单肺通气期间七氟醚或丙泊酚对脑氧代谢的影响

目的观察单肺通气期间七氟醚或丙泊酚联合靶控持续输注瑞芬太尼对脑氧代谢的影响。方法选择行肺叶切除术患者30例,随机分为七氟醚组（S组）或丙泊酚组（P组）,每组各15例。麻醉诱导后,分别持续吸入七氟醚1%-2.5%或静脉持续泵入丙泊酚4-8 mg/（kg.h）。于双肺通气15 min（T1）,单肺通气15 min（T2）,单肺通气30 min（T3）,恢复双肺通气之后15min（T4）时点记录HR、MAP及BIS值,同时采集桡动脉、颈内静脉球血行血气分析,测定颈静脉球氧饱和度（SjvO2）,并计算脑动静氧含量差（AjvDO2）及COER值。结果两组在T2、T3时点的PaO2值较T1时点明显降低（P〈0.05）;S组各时点的SjvO2值、AjvDO2值、COER值与P组相应时点比较,无统计学差异（P〉0.05）。结论单肺通气过程中七氟醚与丙泊酚联合瑞芬太尼均能够达到满意麻醉效果,并保持脑氧供需平衡。     

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.     

七氟醚与丙泊酚在小儿斜视手术麻醉的应用效果观察

目的 探究在小儿斜视手术麻醉中采用七氟醚与丙泊酚的效果。方法 选取我院2021年10月-2023年 10月收治的72例斜视患儿为研究对象,采用随机数字表法分为对照组和观察组,各36例,对照组输注丙泊 酚,观察组吸入七氟醚,比较两组生命体征、麻醉恢复情况、躁动发生率。结果 两组DBP、SBP比较,差 异无统计学意义（P ＞0.05）;观察组T2、T3、T4、T5时刻HR高于对照组（P ＜0.05）;观察组PACU停留 时间、Steward达到4分时间长于对照组,自主呼吸恢复时间短于对照组（P ＜0.05）,拔除气管导管时间短 于对照组,差异无统计学意义（P＞0.05）;观察组麻醉诱导期、麻醉苏醒期躁动发生率高于对照组,但差 异无统计学意义（P＞0.05）。结论 在小儿斜视手术麻醉中使用七氟醚吸入的效果更好,能改善患儿生命 体征,加快自主呼吸恢复时间,值得临床应用。     

Cerebral Metabolism during Propofol Anesthesia in Humans Studied with Positron Emission Tomography

Background: Although the effects of propofol on cerebral metabolism have been studied in animals, these effects have yet to be directly examined in humans. Consequently, we used positron emission tomography (PET) to demonstrate in vivo the regional cerebral metabolic changes that occur in humans during propofol anesthesia.

Methods: Six volunteers each underwent two PET scans; one scan assessed awake-baseline metabolism, and the other assessed metabolism during anesthesia with a propofol infusion titrated to the point of unresponsiveness (mean rate + SD 7.8 + 1.5 mg *symbol* kg1 *symbol* h1). Scans were obtained using the18 fluorodeoxyglucose technique.

Results: Awake whole-brain glucose metabolic rates (GMR) averaged 29 + 8 micro moles *symbol* 100 g1 *symbol* min1 (mean plus/minus SD). Anesthetized whole-brain GMR averaged 13 + 4 micro moles *symbol* 100 g1 *symbol* min1 (paired t test, P < 0.007). GMR decreased in all measured areas during anesthesia. However, the decrease in GMR was not uniform. Cortical metabolism was depressed 58%, whereas subcortical metabolism was depressed 48% (P < 0.001). Marked differences within cortical regions also occurred. In the medial and subcortical regions, the largest percent decreases occurred in the left anterior cingulate and the inferior colliculus.     

Interaction of Propofol and Sevoflurane on Loss of Consciousness and Movement to Skin Incision during General Anesthesia

Background: Loss of consciousness (LOC) and immobility to surgical incision seem to be mediated at different levels of the central nervous system. Pharmacologic studies of hypnotic agents have previously focused on combinations of either volatile or intravenous anesthetics. This study examined the combination of inhaled sevoflurane and intravenous propofol at these two clinically relevant anesthetic end points.

Methods: Thirty-six elective surgical patients were initially enrolled. Conditions approximating steady state were obtained for sevoflurane and target-controlled propofol infusions. Patients were sequentially evaluated for LOC (loud voice plus mild prodding) and immobility to surgical incision. The study was designed using the Dixon up-down method.

Results: The observed propofol effect target with 50% response plus sevoflurane (0.46% end-tidal concentration) was 1.2 [mu]g/ml (95% confidence interval, 1.1-1.3 [mu]g/ml). It was not significantly different from that predicted (1.5 [mu]g/ml; 95% confidence interval, 1.2-1.7 [mu]g/ml) by simple additivity. The effective plasma concentration of propofol that suppressed movement to skin incision in 50% of patients was 5.4 [mu]g/ml (95% confidence interval, 4.8-6.0 [mu]g/ml) plus sevoflurane (0.86%) and was not significantly different from that predicted by additivity (5.4 [mu]g/ml; 95% confidence interval, 4.8-5.9 [mu]g/ml). Both analyses had adequate power (90%) to detect a significant change (+/-19 to 25%) from predicted value. Repeated-measures analysis of variance identified a Bispectral Index value of 70 as the break point between those who responded at LOC or did not.     

Antiemetic Activity of Propofol after Sevoflurane and Desflurane Anesthesia for Outpatient Laparoscopic Cholecystectomy

Background: Controversy exists regarding the effectiveness of propofol to prevent postoperative nausea and vomiting. This prospective, randomized, single-blinded study was designed to evaluate the antiemetic effectiveness of 0.5 mg/kg propofol when administered intravenously after sevoflurane- compared with desflurane-based anesthesia.

Methods: Two hundred fifty female outpatients undergoing laparoscopic cholecystectomy were assigned randomly to one of four treatment groups. All patients were induced with intravenous doses of 2 mg midazolam, 2 [micro sign]g/kg fentanyl, and 2 mg/kg propofol and maintained with either 1-4% sevoflurane (groups 1 and 2) or 2-8% desflurane (groups 3 and 4) in combination with 65% nitrous oxide in oxygen. At skin closure, patients in groups 1 and 3 were administered 5 ml intravenous saline, and patients in groups 2 and 4 were administered 0.5 mg/kg propofol intravenously. Recovery times were recorded from discontinuation of anesthesia to awakening, orientation, and readiness to be released home. Postoperative nausea and vomiting and requests for antiemetic rescue medication were evaluated during the first 24 h after surgery.

Results: Propofol, in an intravenous dose of 0.5 mg/kg, administered at the end of a sevoflurane-nitrous oxide or desflurane-nitrous oxide anesthetic prolonged the times to awakening and orientation by 40-80% and 25-30%, respectively. In group 2 (compared with groups 1, 3, and 4), the incidences of emesis (22% compared with 47%, 53%, and 47%) and requests for antiemetic rescue medication (19% compared with 42%, 50%, and 47%) within the first 6 h after surgery were significantly lower, and the time to home-readiness was significantly shorter in duration (216 +/- 50 min vs. 249 +/- 49 min, 260 +/- 88 min, and 254 +/- 72 min, respectively).     

Leukocyte-Endothelium Interaction in the Rat Mesenteric Microcirculation during Halothane or Sevoflurane Anesthesia

Background: The effects of inhalational anesthetics on the microcirculation, including leukocyte dynamics, remain to be clarified. The authors investigated halothane and sevoflurane anesthesia to determine if these agents evoked leukocyte adhesion through endothelial cell-dependent mechanisms involving such adhesion molecules.

Methods: Rats were anesthetized with halothane or sevoflurane in 100% oxygen and the lungs were mechanically ventilated. Leukocyte behavior in mesenteric venules was recorded through intravital video microscopy under monitoring microvascular hemodynamics. To examine the mechanisms for leukocyte rolling and adhesion, these studies were repeated after animals were pretreated with a monoclonal antibody against P-selectin (MAb PB1.3) or against intracellular adhesion molecule-1 (ICAM-1; MAb 1A29): P-selectin required for rolling of circulating leukocytes and ICAM-1 for firm adhesive interactions with leukocyte integrins.

Results: Under baseline anesthetic conditions (1 minimum alveolar concentration [MAC]), venular wall shear rates, an index of the disperse force on marginating leukocytes, in the sevoflurane-treated rats were about two times higher than those with halothane. At 2 MAC, halothane caused a marked arteriolar constriction and decreasing shear rates concurrent with an increasing density of venular leukocyte adhesion. Sevoflurane at 2 MAC induced leukocyte rolling and adhesion, which were attenuated by PB1.3 and 1A29, without alterations in the wall shear rates. Halothane-induced leukocyte adhesion was not prevented by PB1.3 but it was by 1A29.     

Electroencephalographic Bicoherence Is Sensitive to Noxious Stimuli during Isoflurane or Sevoflurane Anesthesia

Background: The authors previously reported changes in electroencephalographic bicoherence during isoflurane anesthesia combined with epidural anesthesia. Here, they examined the influence of noxious stimuli on electroencephalographic bicoherence as well as on the Bispectral Index (BIS) and the 95% spectral edge frequency (SEF95).

Methods: The authors enrolled 48 elective abdominal surgery patients (aged 22-77 years; American Society of Anesthesiologists physical status I or II). Raw electroencephalographic signals as well as BIS and SEF95 were recorded on a computer using a BIS(R) monitor (A-1050) and Bispectrum Analyzer (BSA) for BIS (the authors' original software). Using BSA for BIS, the authors evaluated the two peak heights of electroencephalographic bicoherence. Anesthesia was induced with 3 mg/kg thiopental and was maintained with, in air-oxygen, 1.0% isoflurane or 1.5% sevoflurane. After confirming the steady state, the authors recorded baseline values. In experiment 1, they administered 3 [mu]g/kg fentanyl 5 min after incision and investigated the changes in electroencephalographic derivatives at 5 and 10 min after incision. In experiment 2, they administered a similar dose of fentanyl 5 min before incision and investigated the changes in electroencephalographic derivatives immediately before and 5 min after incision.

Results: In experiment 1, after incision, both peak heights of electroencephalographic bicoherence significantly decreased but returned to control values after fentanyl administration. By contrast, after incision, BIS and SEF95 showed individual variability. In experiment 2, although fentanyl itself did not affect all electroencephalographic derivatives before incision, the variables remained unchanged after incision.     

Effects of Surgical Levels of Propofol and Sevoflurane Anesthesia on Cerebral Blood Flow in Healthy Subjects Studied with Positron Emission Tomography

Background: The authors report a positron emission tomography (PET) study on humans with parallel exploration of the dose-dependent effects of an intravenous (propofol) and a volatile (sevoflurane) anesthetic agent on regional cerebral blood flow (rCBF) using quantitative and relative (Statistical Parametric Mapping [SPM]) analysis.

Methods: Using H215O, rCBF was assessed in 16 healthy (American Society of Anesthesiologists [ASA] physical status I) volunteers awake and at three escalating drug concentrations: 1, 1.5, and 2 MAC/EC50, or specifically, at either 2, 3, and 4% end-tidal sevoflurane (n = 8), or 6, 9, and 12 [mu]g/ml plasma concentration of propofol (n = 8). Rocuronium was used for muscle relaxation.

Results: Both drugs decreased the bispectral index and blood pressure dose-dependently. Comparison between adjacent levels showed that sevoflurane initially (0 vs. 1 MAC) reduced absolute rCBF by 36-53% in all areas, then (1 vs. 1.5 MAC) increased rCBF in the frontal cortex, thalamus, and cerebellum (7-16%), and finally (1.5 vs. 2 MAC) caused a dual effect with a 23% frontal reduction and a 38% cerebellar increase. In the propofol group, flow was also initially reduced by 62-70%, with minor further effects. In the SPM analysis of the "awake to 1 MAC/EC50" step, both anesthetic agents reduced relative rCBF in the cuneus, precuneus, posterior limbic system, and the thalamus or midbrain; additionally, propofol reduced relative rCBF in the parietal and frontal cortices.     

A Randomized Crossover Comparison of the Effects of Propofol and Sevoflurane on Cerebral Hemodynamics during Carotid Endarterectomy

Background: Intravenous and inhalational anesthetic agents have differing effects on cerebral hemodynamics: Sevoflurane causes some vasodilation, whereas propofol does not. The authors hypothesized that these differences affect internal carotid artery pressure (ICAP) and the apparent zero flow pressure (critical closing pressure) during carotid endarterectomy. Vasodilation is expected to increase blood flow, reduce ICAP, and reduce apparent zero flow pressure.

Methods: In a randomized crossover study, the gradient between systemic arterial pressure and ICAP during carotid clamping was measured while changing between sevoflurane and propofol in 32 patients. Middle cerebral artery blood velocity, recorded by transcranial Doppler, and ICAP waveforms were analyzed to determine the apparent zero flow pressure.

Results: ICAP increased when changing from sevoflurane to propofol, causing the mean gradient between arterial pressure and ICAP to decrease by 10 mmHg (95% confidence interval, 6-14 mmHg; P < 0.0001). Changing from propofol to sevoflurane had the opposite effect: The pressure gradient increased by 5 mmHg (95% confidence interval, 2-7 mmHg; P = 0.002). Ipsilateral middle cerebral artery blood velocity decreased when changing from sevoflurane to propofol. Cerebral steal was detected in one patient after changing from propofol to sevoflurane. The apparent zero flow pressure (mean +/- SD) was 22 +/- 10 mmHg with sevoflurane and 30 +/- 14 mmHg with propofol (P < 0.01). There was incomplete drug crossover due to the limited duration of carotid clamping.     

Anesthesia Depth-dependent Features of Electroencephalographic Bicoherence Spectrum during Sevoflurane Anesthesia

Background: Growth pattern in the electroencephalographic bicoherence spectrum has recently been found to relate to anesthetic depth, and bicoherence analysis can reflect behavior of the thalamocortical reverberating network. Because the thalamocortical network is known to represent a key factor in sleep by anesthesia, systematic and qualitative bicoherence studies of different anesthetic depths is necessary throughout all pairs of frequencies.

Methods: Sixteen patients were anesthetized using sevoflurane (1, 2, or 3%) combined with remifentanil (0.4 [mu]g [middle dot] kg-1 [middle dot] min-1). Raw electroencephalographic signals were collected, and bicoherence was estimated in all pairs of frequencies, between 0.5 and 40 Hz at 0.5-Hz intervals.

Results: Sevoflurane (1%) caused two main peaks, spindle frequencies (11.0 +/- 1.2 Hz, 44.7 +/- 12.3% [bicoherence growth]) and [delta]-[theta] frequencies (5.4 +/- 0.5 Hz, 33.0 +/- 8.4%), in the diagonal line of biphasic bicoherence plots. High concentrations of sevoflurane (2% and 3%) shifted these peaks to 9.8 +/- 1.1 Hz, 46.2 +/- 12.7%; 8.7 +/- 1.3 Hz, 37.2 +/- 13.7% and 4.9 +/- 0.5 Hz, 44.6 +/- 7.0%; 4.3 +/- 0.8 Hz, 45.2 +/- 10.6%, respectively. Sevoflurane caused a third bicoherence peak to appear in another heterogeneous pair frequency (pair of [alpha] basal frequency and its double frequency), outside the diagonal line, which also inherited the behavior of [alpha] bicoherence peaks at different anesthetic depths.     

Local Cerebral Blood Flow, Local Cerebral Glucose Utilization, and Flow-Metabolism Coupling during Sevoflurane versus Isoflurane Anesthesia in Rats

Background: Compared to isoflurane, knowledge of local cerebral glucose utilization (LCGU) and local cerebral blood flow (LCBF) during sevoflurane anesthesia is limited.

Methods: LCGU, LCBF, and their overall means were measured in Sprague-Dawley rats (8 groups, n = 6 each) during sevoflurane and isoflurane anesthesia, 1 and 2 MAC, and in conscious control animals (2 groups, n = 6 each) using the autoradiographic 2-[(14) C]deoxy-D-glucose and 4-iodo-N-methyl-[(14) C]antipyrine methods.

Results: During anesthesia, mean cerebral glucose utilization was decreased: control, 56 +/- 5 [micro sign]mol [middle dot] 100 g-1 [middle dot]-1; 1 MAC isoflurane, 32 +/- 4 [micro sign]mol [middle dot] 100 g-1 [middle dot] min-1 (-43%); 1 MAC sevoflurane, 37 +/- 5 [micro sign]mol [middle dot] 100 g-1 [middle dot] min-1 (-34%); 2 MAC isoflurane, 23 +/- 3 [micro sign]mol [middle dot] 100 g-1 [middle dot] min-1 (-58%); 2 MAC sevoflurane, 23 +/- 5 [micro sign]mol [middle dot] 100 g-1 [middle dot] min-1 (-59%). Local analysis showed a reduction in LCGU in the majority of the 40 brain regions analyzed. Mean cerebral blood flow was increased as follows: control, 93 +/- 8 ml [middle dot] 100 g-1 [middle dot] min-1; 1 MAC isoflurane, 119 +/- 19 ml [middle dot] 100 g-1 [middle dot] min-1 (+28%); 1 MAC sevoflurane, 104 +/- 15 ml [middle dot] 100 g-1 [middle dot] min-1 (+12%); 2 MAC isoflurane, 149 +/- 17 ml [middle dot] 100 g-1 [middle dot] min-1 (+60%); 2 MAC sevoflurane, 118 +/- 21 ml [middle dot] 100 g-1 [middle dot] min-1 (+27%). LCBF was increased in most brain structures investigated. Correlation coefficients obtained for the relationship between LCGU and LCBF were as follows: control, 0.93; 1 MAC isoflurane, 0.89; 2 MAC isoflurane, 0.71; 1 MAC sevoflurane, 0.83; 2 MAC sevoflurane, 0.59).     

Compound A Concentrations during Sevoflurane Anesthesia in Children

Background: Sevoflurane is a new inhalation agent that should be useful for pediatric anesthesia. Sevoflurane undergoes degradation in the presence of carbon dioxide absorbents; however, quantification of the major degradation product (compound A) has not been evaluated during pediatric anesthesia. This study evaluates sevoflurane degradation compound concentrations during sevoflurane anesthesia using a 2-1 fresh gas flow and a circle system with carbon dioxide absorber in children with normal renal and hepatic function.

Methods: The concentrations of compound A were evaluated during sevoflurane anesthesia in children using fresh soda lime as the carbon dioxide absorbent. Nineteen patients aged 3 months-7 yr were anesthetized with sevoflurane (2.8% mean end-tidal concentration) using a total fresh gas flow of 2 l in a circle absorption system. Inspiratory and expiratory limb circuit gas samples were obtained at hourly intervals, and the samples were analyzed using a gas chromatography-flame ionization detection technique. Carbon dioxide absorbent temperatures were measured in the soda lime during anesthesia. Blood samples were obtained before and after anesthesia for hepatic and renal function studies. Venous blood samples were obtained before anesthesia, at the end of anesthesia, and 2 h after anesthesia for plasma inorganic fluoride ion concentration.

Results: The maximum inspiratory concentration of compound A was 5.4 +/-4.4 ppm (mean+/-SD), and the corresponding expiratory concentration was 3.7+/-2.7 ppm (mean+/-SD). The maximum inspiratory compound A concentration in any patient was 15 ppm. Mean concentrations of compound A peaked at intubation and remained stable, declining slightly after 120 min of anesthesia. The duration of anesthesia was 240+/-139 min (mean+/-SD). Maximum soda lime temperature ranged between 23.1 degrees C and 40.9 degrees C. There was a positive correlation between maximum absorbent temperature and maximum compound A concentration (r2 = 0.58), as well as between the child's body surface area and maximum compound A concentration (r2 = 0.59). Peak plasma inorganic fluoride ion concentration was 21.5 +/-6.1 micro mol/l. There were no clinically significant changes in hepatic or renal function studies performed 24 h postanesthesia.     

Changes in Plasma Creatinine Concentration after Cardiac Anesthesia with Isoflurane, Propofol, or Sevoflurane: A Randomized Clinical Trial

Background: Renal impairment often follows cardiac surgery. The authors investigated whether sevoflurane produces greater increases in plasma creatinine concentration than isoflurane or propofol after elective coronary artery surgery.

Methods: As part of maintenance anesthesia, including during cardiopulmonary bypass, patients were randomly allocated to receive one of three agents: isoflurane (n = 118), sevoflurane (n = 118), or propofol (n = 118). Fresh gas flows were 3 l/min. The preoperative plasma creatinine concentration was subtracted from the highest creatinine concentration in the first 3 postoperative days. A median maximum increase greater than 44 [mu]m (0.5 mg/dl) was regarded as clinically important. Data were analyzed on an intention-to-treat basis. Subgroup analyses were performed on per-protocol patients and those with preoperative renal impairment (creatinine concentration > 130 [mu]m [1.47 mg/dl] or urea > 7.7 mm [blood urea nitrogen, 21.6 mg/dl]).

Results: The differences between the groups were small, clinically unimportant, and not statistically significant for the primary analysis and subgroups. The proportions of patients with creatinine increases greater than 44 [mu]m were 15% in the isoflurane group, 17% in the sevoflurane group, and 11% in the propofol group (P = 0.45). The median increases were 8 [mu]m in the isoflurane group, 4 [mu]m in the sevoflurane group, and 6 [mu]m in the propofol group. The differences between the three median maximum increases were 1-4 [mu]m (P > 0.45). In the subgroup with preoperative renal impairment, the median increases were 10 [mu]m in the isoflurane group, 15 [mu]m in the sevoflurane group, and 5 [mu]m in the propofol group (P = 0.72).     

Recovery Profile, Costs, and Patient Satisfaction with Propofol and Sevoflurane for Fast-track Office-based Anesthesia

Background: Office-based surgery is becoming increasingly popular because of its cost-saving potential. Both propofol and sevoflurane are commonly used in the ambulatory setting because of their favorable recovery profiles. This clinical investigation was designed to compare the clinical effects, recovery characteristics, and cost-effectiveness of propofol and sevoflurane when used alone or in combination for office-based anesthesia.

Methods: One hundred four outpatients undergoing superficial surgical procedures at an office-based surgical center were randomly assigned to one of three general anesthetic groups. In groups I and II, propofol 2 mg/kg was administered for induction followed by propofol 75-150 [micro sign]g [middle dot] kg-1 [middle dot] min-1 (group I) or sevoflurane 1-2% (group II) with N2 O 67% in oxygen for maintenance of anesthesia. In group III, anesthesia was induced and maintained with sevoflurane in combination with N (2) O 67% in oxygen. Local anesthetics were injected at the incision site before skin incision and during the surgical procedure. The recovery profiles, costs of drugs, and resources used, as well as patient satisfaction, were compared among the three treatment groups.

Results: Although early recovery variables (e.g., eye opening, response to commands, and sitting up) were similar in all three groups, the times to standing up and to be "home ready" were significantly prolonged when sevoflurane-N2 O was used for both induction and maintenance of anesthesia. The time to tolerating fluids, recovery room stay, and discharge times were significantly decreased when propofol was used for both induction and maintenance of anesthesia. Similarly, the incidence of postoperative nausea and vomiting and the need for rescue antiemetics were also significantly reduced after propofol anesthesia. Finally, the total costs and patient satisfaction were more favorable when propofol was used for induction and maintenance of office-based anesthesia.