The effect of sevoflurane and isoflurane anesthesia on interictal spike activity among patients with refractory epilepsy.

The electrophysiologic effects of sevoflurane are not well characterized in humans. Among patients with refractory epilepsy, this study compared 1) electroencephalographic (EEG) interictal spike activity during wakefulness and sevoflurane anesthesia, and 2) electrocorticographically (ECoG) recorded interictal spike activity during sevoflurane and isoflurane anesthesia. We studied 12 patients undergoing insertion of subdural electrodes. Before commencing anesthesia, awake (baseline) EEG recordings were obtained. After inhaled induction, EEG interictal spike activity was evaluated during stable, normocapnic, and hypocapnic (Paco2 = 28-30 mm Hg), sevoflurane anesthesia administered at 1.5 times the minimum alveolar anesthetic concentration (1.5 MAC). Immediately after surgery, ECoG recordings were obtained from subdural electrodes during 1) 1.5 MAC isoflurane, 2) 0.3 MAC isoflurane, and 3) 1.5 MAC sevoflurane anesthesia. EEG spike frequency increased in all patients during sevoflurane anesthesia compared with awake recordings (P = 0.002). Compared with 0.3 MAC isoflurane anesthesia, ECoG interictal spike frequency was higher in all patients during 1.5 MAC sevoflurane anesthesia (P = 0.004) and in 8 of 10 patients during 1.5 MAC isoflurane anesthesia (P = 0.016). Under sufficiently rigorous conditions, both sevoflurane and isoflurane can provoke interictal spike activity at near burst-suppression doses. This property is more prominent with sevoflurane than isoflurane. IMPLICATIONS: The results of this study suggest that the capacity to modulate neuroexcitability is a dose-dependent feature of volatile anesthetics that is manifested most prominently at near burst-suppression doses (i.e., 1.5 times the minimum alveolar anesthetic concentration) and is minimal or absent at low doses.     

Emergence agitation after sevoflurane versus propofol in pediatric patients

Sevoflurane may be associated with a high incidence of emergence agitation in preschool children. We tested the hypothesis that maintenance of anesthesia with propofol after sevoflurane induction would reduce the incidence of this excitatory behavior compared with continuing sevoflurane for maintenance. We conducted a randomized, single-blinded, two-period, cross-over study in 16 preschool age children undergoing repeated brief general anesthetics for eye examination. After sevoflurane induction, patients were randomly assigned to receive either sevoflurane or propofol anesthesia for maintenance. The alternative anesthetic was used for the maintenance of anesthesia on the second occasion. We compared the speed and quality of recovery characteristics of these anesthetics, as well as, overall parent satisfaction with anesthesia. Eight patients first received sevoflurane and the remaining eight patients first received propofol. Of the patients who received sevoflurane for the maintenance of anesthesia, 38% developed emergence agitation. In contrast, none developed emergence agitation when propofol was administered for maintenance of anesthesia. Despite emergence agitation, sevoflurane provided a shorter postanesthesia care unit stay than propofol. Parent satisfaction with anesthesia was greater with propofol than with sevoflurane. IMPLICATIONS: In this cross-over study, we observed the incidence of emergence agitation with sevoflurane (38%) was significantly greater than with propofol (0%) in premedicated, preschool-aged children undergoing minor noninvasive surgery.     

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.     

The effect of halothane or sevoflurane anesthesia on the extracellular concentration of dopamine and its metabolites examined by in vivo microdialysis techniques

BACKGROUND: Volatile anesthetics induce changes in the extracellular concentration of dopamine (DA) metabolites in the rat striatum and their metabolism might be modified in different manners by different anesthetics. Although, we have studied DA metabolism during anesthesia using in vivo microdialysis techniques, time dimensional changes were not assessed concerning the difference between anesthetics. In the current investigation, the rats were anesthetized with halothane or sevoflurane, which has different blood solubility, and investigated the effect of anesthetics and time-related development on DA metabolism. METHODS: The rats were implanted with a microdialysis probe in the striatum and perfusate was introduced to HPLC every 20 min. Anesthesia was induced with halothane or sevoflurane for 20 or 60 min, and methamphetamine 2 mg x kg(-1) was administered during or after inhalation. RESULTS: Both anesthetic agents increased the concentration of DA metabolites, and dose and time dependency was more obvious with sevoflurane than with halothane. The increase of metabolites was prolonged after halothane anesthesia (20 min), but the effect of methamphetamine administered immediately after anesthesia on DA release was not enhanced by halothane anesthesia. Sevoflurane, not halothane anesthesia, antagonized methamphetamine-induced decrease of metabolites. CONCLUSIONS: Not only the difference of blood solubility between halothane and sevoflurane and anesthetic effect of time dependency, but also another pharmacological property affects DA metabolism, including the change in the activity of dopamine transporter during inhalation of anesthetics.     

地氟烷与七氟烷在门诊手术全身麻醉维持中的对比研究：对苏醒早晚期及围手术期咳嗽的影响

背景目前地氧垸已经用于门诊全身麻醉手术的维持阶段,其相对于七氖烷在围手术期的优略性尚存争议。尽管各研究一致指出,地氟烷比七氟烷苏醒更快,但这种差异对苏醒晚期的影响却未有明确报道。并且,地氟烷与七氟烷相比,对咳嗽发生率的影响也存在争议。方法本研究中纳入了130例在全身麻醉下行浅表门诊手术的患者,随机分为2组。所有患者都静脉注射丙泊酚2mg/kg诱导,置入喉罩,采用1％-3％的七氟烷或3％-8％的地氟炕维持麻醉,吸入混合空气或氧气。调节吸入麻醉药的浓度,维持血流动力学稳定,并维持脑电双频谱指数（BIS）于50—60。并用局部浸润和静脉注射酮洛酸30mg镇痛。在手术结束时给予预防性止吐药物,包括昂丹司琼4mg、地塞米松4mg及甲氧氨普胺10mg。评估标准包括睁眼恢复时间,对指令做出反应的时间,定向力恢复的时间,14分快通道评分,首次进食时间,能坐立,可站立,独立行走及出院时间。手术后早期及离院后24小时内,记录患者对于麻醉的满意度,手术后第1天恢复正常活动的能力,不良反应的发生（如咳嗽、意向性运动、氧饱和度〈90％、咽痛及手术后恶心、呕吐）,手术后镇痛药及止吐药的使用情况。结果2组患者的流行病学资料相近。尽管围手术期地氯烷组咳嗽的总体发生率高于七氟烷组（分别为60％和32％,P〈0．05）,然而在真正应用吸入麻醉药期间（即麻醉维持中）,咳嗽发生率的组间差异无显著性。地氧烷组患者苏醒较快,但两组所有患者在离开手术室之前都达到了快通道恢复标准（快通道评分≥12）。此外,离院时间（七氟炕组90±31分钟,地氟炕组98±5分钟）及手术后第1天能恢复正常活动的患者比率（七氟烷48％,地氟炕60％）,在两组间的差异无显著性。结论用地氧烷进行维持全身麻醉具有苏醒迅速、咳嗽发生率高的特点。尽管与七氟烷相比,地氟炕在麻醉早期恢复较快,但两组晚期恢复的差异无显著性。两种吸入麻醉药都适用于门诊手术的麻醉。     

Recovery characteristics and post-operative delirium after long-duration laparoscope-assisted surgery in elderly patients: propofol-based vs. sevoflurane-based anesthesia

BACKGROUND: Post-operative mental dysfunction may be an important problem in elderly patients. This study was designed to compare the effects of propofol and sevoflurane anesthesia on recovery characteristics and the incidence of post-operative delirium (POD) in long-duration laparoscopic surgery for elderly patients. METHODS: Fifty ASA physical status I-II patients over the age of 65 scheduled for laparoscopic surgery lasting 3 h or more randomly received propofol (group P, n = 25) or sevoflurane (group S, n = 25) for both induction and maintenance of general anesthesia. Both groups were combined with continuous perioperative epidural analgesia. The level of primary anesthetics was adjusted to maintain changes in mean arterial pressure within 20% of the pre-anesthetic values. The emergence times from anesthesia (eye opening, extubation, response to command, and orientation) were recorded, and the occurrence of POD was assessed by the delirium rating scale (DRS) during the first 3 days after surgery. All patients received oxygen and continuous epidural analgesia postoperatively. RESULTS: Immediate emergence, i.e. eye opening and extubation was significantly faster after sevoflurane (P < 0.05). There was no significant difference between the incidences of POD in the two groups during the first 3 days after surgery. The scores for DRS on day 2 and 3 after surgery, however, were significantly higher in group P than in group S (P < 0.01). CONCLUSION: Sevoflurane may be preferable to propofol for general anesthesia in combination with epidural analgesia with respect to less effect on mental function during the early postoperative period for long-duration laparoscopic surgery in elderly patients.     

The effect of sevoflurane and isoflurane on striatal dopamine of awake freely moving rats observed in an in vivo microdialysis study]

We investigated the effect of sevoflurane and isoflurane on the level of interstitial dopamine of in vivo awake, free moving rats brain striatum using microdialysis techniques. Rats were implanted with a microdialysis probe to the right striatum of the brain and administered with 1.2 MAC of each volatile anesthetics for 1 hour, and dialysates from the probe were determined every 20 minutes. Both anesthetics reduced the amount of dopamine derived from dialysate, and increased the efflux of dopamine with pretreatment of nomifensine 10mg. kg-1 i.p. The change of metabolites of dopamine during anesthesia was increased. No significant difference was found between sevoflurane and isoflurane. We hypothesized that these anesthetics might have special actions on interactions between metabolism and re-uptake of dopamine in rats striatum during anesthesia.     

Recovery from Sevoflurane Anesthesia: A Comparison to Isoflurane and Propofol Anesthesia

Backgroud: Sevoflurane has a lower blood:gas partition coefficient than isoflurane, which may cause a more rapid recovery from anesthesia; it also might cause faster emergence times than for propofol-based anesthesia. We evaluated a database that included recovery endpoints from controlled, randomized, prospective studies sponsored by Abbott Laboratories that compared sevoflurane to isoflurane or propofol when extubation was planned immediately after completion of elective surgery in adult patients.

Methods: Sevoflurane was compared to isoflurane in eight studies (N = 2,008) and to propofol in three studies (N = 436). Analysis of variance was applied using least squares method mean values to calculate the pooled mean difference in recovery endpoints between primary anesthetics. The effects of patient age and case duration also were determined.

Results: Sevoflurane resulted in statistically significant shorter times to emergence (-3.3 min), response to command (-3.1 min), orientation (-4.0 min) and first analgesic (-8.9 min) but not time to eligibility for discharge (-1.7 min) compared to isoflurane (mean difference). Times to recovery endpoints increased with increasing case duration with isoflurane but not with sevoflurane (patients receiving isoflurane took 4-5 min more to emerge and respond to commands and 8.6 min more to achieve orientation during cases longer than 3 hr in duration than those receiving sevoflurane). Patients older than 65 yr had longer times to orientation, but within any age group, orientation was always faster after sevoflurane. There were no differences in recovery times between sevoflurane and propofol.     

Effects of spinal anesthesia on the electroencephalogram in the elderly

Elderly patients frequently fall asleep during spinal anesthesia without sedatives. We investigated effects of spinal anesthesia on electroencephalogram (EEG) in elderly patients. Elderly patients were randomly assigned. Patients in Group C (n = 8) received an epidural catheter with no anesthetics as control; patients in Group S (n = 8) received spinal anesthesia. Subsequently, processed EEG data were monitored for 5 minutes. Spinal anesthesia induced significant decreases in 90% spectral edge frequency (SEF90), whereas the control group had no change in SEF90. It was concluded that spinal anesthesia induces decreased SEF90, indicating suppressed cortical activity in early phases of sensory blockade in elderly patients.     

The potentialities of EEG analysis using the Lifescan in anesthesiology]

In 87 patients a new computerized EEG monitor was used in clinical anesthesia. Following aperiodic analysis, the Lifescan shows the computerized EEG in a striking color visualization allowing recognition of changes in the course of the EEG and of interhemispheric differences. The computerized EEG can be read after a brief training period. The changes caused by different clinical situations are visualized in detail. Different changes were observed with the anesthetics used. During induction with thiopentone a sudden increase in activity was obvious. During a lighter level of anesthesia with thiopentone beta activity was easily recognizable. During induction with high-dose fentanyl frequency was slowed over a long period and activity was increased. The monitor shows the changes in the lower frequency range in detail. A bimodal pattern occurred with a higher dosage of enflurane. During lightening of anesthesia with enflurane a typical pattern indicated return to consciousness. When nitrous oxide was administered during anesthesia with halothane, and to a lesser degree during anesthesia with enflurane or isoflurane, remarkable slowing and decrease in activity occurred. The monitor allowed detailed recognition of the different patterns obtained with the various anesthetics. In some cases it was possible to say what dosage of the anesthetic used had been given or what depth of anesthesia had been achieved. The effect of combined anesthesia, however, was difficult to judge. In carotid artery surgery a quick unilateral decrease in activity and slowing of frequency indicated cerebral ischemia and quickly disappeared after insertion of a shunt. This change was particularly obvious with the new monitor.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects on the lower esophageal sphincter of sevoflurane induction and increased intra-abdominal pressure during laparoscopy

BACKGROUND: Today sevoflurane is one of the most frequently used volatile anesthetics. The speed of induction can approach that of intravenous anesthetics, and case reports using sevoflurane induction for emergency anesthesia have been published. The purpose of this study in laparoscopic cholecystectomy patients was to investigate the effects of sevoflurane during inhalation induction on the lower esophageal sphincter pressure (LESP) and barrier pressure (BrP). The effects on lower esophageal sphincter (LES) and BrP of increased intra-abdominal pressure during laparoscopy were also evaluated. METHODS: We recorded LESP and BrP in nine patients using a Dent sleeve device. Recordings were made before and after inhalation induction of anesthesia with 8% sevoflurane, as well as before and after insufflation of CO(2) into the abdomen. RESULTS: After induction with sevoflurane, LESP (P= 0.039) and BrP (P= 0.020) decreased. Nevertheless, BrP was kept positive in all patients. Insufflation of CO(2) into the abdomen during laparoscopy induced a significant increase in LESP (P= 0.02) and gastric pressure (P= 0.004). However, there was no significant change in BrP (P= 0.66); it increased in four patients and decreased in five. CONCLUSION: BrP was kept positive in all patients after induction of anesthesia. Therefore, we believe that in combination with cricoid pressure, inhalation induction with sevoflurane might be a safe choice. As the adaptive increase in LESP during laparoscopy was not enough to retain a barrier pressure in all patients, it is important to be aware of the risk of regurgitation throughout the anesthesia.     

The effect of small dose fentanyl on the emergence characteristics of pediatric patients after sevoflurane anesthesia without surgery

We designed this study to measure the effect of a small dose of IV fentanyl on the emergence characteristics of pediatric patients undergoing sevoflurane anesthesia without any surgical intervention. Thirty-two ASA physical status I or II pediatric outpatients receiving sevoflurane anesthesia for magnetic resonance imaging scans were enrolled and assigned in a random and double-blinded manner to receive either placebo (saline) or 1 micro g/kg IV fentanyl 10 min before discontinuation of their anesthetic. The primary outcome measure was the percentage of patients with emergence agitation. We also evaluated the duration of agitation and time to meet hospital discharge criteria. Patients who received fentanyl had a decreased incidence of agitation (12% versus 56%) when compared with placebo. There was no significant difference in time to meet hospital discharge criteria. We conclude that the addition of a small dose of fentanyl to inhaled sevoflurane anesthesia decreases the incidence of emergence agitation independent of pain control effects. IMPLICATIONS: The addition of a small dose of fentanyl given to patients undergoing nonsurgical sevoflurane anesthesia resulted in a significant decrease in emergence agitation in a prospective, randomized, and controlled trial involving pediatric patients.     

数量化脑电图监测手术切以时的镇痛强度

为评价数量化脑电图（ＥＥＧ）反映镇痛强度的准确性,作者对６５例ＡＳＡＩ级腹部手术患者,快速静脉诱导气管插管后,机械通气。麻醉维持“：Ｏ２－Ｎ２Ｏ（１：２）－七氟醚吸入,切皮带不追加长效肌松药,监测ＴＯＦ。随机分为三组：七氟醚呼气末浓度分别为１％（Ｉ组）、１．５％、２％,至少维持１５ｍｉｎ。应用数量化脑电图监测手术切皮前、后３分钟脑电图和平均动动脉压（ＭＡＰ）、心率（ＨＲ）的变化以及患者的切皮反应改     

Desflurane anesthesia after sevoflurane inhaled induction reduces severity of emergence agitation in children undergoing minor ear-nose-throat surgery compared with sevoflurane induction and maintenance

Emergence agitation may occur after general anesthesia with volatile anesthetics in children. We designed this study to examine the emergence behavior of children undergoing ear-nose-throat surgery after sevoflurane induction and desflurane maintenance versus both sevoflurane induction and maintenance using a recently published Pediatric Anesthesia Emergence Delirium (PAED) scale. In 38 premedicated children aged 12 mo to 7 yr mask induction with sevoflurane was performed and they were randomly assigned to receive either sevoflurane (n = 19) or desflurane (n = 19) for maintenance of general anesthesia. Time to tracheal extubation, modified Aldrete score, emergence behavior, recovery complications, and pain scores were assessed. The PAED scale showed a significant advantage for desflurane (6 [0-15] versus 12 [2-20], maximum total score of 20 for severe agitation). Time to extubation was significantly shorter with desflurane than with sevoflurane (5.4 +/- 1.4 versus 13.4 +/- 1.8 min). The modified Aldrete score on arrival in the postanesthesia care unit (PACU) was significantly lower in children receiving sevoflurane for maintenance. Time to discharge from PACU to normal ward and the incidence of adverse effects were not significantly different between the groups. In conclusion, the use of desflurane for maintenance of anesthesia after sevoflurane induction in children is associated with less severe emergence agitation and faster emergence times.     

A rapid increase in the inspired concentration of desflurane is not associated with epileptiform encephalogram

The large inspired concentration of sevoflurane (S) during mask induction of anesthesia can induce epileptiform electroencephalogram (EEG) associated with tachycardia. Tachycardia is also seen when the concentration of desflurane (D) is abruptly increased. It is not known whether this is associated with epileptiform EEG similar to S. We studied EEG and heart rate (HR) during rapidly increased concentrations of S or D in 31 females during the postintubation period of anesthesia. Anesthesia was induced with propofol and remifentanil, and the tracheas were intubated. Patients were randomized to receive either S or D in nitrous oxide-oxygen mixture after intubation, at a small dose first. After 10 min, S or D vaporizer was advanced to the highest reading of the vaporizer (7% for S, 18% for D) for 5 min. HR and EEG were recorded. Epileptiform EEG activity was recorded in eight of 15 patients in group S and in none in group D (P < 0.05). HR increased in both groups. In group S, HR increased gradually and the highest HR value was 84 bpm at 5 min after the increase in sevoflurane concentration. In group D, HR increased to 93 bpm 2 min after the increase in desflurane concentration (no significant difference, S versus D). A rapid increase in the concentration of S frequently induces epileptiform EEG during normoventilation. Tachycardia during increasing concentrations of D is not associated with epileptiform EEG. IMPLICATIONS: A rapid increase in the concentration of sevoflurane induces epileptiform encephalogram (EEG) with tachycardia. A rapid increase in the concentration of desflurane also induces tachycardia but is not associated with epileptiform EEG.     

Laryngeal mask during emergence from anesthesia in intubated patients with asthmatic attack or ischemic heart disease

We report two patients in whom the presence of a tracheal tube induced asthmatic attack or hemodynamic instability and the laryngeal mask was useful during emergence from anesthesia. Case 1:A 24-year-old man with asthma was scheduled for reconstruction of an amputated finger. After induction of anesthesia and neuromuscular blockade, the trachea was intubated without complications. At the end of 9.5-h uneventful operation under anesthesia with sevoflurane, nitrous oxide and oxygen, inhalational anesthetics were turned off. During emergence from anesthesia, bucking with asthmatic attack occurred. Sevoflurane and theophilline resolved the attack, which recurred after termination of sevoflurane. Under deep anesthesia with sevoflurane, the laryngeal mask was placed, and then the tracheal tube removed without complications. The laryngeal mask was removed when the patient awoke uneventfully. Case 2: A 69-year-old man with a recent history of myocardial infarction was scheduled for skin grafting. After uneventful operation, sevoflurane and nitrous oxide were turned off. Multiple premature ventricular contractions (PVCs) with hypertension and tachycardia occurred, and necessitated the restart of sevoflurane. Under deep anesthesia, the laryngeal mask was inserted and the trachea extubated, and the patient regained consciousness without complications.     

Comparison of recovery profile after ambulatory anesthesia with propofol, isoflurane, sevoflurane and desflurane: a systematic review

In this systematic review we focused on postoperative recovery and complications using four different anesthetic techniques. The database MEDLINE was searched via PubMed (1966 to June 2002) using the search words "anesthesia" and with ambulatory surgical procedures limited to randomized controlled trials in adults (>19 yr), in the English language, and in humans. A second search strategy was used combining two of the words "propofol," "isoflurane," "sevoflurane," or "desflurane". Screening and data extraction produced 58 articles that were included in the final meta-analysis. No differences were found between propofol and isoflurane in early recovery. However, early recovery was faster with desflurane compared with propofol and isoflurane and with sevoflurane compared with isoflurane. A minor difference was found in home readiness between sevoflurane and isoflurane (5 min) but not among the other anesthetics. Nausea, vomiting, headache, and postdischarge nausea and vomiting incidence were in favor of propofol compared with isoflurane (P < 0.05). A larger number of patients in the inhaled anesthesia groups required antiemetics compared with the propofol group. We conclude that the differences in early recovery times among the different anesthetics were small and in favor of the inhaled anesthetics. The incidence of side effects, specifically postoperative nausea and vomiting, was less frequent with propofol. IMPLICATIONS: A systematic analysis of the literature comparing postoperative recovery after propofol, isoflurane, desflurane, and sevoflurane-based anesthesia in adults demonstrated that early recovery was faster in the desflurane and sevoflurane groups. The incidence of nausea and vomiting were less frequent with propofol.     

Electromyographic activity increases the bispectral index up to 98 during anesthesia

We report the patients who developed sudden unpredicted increases of bispectral index (BIS) value during sevoflurane and fentanyl anesthesia. After the epidural catheter placement, anesthesia was induced with propofol and fentanyl, and muscular relaxation was obtained by vecuronium for tracheal intubation. Anesthesia was maintained with 1-1.5% sevoflurane, intermittent administration of fentanyl and epidural infusion of ropivacaine. The nociceptive stimuli might be unchanged during the surgical procedure of reconstruction, but sudden increases of BIS value were found. At first, the BIS was decreased with small dose of supplemental anesthetics, but finally, it was up to 98 and the depth of anesthesia could not be assessed by BIS value. Because slight shivering was found in the patient immediately after emergence, electromyographic activity might have falsely elevated the BIS excessively. No clear recall or explicit memory during operation was observed after anesthesia, but anesthesiologists might better pay much more attentions to unpredictable changes of anesthetic depth during anesthesia.     

Effects of sevoflurane compared with those of isoflurane on arterial oxygenation and hemodynamics during one-lung ventilation

Purpose. This study was designed to compare the effects of sevoflurane and isoflurane on Pao₂ and hemodynamic variables during one-lung ventilation (OLV) in surgical patients. Methods. Twelve patients undergoing an esophageal procedure with thoracotomy for which a long period of OLV was required were studied using a randomized crossover design. Group 1 received 1.2% isoflurane from the induction of anesthesia until 30 min after starting OLV, and then received 1.7% sevoflurane during the remaining period. In group 2, the order of the anesthetics was reversed. All experimental procedures were performed in the left lateral decubitus position with the chest opened. Arterial and mixed venous blood gases and cardiac outputs were analyzed immediately before OLV, during OLV, and after resumption of two-lung ventilation (TLV). Results. OLV produced lower Pao₂ and higher venous admixture (Q _s/Q _t) values than TLV. However, there was no significant difference between sevoflurane and isoflurane in Pao₂ or Q _s/Q _t during OLV. Other hemodynamic variables except for Pvˉo₂ showed no significant differences between the anesthetics. Conclusion. The effects of sevoflurane on Pao₂ and the hemodynamic variables were similar to those of isoflurane during TLV and OLV in the lateral decubitus position. Received for publication on January 29, 1999; accepted on August 6, 1999     

The effects of sevoflurane and desflurane on the hemodynamics and respiratory functions in laparoscopic sleeve gastrectomy

Study objectivesSleeve gastrectomy has been one of the most commonly performed bariatric surgery methods. The study aimed to compare the effects of 2 most commonly used inhalation anesthetics, sevoflurane and desflurane, on the peroperative hemodynamic alterations and postoperative respiratory functions in morbidly obese patients undergoing sleeve gastrectomy.DesignNonrandomized cohort.SettingsOperating room, postoperative period.PatientsEighty-four morbidly obese patients with a body mass index greater than 40 kg/m² who had scheduled to undergo sleeve gastrectomy operation were prospectively included in the study.InterventionsPatients were divided into 2 groups. The maintenance of inhalation anesthesia was performed by sevoflurane in 1 group (sevoflurane group) and desflurane (desflurane group) in the other group.MeasurementsDemographic features, peroperative hemodynamic alterations, and the results of preoperative and postoperative 24th hour respiratory function tests were recorded.ResultsThere was not any statistically significant difference between groups regarding age, sex, body mass index, anesthesia time, peroperative mean arterial pressure, arterial oxygen saturation, end-tidal carbon dioxide, and preoperative or postoperative forced expiratory volume 1/forced vital capacity ratios.ConclusionWe determined that both desflurane and sevoflurane provide similar intraoperative hemodynamic and early postoperative respiratory functions in morbidly obese patients in laparoscopic sleeve gastrectomy. Both agents can be regarded as alternatives for inhalation anesthetics in maintenance of anesthesia.