Showing papers in "BJA: British Journal of Anaesthesia in 1986"
TL;DR: The most important clinical properties of local anaesthetic agents are potency, onset, duration of action and relative blockade of sensory and motor fibres.
Abstract: The most important clinical properties of local anaesthetic agents are potency, onset, duration of action and relative blockade of sensory and motor fibres. These qualities are related primarily to the physicochemical properties of the various compounds. In general, lipid solubility determines the relative intrinsic potency of the various agents, while protein binding influences the duration of anaesthesia and pKa is correlated with the onset of action. In general, the local anaesthetics for infiltration, peripheral nerve blockade, and extradural anaesthesia can be classified into three groups: agents of low potency and short duration, for example procaine and chloroprocaine; agents of moderate potency and duration, for example lignocaine, mepivacaine and prilocaine; and agents of high potency and long duration, for example amethocaine, bupivacaine and etidocaine. These local anaesthetics also vary in terms of onset: chloroprocaine, lignocaine, mepivacaine, prilocaine and etidocaine have a rapid onset, while procaine, amethocaine and bupivacaine are characterized by a longer latency period.
299 citations
TL;DR: This review will concentrate on aspects of the systemic absorption and disposition of local anaesthetics, which are based primarily upon spatio-temporal changes in anaesthetic effect, rather than chemical measurements.
Abstract: Pharmacokinetics seeks to provide a mathematical basis for the description and prediction of the time-course of drugs in the body and an understanding of the processes involved in drug absorption and disposition. In the context of regional anaesthesia, the application of kinetic principles helps specifically in the following ways: (1) To select safe doses for single anaesthetic procedures and safe rates for continuous nerve block techniques. (2) To choose the best agents for particular procedures. (3) To identify patients who may be at particular risk of developing systemic toxic reactions. (4) To understand events after inadvertent intravascular injection. In addition, knowledge of the pharmacokinetics of existing agents should contribute to the design of better local anaesthetics in the future. This review will concentrate on aspects of the systemic absorption and disposition of local anaesthetics. Processes involved in the local disposition of the agents at and near the site of injection also come under the heading of pharmacokinetics. However, understanding of these phenomena is more speculative, since it is based primarily upon spatio-temporal changes in anaesthetic effect, rather than chemical measurements. The reader is referred to reviews by Greene (1983,1985) and Tucker and Mather (1980,1986) for discussion of these aspects.
242 citations
TL;DR: The clinical syndromes associated with phaeochromocytoma are described, the diagnostic procedures which may identify and localize the tumour(s), the principles and practical aspects of pharmacological control, and a method of anaesthetic management which has proved safe and effective in many patients are described.
Abstract: Unless patients harbouring this uncommon tumour are correctly prepared and protected from the effects of excessive catecholamine release, they are greatly at risk when undergoing surgical procedures of any kind. This short review describes the clinical syndromes associated with phaeochromocytoma, the diagnostic procedures which may identify and localize the tumour(s), the principles and practical aspects of pharmacological control, and a method of anaesthetic management which has proved safe and effective in many patients.
179 citations
TL;DR: The effect of EMLA in the alleviation of the pain of venous cannulation was considered significantly better than placebo by both anaesthetist and patient and one conventional pictorial scale showed a statistically significant difference (P less than 0.05).
Abstract: The effect of the topical application of a lignocaine-prilocaine cream (EMLA) on the pain of venous cannulation was tested in a double-blind manner Sixty boys and girls between the ages of 4 and 10 yr who were to undergo surgery participated in the study No analgesic premedic-ation was given and the venous cannulation was performed during the preparation for general anaesthesia Pain was assessed by the anaesthetist and the patient using a verbal rating scale and two different pictorial scales The effect of EMLA in the alleviation of the pain of venous cannulation was considered significantly better than placebo by both anaesthetist (P
178 citations
TL;DR: Propofol may on occasions, lead to myocardial ischaemia in patients with coronary artery disease, but that it is able to block the sympathetic responses to surgical stimulation when combined with a suitable analgesic.
Abstract: The effects of propofol (emulsion formulation) on cardiovascular dynamics, myocardial blood flow and myocardial metabolism were studied in 12 patients scheduled for elective coronary artery bypass surgery. Measurements were performed with the patient awake, during steady-state maintenance anaesthesia with propofol 200 micrograms kg-1 min-1 at rest, and during sternotomy when the propofol was supplemented with fentanyl 10 micrograms kg-1. Propofol alone decreased mean arterial pressure and cardiac index; heart rate was increased. Myocardial blood flow and myocardial oxygen consumption were decreased by 26% and 31%, respectively. Myocardial lactate production was seen in one patient during this period. Surgical stimulation, under propofol-fentanyl anaesthesia, led to the return of arterial pressure and heart rate towards baseline; cardiac index decreased further. Myocardial blood flow and oxygen consumption increased such that they almost achieved their baseline values. Myocardial lactate production was seen in one patient. These results suggest that propofol may on occasions, lead to myocardial ischaemia in patients with coronary artery disease, but that it is able to block the sympathetic responses to surgical stimulation when combined with a suitable analgesic.
175 citations
169 citations
TL;DR: By injecting at L2/3 spinal space (group C) the mean maximum level of anaesthesia (T7) was four segments higher than group A (T11) injected at L3/4, and this was reflected in a greater incidence of arterial hypotension.
Abstract: Plain bupivacaine 0.5% or 0.75% was injected intrathecally in four groups of 10 patients. Group A received 0.75% bupivacaine 2.7 ml at L3/4, group B 0.5% bupivacaine 4 ml at L3/4, group C 0.75% bupivacaine 2.7 ml at L2/3 and group D 0.75% bupivacaine 2ml at L3/4. A very wide range of height of block was found in each group and because of this there were few statistically significant differences between the groups. The mean height of anaesthetic blockade was significantly higher when 20 mg (group C) was injected compared with 15 mg (group D). Decreasing the volume of injection from 4ml (group B) to 2.7 ml (group A) did not decrease this variability. By injecting at L2/3 spinal space (group C) the mean maximum level of anaesthesia (T7) was four segments higher than group A (T11) injected at L3/4, and this was reflected in a greater incidence of arterial hypotension.
155 citations
TL;DR: The mortality following surgical correction of upper femoral fractures was investigated in 578 patients randomly allocated to receive spinal (bupivacaine) or general anaesthesia (enflurane or neurolept) anaesthesia.
Abstract: The mortality following surgical correction of upper femoral fractures was investigated in 578 patients, over the age of 50 yr, randomly allocated to receive spinal (bupivacaine) or general (enflurane or neurolept) anaesthesia. Thirty days after surgery the mortality was 6% after spinal and 8% after general anaesthesia (ns). Six months to 2 years after surgery the mortality was identical in the two groups. There were no differences with respect to ambulation and discharge. The estimated blood loss was smaller (P
141 citations
TL;DR: It is concluded that extradural anaesthesia must be used with extreme caution in patients with reduced intracranial compliance, and should not be used at all in a patient with intrac Cranial hypertension or a space-occupying lesion.
Abstract: The intracranial pressure (ICP) response to the lumbar extradural injection of bupivacaine hydrochloride was measured in two patients on a total of 29 occasions. In the first patient, mean ICP increased from an average figure of 18.8 mm Hg to 39.5 mm Hg after the injection of 10 ml of solution. This increase was maintained for an average of 4.5 min. Both the magnitude and the duration of the increase were less when 5 ml was injected. The second patient had a normal baseline ICP, but the injection of bupivacaine 10ml produced an increase from a mean of 9. 3 mm Hg to 15. 6 mm Hg. Injection of the same volumes of physiological saline in the second patient induced increases in ICP similar to those obtained with bupivacaine. There was a good correlation between baseline ICP and the increase produced by the extradural injection. It is concluded that extradural anaesthesia must be used with extreme caution in patients with reduced intracranial compliance, and should not be used at all in a patient with intracranial hypertension or a space-occupying lesion.
134 citations
TL;DR: Seven out of 12 patients showed significant secondary peaks in blood propofol concentration associated with recovery from anaesthesia, and there were no differences in the derived kinetic indices for the male and female patients, with the exception of a greater Vdss:V gamma ratio in the males.
Abstract: The disposition kinetics of propofoi have been determined in 12 patients (six female) receiving propof of 2.5 mg kg−1 for induction of anaesthesia, which was maintained with 67% nitrous oxide in oxygen and 1–1.5% halothane. Peripheral blood samples were collected at selected times up to 8 h after the injection of the drug, and whole blood propofoi concentrations determined by HPL C with fluorescence detection. Drug concentration–time data were analysed by the non-linear regression program EL SFIT. This showed the data to be describable by a tri-exponential equation, corresponding to a three-compartment model. There were no differences in the derived kinetic indices for the male and female patients, with the exception of a greater Vdss: Vγ ratio in the males. The terminal half-life in the male patients was 262 min (SEM 44), and in the female patients 309min(60). Vdss was 329 litre (67) and 313 litre (69) in male and female patients, respectively. The clearance in both groups was 1.8 litre min−1. Seven out of 12 patients showed significant secondary peaks in blood propofoi concentration associated with recovery from anaesthesia.
133 citations
TL;DR: Double-lumen endobronchial tubes were placed "blindly" in 23 patients undergoing thoracotomy and subsequent fibreoptic bronchoscopy revealed malposition in 48% of cases, with potential hazards associated with these findings.
Abstract: Double-lumen endobronchial tubes were placed "blindly" in 23 patients undergoing thoracotomy. Clinical criteria suggested satisfactory positioning in all cases; however, subsequent fibreoptic bronchoscopy revealed malposition in 48%. Bronchoscopic findings included the inability to view the bronchial cuff. narrowing of the bronchial lumen of the tube at the level of the cuff and herniation of the cuff over the carina. The potential hazards associated with these findings are discussed.
TL;DR: There was a marked increase in noradrenaline concentration, a moderate increase in adrenaline concentration and an arterial pressure response in the group of hypertensive patients, consistent with transient sympathetic overactive patients following noxious stimuli such as laryngoscopy.
Abstract: Arterial pressure and plasma catecholamine concentrations were measured in 16 normotensive and 10 hypertensive patients undergoing elective vascular surgery. Following induction of anaesthesia; both arterial pressure and plasma noradrenaline concentrations decreased in both groups. Following laryngoscopy, there was a moderate increase in arterial pressure in both normotensive and hypertensive patients. In normotensive patients, laryngoscopy was associated with a moderate increase in plasma noradrenaline concentration. There was no change in adrenaline concentration. By contrast, there was a marked increase in noradrenaline concentration, a moderate increase in adrenaline concentration and an arterial pressure response in the group of hypertensive patients. These data are consistent with transient sympathetic overactivity in hypertensive patients following noxious stimuli such as laryngoscopy.
TL;DR: The efficacy of domperidone 20 mg, droperidol 2.5 mg, metoclopramide 10 mg or placebo (saline) administered i.v before induction of anaesthesia, was studied in 199 women undergoing gynaecological surgery as day cases.
Abstract: The efficacy of domperidone 20 mg, droperidol 2.5 mg, metoclopramide 10 mg or placebo (saline) administered i.v. before induction of anaesthesia, was studied in 199 women undergoing gynaecological surgery as day cases. Following a standardized general anaesthetic technique, droperidol or metoclopramide significantly reduced the incidence of nausea and vomiting; domperidone decreased the incidence of postoperative nausea alone. The occurrence of extrapyramidal reactions was similar in all groups. Patients treated with antiemetics were no more sedated than those given placebo. Those receiving droperidol complained of significantly less postoperative pain than those who had received domperidone or metoclopramide.
TL;DR: The absorption of bupivacaine and etidocaine into nerve tissue was identified at steady state, but in extradural and subcutaneous fat etidOCaine was taken up significantly more than bupvacaine, and there was a significantly higher concentration of ropivicaine than lignocaine in all tissues.
Abstract: Absorption of four amide local anaesthetics, including a new experimental agent, ropivacaine, in n-heptane, rat sciatic nerve and human extradural and subcutaneous fat was studied in vitro. The relative n-heptane/buffer (37 °C) partitioning of bupivacaine: etidocaine: lignocaine: ropivacaine was 10: 39: 1: 2.9. The absorption of bupivacaine and etidocaine into nerve tissue was identified at steady state, but in extradural and subcutaneous fat etidocaine was taken up significantly more than bupivacaine. The lowest uptake was with lignocaine, and at steady state its mean concentrations were similar in all three tissues. There was a significantly higher concentration of ropivacaine than lignocaine in all tissues. Mean tissue concentrations of bupivacaine in sciatic nerve and subcutaneous fat, on the other hand, were significantly higher than those of ropivacaine. The ratios of relative mean uptake (mg g−1), at steady state, of bupivacaine, etidocaine, lignocaine and ropivacaine were: sciatic nerve 3.3: 4: 1: 1.8, extradural fat 4.1: 8.3: 1: 2.3 and subcutaneous fat 3.8: 10.6: 1: 1.9, all of which were clearly lower than the theoretical n-heptane/buffer partitioning ratios.
TL;DR: Perfusion with physiological saline produced an analgesic effect comparable to that of bupivacaine as indicated by improvement in VAS, but there was, however, no improvement in FVC, and opioid requirements were greater, in patients whose wounds had been perfused with saline.
Abstract: In a double-blind trial, 50 patients with subcostal incisions performed for cholecystectomy or splenectomy, received 10 mlof either 0. 5% bupi-vacaine plain or physiological saline twice daily by woundperfusion through an indwelling drainage tube for 3 days after operation. Analgesia, assessed by visual analogue score (VAS) and forced vital capacity (FVC), was significantly improved after perfusion with bupivacaine. Perfusion with physiological saline produced an analgesic effect comparable to that of bupivacaine as indicated by improvement in VAS. There was, however, no improvement in FVC, and opioid requirements were greater, in the patients whose wounds had been perfused with saline.
TL;DR: It is possible that changes in evoked potential measurementss may be useful as a neurophysiological indicator of anaesthetic depth.
Abstract: Somatosensory, visual and brainstem auditory evoked potentials were recorded in 10 unpremedicated patients anaesthetized with isoflurane in oxygen. Recordings were made at 0.5%, 1.1% and 1.65% (six patients) end-tidal isoflurane concentration. There were statistically significant increases in the latencies of the somatosensory (N20), visual and brainstem auditory potentials (waves III and V) with increasing concentrations of isoflurane. The central conduction time was prolonged. Amplitudes of the somatosensory and visual potentials were reduced with increasing concentrations of isoflurane. The effects of isoflurane on evoked potentials are similar to those of halothane and enflurane. It is possible that changes in evoked potential measurements may be useful as a neurophysiological indicator of anaesthetic depth.
TL;DR: Fifty-five patients were assigned randomly to receive either a total i.v. anaesthetic based on a two-stage infusion of etomidate plus increments off fentanyl or a regimen based on inhaled nitrous oxide with i.V. fentanyl increments, and 44% of the nitrousoxide group were found to be wakeful at some time during surgery.
Abstract: Fifty-five patients were assigned randomly to receive either a total i.v. anaesthetic based on a two-stage infusion of etomidate plus increments offentanyl or a regimen based on inhaled nitrous oxide with i.v. fentanyl increments. Using the isolated forearm technique, 44% of the nitrous oxide group were found to be wakeful at some time during surgery, whereas only 7% of the etomidate group were wakeful. There was one case of awareness in the nitrous oxide group.
TL;DR: Droperidol alone was effective in protecting against nausea and vomiting after major gynaecological surgery and required less postoperative analgesia than those given domperidone or metoclopramide.
Abstract: Domperidone 20 mg, droperidol 2.5 mg, metoclopramide 10 mg and placebo (saline) were given i.v. 10 min before the end of anaesthesia, to 200 women undergoing major gynaecological surgery, and the incidence of postoperative nausea and vomiting following a standard anaesthetic technique was assessed. Droperidol was significantly more effective than domperidone, metoclopramide or placebo in reducing emetic sequelae. There were no significant differences between the groups in the incidence of extrapyramidal effects and postoperative sedation. Patients given droperidol required less postoperative analgesia than those given domperidone or metoclopramide. It was concluded that, of the drugs studied, droperidol alone was effective in protecting against nausea and vomiting after major gynaecological surgery.
TL;DR: There was a correlation between the height of blockade assessed by pinprick analgesia and the degree of obesity of the patients measured by weight, weight/ height, and weight/height2.
Abstract: In an unblinded study 50 patients undergoing cystoscopic procedures received a spinal anaesthetic of plain 0.5% bupivacaine 4 ml administered in the sitting position at the L3–4 space. There was a correlation between the height of blockade assessed by pinprick analgesia and the degree of obesity of the patients measured by weight/height, and weight/height2. Using this dose of spinal anaesthetic agent, high blockade may be anticipated in obese patients.
TL;DR: When compared with placebo, RO improved alertness and collaboration for 15 min, and suppressed anterograde amnesia for 60 min, when compared with Placebo, the efficacy, usefulness and side effects of RO, a specific benzodiazepine (BZD) antagonist, have been evaluated.
Abstract: The efficacy, usefulness and side effects of RO 15-1788 (RO), a specific benzodiazepine (BZD) antagonist, have been evaluated. Sixty-two patients (ASA l-lll, mean age 72±9 yr) scheduled for urological surgery under regional anaesthesia and BZD sedation received placebo or RO in a randomized, double-blind fashion at the end of the procedure, folio wing sedation with midazolam. When compared with placebo, RO improved alertness and collaboration for 15 min, and suppressed anterograde amnesia for 60 min. No major side effect was noted, although five patients became anxious after administration of RO. Two cases of a paradoxical reaction to midazolam were treated successfully by RO.
TL;DR: The satisfactory maintenance of anaesthesia provided by nitrous oxide supplemented with propofol was associated with haemodynamic stability and rapid, uncomplicated recovery.
Abstract: The study was performed to determine the ED50 and ED95 of a continuous infusion of the emulsion formulation of propofol during 67% nitrous oxide anaestheisa in 57 patients premed-icated with morphine sulphate 0.15 mg kg−1. Anaesthesia was induced with propofol 2 mg kg−1, and maintained before incision with a fixed-rate infusion of propofol to supplement nitrous oxide. The response to the first surgical incision, made at least 30 min after induction of anaesthesia, was observed. The ED50; was 53.5 μg kg−1 min−1 and the ED95 was 112.2 μg kg−1 min−1. At the time of the first surgical incision, the venous whole blood concentrations of propofol at the ED50 and ED95 infusion rates (EC50and EC95 were 1.66 μg ml−1 and 3.39 fig ml−1 respectively. The satisfactory maintenance of anaesthesia provided by nitrous oxide supplemented with propofol was associated with stability and rapid, uncomplicated recovery.
TL;DR: Thirty hypertensive patients scheduled for cholecystectomy or hernia repair under general anaesthesia with thiopentone-fentanyl-nitrous oxide-pancuronium were divided into two groups of 15 and metoprolol significantly reduced arterial pressure both during undisturbed anaesthesia, during intubation and after extubation, and had no effect on variations in systemic vascular resistance.
Abstract: Thirty hypertensive patients scheduled for cholecystectomy or hernia repair under general anaesthesia with thiopentone–fentanyl–nitrous oxide–pancuronium were divided into two groups of 15. One group received metoprolol tablets 200 mg in a slow release form, once daily for at least 2 weeks including the morning of surgery, In addition, metoprolol 15 mg was injected i.v. shortly before the induction of anaesthesia. The other group received placebo tablets and saline. Two patients in the treatment group and one patient in the placebo group were subsequently excluded, because of complications during treatment. Metoprolol significantly reduced arterial pressure both during undisturbed anaesthesia, during intubation and after extubation. A similar tendency was observed also during surgery, although it was not quite significant (P = 0.055). However, metoprolol had no effect on variations in systemic vascular resistance. Mean pulmonary arterial pressures during anaesthesia and surgery were significantly greater in the control, than in the metoprolol, group. Central venous pressure (CVP) and pulmonary arterial occlusion pressure (PAOP) increased significantly in both groups in response to the surgical stimulus. There was no significant difference between the groups in PAOP and CVP. One patient in the metoprolol group and marked bradycardia (minimum heart rate 26 beat min-1) after neostigmine and atropine; otherwise metoprolol pretreatment was tolerated well.
TL;DR: At a time when the agent of choice for paediatric anaesthesia was chloroform, the introduction of spinal anaesthesia produced a considerable reduction in morbidity and mortality and there was an almost total absence of vomiting, with an associated rapid return to normal feeding.
Abstract: At a time when the agent of choice for paediatric anaesthesia was chloroform, the introduction of spinal anaesthesia (Bainbridge, 1900; Gray, 1909a,b, 1910) produced a considerable reduction in morbidity and mortality (Farr, 1920). Other advantages of note were limitation of anaesthesia to the part to be operated on, muscular relaxation and avoidance of the over-distended gut but, more significantly, during the postoperative period there was an almost total absence of vomiting, with an associated rapid return to normal feeding. Gray was also impressed by the long duration of postoperative analgesia and the commensurate reduction in the use of opioids. Local anaesthesia continued to remain popular for use in children into the 1940s and Leigh and Belton( 1948) reported that 10% of all anaesthetics at their hospital were spinal blocks, even for lobectomy and pneumonectomy. The introduction of neuromuscular blocking agents to paediatric anaesthetic practice (Rees, 1950), followed by halothane, coincided with a growing controversy over the use of techniques such as spinal anaesthesia in children. Some authors continued to extol the technique: " Spinal anaesthesia is an excellent method for children" (Berkowitz and Greene, 1951), while others contended that" Spinal anaesthesia in children has been and still is frowned upon by the majority of anaesthetists and surgeons" (Slater and Stephen, 1950). Following the Woolley and Roe case, it was proposed that all forms of local anaesthesia for major surgery should give place to general anaesthesia (Armstrong Davison, 1965).
TL;DR: Pain scores, nausea scores and blood loss were similar in both groups, but patients receiving ibuprofen demanded significantly less morphine in the 24 h after surgery.
Abstract: The effect of the regular administration of ibuprofen on pain following abdominal surgery was investigated in a double-blind placebo-controlled study. The analgesic action of ibu-profen was measured by a reduction in the amount of morphine self-administered from an On-Demand Analgesic Computer. Pain scores, nausea scores and blood loss were similar in both groups, but patients receiving ibuprofen de-manded significantly less morphine in the 24 h after surgery.
TL;DR: After repeated, successful extradural injections in a parturient, the extradural catheter migrated into the subdural space and resulted in an extensive block, which extended to the cranial nerves and paralysed the respiratory muscles.
Abstract: After repeated, successful extradural injections in a parturient, the extradural catheter migrated into the subdural space. The injection of 3% chloro-procaine 10 ml resulted in an extensive block, which extended to the cranial nerves and paralysed the respiratory muscles. The position of the catheter tip was confirmed by fluoroscopy. Subdural injection should always be suspected when tests for subarachnoid injection are negative, but an extensive block occurs gradually within 15–20 min. Respiration and circulation should be supported until the block regresses.
TL;DR: In this study, neuromuscular blockade was prolonged, possibly as a result of interference, by surgical manipulation, with the rapid hepatic uptake of vecuronium.
Abstract: The plasma and bile concentrations, the biliary excretion and the neuromuscular blocking effect of vecuronium bromide were studied during surgery in 13 patients who had received 150 μg kg−1 i.v. The amount of vecuronium in liver biopsies taken after i.v injection was measured in a separate group of six patients. Vecuronium appeared early in the bile, in concentrations that were 30–50 times greater than those in the plasma. On the basis of the measured amount of vecuronium excreted in the bile, together with the accepted average daily bile flow, it was estimated that more than 40% of vecuronium was excreted in the bile in 24 h. Liver biopsies indicated that the liver may contain more than 50% of the i.v. dose 30min after injection. The large distribution of vecuronium into the liver may account for the initial rapid decline in vecuronium plasma concentration and its relatively short duration of action. In this study, neuromuscular blockade was prolonged, possibly as a result of interference, by surgical manipulation, with the rapid hepatic uptake of Vecuronium.
TL;DR: Midazolam was given, by infusion, for the sedation of 10 children receiving intensive care after cardiac surgery, and eight of the 10 children did not cumulate, and these patients excreted the drug in a fashion similar to that by adults.
Abstract: Midazolam was given, by infusion, for the sedation of 10 children receiving intensive care after cardiac surgery. Plasma concentrations greater than 250 ng ml-1 were required for adequate sedation. Midazolam did not cumulate in eight of the 10 children, and these patients excreted the drug in a fashion similar to that by adults. However, midazolam did accumulate in two children, one with profound hepatic disturbance. In one of these patients recovery was slow following cessation of the infusion.
TL;DR: An instrument is described which, when used during the accelerated induction technique, ensures that consistent and adequate cricoid pressure can be applied.
Abstract: An instrument is described which, when used during the accelerated induction technique, ensures that consistent and adequate cricoid pressure can be applied. Mothers undergoing general anaesthesia for elective Caesarean section were studied in order to illustrate the clinical application of the instrument. The consequences to intubating conditions of applying adequate cricoid pressure, and an assessment of the instrument's control over the incidence of regurgitation during operation were investigated.
TL;DR: Results showed that exposure to positive suggestions during general anaesthesia, as compared with noise or operating theatre sounds, protected patients older than 55 against prolonged postoperative stay in hospital.
Abstract: Ninety-one patients undergoing biliary tract surgery were randomly assigned to one of three treatment groups in whitch different sounds were administered, by means of earphones, in a double-blind design. The effects of the administration of positive suggestions, noise or operating theatre sounds on the postoperative course were studied. Results showed that exposure to positive suggestions during general anaesthesia, as compared with noise or operating theatre sounds, protected patients older than 55 against prolonged postoperative stay in hospital.