The reliability of the Bispectral Index for evaluating and monitoring the depth of general anaesthesia in children is not as great as for that in adults. Therefore we analysed Bispectral Index performance in children by comparing changes in Bispectral Index values during a standardized and equipotent anaesthetic regimen using either halothane or sevoflurane for the induction and maintenance of general anaesthesia. Special interest was focussed on excitation during induction, and whether it was associated with simultaneous changes in Bispectral Index scores.

Twenty children (3–15 yr, ASA I–II) scheduled for general surgery were randomly allocated to either halothane (10 patients) or sevoflurane group (10 patients). Anaesthesia was induced by 3% halothane or 7% sevoflurane, either agent administered with 50% N2O in oxygen for 5 min, the period from the beginning of induction until intubation. Thereafter, anaesthesia was maintained by the respective volatile agent at 1 MAC (minimum alveolar concentration; in addition to 70% N2O in oxygen) and supplemented with remifentanil infusion adjusted to maintain the heart rate and mean arterial pressure to within 20% of the baseline values. Excitation at induction was defined as involuntary muscular movements.

Sevoflurane induction produced a more rapid depression in Bispectral Index than halothane, the mean difference being greatest (47 Bispectral Index score) at 105 s. Excitation occurred in three patients during sevoflurane induction, which coincided with increases in Bispectral Index values in two of the three patients. During the maintenance phase at 1 MAC, the Bispectral Index (mean ± SD) was 57±7 for halothane and 47±9 for sevoflurane (P < 0.05). The remifentanil doses did not differ between both groups.

In children, halothane anaesthesia was associated with higher Bispectral Index values than sevoflurane when administered at 1 MAC. Large individual variation in Bispectral Index occurred within both groups. Due to these limitations, one should be cautious when interpreting paediatric Bispectral Index data.

Despite advantages of induction and maintenance of anaesthesia with sevoflurane, postoperative nausea and vomiting occurs frequently. Fentanyl is a commonly used supplement that may contribute to this, although it may alrove analgesia.

This double-blind study examined the incidence and severity of postoperative nausea and vomiting and pain in the first 24 h after sevoflurane anaesthesia in 216 adult day surgery patients. Patients were randomly allocated to either receive or not receive 1 μg kg−1 fentanyl, while a third group received dexamethasone in addition to fentanyl.

Omission of fentanyl did not reduce the overall incidence of postoperative nausea and vomiting, but did reduce the incidence of vomiting and/or moderate to severe nausea prior to discharge from 20% and 17% with fentanyl and fentanyl-dexamethasone, respectively, to 5% (P = 0.013). Antiemetic requirements were reduced from 24% and 31% to 7% (P = 0.0012). Dexamethasone had no significant effect on the incidence or severity of postoperative nausea and vomiting. Combining the two fentanyl groups revealed further significant benefits from the avoidance of opioids, reducing postoperative nausea and vomiting and nausea prior to discharge from 35% and 33% to 22% and 19% (P = 0.049 and P = 0.035), respectively, while nausea in the first 24 h was decreased from 42% to 27% (P = 0.034). Pain severity and analgesic requirements were unaffected by the omission of fentanyl. Fentanyl did reduce minor intraoperative movement but had no sevoflurane-sparing effect and increased respiratory depression, hypotension and bradycardia.

As fentanyl exacerbated postoperative nausea and vomiting without an improvement in postoperative pain and also had adverse cardiorespiratory effects, it appears to be an unnecessary and possibly detrimental supplement to sevoflurane in day surgery.

Sevoflurane has been shown to distinctly reduce bronchial mucus transport velocity, an essential determinant of mucociliary clearance and pulmonary complications. However, sevoflurane is regarded as one of the least irritant volatile anaesthetics, especially when compared with desflurane. Hence, the aim of this double-blind, randomized, controlled trial was to assess differences in bronchial mucus transport velocity between sevoflurane and desflurane.

Twenty patients listed for general surgery were randomized to receive either maintenance of anaesthesia with desflurane and fentanyl, or sevoflurane and fentanyl. Thirty minutes after tracheal intubation, bronchial mucus transport velocity was assessed by fibreoptic observation of the movement of methylene blue dye applied to the dorsal surface of the right main bronchus.

Both agents distinctly reduced bronchial mucus transport velocity when compared with previous studies, but the degree of impairment did not significantly differ between the investigated groups (median [25%/75% percentile]): desflurane 1.5 [0.5/4.2] vs. sevoflurane 1.3 [0.3/2.9] mm min−1, P = 0.343).

Desflurane is commonly regarded as more irritant to the airway, but as far as bronchial mucus transport velocity is concerned, the choice between sevoflurane and desflurane does not seem to matter.

This study was carried out to clarify the effect of the combination of acute hypervolaemic haemodilution and hypotensive anaesthesia induced with sevoflurane on human middle cerebral artery flow velocity using transcranial Doppler ultrasonography.

Thirty patients who were maintained with N2O–O2–sevoflurane anaesthesia undergoing hip surgery were randomly divided into two groups (no controlled hypotension group, Group A, and controlled hypotension group, Group B). Haemodilution was produced by acute preoperative infusion of 1000 mL of hydroxyethylstarch without removing blood in both groups. Mean arterial pressure was maintained at approximately 95 mmHg in Group A and at 55 mmHg for 80 min by increasing the inspired concentration of sevoflurane in Group B. Middle cerebral artery flow velocity was measured before haemodilution, after haemodilution, 80 min after starting hypotension, and 60 min after recovery from hypotension.

Middle cerebral artery flow velocity significantly increased in both groups after haemodilution; by 28%, in Group A, P < 0.05 vs. before haemodilution and by 30% vs. before haemodilution in Group B, P < 0.05). During controlled hypotension, it decreased towards the pre-haemodilution value (P < 0.05 vs. after haemodilution).

Sevoflurane-induced hypotension to a mean arterial pressure of 55 mmHg would reduce middle cerebral artery flow that had been increased by acute hypervolaemic haemodilution, such as haematocrit value of 26%, whereas it could preserve the flow in pre-haemodilution condition during normocapnia.

The inhibition of thermoregulatory control by anaesthesia is manifested by reduced vasoconstriction and shivering thresholds. As intraoperative bleeding can result in haemodynamic changes, including vasoconstriction, we investigated the effect of experimental bleeding on the shivering threshold in rabbits.

Twenty-four rabbits were randomly assigned to one of three treatment strategies: (1) no blood removal (control), (2) 5 mL kg−1 isovolaemic blood removal and (3) 10 mL kg−1 isovolaemic blood removal. After tracheal intubation under isoflurane anaesthesia, anaesthesia was maintained with 50% nitrous oxide in oxygen. The removed blood volume was replaced with the same volume of warm hydroxyethyl starch colloid solution. Oesophageal temperature was measured as a core temperature at 1-min intervals. After blood removal, the animal’s body was cooled at a rate of 2–3°C h−1 by perfusing water at 10°C through a U-shaped thermode positioned in the colon. Hypothermic shivering was evaluated by visual inspection, and the core temperature at which shivering was triggered was identified as the thermoregulatory threshold for this response.

Just before the cooling, the body temperature of the animals was around 38.6°C in all of the three groups. The shivering threshold in the control group was 37.2 ± 0.2°C (mean ± SD). The shivering thresholds in the 5 mL kg−1 (36.9° ± 0.3°C) and 10 mL kg−1 (36.5° ± 0.5°C) blood removal groups were significantly lower and in proportion with the volume of blood removed than that in the control group.

Isovolaemic haemodilution decreased the shivering threshold in rabbits in proportion with the volume of blood removed.

The induction of general anaesthesia is associated with the greatest cardiovascular changes in elderly patients. Induction can be performed either intravenously or with gaseous induction. Sevoflurane has advantages over propofol for induction of anaesthesia in the elderly, since the lower reduction in mean arterial pressure with sevoflurane is both statistically and clinically significant. This prospective randomized controlled trial investigated the cardiovascular benefits of co-induction of anaesthesia with 0.75 mg kg−1 propofol and 8% sevoflurane, when compared with 8% sevoflurane alone in patients requiring surgery for fractured neck of femur.

In total, 38 patients aged 75 or over were allocated into the two groups, receiving either 0.75 mg kg−1 of propofol followed by 8% sevoflurane or 8% sevoflurane alone. Vital signs were recorded until successful insertion of a laryngeal mask. Induction times, induction events and patient satisfaction scores were also recorded.

Results showed that there were no differences in the cardiovascular parameters between the two groups. Induction times were faster in the propofol and sevoflurane group (62 vs. 81 s; P = 0.028). The postoperative questionnaire showed that the majority of patients in both groups were satisfied with the induction process.

We concluded that 0.75 mg kg−1 of propofol followed by sevoflurane induction is an acceptable alternative to sevoflurane induction. It is associated with similar haemodynamic variables, faster induction times and is very well tolerated.

The measurement of α-glutathione-S-transferase enzyme is one of the most sensitive indicators of hepatocellular function. Variation in the glutathione-S-transferase P1 gene clusters has been intensively investigated and polymorphism has been described. The aim of the study was to assess whether an association exists between glutathione-S-transferase P1 gene polymorphism and serum α-glutathione-S-transferase concentrations for the first postoperative day in patients who underwent anaesthesia with sevoflurane.

In all, 54 unrelated patients were enrolled in this study. Anaesthesia was induced with thiopental and fentanyl. Vecuronium was used for neuromuscular relaxation before endotracheal intubation. Anaesthesia was maintained with sevoflurane in a gas mixture containing 50% nitrous oxide in oxygen. Peripheral venous blood samples to determine serum α-glutathione-S-transferase concentrations were collected before induction (T1), at the end of anaesthesia (T2) and at 24-h postoperatively (T3). Enzyme-linked immunosorbent assay (ELISA) immunoassay was used to measure α-glutathione-S-transferase levels. Genomic DNA was isolated from serum samples using a genomic DNA purification kit. In order to detect the variants of glutathione-S-transferase P1, polymerase chain reaction – restriction fragment length polymorphism analysis was employed.

Early postoperative serum α-glutathione-S-transferase levels for all patients were significantly increased when compared with preanaesthetic and 24-h postoperatively (P < 0.05). Serum α-glutathione-S-transferase concentrations, in individuals with glutathione-S-transferase P1 Ile105Val genotypes (heterozygote gene), remained elevated at 24 h (P < 0.05), whereas levels in individuals with glutathione-S-transferase P1 Ile105Ile (wild gene) decreased (P > 0.05).

Although α-glutathione-S-transferase levels were elevated in all patients after sevoflurane anaesthesia, levels remained high at 24 h in patients with glutathione-S-transferase P1 Ile105Val genotypes compared to controls.

We compared heart rate dynamics during surgical levels of propofol and sevoflurane anaesthesia in a highly standardized setting.

We recorded electrocardiography from 24 anaesthetized healthy male subjects. In the first parallel part of the study, the subjects were anaesthetized either with sevoflurane (n = 8) or propofol (n = 8) targeted to match 1.0, 1.5 and 2.0 minimal alveolar concentration/effective concentration 50. In the second part, a separate group (n = 8) underwent four different anaesthetic regimens targeted to bispectral index 40: sevoflurane alone, sevoflurane + 70% nitrous oxide, propofol alone and propofol + 70% nitrous oxide. The electrocardiography data were analysed using conventional time and frequency domain methods, and the approximate entropy method, which estimates the complexity of the data.

The induction of anaesthesia was followed by an overall reduction of heart rate variability, evident in all frequency bands in the spectral analysis, and also in the time domain measures. Approximate entropy decreased at 1 effective concentration 50 with propofol and at 2 minimal alveolar concentration with sevoflurane. In the second part of the study, the time domain variables and high-frequency spectral power were all similarly reduced by sevoflurane and propofol anaesthesia, with and without nitrous oxide. Approximate entropy tended to decrease during propofol anaesthesia.

Hypnotic levels of sevoflurane and propofol anaesthesia suppressed the heart rate variability measured using conventional analysis methods. Deeper surgical levels of anaesthesia also reduce the complexity of heart rate variability.

Endoscopic endonasal transphenoidal surgery has been recently proposed as a minimally invasive procedure for the treatment of pituitary adenomas. The main objective of the anaesthesiologist is to induce sufficient haemodynamic control together with rapid recovery at the end of surgery. The aim of this study was to examine recovery profile, surgical operative conditions and haemodynamic differences using remifentanil infusion with either propofol target controlled infusion system or sevoflurane.

Forty-four adult patients were enrolled in a prospective, randomized, single-blind, two-group study: Group P received propofol target controlled infusion system and remifentanil; Group S received sevoflurane and remifentanil for maintenance of anaesthesia.

No statistically significant differences between the two groups with regards to the haemodynamic changes, operative conditions as assessed by a four-step bleeding score (0–3), were obtained. Recovery times were considerably shorter after remifentanil–sevoflurane in comparison with remifentanil–propofol target controlled infusion system group (7.4 vs. 12.8 min, P < 0.01).

This study demonstrates that sevoflurane–remifentanil gives a faster recovery and equivalent intraoperative status compared with propofol target controlled infusion system with remifentanil for the endoscopic endonasal transphenoidal approach.