There is disagreement concerning the role of nitric oxide (NO) in general anaesthesia. The present study was conducted to determine whether the anaesthetic drug isoflurane alters levels of NO metabolites, NOx (NO2 and NO3), in the hippocampus of rats during and after anaesthesia. Results showed resting hippocampal NOx levels of about 20 pmol in freely moving control rats. Five minutes after the induction of isoflurane anaesthesia (4.72%=4 minimum alveolar concentrations, detected by righting reflex), there was loss of the righting reflex coincident with a significant elevation in hippocampal NOx levels. During isoflurane anaesthesia, the maximum NOx concentration rose ≈2.4-fold higher than control levels; the NO3 level increased about 5-fold higher than resting levels. NOx levels returned to control levels following discontinuation of the anaesthetic. When rats were pre-treated with L-NG-nitro arginine methyl ester, an NO synthase-inhibitor, the isoflurane-induced increases in NOx were markedly suppressed. D-NG-nitro arginine methyl ester was ineffective in preventing these neurochemical changes, thus indicating the stereoselective nature of the inhibition by L-NG-nitro arginine methyl ester. Furthermore, L-NG-nitro arginine methyl ester pre-treatment likewise prevented increases in both NO2 and NO3 levels. When rats were exposed to 80% nitrous oxide in oxygen, there was loss of the righting reflex but no change in hippocampal NOx levels. These findings indicate that isoflurane increases production of hippocampal NO and that this may be pertinent to general anaesthetic drug effects.

A telephone survey was undertaken of all UK centres (total 70) licensed for performing in vitro fertilization (IVF) and gamete intra-fallopian transfer (GIFT) by the Human Fertilisation and Embryology Authority (HFEA). The survey was carried out during the months of November and December 1997. Thirty-seven (52.1%) centres were in the NHS sector and 33 (47.8%) in the private sector. A response was available from 60 (84%) centres. A standard questionnaire was used which requested information about the procedures carried out, anaesthetic technique and pharmacological agents used. Forty-seven centres carried out IVF, two centres GIFT and 11 centres both. Out of 58 centres carrying out IVF, sedation was used in 28, general anaesthesia in 17, sedation combined with regional anaesthesia in seven and regional anaesthesia in one. Five centres gave a choice. Out of 22 centres using general anaesthesia for IVF, 12 used inhalational agents (isoflurane eight, enflurane four, sevoflurane two), eight used total intravenous anaesthesia (TIVA) with propofol and two centres inhalational agents or TIVA. Propofol was the induction agent in all but two centres. For IVF under sedation, 18 centres used midazolam, five used diazepam, three used opioids, one used entonox and the remaining ones a combination. When sedation was combined with regional anaesthesia, four centres used midazolam, two used propofol, one used midazolam with propofol, one used opioids and one used entonox. The regional technique in the 11 centres was either paracervical block with lignocaine (eight) or subarachnoid block with bupivacaine (three). Systemic analgesia was secured with fentanyl (22), pethidine (16), alfentanil (15), diclofenac (14), piroxicam (two), ketorolac (one) and ibuprofen (one). Five centres did not use any opioids; 40 centres did not use any non-steroidal agents (NSAIDs). Out of the 13 centres that carried out GIFT, 12 used general anaesthesia while the thirteenth gave the patient a choice between general or regional anaesthesia. 11 centres used inhalational agents (isoflurane nine, enflurane two) while two used TIVA with propofol; propofol was the induction agent used in six centres while thiopentone was used in five. The range of analgesics was wide – fentanyl in six centres, alfentanil in three, morphine in two, diclofenac in five and ketorolac in one. Two centres did not use any opioids and seven centres did not use an NSAID. The only agreement at present appears to be that halothane is an unwise choice for IVF. No other technique has yet been proven to be either advantageous or detrimental.

Elderly patients with hyperkalaemia often have low concentrations of plasma renin and aldosterone, perhaps secondary to reduced glomerular filtration and sympathetic insufficiency. The endocrine response to surgical stress and volume expansion during anaesthesia was studied in seven elderly patients with hyperkalaemia (mean age 87.7±SD 5.3 years), 18 elderly patients without hyperkalaemia (86.5±5.5 years), and 18 younger patients (52.6±7.2 years) as controls. Base-line values, in hyperkalaemic elderly patients, for plasma renin activity and plasma aldosterone concentration were 0.8±0.3 ng mL−1 h−1 and 2.8±0.8 pg mL−1 respectively (significantly lower than in the younger patients), and 287±42 pg mL−1 for plasma atrial natriuretic peptide levels, which were significantly higher. The plasma renin activity and aldosterone concentrations in elderly patients with hyperkalaemia were at all times lower, but not significantly, than those of the elderly patients without hyperkalaemia. The atrial natriuretic peptide concentrations (351±48 pg mL−1) in the hyperkalaemic elderly were significantly higher 90 min after induction of anaesthesia than in the normokalaemic elderly (108±38 pg mL−1). Hormone concentrations in the hyperkalaemic patients did not change during anaesthesia, but plasma atrial natriuretic peptide concentrations increased significantly in the normokalaemic elderly, and plasma renin activity and aldosterone of the younger patients increased significantly during anaesthesia. These results indicate that plasma renin activity, and the concentrations of aldosterone and of atrial natriuretic peptide in elderly patients with hyperkalaemia are unresponsive to surgical stress and volume expansion.

Controversy persists over the efficacy of intercostal nerve block administered through a tunnelled extrapleural catheter. We have undertaken a randomized, prospective double-blind trial of two different local anaesthetic regimes to evaluate the effect of this technique on post-thoracotomy pain relief and pulmonary function. Sixty-eight patients were randomized to receive bupivacaine 0.25% (n=22), lignocaine 1% (n=21) or 0.9% NaCl (saline) (n=20) via an extrapleural catheter, inserted peroperatively. All patients underwent a standard posterolateral thoracotomy. Pain was assessed using a visual analogue pain score and by the requirement for opiate analgesia. Pulmonary function was measured using bedside spirometry. Pain scores were lower in the local anaesthetic groups at 24, 32 and 72 h compared with placebo (P< 0.05) and the total amount of opiate required was less than placebo for both lignocaine and bupivicaine (P< 0.05). Pulmonary function was better in the local anaesthetic groups throughout the post-operative period and was most pronounced at 24 h with a mean improvement of 30% for forced expiratory volume (FEV1), 24% for forced vital capacity (FVC) and 19% for peak expiratory flow rate (PEFR) compared with placebo. There was no significant difference between pain scores, opiate requirement or pulmonary function between lignocaine and bupivicaine. CT scanning demonstrated containment of the local anaesthetic in an extra-pleural tunnel. Extra-pleural infusion of local anaesthetics is a simple technique, with low risk of complications and provides effective pain relief as well as an improvement in post-operative pulmonary function. Lignocaine is equally as effective as bupivacaine and its use would result in some cost-saving.

Dopamine decreases gastric tone and may therefore influence gastrointestinal motility. The aim of this investigation was to study the effects of a continuous infusion of dopamine on gastric emptying and orocaecal transit time. Nine healthy male volunteers were studied on two occasions in a randomized order. All volunteers received on separate days a continuous infusion of dopamine 5 μg kg−1 min−1 on one occasion and normal saline on the other occasion. Gastric emptying was measured by the paracetamol absorption test and orocaecal transit time by the hydrogen breath test. During the dopamine infusion the area under the paracetamol concentration curve was significantly smaller than during control conditions (P=0.02). Orocaecal transit time was prolonged during the dopamine infusion (P=0.02). Dopamine delays gastric emptying and prolongs orocaecal transit time.

The purpose of this study is to compare the incidence of undesirable respiratory events when the laryngeal mask airway is either removed from patients who are fully awake or from patients who are deeply anaesthetized. Three-hundred patients aged 1.5–81 years were randomly assigned to have their laryngeal mask airway removed either when deeply anaesthetized or after airway reflexes had returned. The occurrence of adverse respiratory events (coughing, oxygen desaturation and airway obstruction) was recorded. Airway obstruction after laryngeal mask airway removal was evident in 20% of patients in the deep anaesthesia group and in 8% of patients in the awake group (P=0.007). In spite of this finding, oxygen desaturation in children of less than 6 years of age (SaO2 < 96%) occurred most frequently after awake removal (31.3%) compared with deep anaesthesia removal (4.5%) (P=0.023).

A case of right hemidiaphragm rupture and abdominal herniation into the thorax occurring during the immediate post-operative course of double-lung transplantation is reported. This complication has not been reported previously. We examine the possible aetiology and suggest that the direct cause could be an increase in intra-abdominal pressure during chest physiotherapy.

We report the successful use of the intubating laryngeal mask airway in a patient with maxillo-facial trauma for whom the facemask and laryngoscope were relatively contraindicated and the fibreoptic scope potentially difficult to use.

Bone injury while undergoing electro-convulsive therapy is thought to be rare. We report a case of hip fracture during treatment which was associated with osteoporosis. Patients at increased risk could be identified.

We describe the case of a 36-year-old woman, with a previous history of recurrent abortion due to protein S deficiency, undergoing an elective Caesarean section at 39-weeks gestation. During pregnancy no signs of hypertension or cardiovascular disease were reported, but at the end of the surgical procedure, the patient developed acute hypertension, leading to myocardial infarction, severe heart failure and death. The autopsy revealed a 2-cm undiagnosed phaeochromocytoma in the right adrenal gland. Clinical diagnostic features of phaeochromocytoma during pregnancy as well as the main therapeutic approaches suggested in the literature are discussed.