To evaluate the effects of adding low-dose fentanyl to 0.75% ropivacaine during peripheral nerve blocks, 30 ASA physical status I–II patients undergoing hallux valgus repair under combined sciatic–femoral nerve block were randomly allocated in a double-blind fashion to receive nerve block placement with 30 mL of either 0.75% ropivacaine alone (group: ropivacaine, n=15) or 0.75% ropivacaine plus fentanyl 1 μg kg−1 (group: ropivacaine–fentanyl, n=15). A blinded observer recorded haemodynamic variables and sedation, as well as the time required to achieve surgical block and the first request for analgesia. Readiness to surgery required 10 min (5–20 min) with 0.75% ropivacaine and 10 min (3–20 min) with the ropivacaine–fentanyl mixture. No differences in the degree of sedation, peripheral oxygen saturation, and haemodynamic variables were observed between the two groups. The degree of pain measured at first analgesic request, and the consumption of postoperative analgesics, was similar in the two groups, while the mean time from block placement to the first request for pain medication was 13.7 h (25–75th percentiles: 11.8–14.5 h) in the ropivacaine group and 13.9 h (25–75th percentiles: 10.5–14.5 h) in the ropivacaine–fentanyl group (P=not significant). We conclude that adding fentanyl 1 μg kg−1 to 0.75% ropivacaine did not provide clinically relevant advantages in terms of onset time, quality and duration of combined sciatic–femoral nerve block in patients undergoing elective hallux valgus repair.

There is a risk of regurgitation if a laryngeal mask airway is used with intermittent positive pressure ventilation. The lower the pressure gradient between airway and stomach, the less will be the likelihood of stomach insufflation with gas and consequent regurgitation. A flow generator ventilator, such as the Penlon Nuffield 200 which achieves a peak pressure at the end of inspiration at any given tidal volume, is likely to produce a higher peak airway pressure than a pressure generator. Replacing the expiratory valve by a venturi gives a preferable flow pattern with an inspiratory pressure plateau. At equal tidal volumes, the venturi modification provided a 10% lower inflation pressure (standard deviation 6%, P < 0.01) and a 1.8% smaller leak (P < 0.05) past the laryngeal mask airway. The same comparison but using identical inflation pressures, gave 8% larger tidal volumes (standard deviation 5.1%, P < 0.01) and a 2% smaller leak (P < 0.01) past the laryngeal mask airway.

The concentrations of nitrous oxide, sevoflurane and oxygen in the circle system of a closed-circuit anaesthesia machine, the PhysioFlex™, were measured in seven patients. During anaesthesia, the settings for each gas were changed and their concentrations recorded. At the induction of anaesthesia, it took 80– 510s (median 190 s) for the end-tidal sevoflurane concentration to reach 2.0%, and 920–2640 s (median 1500 s) for the oxygen in the breathing circuit to reach 30%. At this time, the nitrous oxide concentration was 60±3% (mean±SD). During anaesthesia, it took 90–480 s (median 140 s) for the end-tidal sevoflurane concentration setting to decrease from 3.0 to 1.0%, and 90–400 s (median 110 s) to return from 1.0 to 3.0%. When the inspired oxygen was increased from 30 to 50%, circuit concentrations reached equilibrium in 40–60 s (median 40 s), and when decreased from 50% back to 30%, equilibrium took 310–470 s (median 450 s). During recovery from anaesthesia, inspiratory sevoflurane concentration took 40–70 s (median 50 s) to decrease to 0.2%. The PhysioFlex™ provided adequate control of sevoflurane and oxygen concentrations, but not of increasing nitrous oxide concentrations.

Despite a plethora of findings associated with the pathophysiology of malignant hyperthermia (MH), the in vitro contracture test (IVCT) is the only reliable test for diagnosis of this heterogeneous syndrome in man. An increase of 1,4,5-IP3 (inositol 1,4,5-trisphosphate), a second messenger involved in cellular calcium homeostasis, has been observed in muscle tissue of MH susceptible (MHS) patients. The aim of this study was to evaluate if the known differences of 1,4,5-IP3 content in muscle tissue might be reproduced in mononucleated white blood cells (MWBCs). Subsequently, MWBCs of 23 healthy controls and 12 patients with a clinical suspicion for MH disposition were isolated and screened for 1,4,5-IP3 content. An IVCT according to the protocol of the European Malignant Hyperpyrexia Group (EMHG) was performed on muscle specimens of 12 patients. Eight MHN and four MHS individuals were diagnosed. Additionally, 1,4,5-IP3 synthesis in MWBCs was detected following in vitro exposure to IVCT test substances halothane (2%), caffeine (1–30 mM), and ryanodine (1–5 μM). A broad inter-individual variability of 1,4,5-IP3 content was observed in MWBCs of all volunteers, but no differences were detected between MHS and MHN individuals. These findings are in strong contrast to those observed in muscle tissue. In vitro exposure of isolated MWBCs to halothane, caffeine and ryanodine yielded no statistically significant differences between groups. A time and concentration-dependent increase in cellular 1,4,5-IP3 content could be induced in some but not all individuals of both groups. Since no correlation was obtained between induction of 1,4,5-IP3-synthesis following in vitro exposure of MWBCs to MH test substances and MH disposition, this study was terminated. We conclude from our data that the detection of 1,4,5-IP3 synthesis in MWBCs is not suitable for diagnosis of MH disposition. It remains questionable whether an altered 1,4,5-IP3 metabolism in MWBCs is involved in pathologic cascades of MH. Therefore, other cell tissues should be evaluated in further studies to clarify the role of the 1,4,5-IP3 metabolism in MH.

Amide local anaesthetics inhibit platelet function. We hypothesized that residual anaesthetic in the epidural space could decrease efficacy of an epidural blood patch in preventing postdural puncture headache. Levobupivacaine has recently been approved for epidural anaesthesia. Its effects on coagulation have not previously been studied. The aim of this study was to determine the effects of levobupivacaine on clotting using thromboelastography. Ten ASA Class I volunteers were studied. Venous blood samples were analysed using a Haemoscope 2000D TEG analyser. Whole blood, a 50% saline control and two levobupivacaine solutions (2.5 mg mL−1 and 2.5 μg mL−1 in blood) were compared. The former reproduces that produced in the epidural space by blood (20 mL for an epidural blood patch) and levobupivacaine 0.5% (20 mL). The latter approximates plasma concentrations following epidural injection of levobupivacaine 0.5% (20 mL). P < 0.05 was considered significant. Maximum amplitude (MA), a measure of clot strength, is decreased by levobupivacaine 2.5 mg mL−1. Levobupivacaine 2.5 mg mL−1 decreases clot strength and may reduce efficacy of a prophylactic epidural blood patch.

The aim of this study was to evaluate whether the addition of clonidine, or sufentanil, or both, to a bupivacaine solution for a caudal block prolonged the period of analgesia after operation in children. Sixty ASA class I or II boys, aged between 8 months and 13 years, admitted for hypospadias repair were enrolled into a prospective randomised study. After induction of general anaesthesia and endotracheal intubation the children were allocated into four groups. Group I received 0.5 mL kg−1 bupivacaine 0.25% caudally, in addition group II received 1 mg kg−1 clonidine, group III 0.5 mg kg−1 sufentanil and group IV 0.5 mg kg−1 clonidine and 0.25 mg kg−1 sufentanil. The concentrations of clonidine and sufentanil in group IV were halved to reduce possible side-effects with higher dosages. Analgesia and side-effects were assessed 2, 4, 6, 8 and 12 h after operation. No significant differences were found among the four groups for the pain scores at 2, 4, 6, 8 and 12 h. All groups had a similar frequency of vomiting and a comparable appetite and quality of night rest during the first 24 h following the operation. There was no signficant difference in the requirement for additional doses of analgesics. The addition of sufentanil, or clonidine, or both, to bupivacaine for caudal administration provides no additional clinical benefit over bupivacaine alone.

Nimodipine, a calcium channel blocking drug, is used in the treatment of cerebral arterial spasm after subarachnoid haemorrhage due to bleeding from an intracranial aneurysm. The purpose of this study was to evaluate the effects of nimodipine on neuromuscular blockade after vecuronium had been given to facilitate tracheal intubation and maintenance of muscle paralysis in patients undergoing clipping of intracranial aneurysm. Twenty patients were divided into two groups: a control group (n = 10) who received no calcium channel blocking drug, and a nimodipine group (n = 10) consisting of patients treated with nimodipine at clinically used doses of 0.03 mg kg−1 h−1 pre- and perioperatively. Anaesthesia was induced with atropine 10 μg kg−1, dehydrobenzperidol 5 mg, fentanyl 5 μg kg−1, thiopental 5 mg kg−1 and maintained with a mixture of N2O and isoflurane (0.5–1% inspired concentration) in O2, and additional doses of fentanyl 2.5 μg kg−1. Neuromuscular responses were monitored by acceleromyograpy. The first twitch of the train-of-four response (T1) was considered as twitch height.After a stabilization period, an intubating dose of vecuronium 0.1 mg kg−1 was administered. The onset of action, the time of first appearance of T−1 and clinical duration of action were recorded. Then, maintenance doses of vecuronium 0.03 mg kg−1were administered twice more when T1 had recovered to 25% of control twitch height. The study ended when the recordings of the 3rd 25% T1 recovery had been obtained. There were no statistical differences in the onset time (120±44 s in the control group, 141±33 s in the nimodipine group), in the first appearance time of T1 (28±6 min in the control group, 30±8 min in the nimodipine group), and in the times for 25% recovery in T1 (41±11, 32±2, 40±13 min in the control group, respectively, and 44±16, 36±15, 38±15 min in nimodipine group, respectively) between the groups studied. The time between the injection of the intubating dose of vecuronium and the third recovery of T1–25% of control was not significantly different between the control group (113±34 min) and the nimodipine group (117±42 min). This study indicates that nimodipine does not have any significant effect on the time course of action of vecuronium including the onset time and its clinical duration of action after the initial and the two maintenance doses in these patients.

Patients with bilateral corneal blindness in whom corneal transplantation has either been unsuccessful or inappropriate may be considered for osteo–odontokeratoprosthesis surgery. During a two–stage procedure the surface of the cornea is removed and covered with a graft of buccal mucosa. An optical cylinder, supported by an osteo–odonto lamina planed from a tooth is then inserted into the mucosa to act as a lens. The anaesthetic implications of this operation include care of patients from a wide age range, often with underlying medical problems undergoing two operations of prolonged duration. The eye can be ‘open’ during both stages of the operation and anaesthetic techniques directed towards prevention of rises in vitreal pressure are essential. This article outlines the surgical process of osteo-odonto-keratoprosthesis surgery with reference to our anaesthetic experiences from nine cases.

Sudden accidental loss of the airway during surgery is potentially hazardous especially when the patient is lying in any position which prevents easy intubation of the trachea. We describe two patients lying in the lateral position who required urgent airway management and endotracheal intubation. In both cases endotracheal intubation was achieved successfully using a light–guided technique – with a prototype illuminated flexible catheter – through an intubating laryngeal mask airway.

Megaoesophagus resulting from achalasia is a rare but serious cause of airway obstruction. The exact aetiology remains unclear. Although 29 cases have previously been reported, the potential need for urgent treatment has not been suf®ciently emphasized. Some forms of treatment with drugs or decompression with a ®ne tube have been advocated but emergency tracheal intubation may become necessary. A 90-year-old lady had a bolus of food lodged in her oesophagus but with no respiratory symptoms.

A 90-year-old lady had a bolus of food lodged in her oesophagus but with no respiratory symptoms. The bolus was removed under anaesthesia. Six weeks later she suffered similar symptoms after eating but developed severe airway obstruction over 10 min. Emergency intubation of the trachea was necessary before removing the food bolus under general anaesthesia. This case demonstrates the urgency with which these patients may need to be treated. The condition can rapidly worsen due to swallowing of air and saliva.