Patients who awake from sevoflurane anaesthesia with symptoms of agitation may have some underlying functional substrate that is sensitive to the low concentrations of anaesthetic encountered during emergence. One candidate for such a substrate could be neurocircuitry implied in the pathophysiology of both agitation and movement disorders with hyperactivity. We postulated that hyperactive animals would show a further increase in activity in the presence of low concentrations of volatile anaesthetics, such as sevoflurane.

To confirm our hypothesis, we examined the effects of two subanaesthetic concentrations of sevoflurane, isoflurane and halothane (0.1 and 0.2 MAC (minimum alveolar concentration)) on spontaneous activity in N-methyl-d-aspartate receptor GluRε1 subunit knockout mice exhibiting locomotor hyperactivity in a novel environment and compared these results with those for wild-type controls. We also compared the effects of anaesthetic concentrations of sevoflurane (1.2 MAC) on mice activity during postanaesthesia recovery.

Out of the three anaesthetics used, only sevoflurane administered at 0.1 MAC caused a significantly different response between the two experimental groups. Exposure to this subanaesthetic concentration of sevoflurane reduced the activity of wild-type mice, whereas mutant animals showed a further increase in hyperactivity. The effects of 1.2 MAC sevoflurane anaesthesia on mice activity during postanaesthesia recovery also differed significantly between the two genotypes. Exposure to anaesthetic concentrations of sevoflurane had a sedative effect on wild-type mice, whereas mutant mice preserved their high levels of activity upon emergence from the anaesthesia.

The presence of an inherent anomaly in mutant mice that becomes more manifest during exposure to 0.1 MAC sevoflurane and is still present after the emergence from sevoflurane anaesthesia suggests the presence of and necessitates a search for some putative substrate that may, by analogy, underlie emergence agitation in the clinical setting.

The flexible laryngeal mask airway has been mostly used in spontaneous ventilated children during short procedures to avoid the risk of kinking; little information has been reported about its airway morbidity. The aim of the study was to compare this airway device with the reinforced tracheal tube in mechanically ventilated adult patients.

120 adult patients undergoing general anaesthesia for breast, head and neck oncoplastic surgery, expected to last up to 3 h, were stratified into two airway groups: flexible laryngeal mask airway (n = 60) or reinforced tracheal tube (n = 60). Within each group, patients were randomly allocated to one of the two maintenance anaesthetic subgroups: propofol (n = 30) or sevoflurane (n = 30). Ease of insertion and haemodynamic stress response to placement, ventilation and postoperative morbidity were studied.

Easy insertion rate was greater for the flexible laryngeal mask airway (93% vs. 77%, P = 0.01), and the overall success in insertion rate was 100% for both groups. Haemodynamic changes were significantly higher after inserting reinforced tracheal tube (P < 0.001). Oxygen saturation and capnography were comparable in both groups but airway pressure was lower with flexible laryngeal mask airway (P = 0.002). Sore throat, cough and dysphonia were lest frequent with flexible laryngeal mask airway (P < 0.01); also more patients in this group felt comfortable. Sevoflurane gave better results in emergence time, regardless of the airway device used.

During anaesthesia in mechanically ventilated adult patients, both devices function adequately, are stable and protect the airway. Flexible laryngeal mask airway results in less postoperative morbidity than reinforced tracheal tube.

For perioperative volume therapy in infants and young children, human albumin has frequently been the colloid of choice. Recently, HES 130/0.4 (6% hydroxyethyl starch, Voluven®; Fresenius Kabi, Bad Homburg, Germany) was developed, which demonstrated improved pharmacokinetics and a favourable safety profile in adults compared with hydroxyethyl starch products with a less rapid metabolization.

Our prospective, controlled, randomized, open, multicentre pilot study was designed to obtain data on the effects of HES 130/0.4 compared with human albumin 5% with regard to haemodynamics in children <2 yr scheduled for elective non-cardiac surgery.

A total of 81 patients were treated. Comparable amounts of both study solutions (16.0 mL kg−1 hydroxyethyl starch 130/0.4 vs. 16.9 mL kg−1 human albumin 5%) as well as add-on crystalloids were used until 4–6 h postoperatively. No differences were detected between the two treatment groups regarding perioperative stabilization of haemodynamics, coagulation parameters, blood gas analyses or other laboratory values. Blood loss was 96 ± 143 mL for hydroxyethyl starch and 145 ± 290 mL for human albumin (P > 0.05). There were no relevant differences in the amount of red blood cells, fresh frozen plasma or platelet concentrates in both treatment groups. Median length of ICU stay was 3.5 days (range 1–57 days, mean ± SD 7.6 ± 11.5 days) in the hydroxyethyl starch group and 6.0 days (range 1–71 days; mean ± SD 9.1 ± 14.2 days) in the human albumin group. There was no difference for hospital stay (median: 12 days for both groups).

Both HES 130/0.4 and human albumin 5% were effective for haemodynamic stabilization in non-cardiac surgery of young infants with no adverse impact on coagulation or other safety parameters in our study population.

To determine whether intraoperative systemic dexmedetomidine improves postoperative pain and interacts with epidural neostigmine to produce analgesic effects.

Sixty patients undergoing gynaecological surgery were randomly divided into four groups to receive epidural neostigmine and/or systemic dexmedetomidine: control (Group C), epidural neostigmine (Group N), systemic dexmedetomidine (Group D) and co-administered neostigmine and dexmedetomidine (Group ND). Epidural neostigmine (0.3 mg) was administered with 10 mL of 0.75% ropivacaine before the induction of general anaesthesia. Systemic dexmedetomidine (loading dose of 1 μg kg−1 over 10 min followed by 0.4 μg kg−1 h−1) was infused after the induction of general anaesthesia and continued until the end of surgery. The pain status of patients was assessed using the visual analogue scale at 2, 4, 6, 24 and 72 h postoperatively.

Intraoperative systemic dexmedetomidine alone did not reduce postoperative pain scores. However, co-administered neostigmine and dexmedetomidine significantly decreased scores at 24 and 72 h (Group C: 3.0 [1.0–5.8] and 2.0 [0.3–3.0]; Group N: 1.5 [0.3–3.4] and 0 [0–1.3]; Group D: 3.5 [0–5.0] and 0 [0–1.4]; and Group ND: 0 [0–1.0]* and 0 [0–0]†; median [interquartile range] *P = 0.0031, †P = 0.0045 compared with Group C).

The intraoperative systemic infusion of dexmedetomidine alone at doses causing sedation does not result in postoperative analgesic effects. However, the co-administration of systemic dexmedetomidine and epidural neostigmine at higher doses may be a useful method to improve postoperative pain although side-effects have to be evaluated.

We compared the efficacy of intravenous lornoxicam vs. dipyrone in patient-controlled analgesia for postoperative analgesia.

The study included 105 patients who had undergone elective septorhinoplasty after receiving general anaesthesia. Patients were divided into three groups to receive lornoxicam (24 mg day−1), dipyrone (5 g day−1) or placebo. Pain was evaluated using a 0–100 mm visual analogue scale at 2, 4, 6, 8, 12, 16, 20 and 24 h postoperatively. Pethidine (1 mg kg−1) was administered intramuscularly to patients requiring rescue analgesia. Pethidine requirements were recorded during the first 24 h postoperatively, and treatment-related adverse effects were noted.

Postoperative pain scores were significantly lower with lornoxicam compared with dipyrone at 8 h (P = 0.016). No significant differences regarding pain scores at 2, 4, 6, 12, 16, 20 and 24 h were found. Significantly fewer patients in the lornoxicam group required rescue analgesics (vs. dipyrone, P = 0.046; vs. placebo, P = 0.001); fewer patients in the dipyrone group required rescue analgesics compared with placebo (P = 0.008). Significantly fewer patients in the lornoxicam group had nausea (vs. dipyrone, P = 0.022; vs. placebo, P = 0.006); no significant differences were found between the other two groups. Antiemetic use was significantly lower in the lornoxicam group (vs. dipyrone, P = 0.002; vs. placebo, P = 0.001).

Lornoxicam has better tolerability and is a more effective analgesic than dipyrone when administered by patient-controlled analgesia for postoperative analgesia after septorhinoplasty.

Transmitral inflow patterns have been used for detection of myocardial ischaemia. However, its diagnostic value has not been tested in anaesthetized and mechanically ventilated patients undergoing coronary artery bypass graft surgery.

Transmitral inflow patterns were studied by transoesophageal Doppler echocardiography in 43 patients undergoing coronary artery bypass graft surgery without cardiopulmonary bypass after opening of the sternum (baseline) and during grafting of the left anterior descending artery. Peak early (E) and peak late (A) transmitral velocities and their ratio (E/A) were recorded. Myocardial ischaemia was defined by standard criteria using two-dimensional echocardiography and seven-lead electrocardiogram.

Thirty-one patients (64 ± 8 yr, 9 women) fulfilled the predefined inclusion criteria for analysis. During distal revascularization, 16 patients showed myocardial ischaemia and 15 did not. The use of vasoactive drugs, haemodynamic findings and transmitral inflow patterns were similar in both groups at baseline and during grafting. In the ischaemic group, E was 67.1 ± 13.9 cm s−1 at baseline and 69.5 ± 23.2 cm s−1 during grafting, and the E/A ratios were 1.3 ± 0.3 and 1.4 ± 0.9, respectively. In the non-ischaemic group, E was 64.0 ± 17.1 cm s−1 at baseline and 60.9 ± 14.8 cm s−1 during grafting, and the E/A ratios were 1.4 ± 0.7 and 1.2 ± 0.3, respectively.

Analysis of Doppler findings of transmitral inflow patterns did not allow for detection of myocardial ischaemia during surgical revascularization of the myocardium.

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.

Analgesia and sedation are usually required during extracorporeal shock wave lithotripsy. In the present study, the recovery time and effectiveness of sedation and analgesia of dexmedetomidine was compared with a midazolam/fentanyl combination in outpatient extracorporeal shock wave lithotripsy.

Forty-nine patients scheduled for outpatient extracorporeal shock wave lithotripsy were randomly assigned to two groups: a dex group (n = 25; dexmedetomidine 1 μg kg−1 loading dose followed by dexmedetomidine 0.2 μg kg−1 h−1) and a control group (n = 24; midazolam 0.05 mg kg−1 and fentanyl 1 μg kg−1). Recovery time, rescue analgesics (fentanyl 25 μg) and sedatives (midazolam 1 mg), and patients’ satisfaction rates were recorded.

The two groups were similar regarding patient characteristics and procedure-related details (P > 0.05). Recovery time was significantly prolonged in the dex group when compared with the control group (116.4 ± 39.3 vs. 50.8 ± 19.8 min, respectively, P < 0.001). The percentage of patients requiring rescue doses of fentanyl and the applied doses were significantly higher in the dex group than in the control group (96% vs. 67%, P = 0.01; and 69.0 ± 31.7 vs. 38.8 ± 42.9 μg, respectively, P = 0.007). More patients in the dex group received rescue midazolam (96% vs. 58%, P = 0.002). More patients in the control group were highly satisfied with their sedation/analgesia (83% vs. 56%, P = 0.038).

Dexmedetomidine was associated with a longer recovery time than a midazolam/fentanyl combination when used for sedation and analgesia during outpatient extracorporeal shock wave lithotripsy in this study. The incidence of rescue sedative and analgesic need was also significantly higher when dexmedetomidine was used.

Numerous in vitro studies have shown that volatile anaesthetics react with desiccated carbon dioxide (CO2) absorbents to produce carbon monoxide (CO). The effects of anaesthetic concentration, fresh gas flow rate, and the hydration of absorbent or the excretion of CO2 by patients on CO production have also been investigated. This work aims to identify the most significant one of these factors on CO concentration in a low-flow anaesthesia system, without control of the hydration of the absorbents.

A simulated clinical circle anaesthetic breathing system was used to study the CO concentration under various conditions. Desflurane was used at three different concentrations. Two CO2 flow rates and three fresh gas flow rates were used. The absorbent temperatures and hydration were measured simultaneously.

Desflurane degraded to produce CO in the breathing tube, when the CO2 absorbents were not dried beforehand. In this imitation clinical low-flow setting, fresh gas flow affected the CO production more than the CO2 did (31.7% vs. 9.5%). The actual desflurane partial pressure was not a significant factor. The CO2 flow rate explained 18.2% and 54.0% of the variation of the absorbent hydration changes (%) and temperature, respectively.

In clinical practice, the CO2 production varies among patients and is uncontrollable, but markedly affects CO production. The only controllable factor is the fresh gas flow rate if the ultimate goal is to reduce the undesirable exposure of patients to CO from the breathing tube according to this bench model without counting the oxygen consumption.

To compare induction, pre- and post-discharge recovery characteristics and patient preferences between four anaesthetic regimens in adult day-surgery.

Randomized controlled trial. In all, 1158 adults assigned to: propofol induction and maintenance, propofol induction with isoflurane/N2O, or sevoflurane/N2O maintenance, or sevoflurane/N2O alone. We prospectively recorded induction and pre-discharge recovery characteristics, collected 7-day post-discharge recovery characteristics using patient diaries and patient preferences by telephone follow-up.

Recruitment rate was 73% – of the 425 refusals, 226 were not willing to risk a volatile induction. During induction, excitatory movements and breath holding were more common with sevoflurane only (P < 0.01). Injection pain and hiccup were more common with propofol induction (P < 0.01). In the recovery room and the postoperative ward, both nausea and vomiting were more common with sevoflurane only (P < 0.01). This difference disappeared within 48 h. There was no difference between groups in the mental state on awakening, recovery time, time to discharge or overnight admissions; then was also no difference in pain between the four groups for each of the seven postoperative days (P < 0.01), nor any differences in concentration or forgetfulness. Patients took 6.5 days (95% CI: 6.0–7.0, n = 693) to resume normal activities. Patients who received sevoflurane only were more likely to recall an unpleasant induction and least likely to want the same induction method again (P < 0.01).

Differences in outcome between the four regimens are transient; sevoflurane is not an ideal sole agent for adult day case anaesthesia and, in this setting, patients base their preferences for future anaesthetics on the method of induction.