Background and objective: Cost consciousness has become increasingly important in anaesthesia as elsewhere in healthcare. Cost-minimization with uncompromised patient safety and quality requires systematic comparisons of alternative techniques. Inhalation anaesthesia with desflurane or sevoflurane is compared in this study with propofol delivered by the target controlled infusion technique. Directly measured drug consumption and costs and emergence times are compared.

Methods: Consumed anaesthetics were measured during elective arthroscopy of the knee, and costs were calculated for ASA I–II patients (n = 102) randomized to 3 groups: one group received anaesthesia using propofol administered by target controlled infusion, the others inhalation anaesthesia with either desflurane or sevoflurane in combination with nitrous oxide. A partial rebreathing system was used with a laryngeal mask airway. Vaporizers were weighed before and after each anaesthetic.

Results: Aaesthetic duration, postoperative pain and emesis as well as discharge time did not differ between groups. Inhaled anaesthetic techniques with desflurane or sevoflurane were associated with 2–3min shorter emergence times (P < 0.001) and approximately 45% lower cost for consumed anaesthetics as compared with propofol technique based on target controlled infusion. The inclusion of waste costs improved the cost reduction to 55%.

Conclusions: For this patient group, use of inhalation anaesthesia reduced drug costs by half and shortened emergence times compared to target controlled infusion with propofol with equal perioperative patient conditions.

Both the numbers of children undergoing day case surgery and the type of procedures performed in this way are increasing. This expansion will only be beneficial if anaesthesia and surgery are provided with minimal postoperative morbidity e.g. postoperative delirium or nausea and vomiting. The choice of anaesthetic technique is considered critical to optimizing the service provided to patients and for this reason much research has addressed this question. This review considers the effect of anaesthetic technique on postoperative outcome in paediatric day case surgery. The outcome measures reviewed by this article are induction of anaesthesia, effects on the cardiovascular system, recovery from anaesthesia and postoperative nausea and vomiting. In each section both quantitative and qualitative outcome measures are discussed. Comparisons are made between sevoflurane and halothane, sevoflurane and propofol, propofol and halothane, desflurane and halothane and the presence or absence of nitrous oxide.

Background and objective Low-flow anaesthesia is economical and less polluting. The purpose of this study was to determine the inspired and end-tidal desflurane concentrations during anaesthesia with a vaporizer setting maintained at 5%, during low-flow anaesthesia after 120 min with fresh gas inflows of 1.0 and 2.0 L min−1.

Methods The study was both prospective and randomized, including 56 patients (28 patients in each group) scheduled for elective surgery of an expected anaesthesia time of at least 120 min. Inspired and end-tidal concentrations of desflurane were measured during low-flow anaesthesia with fresh gas inflows of 1.0 and 2.0 L min−1. The vaporizer setting was fixed at 5% desflurane.

Results The inspired and end-tidal concentrations of desflurane in the 1.0 L min−1 group after 120 min were 4.54% vs. 4.37% (P < 0.001). In the 2.0 L min−1 group, the inspired and end-tidal concentrations of desflurane were 4.76% vs. 4.58% (P < 0.001). The estimated end-tidal/inspired ratios at 120 min of anaesthesia were 0.96 in both groups. At a fresh gas flow of 1.0 L min−1, the end-tidal concentration was 0.87 of the vaporizer setting. Increasing the fresh gas flow to 2.0 L min−1 increased the end-tidal value by 0.05.

Conclusion There is a significant difference between the inspired and end-tidal concentrations of desflurane when fresh gas inflows were 1.0 and 2.0 L min−1, but not for the ratio of inspired/end-tidal.

Background and objective This study investigates the interaction of sevoflurane and nitrous oxide on EEG median power frequency of 2.5 Hz during surgery.

Methods Sevoflurane concentrations required for electroencephalographic median power frequency between 2 and 3 Hz were measured in 25 patients during gynaecological laparotomies. Nitrous oxide was randomly administered at 0, 20, 40, 60 and 75 vol%, subsequently two different concentrations in each patient. The data were analysed using isobolographic analysis together with previously published data on nitrous oxide-isoflurane, -enflurane, or -desflurane interaction.

Results The interaction is described by the equation: C volatile anaesthetic/C0 volatile anaesthetic + C N2O/C0 N2O = 1 (C is the concentrations for a drug combination to achieve the desired effect; C0 is the concentration for single drug use). The parameters are C0 isoflurane = 1.11 vol% (95% CI 1.03–1.19), C0 enflurane = 1.64 (1.52–1.77), C0 desflurane = 5.31 (4.92–5.73), C0 sevoflurane = 2.12 (1.96–2.29), C0 N2O = 174 (153–202). These parameters decrease by 6% (2.5–10) for every 10 years of patients’ age > 40 years.

Conclusions The interaction is compatible with additivity. The potency of nitrous oxide to substitute the volatile anaesthetics is less than anticipated from previously reported MAC values.

A 45-year-old man with cryptorchism, who was known to suffer from generalized myasthenia gravis, was admitted to hospital for surgical treatment using laparoscopy. Such minimally invasive surgery requires good muscle relaxation. However, the use of neuromuscular blocking agents in patients with myasthenia gravis may lead to prolonged apnoea after operation, thus necessitating mechanical ventilation of the lungs. We used a combination of general anaesthesia (with desflurane), and epidural anaesthesia (with the amide local anaesthetic ropivacaine) to obtain excellent abdominal relaxation during surgery. Tracheal extubation was possible immediately after the operation and no adverse effects were observed. The patient was discharged from hospital on the second day after operation. The combination of regional and general anaesthesia for minimally invasive surgery in this patient permitted safe anaesthetic management.

The effects of inhalational anaesthetic agents on renal sympathetic nerve activity (RSNA) were compared in anaesthetized rabbits. Concentrations of 6% desflurane, 1.2% isoflurane, and 2.4% enflurane increased mean RSNA up to 32, 36 and 44% while higher concentrations, of 12, 2.4 and 3.2% depressed it by 42, 83 and 5%, respectively. For halothane RSNA was unchanged up to 0.8% and decreased by 36% at 1.6% concentration. Nitrous oxide increased RSNA up to 28% at 50% concentration. Maximum reductions in mean arterial pressure (MAP) were 60% for both 2.4% isoflurane and 3.2% enflurane, 50% for 12% desflurane and 1.6% halothane, while 70% nitrous oxide increased MAP by 22%. In conclusion, unlike the entirely depressive effects of halothane, the effects of desflurane, isoflurane and enflurane were biphasic involving excitation at lower concentrations and depression of RSNA and a reduction in MAP at higher concentrations. Nitrous oxide caused increases in both RSNA and MAP.

Application of high-silica zeolites in a special adsorber anallows complete selective adsorption of the inhalation anaesthetic desflurane from the outlet port of the scavenging system of the anaesthesia machine. In comparison with charcoal filters, zeolites allow almost complete desorption at moderate temperatures followed by condensation of the desflurane to the liquid phase. The adsorption of scavenged desflurane by zeolites was measured in 13 patients. The duration of the anaesthesia was between 70 and 130 min. A minimal-flow regime (0.5 L min−1 fresh gas inflow) was used for maintenance in seven patients and a higher-flow regime (3 L min−1 fresh gas flow) was used for maintenance in six patients. In minimal-flow anaesthesia, 62% of the delivered desflurane was adsorbed by the zeolite while 86% of the delivered desflurane was adsorbed in higher-flow anaesthesia. Preliminary results show that about 85% of the adsorbed desflurane could be recovered as liquid with high purity via desorption.

Desflurane has been reported to cause tachycardia and hypertension during induction of anaesthesia. The aim of this study was to determine the effects of desflurane on cerebral blood flow (CBF) velocity using transcranial Doppler ultrasonography in a setting that closely resembled usual clinical practice. In two groups (n = 9 in each) ASA Grade I or II patients, anaesthesia was induced with etomidate and vecuronium intravenously (i.v.), sufentanil (0.3 μg kg−1 i.v.) was added in the second group. Patients were ventilated by facemask for 2 min before desflurane was administered in steps of 0.5 MAC min−1 until 1.5 MAC was reached and maintained for 7 min. Haemodynamic variables and CBF velocity in the middle cerebral artery (MCA) were monitored throughout the study period. In group 1 heart rate increased to 108 ± 2 b.p.m. (37% increase) whereas MAP increased to 114 ± 6 mmHg after administration of desflurane (33% increase). CBF velocity increased to 86 ± 7 cm s−1 (69% increase). In group 2 no significant changes in systemic haemodynamic responses were measured after desflurane administration; however, CBF velocity increased to 73 ± 5 cm s−1 (59% increase). The results indicate that desflurane increases CBF velocity concurrently with induction of tachycardia and hypertension. Although sufentanil and N2O attenuate the systemic haemodynamic alterations caused by desflurane, the CBF velocity increases. These data suggest that the abrupt addition of desflurane may have adverse consequences in patients at risk for intracranial hypertension.

Desflurane is a new inhalation anaesthetic with a low blood/gas solubility which should allow a fast emergence from anaesthesia. In a prospective open randomized study, desflurane was compared with isoflurane paying special attention to recovery and the quality of the post-operative period. The occurrence of pain and post-operative nausea and vomiting (PONV) was recorded during the first 20 post-operative hours. Seventy women ASA Grade I-II scheduled for elective gynaecological laparoscopic procedures were studied. Patients receiving desflurane were extubated earlier than patients receiving isoflurane, 5±1 and 9±1 min respectively (P < 0.05) and the patients anaesthetized with desflurane were able to tell their name and date on average 5 min earlier than those who had received isoflurane; however, time in the recovery room was the same for both groups of patients. Twenty-two of 35 patients receiving desflurane, and 18 of 35 receiving isoflurane required analgesia. PONV was recorded in 18 patients anaesthetized with desflurane and 12 patients anaesthetized with isoflurane. In both groups PONV was more frequently observed in patients after leaving the recovery room. PONV in the recovery room was associated with a delayed discharge, 139 vs. 114 min respectively. Desflurane seems to be an useful alternative to isoflurane for laparoscopic procedures.