）。结论与异氟醚比较,吸入七氟醚患者麻醉恢复较快,且麻醉恢复质量较好。     

Comparison of renal function following anesthesia with low-flow sevoflurane and isoflurane.

STUDY OBJECTIVE: To evaluate postoperative renal function after patients were administered sevoflurane under conditions designed to generate high concentrations of compound A. STUDY DESIGN AND SETTING: A multicenter (11 sites), multinational, open-label, randomized, comparative study of perioperative renal function in patients who have received low-flow (< or = 1 L/min) sevoflurane or isoflurane. PATIENTS: 254 ASA physical status I, II and III patients requiring endotracheal intubation for elective surgery lasting more than 2 hours. INTERVENTIONS: After induction, low-flow anesthesia was initiated at a flow rate < or = 1 L/min. Blood and urine samples were studied to assess postoperative renal function. MEASUREMENTS AND MAIN RESULTS: Measurements of serum BUN and creatinine, and urine glucose, protein, pH, and specific gravity were used to assess renal function preoperatively and up to 3 days postoperatively. Serum inorganic fluoride ion concentration was measured at preinduction, emergence, and 2, 24 and 72 hours postoperatively. Compound A concentrations were measured at two sites for those patients receiving sevoflurane. Adverse experience data were analyzed. One hundred eighty-eight patients were considered evaluable (98 sevoflurane and 90 isoflurane). Peak serum fluoride concentrations were significantly higher after sevoflurane (40 +/- 16 microM) than after isoflurane (3 +/- 2 microM). Serum creatinine and BUN decreased in both groups postoperatively; glucosuria and proteinuria occurred in 15% to 25% of patients. There were no clinically significant differences in BUN, creatinine, glucosuria, and proteinuria between the low-flow sevoflurane and low-flow isoflurane patients. CONCLUSIONS: There were no statistically significant differences in the renal effects of sevoflurane or isoflurane in surgical patients undergoing low-flow anesthesia for up to 8 hours. Low-flow sevoflurane anesthesia under clinical conditions expected to produce high levels of compound A appears as safe as low-flow isoflurane anesthesia.     

Cerebrovascular carbon dioxide reactivity during general anesthesia: a comparison between sevoflurane and isoflurane

We compared cerebrovascular carbon dioxide reactivity during the administration of sevoflurane and isoflurane anesthesia by measuring cerebral blood flow velocity (CBFV) as an indirect measurement of cerebral blood flow. Thirty patients, 20-70 yr old, undergoing lower abdominal surgery and without known cerebral or cardiovascular system disease, were randomly assigned to either sevoflurane or isoflurane treatment groups. Anesthesia was induced with thiopental 5 mg/kg IV and maintained with either sevoflurane or isoflurane in 67% nitrous oxide and oxygen. The CBFV and pulsatility index (PI) of the left middle cerebral artery were monitored with transcranial Doppler. The P(ETCO)2 was increased stepwise from 20 to 50 mm Hg by changing the respiratory rate with a constant tidal volume. At every 5-mm Hg stepwise change in P(ETCO)2, CBFV and PI were recorded. CBFV increased with increasing P(ETCO)2. CBFV was significantly smaller in the isoflurane group at P(ETCO)2 = 20-40 mm Hg than in the sevoflurane group. The rate of change of CBFV with changes in CO2 was larger in the isoflurane group than in the sevoflurane group. PI was constant over time and was not different between groups. In conclusion, hypocapnia-induced reduction of intracranial pressure might be more effective during the administration of isoflurane than sevoflurane. IMPLICATIONS: Changes in cerebral blood flow caused by the changes of carbon dioxide tension are greater during the administration of isoflurane anesthesia compared with sevoflurane anesthesia. Attempts to decrease intracranial pressure by decreasing carbon dioxide tension may be more successful during isoflurane than sevoflurane anesthesia administration.