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.     

Single-breath Vital Capacity Rapid Inhalation Induction in Children: 8% Sevoflurane versus 5% Halothane

Background: The authors compared the speed of induction of anesthesia with sevoflurane with and without nitrous oxide with the speed of halothane and nitrous oxide using a single-breath vital capacity induction.

Methods: With informed parental consent, 51 healthy unpremedicated children aged 5-12 yr were randomized to inhale a single breath of one of three gas mixtures: 8% sevoflurane in 66% nitrous oxide, 8% sevoflurane in oxygen, or 5% halothane in 66% nitrous oxide. A blinded observer recorded the times to loss of the eyelash reflex, return of conjugate gaze, the presence of airway reflex responses, involuntary movement, and hemodynamic responses.

Results: Forty-two children completed the study. The times (mean +/- SD) to loss of the eyelash reflex with sevoflurane/nitrous oxide, 38 +/- 8 s, and for sevoflurane-oxygen, 34 +/- 12 s, were less than that with halothane-nitrous oxide, 58 +/- 17 s (P < 0.01). Movement occurred less frequently during sevoflurane than during halothane anesthesia (P < 0.05). The times to return of conjugate gaze and the incidence of airway reflex responses were similar among the groups. The incidence of dysrhythmias in the sevoflurane groups was less than that in the halothane group (P < 0.01).     

Comparison of renal function under deliberate hypotension during epidural plus light-enflurane anesthesia and during enflurane anesthesia

We compared the effects of deliberate hypotension induced with trimethaphan on renal function and renal tubular damage under combined epidural and light-enflurane anesthesia (epidural group) and enflurane anesthesia alone (enflurane group). The mean arterial blood pressure was maintained at 50–55 mm Hg for 2.5 h in both groups using continuous infusion of trimethaphan. The urine volume and free water clearance were significantly greater in the epidural group than in the enflurane group [1.8±1.8 (SD)vs 0.4±0.3 ml·kg⁻¹·h⁻¹ and 0.81±1.30vs −0.15±0.22 ml·min⁻¹, respectively] (P<0.05). The creatinine clearance and fractional sodium excretion rate did not differ significantly between the two groups. Urinary excretion of norepinephrine was significantly less in the epidural group than in the enflurane group (P<0.05); however, epinephrine excretion did not differ. Urinary excretion ofN-acetyl-β-d-glucosaminidase was significantly less in the epidural group than in the enflurane, group (4.2±2.5vs 12.2±4.6 U·g⁻¹ CR) (P<0.01). The plasma antidiuretic hormone concentration was significantly lower in the epidural group compared to the enflurene group (13±23vs 57±42 pg·ml⁻¹) (P<0.05). No significant difference in plasma atrial natriuretic peptide concentration was found between the groups. We conclude that renal function during trimethaphan-induced hypotension is better maintained under epidural plus light-enflurane anesthesia than under enflurane anesthesia alone.     

Effects of enflurane, isoflurane, and sevoflurane on renal tubular functions]

Twenty-seven patients without renal disease were divided randomly into three groups of each nine patients. Each group received either enflurane, isoflurane or sevoflurane. The renal tubular functions were examined during anesthesia and on the first postoperative day. By inhalation of 1.49 MAC hours of enflurane, 2.17 MAC hours of isoflurane or 1.29 MAC hours of sevoflurane, creatinine clearance, Na excretion rate, urine beta 2-microglobulin and urine N-acetyl-beta-D-glucosaminidase showed no significant changes during anesthesia and the during postoperative period among anesthetic agents used. These results indicate that enflurane, isoflurane or sevoflurane does not affect renal tubular function specifically under anesthesia when each was given for less than four hours.     

Effects of sevoflurane on intracranial pressure and formation and absorption of cerebrospinal fluid in cats]

The effects of sevoflurane on intracranial pressure (ICP) and the formation and absorption of cerebrospinal fluid (CSF) were examined in cats. Changes in ICP and superior sagittal sinus pressure (SSSP) were studied for 180 minutes during anesthesia with 1MAC sevoflurane (2.6%, inspired) and 50% N2O in O2. ICP increased significantly immediately after the start of anesthesia. The level remained for the subsequent 120 minutes, but increased significantly again 140 minutes after the start of anesthesia. There was no change in SSSP. The rate of CSF formation (Vf) was examined using the open ventriculocisternal perfusion method during anesthesia for 180 minutes with 1MAC sevoflurane or 1MAC enflurane (2.4%, inspired) and 50% N2O in O2. During sevoflurane administration, Vf decreased significantly 30 minutes after the start of anesthesia. In contrast, during enflurane administration, Vf increased significantly 10 minutes after the start of anesthesia. Finally, Vf and the rate of CSF absorption (Va) were measured under 1MAC sevoflurane or 1MAC enflurane and 50% N2O in O2 anesthesia, or under 50% N2O in O2 anesthesia. They were compared with ICP level. Vf decreased significantly when ICP level increased in all groups. The increase in Va when ICP level increased, was greater in the N2O group than in those anesthetized with sevoflurane or enflurane. The delayed increase of ICP under sevoflurane may have resulted in part from the cranial accumulation of CSF due to increased resistance to CSF absorption.     

Multiple-deep-breath inhalation induction with 5% sevoflurane and 67% nitrous oxide: comparison with intravenous injection of propofol

Purpose. To evaluate the clinical characteristics of multiple-deep-breath inhalation induction with sevoflurane and nitrous oxide followed by the same inhalational anesthetics for maintenance, we compared the technique with intravenous propofol anesthesia. Methods. Forty patients scheduled for ophthalmic surgery under general anesthesia with a laryngeal mask airway (LMA) were assigned to two groups. Anesthesia was induced with multiple-deep-breath inhalation of 5% sevoflurane and 67% nitrous oxide in oxygen (group S: n = 20) or intravenous injection of 1% propofol at the rate of 1200 ml·h⁻¹ with spontaneous inhalation of 67% nitrous oxide in oxygen until the patient lost consciousness or received propofol up to 2 mg·kg⁻¹ (group P: n = 20). We attempted to insert an LMA when the patient's jaw relaxation was adequate. We compared induction times, recovery times, occurrence of adverse events, and patient satisfaction between the two groups. Results. The mean time to insertion of the LMA was significantly shorter in group P (209 ± 118 s) than in group S (302 ± 102 s; P < 0.05). The recovery times did not differ significantly between the groups. There were no serious side effects during the induction and recovery period in either group. Significantly more patients in group P than in group S wanted to have the same anesthetic method (90% vs 50%; P < 0.05). Conclusion. Multiple-deep-breath inhalation induction with 5% sevoflurane and 67% nitrous oxide followed by the same inhalational anesthetics for maintenance was safely performed without serious adverse events. However, the induction time was shorter and patient satisfaction was higher in propofol group than in the inhalational group. Received: April 11, 2001 / Accepted: November 6, 2001     

A multicentre trial in spontaneously breathing patients. A comparison of recovery following alfentanil or enflurane

Recovery from anesthesia and the effect of premedication, induction agent and the individual anesthetist on the measure of recovery was assessed in 707 patients scheduled to undergo short surgical procedures. Patients were randomly allocated to receive either alfentanil or enflurane as a supplement to an induction agent, nitrous oxide/oxygen anesthetic technique with or without premedication. Patients who received alfentanil had a faster immediate recovery than those who received enflurane (p less than 0.001). Total anesthetic time was shorter in the alfentanil group (p = 0.02). For 36 of 37 anesthetists recovery was faster in the alfentanil group compared to the enflurane group. Choice of premedication and induction agent had a significant effect on recovery, thiopentone or lorazepam prolonged recovery time in each group. Although the alfentanil group had a higher incidence of apnoea, movement and vomiting (p less than 0.001), the enflurane group had a higher incidence of coughing (p less than 0.001) and shivering (p = 0.004). Overall the anesthetists assessed the alfentanil technique as excellent or good in more patients than the enflurane technique.     

Comparative clinical study of induction and emergence time in sevoflurane and enflurane anaesthesia

The induction and emergence times in patients who received minor oral surgery under sevoflurane with nitrous oxide or enflurane with nitrous oxide were compared. The induction time required for the loss of eyelid reflex when using sevoflurane (1.6 +/- 0.2 min) was significantly shorter than that in the enflurane group (2.9 +/- 0.4 min). There was no significant difference in the recovery time in the two groups.     

Vital capacity rapid inhalation induction technique: comparison of sevoflurane and halothane

Induction of anaesthesia using the vital capacity rapid inhalation induction (VCRII) technique with either sevoflurane or halothane was compared. The induction time, characteristics, and acceptability were assessed. Thirty-two volunteers were given one of the vapours: 17 received sevoflurane and 15 halothane. Subjects were unpremedicated and breathed approximately 2.6 × minimum alveolar concentration (MAC) equivalent of either agent. There were no differences in the patients’ cardiovascular or respiratory variables. The mean time for induction of anaesthesia with halothane (153 ± 46 sec, SD) was slower than with sevoflurane (81 ± 22 sec, SD, P < 0.05), reflecting its higher blood:gas solubility. There were fewer induction complications such as coughing and movement in the sevoflurane than in the halothane group. Subjects in the sevoflurane group found the smell of anaesthetic more acceptable than those in the halothane group (65% vs 13%, respectively). Subjects in both groups had no objection to undergoing the procedure again. It is concluded that both halothane and sevoflurane are effective in VCRII of anaesthesia without premedication. However, the slower speed of induction with halothane frustrated the anaesthetist because of the longer induction time, and may increase the chance of pronounced excitatory phenomena occurring.     

Rapid induction with 7% sevoflurane inhalation—not the single-breath method

The usefulness of the rapid anesthesia induction method with 7% sevoflurane, not the single-breath method, was investigated in 88 patients with ASA physical status 1. Anesthesia was induced with 3 l·min⁻¹ nitrous oxide in 3 l·min⁻¹ oxygen and sevoflurane 7% for 3 min (group A), 7% for 5 min (group B), 7% for 7 min (group C), and 5% for 7 min in conventional induction (group D). There were 22 patients in each group. Each sevoflurane concentration was given at the same time as the start of nitrous oxide inhalation except for group D. The changes in blood pressure and heart rate were the smallest in group A. The time for the loss of consciousness was shorter in groups A (47.2 s), B (44.9 s), and C (49.8 s) than in group D (73.4 s). During induction, body movements were seen in 18.2% in group A and 13.6% in the other 3 groups, but no other complications such as coughing, breath holding, or laryngospasm were seen in any group. In conclusion, the anesthesia induction method with 3 min of 7% sevoflurane inhalation was useful for rapid induction.     

Transient hyperdynamic response associated with controlled hypocapneic hyperventilation during sevoflurane-nitrous oxide mask induction in adults.

We assessed hemodynamic variables during sevoflurane face mask anesthetic induction in female ASA physical status I or II patients. Anesthesia was induced with a single-breath inhalation method with 8% sevoflurane in 50% nitrous oxide in oxygen. Thirty patients were randomized either to breathe spontaneously (SB group, n = 15) or to receive controlled ventilation (CV group, n = 15) for 6 min after the loss of consciousness. Noninvasive blood pressure and heart rate (HR) were recorded at 1-min intervals. Mean +/- SD HR increased from 83+/-18 to 112+/-24 bpm at 4 min in the CV group (P < 0.001 between groups and within group compared with baseline). Mean arterial pressure increased from 97+/-9 to 106+/-26 mm Hg at 4 min in the CV group, which was significantly higher than that in the SB group (P < 0.01). In the SB group, mean arterial pressure decreased significantly, from 96+/-8 to 78+/-13 mmHg, at 6 min (P < 0.001), and HR remained unchanged. Therefore, hyperventilation should be avoided during the induction of sevoflurane anesthesia via a mask. IMPLICATIONS: In this randomized, prospective study, we found that controlled hypocapneic hyperventilation delivered manually during sevoflurane/ N2O/O2 mask induction was associated with a significant transient hyperdynamic response. This kind of hemodynamic arousal can be detrimental to many patients and can be avoided by conducting sevoflurane mask induction with unassisted spontaneous breathing.     

Comparison of sevoflurane with propofol for laryngeal mask airway insertion in adults

We performed a prospective, randomized, controlled trial to compare the quality and ease of laryngeal mask airway (LMA) insertion after either rapid inhaled sevoflurane or i.v. propofol induction of anesthesia. Seventy-six unpremedicated ASA physical status I or II patients were anesthetized with either a single vital capacity breath of sevoflurane 8% or i.v. propofol 3 mg/kg, which produced equally rapid loss of consciousness (40.5 +/- 13.9 vs 37.7 +/- 9.9 s; P > 0.05). The LMA was inserted more rapidly in patients in the propofol group (74 +/- 29 vs 127 +/- 35 s; P < 0.01) and required fewer attempts (1.2 vs 1.6; P < 0.05) than the sevoflurane group. There was a greater incidence of initially impossible mouth opening in the sevoflurane group (45% vs 21%; P < 0.05). Once mouth opening was possible, the degree of attenuation of laryngeal reflexes was similar. The overall incidence of complications related to LMA insertion, especially apnea (32% vs 0%; P < 0.01), was more frequent in the propofol group (82% vs 26%; P < 0.01). There were four failures of LMA insertion in the propofol group and none in the sevoflurane group. Both groups had stable hemodynamic profiles and good patient satisfaction. We conclude that sevoflurane vital capacity breath induction compares favorably with i.v. propofol induction for LMA insertion in adults. However, prolonged jaw tightness after the sevoflurane induction of anesthesia may delay LMA insertion. Implications: In this randomized, controlled trial, we compared the ease of insertion of the laryngeal mask airway in adults after induction of anesthesia with either a sevoflurane vital capacity breath technique or propofol i.v.. We conclude that sevoflurane compares favorably with propofol, although prolonged jaw tightness may delay laryngeal mask airway insertion.     

The influence of additional nitrous oxide during rapid anesthetic induction with sevoflurane

In this study, a vital capacity rapid inhalation induction technique was used, and 4.5% sevoflurane in 100% oxygen and with 66% nitrous oxide in oxygen were compared. Each anesthetic gas was used on a group of 17 unpre-medicated volunteers. The induction time of sevoflurane in nitrous oxide with oxygen and sevoflurane in oxygen were 55±10 s and 81±22 s (SD), respectively, (P<0.05). Notable cardiovascular instability was not observed in either group. Serious complications such as laryngospasm, breath holding, and excessive salivation were not observed in either group. In conclusion, the addition of nitrous oxide to sevoflurane in oxygen is a useful technique because there were no increases in complications during the accelerated rapidity of induction.     

七氟醚麻醉诱导在患儿全身麻醉中的应用

目的 观察七氟醚麻醉诱导与氯胺酮麻醉诱导在患儿全身麻醉中的应用.方法 选择30例3～7岁的患儿,随机均分为七氟醚组和氯胺酮组.观察两组诱导时间、苏醒时间、麻醉费用以及对循环、呼吸功能的影响.结果 七氟醚组诱导时间、苏醒时间短于氯胺酮组(P<0.01);七氟醚组血流动力学变化较氯胺酮组小(P<0.05);两组的呼吸抑制作用都较轻;七氟醚组入室时SpO<,2>低于氯胺酮组(P<0.05),但在可以接受的范围内.两组患儿的麻醉费用差异无统计学意义.结论 七氟醚麻醉诱导起效快,苏醒快,对循环呼吸影响小,手术室停留时问短,麻醉费用低廉,易于推广.     

Recovery characteristics of sevoflurane- or propofol-based anaesthesia for day-care surgery

Background: Sevoflurane has a low blood-gas partition coefficient resulting in a rapid recovery. Few studies have examined the maintenance and recovery characteristics of sevoflurane compared with propofol in a standardized outpatient population. Methods: The study was a multicentre study performed in 10 centres. One hundred and sixty-nine elective outpatients due for knee-arthroscopy received 100 mg diclofenac rectally as pain prophylaxis prior to induction of general anaesthesia with fentanyl 1.0–1.5 μg/kg+propofol 2.0–2.5 mg/kg iv. Anaesthesia was maintained with 60% nitrous oxide in oxygen through a laryngeal mask and continuous administration of either: sevoflurane (group S) or propofol infusion (group P) in order to maintain stable haemodynamics. Data of postoperative function and side-effects were collected in a double-blind design, including a patient interview after 24 h. Results: The sevoflurane patients had a significantly faster emergence from anaesthesia, with response to commands at 6.9±0.4 min versus 8.2±0.4 min in the propofol group (P < 0.05, mean±SD). At 15 min after surgery, group S had a better score in the digit symbol substitution test and felt less confused in a visual analogue scale test compared with group P (P<0.05). Peroperative bradycardia, nausea and vomiting and late postoperative dizziness were more common in group S. In the sevoflurane group, 32% had nausea or vomiting in the 24 h observation period compared with 18% for propofol (P < 0.05). There was no difference between group S and group P in postoperative pain, eligibility for recovery room discharge (75±12 versus 70±11 min) or home-readiness (155±12 versus 143±11 min). Conclusion: Maintenance of anaesthesia with sevoflurane results in a more rapid emergence, but a higher incidence of nausea and vomiting compared with propofol. The side-effects were minor in our study, and did not result in any difference in time to discharge from the recovery ward or the hospital.     

Cortisol levels during enflurane anesthesia in man

Serum cortisol levels were determined in 44 patients who underwent hysterectomy under enflurane or under halothane anesthesia by means of a radioimmunoassay technique. Of the 44 patients, in 21 anesthesia was maintained by enflurane and d-tubocurarine and 23 patients maintenance of anesthesia was carried out by halothane and d-tubocurarine. Blood samples for serum cortisol estimations were obtained from each patient before induction of anesthesia, 10 min. after induction, 10 min. after skin incision, at the end of the operation and in the ward on the fourth postoperative day. Cortisol levels increased in both groups at the end of the operation with a significantly higher mean value in the enflurane group (p less than 0.05) compared to that of the halothane group.     

人参皂苷Rg1对七氟醚麻醉所致幼鼠远期认知功能障碍的保护作用及机制

目的 观察人参皂苷Rg1(ginsenoside Rg1,Rg1)对七氟醚麻醉所致幼鼠远期认知功能障碍的改善作用及其机制.方法 72只新生6日龄C57BL/6J小鼠采用随机数字表法分为4组(每组18只):对照+生理盐水组(Con+NS组)、对照+Rg1组(Con+Rg1组)、七氟醚麻醉+生理盐水组(Sev+NS组)、七氟醚麻醉+Rg1组(Sev+Rg1组).Sev+NS组和Sev+Rg1组分别在出生后6~8 d每天接受3%七氟醚+100%氧气麻醉2 h,Con+NS组及Con+Rg1组小鼠在相应日龄吸入相同时间100%氧气.麻醉前30 min各组分别进行生理盐水(1 ml·kg-1·d-1)或Rg1(10 mg·kg-1·d-1)腹腔注射.各组取12只小鼠于第31~37天行水迷宫实验,行为学测试结束后取海马行Western blot检测突触后密度蛋白95(postsynaptic density 95,PSD-95)含量,其余小鼠(每组6只)于第8天麻醉手术后即刻行ELISA检测海马ATP及活性氧簇(reactive oxygen species,ROS)水平.结果 与Con+NS组比较,Sev+NS组第35~37天水迷宫实验逃避潜伏期[(35.6±4.5)、(28.3±3.5)、(21.9±2.4)s比(45.7±8.1)、(41.9±8.8)、(35.1±12.4)s]明显延长(P<0.05),平台次数[4(8,2)次比2(6,0)次]明显减少(P<0.05),PSD-95水平[(100±6)%比(77±6)%]明显降低(P<0.05),ROS水平[(100±4)%比(121±11)%]明显升高(P<0.05),ATP水平[(100±6)%比(82±7)%]明显降低(P<0.05).Sev+Rg1组与Con+Rg1组比较,31~37 d水迷宫实验逃避潜伏期、 穿越平台次数、PSD-95水平、ROS水平及ATP水平差异均无统计学意义(P>0.05).结论 Rg1可改善七氟醚麻醉所致的幼鼠远期认知功能障碍,其机制可能与抑制氧化应激保护线粒体功能并增强突触可塑性有关.     

Propofol 2 mg/kg is superior to propofol 1 mg/kg for tracheal intubation in children during sevoflurane induction

Background: Propofol has been used to facilitate tracheal intubation within a short time of sevoflurane induction without a muscle relaxant in children. We compared as the primary outcome the incidence of excellent intubating conditions after 8% sevoflurane and propofol 1 or 2 mg/kg. Methods: One hundred and four patients (2–7 years) were randomly assigned to receive propofol 1 mg/kg in group SP1 (n=53) or propofol 2 mg/kg in group SP2 (n=51) after inhalation induction using sevoflurane 8% in oxygen. Forty‐five seconds after propofol and controlled ventilation, intubating conditions were assessed using a four‐point scoring system based on ease of laryngoscopy, vocal cords position, coughing, jaw relaxation and limb movement. Heart rate and systolic blood pressure were measured as baseline, after sevoflurane induction, propofol, intubation and at 2 and 5 min following intubation. Results: Three patients in group SP1 were excluded from analysis. Time from sevoflurane induction to intubation (248.9±71.3 s in group SP1 vs. 230.9±61.3 s in group SP2) and endtidal sevoflurane before intubation (5.6±1.6% in group SP1 vs. 5.2±1.5% in group SP2) did not differ between the two groups. The incidence of excellent intubating conditions was significantly higher in group SP2 compared with group SP1 [47/51 (92%) vs. 28/50 (56%)]. The incidence of acceptable intubating conditions was significantly higher in group SP2 compared with group SP1 [48/51 (94%) vs. 35/50 (70%)]. No hemodynamic difference was noted at any time point between the two groups. Conclusion: Propofol 2 mg/kg during 8% sevoflurane induction resulted in a higher proportion of excellent intubating conditions compared with propofol 1 mg/kg.     

The effects of sevoflurane, halothane, enflurane, and isoflurane on hepatic blood flow and oxygenation in chronically instrumented greyhound dogs.

Inhalational anesthetics produce differential effects on hepatic blood flow and oxygenation that may impact hepatocellular function and drug clearance. In this investigation, the effects of sevoflurane on hepatic blood flow and oxygenation were compared with those of enflurane, halothane, and isoflurane in ten chronically instrumented greyhound dogs. Each dog randomly received enflurane, halothane, isoflurane, and sevoflurane, each at 1.0, 1.5, and 2.0 MAC concentrations. Mean arterial blood pressure and cardiac output decreased in a dose-dependent fashion during all four anesthetics studied. Heart rate increased compared to control during enflurane, isoflurane, and sevoflurane anesthesia and did not change during halothane anesthesia. Hepatic arterial blood flow and portal venous blood flow were measured by chronically implanted electromagnetic flow probes. Hepatic O2 delivery and consumption were calculated after hepatic arterial, portal venous, and hepatic venous blood gas analysis. Hepatic arterial blood flow was maintained with sevoflurane and isoflurane. Halothane and enflurane reduced hepatic arterial blood flow during all anesthetic levels compared to control (P less than 0.05), with marked reductions occurring with 1.5 and 2.0 MAC halothane concomitant with an increase in hepatic arterial vascular resistance. Portal venous blood flow was reduced with isoflurane and sevoflurane at 1.5 and 2.0 MAC. A somewhat greater reduction in portal venous blood flow occurred during 2.0 MAC sevoflurane (P less than 0.05 compared to control and 1.0 MAC values for sevoflurane). Enflurane reduced portal venous blood flow at 1.0, 1.5, and 2.0 MAC compared to control. Halothane produced the greatest reduction in portal venous blood flow (P less than 0.05 compared to sevoflurane).(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of sufentanil and enflurane-nitrous oxide anesthesia for myocardial revascularization

This study compared the stress response in patients with coronary artery disease undergoing myocardial revascularization anesthetized with either sufentanil and oxygen or enflurane-nitrous oxide and oxygen. Throughout induction and maintenance of anesthesia, and while the patients were in the intensive care unit, hemodynamics plus plasma catecholamine, sufentanil, and enflurane concentrations were recorded and compared. Three groups were studied: sufentanil, 15 micrograms/kg at induction; sufentanil, 15 micrograms/kg at induction plus 10 micrograms/kg on initiation of cardiopulmonary bypass (CPB); and enflurane anesthesia. Hemodynamics were remarkably stable in all groups but required considerable fine tuning when enflurane was administered. The "stress" of CPB was blunted by the additional dose of sufentanil, as well as by enflurane. This was reflected in those patients receiving the extra sufentanil or enflurane by less severe increases in their epinephrine or norepinephrine concentrations and by less frequent use of sodium nitroprusside to control mean arterial pressure compared to the group of patients given the lower-dose sufentanil. This study suggests that higher blood levels of sufentanil can attenuate, but not eliminate, the stress response to CPB, as can enflurane, and that both the narcotic and inhalation anesthetic techniques for patients with coronary artery disease were quite satisfactory.