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.

Background and objective Patients undergoing coronary artery bypass grafting often require volume loading after operation. In this situation hypertonic saline may be beneficial in restoring the haemodynamic balance and removing excess extravascular fluid.

Methods Forty coronary artery bypass grafting patients were randomly assigned to receive either hypertonic saline 7.5% (20 patients) or 0.9% saline (20 patients) as a single dose of 4 mL kg−1 over 30 min in the postoperative rewarming phase in the intensive care unit.

Results Mean arterial pressure increased in the hypertonic saline group from 82 ± 10 (SD) to 104 ± 17 mmHg (P = 0.002 vs. the normal saline group), and the cardiac index rose from 2.3 ± 0.5 to 3.4 ± 0.8 L min−1 m2 (P = 0.002 vs. the normal group). The haemodynamic effect of hypertonic saline lasted only about 1 h. Diuresis was greater in the hypertonic saline group both at 1 h (hypertonic saline: 490 ± 274 vs. normal saline: 204 ± 130mL; P = 0.001) and 10 h (hypertonic saline: 1952 ± 554vs. normal saline: 1421 ± 514mL; P = 0.003).

Conclusions No adverse effects were seen. The hypertonic saline had a strong diuretic effect and may be beneficial in coronary artery bypass graft patients after operations. This is because of its value as a short-term plasma expander and the diuresis eliminates excessive fluid from the body. A larger study is needed to determine whether the benefits outweigh the possible side-effects in these patients.

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.

Summary

Background and objective: This study was conducted to determine the effect of ketamine on metabolic homoeostasis and particularly in lipoprotein lipase (LPL) activity in adipose tissue.

Methods: Sixty male Wistar rats were divided into six groups of 10 each. Group A served as controls, while Groups B–F received, respectively, ketamine 60, 80, 100, 120 and 140 mg kg−1 intraperitoneally. The animals were sacrificed 20 min after the administration of ketamine. Insulin concentrations in plasma and total cholesterol, triglyceride, high-density lipoprotein (HDL) and free fatty acid (FFA) concentrations in serum were measured. LPL activity in adipose tissue and medium-chain acyl-CoA dehydrogenase (MCAD) content in muscle were determined.

Results: FFA concentrations in serum significantly increased from the second lowest dose of ketamine. Insulin concentrations in plasma did not exhibit any significant difference between groups. MCAD levels were 0.5-fold more in Group F than in Group A, while there were no significant differences between control group and Groups B–E. Furthermore, high concentrations (120 and 140 mg kg−1) of ketamine interfered with in metabolic homoeostasis by significantly reducing LPL activity, thus elevating triglyceride concentrations in serum without affecting cholesterol and HDL metabolism.

Conclusions: Ketamine induces various metabolic effects due to changes in adipose LPL activity and MCAD levels in muscles. These findings seem to be significant only at high doses.

In clinical practice, anaesthetists encounter many patients who are on concurrent medication which may have the potential to interact with drugs used during anaesthesia. Many patients are receiving as many as a dozen drugs of various kinds, thus, increasing the risk of a drug interaction occurring. Unfortunately, anaesthetists tend not to report drug interactions which occur during anaesthesia—especially those of a minor nature such as flushing—and hence, the true number of drug interactions is unknown. We have developed a chart indicating the nature of important interactions that the anaesthetist may encounter.

Summary

Background and objective: Irradiation of intraoperative cell salvage blood has recently been used to inactivate tumour cells before retransfusion, during cancer surgery. No information is available about a potential inflammatory response of the recipient to the retransfusion of irradiated intraoperative cell salvage blood. This pilot study was conducted to investigate the possible release of the pro-inflammatory mediators, tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β), eotaxin and monocyte chemo-attractant protein-1 (MCP-1), in the serum of recipients by intraoperative retransfusion of irradiated intraoperative cell salvage blood.

Methods: Nine patients undergoing gynaecological cancer surgery were included in this study. Intraoperative cell salvage blood was irradiated with 50 Gy and retransfused to the patient. Serum and intraoperative cell salvage blood concentrations of TNF-α, IL-1β, eotaxin and MCP-1 were repeatedly analysed before and after retransfusion, respectively before and after irradiation.

Results: Traces of mediators were detected in intraoperative cell salvage blood but no increase due to irradiation was observed. Following transfusion of intraoperative cell salvage blood, minute quantities (all <30 pg mL−1) of mediators were detected in the serum of patients. However, there was no significant upregulation compared to serum values before retransfusion.

Conclusions: These results provide evidence that retransfusion of irradiated intraoperative cell salvage blood might represent a blood-saving strategy in cancer surgery without an immunological inflammatory response as shown by a lack of upregulation of inflammatory mediators.

We evaluated the relation between dose and response for the neuroprotective effect of propofol in a rat model with incomplete cerebral ischaemia. For clarification of the mechanism of neuroprotection, plasma catecholamines and tumour necrosis factor-α levels were measured. Three doses (low, moderate and high-dose) of propofol were tested. These produced, respectively, a low amplitude, slowing and a burst-suppression pattern of electroencephalographic activity. Incomplete cerebral ischaemia was produced by right carotid artery occlusion combined with haemorrhagic hypotension (35 mmHg) for 30 min. Neurological outcome at 72 h post-ischaemia in the high-dose group was significantly better than that in both low-dose and moderate-dose groups. Propofol exhibited a trend in the dose-related attenuation of the increases in plasma adrenaline and noradrenaline during ischaemia. Tumour necrosis factor-α increased during and after ischaemia in all groups with no intergroup differences. The results indicate that a burst-suppression dose of propofol provides neuroprotection. The protective effect can not be completely explained by the attenuating effect on circulating catecholamines.

Summary

Background and objective: Propofol is an intravenous (i.v.) anaesthetic agent that possesses many of the qualities of an ideal anaesthetic agent. The most significant side-effect associated with propofol is pain on injection. Despite optimal therapy, the incidence of pain on propofol injection remains a problem. This prospective, randomized, double blinded study evaluated the effect of three different treatment strategies in decreasing pain on propofol injection.

Methods: We studied 102 adult, ASA I–II patients, scheduled for elective surgical procedures. Combination of i.v. lidocaine and nitrous oxide (N2O) in oxygen (O2) inhalation pre-treatment was compared with either treatment alone in the prevention of pain on propofol injection. A standard propofol injection technique and scoring system, to measure the pain on injection was used.

Results: Demographic variables were similar between the groups. The incidence of no pain on propofol injection was similar in the lidocaine and N2O groups (63.6% vs. 57.5%) (95% confidence interval (CI): 0.17–0.29, P = 0.61). Combination therapy was associated with a greater incidence of no pain on injection (84% vs. 63.6%) (95% CI: 0.06–0.48, P = 0.04).

Conclusion: Combination of i.v. lidocaine and N2O in O2 inhalation pre-treatment is more effective than either treatment alone in decreasing pain on propofol injection.

The effects of propofol and thiopental on three vasoconstrictors, acetylcholine, histamine, and serotonin were studied in isolated porcine and human coronary artery rings. Propofol and thiopental attenuated the contractile response to all mediators in a dose-dependent manner. This dilating effect was fairly weak using low concentrations (propofol 1 μg mL−1 and 10 μg mL−1, thiopental 5 μg mL−1 and 10 μg mL−1). In the presence of high concentrations (propofol 100 μg mL−1, thiopental 50 μg mL−1) marked relaxation was observed (propofol −32% up to −49%, P < 0,05; thiopental −23% up to −67%, P < 0.05). These dilating effects were seen both in intact and denuded rings, the differences were not significant. Human coronary artery segments were relaxed by thiopental (−22% to −76%) and propofol (−11% to −67%) to a similar extent. Our data indicate that propofol and thiopental relax isolated coronary segments in a dose-dependent manner, and that there is no evidence that these effects are dependent of endothelial factors.

Summary

Background and objective: Every member of healthcare personnel should be able to perform basic life support including defibrillation (CPR-D). The biggest cost of implementation is training and these costs need to be reduced. The purpose of this randomized study was to evaluate the applicability of distance learning as a method to teach CPR-D. Methods: Nurses (n = 56) working in a geriatric hospital were randomized into three groups. The first group was given the Internet-based CPR-D course and the second was given a traditional, small-group CPR-D course. A third group without specific training in CPR-D served as a control group. An objective structured clinical examination (OSCE) was performed 2 weeks after the courses with a manikin patient having a cardiac arrest. Results: The median score of all participants was 31/49 (range 21–38). The reliability of the checklist was adequate (Cronbach alpha 0.77). Nurses receiving traditional CPR-D performed better than those receiving the Internet-based course (median score 34 vs. 28, P < 0.05) and the control group (median score 34 vs. 26, P < 0.0001). Nurses receiving Internet-based course performed similarly as the control group (median score 28 vs. 26, ns). Conclusions: Distance learning cannot substitute for traditional small-group learning.

Summary

Background: The suggested induction dose of methohexital for electroconvulsive therapy (ECT) varies widely influencing efficacy of ECT and safety of anaesthesia. Bispectral index (BIS), a monitor of consciousness, may be useful to assure adequate hypnosis with optimized methohexital dose. Methods: Patients with medically resistant major depression (ICD10), scheduled for multiple ECT's, were studied. Depth of anaesthesia was BIS controlled. ECT was not performed until BIS dropped below 50. Initially anaesthesia was induced with methohexital 1.0 mg kg−1, and stepwise reduced by 0.1 mg kg−1 during consecutive treatments. If BIS did not drop below 50, the methohexital was supplemented by further boluses of 0.5 mg kg−1, until the desired level of hypnosis was reached. The adequacy of the anaesthetic recommendation for methohexital (1.0–1.5 mg kg−1) as well as the psychiatric recommendation (0.75–1 mg kg−1) was investigated. Results: One-hundred and nine ECT's in 14 patients were studied. The recommended anaesthetic dose (1.0–1.5 mg kg−1) was inadequate in 40% of the treatments, with 12% exceeding 1.5 mg kg−1, and 28% below 1.0 mg kg−1. Psychiatric recommendation (0.75–1.0 mg kg−1) was inadequate in 49%, with 39% exceeding 1.0 mg kg−1 and 10% undershooting at 0.75 mg kg−1. Conclusions: Methohexital for ECT showed a great variability, exceeding as well as undershooting the dosage recommendations widely. BIS monitoring may be useful to secure adequate hypnosis during muscle relaxation and treatment and may optimize ECT efficacy.

Summary

Background and objective: The aim of this study was to assess target-controlled propofol infusion as a technique of sedation for shoulder surgery under interscalene brachial plexus block in the sitting position and to evaluate the effect of sedation on hypotensive/bradycardic events during this procedure. Methods: One hundred and forty patients undergoing elective shoulder surgery in the sitting position under interscalene brachial plexus block (with 30 mL of ropivacaine 0.75%) were prospectively enrolled. All patients were premedicated with hydroxyzine 1 mg kg−1, none received beta-blockers. No patients were given atropine except for the patients who experienced a vasovagal event either during the block procedure or intravenous catheter placement. The target-controlled propofol infusion was started immediately after positioning the patient on the operating table. The initial target concentration was 1 μg mL−1. The infusion rate was adjusted every 15 min by increasing or decreasing the target concentration by 0.2 μg mL−1 steps to maintain the patient rousable to verbal commands (score of 3 on Wilson sedation scale). The following parameters were assessed: minimal, maximal, optimal target concentration, respiratory and haemodynamic parameters, total propofol dose, additional alfentanil needs, occurrence of hypotensive/bradycardic events, complications. Results are mean ± SD. Statistical analysis used t-test and χ2-tests. Results: The optimal propofol target concentration was 0.8 μg mL−1. No respiratory complications or conversion to general anaesthesia was reported. Two patients experienced transient and inconsequential intraoperative agitation. The incidence of hypotensive/bradycardic events during the procedure was 5.7% (eight patients). Conclusion: Target-controlled propofol infusion (0.8–0.9 μg mL−1) following hydroxyzine premedication is a safe and effective technique for sedation when combined with interscalene brachial plexus block during shoulder surgery in the sitting position.

Background and objective The intubating laryngeal mask (intubating laryngeal mask airway) was designed to facilitate blind intubation. Its value as an adjunct to fibreoptic laryngoscopy has not been evaluated. This study compares the intubating laryngeal mask airway with the standard laryngeal mask airway as conduits for fibreoptic laryngoscopy.

Methods The fibreoptic view of the laryngeal inlet was graded via both devices in 60 anaesthetized patients. The fibreoptic view through the intubating laryngeal mask airway was assessed after the central epiglottic elevator bar had been lifted out of the field of vision by an 8-mm Euromedical® tracheal tube, which was inserted to a depth of 18 cm. The fibreoptic view from the aperture bars of the laryngeal mask was recorded.

Results The vocal cords were viewed less frequently through the intubating laryngeal mask airway (52%) than through the laryngeal mask airway (92%) [difference = 40% (95% CI = 26% to 54%), P < 0.0001].

Conclusion The view of the laryngeal inlet is better through the laryngeal mask airway than through a tracheal tube inserted to 18 cm in the intubating laryngeal mask.

Summary

Background and objective: We compared the dose requirement and side effect profile of total intravenous anaesthesia using Diprivan® to generic propofol at a specific anaesthetic target level utilizing the bispectral index monitor to determine efficacy differences between the two products. Methods: Sixty women undergoing abdominal hysterectomy were induced with propofol 2 mg kg−1 and maintained with infusion (20–200 μg kg−1 min−1) adjusted to maintain a bispectral index of 50–65. Plasma propofol concentration was measured at 1 and 2 h post induction in 25 patients. Results: Mean (SD) drug doses adjusted for weight and time were similar in the Diprivan® and generic propofol groups: 90 (30) μg kg−1 min−1 vs. 90 (20) μg kg−1 min−1 respectively. Mean (SD) plasma propofol levels at 1 and 2 h were also similar (3.0 (1.0) μg mL−1 vs. 3.6 (1.4) μg mL−1, P = 0.2 and 3.0 (1.9) μg mL−1 vs. 3.4 (1.6) μg mL−1, P = 0.58). Conclusions: Diprivan® and generic propofol have similar efficacy at a specified, bispectral index-defined, depth of anaesthesia.

This study was undertaken to determine the minimum effective dose of granisetron, a selective 5-hydroxy-tryptamine type 3 receptor antagonist, for the prevention of post-operative nausea and vomiting (PONV) in female patients undergoing elective laparoscopic cholecystectomy. In randomized, placebo-controlled, double-blind study, 120 women were assigned to receive either placebo (saline) or granisetron at three different doses (20 μg kg−1, 40 μg kg−1 or 80 μg kg−1) intravenously immediately before the induction of anaesthesia. All patients received standardized aesthesia consisting of isoflurane and nitrous oxide in oxygen. The incidence of PONV during the first 24 hours after anaesthesia was 43, 40, 13 and 13% after administration of placebo and granisetron 20 μg kg−1, 40 μg kg−1 and 80 μg kg−1, respectively (P<0.05, overall Fisher's exact probability test). Adverse effects post-operatively were not different among the groups. In conclusion, granisetron 40 μg kg−1 is the minimum effective dose in the prevention of PONV after laparoscopic cholecystectomy.