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Summary Increased levels of exhaled nitric oxide (eNO) may be a more objective predictor in identifying children at higher risk of peri-operative adverse respiratory events than the presence of risk factors such as recent cold or wheeze. Children with either none or ≥ 2 risk factors had eNO measured before surgery and any peri-operative adverse respiratory events were recorded. We found that an elevated eNO level was only predictive of adverse respiratory events in children with ≥ 2 risk factors (OR 2.96 (95% CI 1.48–5.93), p = 0.002). The presence of risk factors had a better predictive capability than a raised eNO level (OR 3.83 (95% CI 1.85–7.95), p

Probit analysis was used to predict an optimal dose of fentanyl, co-administered with propofol 2.5 mg.kg(-1), when inserting the laryngeal mask airway. In all, 21 male and 54 female healthy Chinese patients, aged 18-63 years, requiring anaesthesia for minor surgery were recruited. They were assigned to one of five groups: placebo, 0.5, 1.0, 1.5 and 2.0 microg.kg(-1). Insertion was performed 90 s after administration and insertion conditions assessed using a six-category score. Dose-response curves could only be drawn for swallowing and movement categories, and only the ED(50) could be predicted with certainty. To provide optimal conditions in over 95% of patients, fentanyl doses well above the clinical range were required. A standard fentanyl dose of 1 mug.kg(-1), co-administered with propofol 2.5 mg.kg(-1), provided optimal conditions in 65% of cases. Ninety seconds may have been insufficient time for fentanyl to reach its peak effect.

In a double-blind, randomised study of patients scheduled for minor hand surgery 0.5% 2-chloroprocaine (n = 30) and 0.5% prilocaine (n = 30) in a volume of 40 ml were compared for intravenous regional anaesthesia. The onset of sensory and motor block and recovery of sensory block were determined, and the occurrence of side-effects was noted. Twenty-four patients in the 2-chloroprocaine group and 17 in the prilocaine group developed complete sensory block by 15 min after injection (p0.05). Complete recovery of sensation was faster after prilocaine (7.1 min) than 2-chloroprocaine (9.8 min) (p0.01). Venous irritation and/or urticaria after tourniquet release was observed on 10 occasions in those receiving 2-chloroprocaine and twice in those receiving prilocaine. An increase in heart rate of20% above control values occurred in three patients, all of whom had been given 2-chloroprocaine. Clinically, local anaesthetic properties of 0.5% 2-chloroprocaine and prilocaine were similar, but there were more side-effects with the former drug.

The 50% and 95% effective doses of desflurane for removal of the classic laryngeal mask airway after suction of the upper airway, in anaesthetised spontaneously breathing adult patients, are not known. To determine these, we studied 38 healthy patients, aged between 18 and 44 years. The target desflurane concentration in each individual patient was determined by the Dixon up-and-down method. When the predetermined target end-tidal desflurane concentration reached steady state, we kept a constant end-expiratory partial pressure between the alveolus and the brain for 10 min before attempting to remove the classic laryngeal mask airway after suctioning the upper airway. The initial desflurane target concentration was set at 6% and up-down desflurane increments were 0.1%. This continued until there were at least six crossover pairs. From the probit analysis, the 50% effective dose of desflurane was 5.29% (95% CI 5.132-5.379%) and the 95% effective dose was 5.55% (95% CI 5.429-6.394%).

Obesity impairs peri-operative lung function. To evaluate the impact of pressure support ventilation vs pressure controlled ventilation in moderately obese adults upon early postoperative lung function, we randomly assigned 68 moderately obese patients (body mass index 25-35 kg x m(-2)) undergoing minor surgery to receive intra-operative ventilation either with pressure support or pressure controlled ventilation. We performed intra-operative blood gas analysis and measured pulse oximetry saturation, spirometry values at pre-operative assessment (baseline) and at 10 min, 30 min, 2 h and 24 h after extubation. The intra-operative oxygenation index (arterial partial pressure of oxygen/fraction of inspired oxygen) in the pressure support ventilation group was significantly improved over time (p < 0.0001). Postoperatively, the pressure support ventilation group also had better lung function and oxygenation values than did the pressure controlled ventilation group (p < 0.005). We conclude that pressure support ventilation better maintains lung function than pressure controlled ventilation in moderately overweight patients scheduled for minor surgery.

This study assessed two disposable devices; the newly developed supraglottic airway device i-gel and the LMA-Unique in routine clinical practice. Eighty patients (ASA 1-3) undergoing minor routine gynaecologic surgery were randomly allocated to have an i-gel (n = 40) or LMA-Unique (n = 40) inserted. Oxygen saturation, end-tidal carbon dioxide, tidal volume and peak airway pressure were recorded, as well as time of insertion, airway leak pressure, postoperative sore-throat, dysphonia and dysphagia for each device. Time of insertion was comparable with the i-gel and LMA-Unique. There was no failure in the i-gel group and one failure in the LMA-Unique group. Ventilation and oxygenation were similar between devices. Mean airway pressure was comparable with both devices, whereas airway leak pressure was significantly higher (p0.0001) in the i-gel group (mean 29 cmH(2)O, range 24-40) compared with the LMA-Unique group (mean 18 cmH(2)O, range 6-30). Fibreoptic score of the position of the devices was significantly better in the i-gel group. Post-operative sore-throat and dysphagia were comparable with both devices. Both devices appeared to be simple alternatives to secure the airway. Significantly higher airway leak pressure suggests that the i-gel may be advantageous in this respect.

The first 24 hours of the postoperative course of 2153 consecutive patients who had operations at the Nottingham Hospitals were studied in detail. Five per cent of patients had serious complications during this period; 15% of those having major operations, 1.8% having intermediate operations and 1.4% having minor operations. Thus, a significant number of patients were in an unstable condition for many hours after they were discharged from the main theatre recovery areas to the surgical wards. In 17 out of 23 patients who died and six out of six patients who suffered severe disability as a result of their surgery, the final outcome was a direct result of a sequence of events which began with an initial deterioration within 24 hours of surgery. We considered that, for at least 10 of these 29 patients, the outcome might have been different had more sophisticated postoperative facilities been available. In the light of this study we have identified the operations for which high dependency facilities are most likely to be required.

The number of fluctuations of skin conductance per second correlates with postoperative pain. The aim of this prospective study was to test the cut-off value for the number of fluctuations of skin conductance per second obtained from a previous study. Seventy-five patients were asked to quantify their level of pain on a numeric rating scale (0-10) in the recovery room. The number of fluctuations of skin conductance per second was recorded simultaneously. The number of fluctuations of skin conductance per second was different between patients with no (0.07), mild (0.16), moderate (0.28) and severe pain (0.33); p0.001. The tested cut-off value for the number of fluctuations of skin conductance per second (0.1) distinguished a numeric rating scale/= 3 from3 with 88.5% sensitivity and 67.7% specificity. The number of fluctuations of skin conductance per second may be a useful means of assessing postoperative pain.

Postoperative morbidity and serum osmolality were studied in 46 patients who were encouraged to drink water until 3 h pre-operatively and 49 receiving the normal fasting regimen prior to minor surgery. There was significantly less thirst in the postoperative period in those patients allowed to drink and subjectively better recovery than after previous anaesthesia. There was no morbidity from ingestion of up to 11 of water 2.5 h pre-operatively. Although there was only a moderate improvement in postoperative recovery we feel that allowing patients to drink water pre-operatively improves patient comfort, especially since patients may have to fast for much longer than guidelines recommend, simply because of the traditional organisation of operating lists.

Summary Twenty patients scheduled for minor gynaecological surgery were studied. Anaesthesia was induced with propofol and maintained either with enflurane/oxygen/nitrous oxide or propofol/oxygen/nitrous oxide. The rate of gastric emptying was measured indirectly by the paracetamol absorption model. The results showed that there was no significant difference in gastric emptying rate between the two groups. Recovery in the propofol group was more rapid in that paracetamol ingestion occurred earlier in the recovery period compared with the enflurane group.

Sixty adult patients undergoing minor peripheral surgery under general anaesthesia were randomly allocated to receive either the laryngeal mask airway (laryngeal mask airway; size 4 for females and size 5 for males) or the PAXpress (adult size), inserted by a single operator with experience of50 insertions of each device. The laryngeal mask airway was correctly placed on the first attempt in 27 patients (90%) compared with 20 patients (67%) when using the PAXpress (p0.01). No patient required more than two attempts at insertion and there were no failures with the laryngeal mask airway, compared with four (13%) who needed three attempts and two failures (7%) with the PAXpress (p0.001 and p0.01, respectively). Mean (SD) total placement time was shorter with the laryngeal mask airway [24.6 (3.1) s] than with the PAXpress[35.4 (2.5) s; p0.01]. The most common complication was sore throat, which occurred less frequently with the laryngeal mask airway (8 patients; 26%) than with the PAXpress (15 patients; 53.5%; p0.001).

The aim of this study was to investigate the effect of halothane vs. isoflurane on cytokine production during minor elective surgery. Forty adult patients, ASA I-II were randomly allocated to receive halothane or isoflurane. Venous samples for interleukin (IL)-1beta, IL-2, IL-6, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) were taken before anaesthesia, before incision, at the end of anaesthesia and 24 h postoperatively. In both groups, IL-6 and TNF-alpha levels remained low throughout the study period. Before incision, in both groups IL-1beta and IFN-gamma showed a decrease (p0.01 for IL-1beta in isoflurane group and p0.05 for the others) compared with pre-induction. By the end of anaesthesia and surgery, IL-1beta had increased significantly (p0.05) and IFN-gamma had decreased significantly (p0.05) in both groups compared with pre-incisional levels. By 24 h postoperatively in both groups, IL-1beta had decreased significantly (p0.05), whereas IFN-gamma had increased significantly (p0.05) compared with the end of anaesthesia and surgery level. Pre-incisionally, IL-2 increased in the halothane group (p0.01), whereas it decreased significantly in the isoflurane group (p0.001) compared with the pre-induction level. By the end of anaesthesia and surgery and by 24 h postoperatively, IL-2 had decreased significantly in the halothane group (p0.001), whereas it increased significantly in the isoflurane group (p0.001) compared with pre-incision and end of anaesthesia and surgery levels, respectively.

Summary We have used eltanolone to induce anaesthesia and by intermittent injection to supplement nitrous oxide during maintenance in 50 patients undergoing minor gynaecological surgery; opioids were not used. Induction of anaesthesia was remarkably trouble free and achieved with a single dose of 0.5 mg.kg−1 in 90% of patients. Pain on injection was not a feature. Satisfactory anaesthesia was achieved in 84% of patients; eight required addition ofisoflurane. There were minimal cardiovascular changes and apnoea on induction occurred in only one patient. Recovery times were acceptable.

Twenty patients, scheduled for minor gynaecological surgery, were studied. Anaesthesia was induced with propofol and maintained with oxygen, nitrous oxide and enflurane. Patients were randomly allocated to two groups: group 1 were given alfentanil 0.2 mg; group 2 were given morphine 5 mg. The rate of gastric emptying was measured indirectly by the paracetamol absorption technique. The results showed that morphine caused greater delay in gastric emptying compared with alfentanil (p < 0.05). The observed effect on gastric emptying rate may potentially affect the risk of peri-operative regurgitation and aspiration. This study provides further evidence that in short day-case procedures, when oral medication may be required postoperatively, alfentanil may be preferable to morphine as an intra-operative opioid.

Summary Temazepam, a benzodiazepine, hitherto used only as a hypnotic, was studied as a pre-anaesthetic medication in adult women undergoing minor gynaecological surgery in a dose of 30 mg and compared to 10 mg of diazepam. The sedative effect of temazepam was found to be superior to that of diazepam, using both objective and subjective criteria for assessment. There was also a highly significant degree of patient acceptance of the drug. It is suggested that temazepam is a suitable drug for premedication for minor surgery.

Althesin anaesthesia alone had no significant effect on plasma cortisol concentration. When Althesin induction was followed by maintenance with N2O and halothane there was a statistically insignificant fall, but with N2O, pancuronium and I.P.P.V there was a tendency for plasma cortisol concentrations to rise. This, too, was statistically not significant. A significant elevation in the mean plasma cortisol concentration was only found in patients during abdominal surgery.

Summary In 38 patients subjected to minor surgery, totally intravenous anaesthesia with low dose ketamine and Althesin produced adequate operating conditions in 92% of patients with minimal cardiorespiratory disturbance. Problems arose from muscular hyper tonus, spontaneous movement and occasionally salivation. Initial recovery was quicker and the incidence of side-effects lower, than those reported when ketamine was used as the sole agent. The technique could be useful in difficult situations as an alternative to inhalation anaesthesia or other intravenous techniques.

Paracetamol absorption after oral administration was studied in eleven patients immediately after a short general anaesthetic for cystoscopy and also in eight healthy volunteers. There were no statistical differences between the rate of paracetamol absorption in the two groups. This suggests that oral medication may be given immediately following a short general anaesthetic when opioid drugs are avoided.

An anaesthetic technique for unpremedicated patients undergoing minor surgery is described. After the administration of atropine and fentanyl, anaesthesia was induced with methohexitone and maintained with nitrous oxide supplemented when necessary by further small doses of methohexitone. This technique provided good operating conditions and was free from major complications. Recovery was rapid and pleasant.

In a prospective randomised study in 20 insulin-dependent diabetics who had minor surgery under general anaesthesia we compared the metabolic responses to intravenous glucose-insulin-potassium infusion with those who had conventional subcutaneous insulin administration. The former treatment resulted in lower blood glucose levels both during the infusion period (p less than 0.05) as well as the entire observation period (operative, first and second postoperative days; p less than 0.01). More blood glucose values were within the intended range of 5 to 10 mmol/litre in the glucose-insulin-potassium as compared to the conventional group (48% versus 24%; p less than 0.01). The levels of lactate, 3-hydroxybutyrate, glycerol, alanine, glucagon, insulin and growth hormone did not differ between the two groups. The infusion regimen resulted in better glycaemic control both peri-and postoperatively than the conventional subcutaneous insulin regimen in insulin-dependent diabetic patients who have minor surgery.

Summary Fourteen patients received oral premedication of temazepam in soft gelatin capsules before minor surgery. The plasma concentrations of temazepam and its sedative, anxiolytic and amnesic effects were measured for 24 hours. Absorption was rapid and peak concentrations occurred 49 minutes after administration. Clinical effects were evident at 30 minutes and persisted for about 4 hours. The decline in plasma concentration was biexponential with a distribution half-life of 1.24 hours. The end of the distribution phase coincided approximately with the termination of its clinical effects. A relationship between plasma concentration and effect was observed: concentrations above 300 ng/ml produced measurable changes in tests of mental function. Patients had recovered fully from the effects of temazepam after 24 hours. This dose of temazepam is reliable and efective as premedication before surgery.