Showing papers in "BJA: British Journal of Anaesthesia in 1988"
TL;DR: The amount of larynx seen at intubation was assessed in 633 adult patients undergoing routine surgery and a simple predictive rule was developed and tested on a prospective set of 778 patients, in 1.5% of whom laryngoscopy was found to be difficult.
Abstract: The amount of larynx seen at intubation was assessed in 633 adult patients undergoing routine surgery. Various measurements of the head and neck were made in an attempt to discover which features were associated with difficulty with laryngoscopy (defined as the inability to see even the arytenoids). In addition 38 patients, reported by colleagues because they had been "difficult to intubate", were measured. Five useful risk factors, measured at three levels of severity, were identified. A simple predictive rule was developed and tested on a prospective set of 778 patients, in 1.5% of whom laryngoscopy was found to be difficult. Depending on the threshold chosen, the rule allowed the detection of, for example, 75% of the "difficult" laryngoscopies at a cost of falsely identifying 12% of the "not difficult" patients.
710 citations
TL;DR: It is concluded that the arterial hypotension associated with the induction and infusion of propofol is mainly a result of a decrease in afterload without compensatory increases in heart rate or cardiac output.
Abstract: SUMMARY The haemodynamic effects of propofol, given as a single dose of 2 mg kg−1 immediately followed by a continuous infusion of 6 mg kg−1 h−1, were studied in 10 elderly patients premedicated with lorazepam 1 mg i.v. All patients breathed room air spontaneously. Unconsciousness was successfully induced in all patients and persisted during the 60 min of the infusion. Statistically significant decreases in systolic and diastolic arterial pressures were observed 2 min after induction (28% and 19% respectively) and during infusion (30% and 25% respectively) and were related to decreases in systemic vascular resistance (21% following induction and 30% during infusion). Cardiac output was not affected at any time nor were stroke volume and heart rate. We conclude that the arterial hypotension associated with the induction and infusion of propofol is mainly a result of a decrease in afterload without compensatory increases in heart rate or cardiac output.
507 citations
TL;DR: In children, circulatory failure was as frequent as respiratory failure and complications were observed almost equally during induction and maintenance and on recovery, and the rate of complications increased significantly with the ASA score and the number of co-existing diseases.
Abstract: A prospective survey of anaesthesia-related mortality and morbidity in infants and children was carried out in a representative sample of anaesthetics performed in 440 institutions chosen at random in France. A total of 40240 anaesthetics were administered to patients younger than 15 yr, 2103 (5%) involving infants (younger than 1 yr). Twenty-seven major complications related to anaesthesia occurred during or within 24 h of the anaesthesia—an incidence of 0.7 per 1000 anaesthetics. Nine, of which four were associated with cardiac arrest, were observed in infants, whereas in children there were 18 complications of which eight were associated with cardiac arrest, one with fatal outcome. The risk of complications was significantly higher (P
376 citations
TL;DR: The pharmacokinetics of propofol (2,6 diisopropylphenol) were compared in patients aged 65-80 yr and 12 patients aged 18-35 yr and showed no trend with time after dose.
Abstract: The pharmacokinetics of propofol (2,6 diisopropylphenol) were compared in 12 patients aged 65-80 yr and 12 patients aged 18-35 yr. After premedication with papaveretum i.m., anaesthesia was induced with propofol 2.0 mg kg-1 in the elderly and 2.5 mg kg-1 in the younger patients. Alcuronium 12-20 mg was then given and the patient's lungs ventilated with halothane and nitrous oxide in oxygen. Blood was taken after various time intervals up to 24 h for the measurement of propofol concentrations by HPLC and for the estimation of propofol protein binding. The mean blood propofol concentration was generally higher in the elderly group, but this difference was only significant at 2 min after induction. The clearance of propofol was significantly lower in the elderly (1.44 +/- 0.10 (SE) litre min-1) than in the younger patients (1.79 +/- 0.12 litre min-1). The volume of the central compartment in the elderly patients was significantly smaller (19.6 +/- 5.2 litre) than that in the young (26.3 +/- 2.9 litre). There was no difference in the volume of distribution at equilibrium (1608 +/- 246 litre in the elderly and 1757 +/- 360 litre in the young), in the volume of distribution at steady state (691 +/- 139 litre in the elderly and 771 +/- 236 litre in the young) or in the half-lives of distribution and elimination. The plasma protein binding of propofol was similar in both groups and showed no trend with time after dose.
288 citations
TL;DR: Functional residual capacity was measured before and after induction of anaesthesia for jejunoileal bypass surgery in 30 morbidly obese patients and reduction in FRC is related to baseline vital capacity (VC) and FRC and is much greater than that reported for patients of normal weight.
Abstract: Functional residual capacity (FRC) was measured before and after induction of anaesthesia for jejunoileal bypass surgery in 30 morbidly obese patients. The onset of anaesthesia was associated with a 51% reduction in FRC from 2.2 litre to 1.0 litre. Eighteen of the patients were investigated more extensively; in these subjects FRC was reduced below the control values of residual volume (RV) with the onset of anaesthesia, but recovered towards baseline after laparotomy incision. Reduction in FRC is related to baseline vital capacity (VC) and FRC and is much greater than that reported for patients of normal weight.
191 citations
TL;DR: Serum concentrations of fentanyl increased slowly (15 h to plateau) and decreased slowly (apparent half-life, 21 h) and it is concluded that delivery of analgesic doses of fentanyl is feasible by the transdermal route.
Abstract: We have investigated the use of constant-rate delivery of fentanyl by i.v. and transdermal routes for the treatment of pain after major surgery. Forty-five males, ASA I-III, received in a double-blinded fashion either placebo (n = 6) or fentanyl (n = 39) i.v. at one of four dose rates (25, 50, 100 or 125 micrograms h-1). Stable serum concentrations of fentanyl were produced by the end of surgery and were maintained for a total of 24 h. Calculated clearance of fentanyl was 1.05 +/- 0.38 litre min-1 and was not related to weight or age. Both the 100- and 125-micrograms h-1 dose rates produced significant analgesic efficacy as assessed by postoperative morphine requirements. Mean serum concentrations of fentanyl in these groups were 1.42 +/- 0.14 (SD) and 1.90 +/- 0.30 ng ml-1, respectively. One of 10 patients receiving fentanyl 100 micrograms h-1 and three of nine patients receiving 125 micrograms h-1 had evidence of respiratory depression. Eight additional patients were treated with a transdermal drug delivery system containing fentanyl (TTS-fentanyl). Steady-state serum concentrations in this group were 2.15 +/- 0.92 (SD) ng ml-1. Post-operative morphine requirements were minimal (less than 0.5 mg h-1) and PaCO2 remained acceptable in all patients. Serum concentrations of fentanyl increased slowly (15 h to plateau) and decreased slowly (apparent half-life, 21 h). We conclude that delivery of analgesic doses of fentanyl is feasible by the transdermal route.
182 citations
TL;DR: It is concluded that myocardial ischaemia is prevalent during anaesthesia in untreated hypertensive patients, and that pretreatment with atenolol, but not diuretics, provides prophylaxis.
Abstract: Hypertensive patients were monitored for myocardial ischaemia during anaesthesia and surgery with the V5 lead of a standard electrocardiograph. Myocardial ischaemia was detected in 11 of 39 untreated hypertensive patients and in four of seven receiving therapy with a diuretic, but in none of 44 receiving atenolol. Fourteen of the atenolol-treated patients were receiving the drug on a long-term basis and the remaining 30 were treated acutely only on the morning of surgery. When myocardial ischaemia was observed, it was always associated with noxious stimulation and tachycardia, but a conspicuous increase in arterial pressure was not usually present. We conclude that myocardial ischaemia is prevalent during anaesthesia in untreated hypertensive patients, and that pretreatment with atenolol, but not diuretics, provides prophylaxis.
163 citations
TL;DR: The effect of hysterectomy on natural killer (NK) cell activity, the distribution of lymphocyte subpopulations, and the endocrine stress response was studied in 16 patients allocated to receive extradural analgesia S5-T4 (group I) or neuroleptanaesthesia (NLA) (group II) as discussed by the authors.
Abstract: The effect of hysterectomy was studied on natural killer (NK) cell activity, the distribution of lymphocyte subpopulations, and the endocrine stress response in 16 patients allocated to receive extradural analgesia S5-T4 (group I) or neuroleptanaesthesia (NLA) (group II). In group II a significant decrease in NK cell activity was found after operation for at least 3 days, while surgery during extradural analgesia did not induce significant changes. The impaired NK cell activity was accompanied by leucocytosis and lymphopenia affecting the T-lymphocytes (OKT3+ and OKT4+), the B-lymphocytes (B1+) and NK cells (Leu 11+). Compared with group II, extradural analgesia significantly reduced the cortisol and noradrenaline response to surgery, while the adrenaline response in both groups was abolished. The results suggest that the decrease in NK cell activity and alterations in lymphocyte subsets induced by surgery and general anaesthesia can be prevented to a certain degree by extradural analgesia.
161 citations
TL;DR: This review has concentrated on the epidemiological aspects of PMI and the risk factors that have practical consequences in the treatment of patients and similarities in some of the results in spite of differences in methodology are impressive.
Abstract: The risk of developing myocardial infarction (MI) in connection with surgery and anaesthesia has been recognized for at least 75 years [19, 79, 93, 101]. Since then numerous reports have been published, some describing the incidence and characteristics of perioperative myocardial infarction (PMI), others the risk factors involved. To compare these publications is difficult because of the great span in years between various studies, and the variability in study conditions such as selection and size of population, the use of a retrospective or a prospective approach, variations in postoperative care, the method of diagnosis of PMI etc. These factors can at least partly explain the variability and even contradictions observed in results. In most of these studies statistical evaluation also leaves much to be desired. The questions are often multifactorial, without the appropriate tests being performed. Performing simple chi-squared tests on whether sex, age, type or duration of anaesthesia etc, influence the infarction rate, does not provide a correct picture. There is often some co-variation between many of these factors, such as duration of anaesthesia and type of surgery. Thus the papers should be evaluated critically and the effects of a single factor reported in a single paper should be interpreted with caution. Even more impressive, therefore, are the similarities in some of the results in spite of these differences in methodology, and certain trends appear in the literature that are important to the daily work of the anaesthetist. In this review we have concentrated on the epidemiological aspects of PMI and the risk factors that have practical consequences in the treatment of patients. Frontline research concerning the pathophysiology of myocardial ischaemia and infarction and possible effects of
151 citations
TL;DR: The use of cryostat sectioning for measurement of Ca uptake by sarcoplasmic reticulum in patients susceptible to malignant hyperthermia and its application in patients with osteogenesis imperfecta is recommended.
Abstract: s of the 4th International Malignant Hyperpyrexia Workshop, Leeds, England. 22. Leeds DE, Gadde PL, Macnamara TE. Malignant hyperthermia in association with Burkett's lymphoma: Report of a third case. Anesthesia and Analgesia 1980; 59, 514-515. 23. Linter SPK, Thomas PR, Withington PS, Hall MG. Suxamethonium associated hypertonicity and cardiac arrest in suspected pseudohypertrophic muscular dystrophy. British Journal of Anaesthesia 1982; 4: 1331-1332. 24. Lotstra F, Linkowski P, Mendlewicz J. General anesthesia after neuroleptic malignant syndrome. Biological Psychiatry 1983; 18: 243-247. 25. Mabuchi K, Sreter FA. The use of cryostat sectioning for measurement of Ca uptake by sarcoplasmic reticulum. Analytical Biochemistry 1978; 86: 733-742. 26. McPherson EW, and Taylor CA. The King Syndrome: Malignant hyperthermia, myopathy, and multiple anomalies. American Journal of Medical Genetics 1981; 8: 159-165. 27. Nagarajan K, Fishbein WN, Carlin HM, Pezeshkpour G, Muldoon SM. Frozen section calcium-uptake versus halothane and caffeine contracture tests on human muscle. Anesthesiology 1985; 83: A307. 28. Nakazota A, Shime H, Morooka K, Nonaka K. Anesthesia-induced rhabdomyolysis in a patient with Fukuyama-type muscular dystrophy. Brain and Development 1983;5: 243. 29. Ohtani Y, Miike T, Ishitsu T, Matsuda I, Tamari H. A case of malignant hyperthermia with mitochondrial dysfunction. Brain and Development 1985; 7: 249. 30. Oka S, Igarashi Y, Takagi A, Nishida M, Sato K, Nakada K, Ikeda K. Malignant hyperpyrexia and Duchenne muscular dystrophy: a case report. Canadian Anaesthetists Society Journal 1982; 29: 627-629. 31. Ording H. Incidence of malignant hyperthermia in Denmark. Anesthesia and Analgesia 1985; 64: 700-704. 32. Rampton AJ, Kelly DA, Shanahan EC, Ingram GS. Occurrence of malignant hyperpyrexia in a patient with osteogenesis imperfecta. British Journal of Anaesthesia 1984; 56: 1443-1446. 33. Rosenberg H, Fisher CA, Reed SB, Addonizio P. Platelet aggregation in patients susceptible to malignant hyperthermia. Anesthesiology 1981; 55: 621-624. 34. Scarlett JD, Zimmerman R, Berkovic SF. Neuroleptic malignant syndrome. Australian and New Zealand Journal of Medicine 1983; 13: 70-73. 35. Seay AR, Ziter FA, Thompson JA. Cardiac arrest during induction of anesthesia in Duchenne muscular dystrophy. Journal of Pediatrics 1978; 93: 88-90. 36. Seay AR, Ziter FA. Malignant hyperpyrexia in a patient with Schwartz-Jampel syndrome. Journal of Pediatrics 1978; 93: 83-84. 37. Shuaib A, Paasuke RT, Brownell AKW. Central core disease: A reappraisal of its clinical features and new management recommendations. Medicine (Baltimore) 1987; 66: 389-396. 38. Solomons CC, Masson NC. Platelet model for halothaneinduced effects on nucleotide metabolism applied to malignant hyperthermia. Acta Anaesthesiologica Scandinavica 1984; 28: 185-190. 39. Takagi A, Sunohara N, Ishihara T, Nonaka I, Sugita H. Malignant hyperthermia and related neuromuscular diseases : caffeine contracture of the skinned muscle fibers. Muscle and Nerve 1983; 6: 510-514. 40. Thach BT. Sudden infant death syndrome. New England Journal of Medicine 1986; 315: 126-128. 41. Tollefson G. A case of neuroleptic malignant syndrome: in vitro muscle comparison with malignant hyperthermia. Journal of Clinical Psychopharmacology 1982; 2: 266-270. 42. Tsueda K, Dubick MN, Wright BD, Sachatello CR. Intraoperative hyperthermic crisis in two children with undifferentiated lymphoma. Anesthesia and Analgesia 1978; 57: 511-514.
141 citations
TL;DR: Plasma fentanyl concentrations were measured during and after transdermal fentanyl delivery in groups of patients undergoing general surgery, finding that concentrations decreased slowly after removal of thetransdermal system.
Abstract: SUMMARY Plasma fentanyl concentrations were measured during and after transdermal fentanyl delivery in groups of patients undergoing general surgery. At 8 and 12 h, concentrations did not differ from those observed in a matched group of patients receiving fentanyl by i.v. infusion. At 24 h, concentrations were significantly lower in one of the transdermal groups. Plasma fentanyl clearance did not differ significantly between the groups. Plasma fentanyl concentrations decreased slowly after removal of the transdermal system.
TL;DR: The amplitude of cortical waves in the AER are sensitive not only to anaesthetic concentration but also to surgical stimulation, and may provide a useful index of depth of anaesthesia, that is the balance between the effects of surgical stimulation and anaesthetic depression on central nervous system activity.
Abstract: Previous studies have shown a dose-related effect of a number of general anaesthetic agents on the early cortical waves in the auditory evoked response (AER). In this study the effect of surgical stimulation on these waves was examined in 11 patients anaesthetized with thiopen-tone, nitrous oxide and halothane and paralysed with pancuronium. The inspired nitrous oxide concentration and end-tidal halothane concentration were held constant at 70% and 0.3%, respectively, and baseline AER recordings were made. Following surgical stimulation there was a progressive and significant increase in the amplitude of waves Nb and Pb/Pc. Unambiguous autonomic responses were seen in three patients, but these were not significantly correlated with changes in the AER. We conclude from this, and previous studies, that the amplitude of cortical waves in the AER are sensitive not only to anaesthetic concentration but also to surgical stimulation. The may, therefore, provide a useful index of depth of anaesthesia, that is the balance between the effects of surgical stimulation and anaesthetic depression on central nervous system activity.
TL;DR: Propofol (mean dose 2.85 mg kg-1 h-1) was administered for 4 days by continuous i.v. infusion for sedation in 14 agitated and restless ICU patients to provide rapid control of the level of sedation.
Abstract: Propofol (mean dose 2.85 mg kg −1 h −1 ) was administered for 4 days by continuous i. v. infusion for sedation in 14 agitated and restless ICU patients. This provided rapid control of the level of sedation. When the infusion was discontinued, adequate recovery with response to commands was obtained in most patients by 10 min. Recovery times and the decrease in blood propofol concentration were similar after 24, 48, 72 and 96 h of infusion. Cumulative effects, tachyphylaxis, or other untoward effects were not observed.
TL;DR: A significant relationship was shown between postoperative emetic symptoms and the antagonism of neuromuscular blockade by neostigmine and atropine in patients undergoing elective hip or knee surgery.
Abstract: Thirty-eight patients undergoing elective hip or knee surgery were randomly allocated to two groups. Neuromuscular blockade in group A was antagonized with neostigmine 2.5 mg and atropine 1.2 mg, while group B received no drugs to facilitate antagonism of blockade. The incidence and severity of postoperative nausea and vomiting were assessed 24 h after operation. Nausea and vomiting were significantly reduced in group B. The incidence of nausea in group A was 68%, compared with 32% in group B (P
TL;DR: Chloral hydrate 75 mg kg-1 provided good anxiolysis in both age groups; however, it was less palatable than the midazolam.
Abstract: Chloral hydrate 25, 50 or 75 mg kg−1 or midazolam 0.4, 0.5 or 0.6 mg kg−1, all given by mouth in combination with atropine 0.03 mg kg−1, were compared as premedication in 248 children in a randomized, double-blind study. Chloral hydrate was significantly less palatable than midazolam. The anxiolytic effect of chloral hydrate 75 mg kg−1 was “good” in children younger than 5 yr, whereas the other doses of chloral hydrate, and all doses of midazolam, provided only “fair” anxiolysis in this age group. All doses of both premedicants provided good anxiolysis in the older children. A satisfactory antisialagogue effect was seen in 83–90% of each group. About 20 min after extubation, restlessness was observed in 15–25% of the younger children premedicated with chloral hydrate 25 mg kg−1 or with midazolam 0.4 or 0.6mgkg−1. The mean total recovery score (0–10) based on activity, ventilation, heart rate, conscious level and colour ranged between 5.8 and 6.8 at 10 min and between 9 and 9.5 at 70 min after extubation in all groups. Midazolam 0.5 mg kg−1 is recommended for children less than 5 yr of age and midazolam 0.4–0.5 mg kg−1 for older ones. Chloral hydrate 75 mg kg−1 provided good anxiolysis in both age groups; however, it was less palatable than the midazolam.
TL;DR: There was marked individual variation in the serum morphine concentrations produced following each route of administration, and the maximum serum morphine concentration following inhaled morphine was approx.
Abstract: During anaesthesia seven patients received a bolus of morphine 10 mg injected into the nebulization reservoir placed between the tracheal tube and the anaesthetic circle (lH). Five days after operation the same seven patients received morphine 10 mg i.m. On both occasions, venous blood samples were taken before and every 15 min after administration over 4.5 h for measurement of free morphine immunoreactivity by radioimmunoassay. There was marked individual variation in the serum morphine concentrations produced following each route of administration. The maximum serum morphine concentration following inhaled morphine was approx. six times lower than that after morphine i.m. and the time of occurrence differed significantly (P
TL;DR: Despite its mainly hepatic elimination, midazolam disposition appears to be only slightly impaired in cirrhotic patients.
Abstract: The pharmacokinetics of midazolam were compared in cirrhotic patients (n = 10) and control patients (n = 9), during general anaesthesia Total plasma clearance was 637 ± 223 ml min−1 (mean ± SD) in control patients and 402 ± 170 ml min−1 in cirrhotic patients (P
TL;DR: There was a significant correlation between the infusion rate of mivacurium required to maintain 95% twitch depression and the plasma cholinesterase activity of individual subjects.
Abstract: Mivacurium chloride (BWB1090U) is a new, short-acting non-depolarizing neuromuscular blocking agent. It is a synthetic bis-benzylisoquinolinium diester, which is hydrolysed rapidly by plasma cholinesterase. This study compares mivacurium, atracurium and vecuronium by continuous i.v. infusion. The duration of mivacurium infusion ranged from 29.5 to 286 min. The steady state infusion rates necessary to maintain 95 (SEM 4)% twitch suppression were: mivacurium 8.3 (0.7) μg kg−1 min−1; atracurium 7.9 (0.4) μg kg−1 min−1; vecuronium 1.2 (0.3) μg kg−1 min−1. Following infusions of mivacurium, various recovery times (for example: 25–75%, 6.9 (0.3) min; 25–95%, 11.0 (0.4) min; 5–95% 14.5 (0.4) min) did not differ significantly from those following single bolus doses. Recovery times following cessation of mivacarium infusions were approximately 50% of those for equivalent durations of infusion of atracurium (10.9 (0.3) min for 25–75% recovery and 26.6 (0.4) min for 5–95% recovery). For vecuronium, corresponding recovery times were 13.8 (0.9) and 32.0 (1.2) min, respectively. Comparative recovery times for mivacurium were 40–50% of those for vecuronium. There was a significant correlation between the infusion rate of mivacurium required to maintain 95% twitch depression and the plasma cholinesterase activity of individual subjects.
TL;DR: The results indicate that inhalation anaesthetics act at multiple and selective hydrophobic recognition sites which are heterogenously distributed on different synaptic pathways, including stratum oriens excitatory inputs to CA1 neurones, and on antidromic responses.
Abstract: SUMMARY The effects of halothane, isoflurane and enflurane were compared on three CNS excitatory synaptic pathways in vitro, to determine whether selective actions described in vivo result from differential effects on anatomically distinct cortical pathways and neurone populations. Halothane (0.25–1.25 vol%) depressed postsynaptic excitability of CA1 pyramidal neurones in response to activation of stratum radiatum synaptic inputs, and concentration-dependent excitatory (0.25–1.25 vol%) and depressant (1.5–2.0 vol%) actions were observed on dentate granule neurone excitability and perforant path evoked synaptic responses. In contrast, isoflurane increased CA1 neurone excitability (0.25–0.75 vol%) and produced postsynaptic depression of dentate neurones (0.5–4.0 vol%). Enflurane also increased CA1 excitability (0.5–4.0 vol%), but depressed synaptic responses at equivalent concentrations, and produced mixed excitatory (0.25–1.0 vol%) and depressant (1.0–4.0 vol%) effects on dentate synaptic responses. Differential actions were also observed for the three anaesthetics on stratum oriens excitatory inputs to CA 1 neurones, and on antidromic responses. A good correlation (r = 0.992) exists between the membrane / buffer partition coefficients of these anaesthetics and their half-maximal concentrations for depression of synaptic responses; however, this correlation does not reflect the different, anaesthetic-specific actions observed. The results indicate that inhalation anaesthetics act at multiple and selective hydrophobic recognition sites which are heterogenously distributed on different synaptic pathways.
TL;DR: Propofol may not be an appropriate anaesthetic for ECT because of its adverse effect on seizure duration, and patients received either methohexitone or propofol to induce anaesthesia during two separate ECT treatments.
Abstract: Twenty-five patients received either metho-hexitone 1.0 mg kg−1 or propofol 1.3 mg kg−1 to induce anaesthesia during two separate electro - convulsive therapy (ECT) treatments. A forearm was isolated before administration of suxa-methonium 0.5 mg kg−1, so that unmodified seizure duration could be measured. Bifronto-temporal electrodes were applied to administer a standard 3-s ECT shock. Median (quartile deviation) duration of seizure was reduced significantly after propofol (19.0 (9.0) s), compared with after methohexitone (33.0 (7.8) s). Therefore propofol may not be an appropriate anaesthetic for ECT because of its adverse effect on seizure duration.
TL;DR: In this paper, it is shown that the monoamine oxidase inhibitor-pethidine interaction has two distinct forms: "excitatory" and "depressive", and this lack of appreciation has led to much confusion when dealing with patients taking MOP inhibitors.
Abstract: There has been a recent renewal of interest in the use of monoamine oxidase inhibitors in psychiatry. The concurrent administration of anaesthetic agents, particularly narcotic analgesics, is often a cause for concern. Although many monoamine oxidase inhibitor-drug interactions have been reported, in practice it is only the interaction with pethidine which has led to fatalities. What is not appreciated is that the monoamine oxidase inhibitor-pethidine interaction has two distinct forms-"excitatory" and "depressive". It is this lack of appreciation that has led to much confusion when dealing with patients taking monoamine oxidase inhibitors.
TL;DR: The results suggest that, if there are age-related differences in response to fentanyl, the likely pharmacokinetic explanation is the higher concentration of fentanyl in the elderly immediately following its administration.
Abstract: SUMMARY The pharmacokinetics of fentanyl were determined in seven elderly (71–82 yr) and seven younger adults (18–41 yr) anaesthetized with thiopentone, nitrous oxide in oxygen and morphine. Fentanyl was administered as a 2-min i.v. infusion at doses of 15 μg kg−1 for elderly patients and 20 μg kg−1 for the younger patients. Plasma samples were obtained for 4 h and fentanyl concentrations determined by radio-immunoassay. Fentanyl concentration, per μg kg−1 administered, was higher in elderly than in young patients at 2 min (7.73±3.14 v. 4.54 ± 1.83 ng ml−1 (mean±SD), respectively) and at 4 min after the start of infusion (3.26 ± 1.44 v. 1.78 ±0.72 ng ml−1, respectively). Concentrations were similar at all other sampling times. Pharmacokinetic variables were determined by non-compartmental techniques. Total plasma clearance was similar for the two age groups. Volume of distribution at steady-state (VDss) was smaller in elderly patients (1.36 ± 0.44 v. 2.27 ± 0.82 litre kg −1). Despite age-related changes in VDss, plasma fentanyl concentrations for the two groups were similar throughout the 4-h sampling period except immediately following administration. These results suggest that, if there are age-related differences in response to fentanyl, the likely pharmacokinetic explanation is the higher concentration of fentanyl in the elderly immediately following its administration.
TL;DR: It is suggested that intrathecal morphine provided better analgesia after cardiac surgery than did a conventional regimen and the lower dose (1 mg) was associated with less respiratory depression as assessed by PaCO2 measurements.
Abstract: SUMMARY Forty-four patients undergoing coronary revascularization received either intrathecal morphine 1 mg (n = 15), intrathecal morphine 2 mg (n = 15), or i.v. morphine 30 mg (n = 14) after the induction of anaesthesia. Morphine 2.5 mg i.v. was given, as required, in the postoperative period and pain score, respiratory rate and PaC02 measured every 2 h. FVC, FEV1 and PEFR were measured before, and 24 h after, the induction of anaesthesia. Mean overall pain scores in both intrathecal groups were significantly lower than in the i.v. group (P
TL;DR: It is demonstrated that trainees who undergo a graduated training programme using simulators are initially more successful at awake fibreoptic nasotracheal intubation than those who have learned in the traditional manner.
Abstract: This study compared a graduated training programme with that of a traditional teaching method to facilitate the learning of the technique of fibreoptic nasotracheal intubation. Thirty-two anaesthesia trainees were randomly assigned to two groups. The graduated programme involved: practice on a bronchoscopy teaching model: exposure of the epiglottis and vocal cords in patients recovering from general anaesthesia; performance of fibreoptic nasotracheal intubation in awake sedated patients. The traditional programme involved: demonstration (on a patient) of one fibreoptic nasotracheal intubation by the instructor; performance of fibreoptic nasotracheal intubation (by the trainee) in awake sedated patients. Nasotracheal intubation was accomplished significantly more often by the trainess in the graduated programme (86 out of 96 (89.6%) v. 64 out of 96 (66.5%) (P
TL;DR: There was a significantly greater incidence of severe spinal headaches in the "bed-rest" group and three patients in this group required blood patch treatment for their headache, suggesting early mobilization is the recommended management after spinal anaesthesia for these types of obstetric procedure.
Abstract: Eighty obstetric patients receiving subarachnoid anaesthesia for second and third stage procedures, excluding Caesarean section, were studied. They were randomly allocated post-partum to either 24 h bed rest or early (6 h post spinal) mobilization. Patients were followed up at 48 h post-partum and the incidence and severity of post-spinal headache noted. There was a significantly greater incidence of severe spinal headaches in the “bed-rest” group and three patients in this group required blood patch treatment for their headache. Early mobilization is, therefore, the recommended management after spinal anaesthesia for these types of obstetric procedure.
TL;DR: The effect of single-dose clonidine premedication on the vapour requirement for isoflurane-induced hypotension in patients undergoing middle ear or nasal surgery was evaluated in an open, controlled, randomized study.
Abstract: The effect of single-dose clonidine premedication on the vapour requirement for isoflurane-induced hypotension in patients undergoing middle ear or nasal surgery was evaluated in an open, controlled, randomized study. Inspired isoflurane concentration was regulated by a microcomputer-based, self-tuning control program when hypotension was required. Patients given clonidine 0.6 mg by mouth 2h before operation required a mean inspired isoflurane concentration of 2.0% to induce hypotension (mean intra-arterialpressure 50 mm Hg) compared with 3.01 % in the control group (P
TL;DR: Patients with renal failure had a significantly longer mean elimination half-life for laudanosine and Vd than the patients with normal renal function; and the pharmacokinetic parameters derived for atracurium were the same.
Abstract: A study of plasma atracurium and laudanosine concentrations was undertaken in 14 critically ill patients who received a bolus dose of atracurium 0.6 mg kg−1 followed by an infusion of 0.6mg kg−1 h−1 for a period of 11–47 h. Seven of the patients had normal renal function and seven were in acute renal failure. In both groups plasma concentrations of atracurium reached a plateau of approximately 1300 ng ml−1within 30 min of the bolus dose. The drug disappeared from the plasma within 120 min after discontinuation of the infusion. There was no difference between the two groups with respect to the pharmacokinetic parameters derived for atracurium. In the patients with normal renal function, plasma laudanosine concentration reached a plateau of apprpximately 1200ng ml−1 within 10h. In patients with renal failure there was a greater variation in the plasma laudanosine concentration: the highest value recorded was 4300 ng ml−1. Patients with renal failure had a significantly longer mean elimination half-life for laudanosine (1418 min v. 375min; P
TL;DR: Three solutions administered by continuous extradural infusion for postoperative analgesia were compared in a randomized, double-blind manner and the bupivacaine-diamorphine mixture provided significantly superior analgesia compared with either bupicaine or diamorphine alone.
Abstract: Three solutions administered by continuous extradural infusion for postoperative analgesia were compared in a randomized, double-blind manner. All patients underwent major abdominal gynaecological surgery and received 0.125% bupivacaine in 0.9% saline/diamorphine in 0.9% saline (0.5 mg in 15 ml) or diamorphine mixed with 0.125% bupivacaine (0.5 mg in 15 ml), at a rate of 15 ml h−1. The bupivacaine-diamorphine mixture provided significantly superior analgesia compared with either bupivacaine or diamorphine alone. No major side effects were encountered.