Etomidate in urological outpatient anaesthesia. A clinical evaluation

Induction of anaesthesia with the new short acting agent etomidate has been studied in 200 patients undergoing urological outpatient procedures. These patients exhibited a similar pattern of recovery to those receiving 7 mg/kg propanidid but had greater cardiac and respiratory stability. However, there was a 25% incidence of pain which was reduced to 13-9% by increasing the rate of injection from 30 to 15 seconds. The incidence of involuntary movements was 29-7% which was reduced to 15% by the faster rate of injection. The omission of atropine premedication did not affect cardiac stability. Etomidate appears to have many desirable features as an induction agent except for a high incidence of pain on injection which is reduced by rapid injection.     

Alfentanil or fentanyl during isoflurane-based anaesthesia for day-care knee arthroscopy?

Previously published ultrasound screening programmes for abdominal aortic aneurysm (AAA) have concentrated on males in the 65 to 75 year age range, suggesting this as the most cost-effective cohort to target. In this unique study we have broadened the criteria for screening. General practitioners in one health district were approached to supply details of all males aged 50 years and over to be offered aortic ultrasound scanning. Over a period of 18 months, 4145 individuals were asked to attend and 3030 (73%) have attended. Attendance rates were: between 50 and 64 years, 73%; between 65 and 79 years, 75%; for 80 years and over, 64%--significantly less (p = 0.01-0.001) than the other two age bands. Aortic dilatation (diameter > or = 2.5 cm) was found in 6.3% of the 50 to 64 year age group, 16.8% of the 65 to 79 year age group, and 23.3% of the 80 years and over age group. An established aneurysm (> or = 4.6 cm) was found in 0.3%--6 individuals (50-64 years), 2.5% (65-79 years) and 4.1% (> or = 80 years). The results suggest that aortic screening may be worthwhile extending to a wider age band. By focusing follow-up, this should give greater value for younger men in terms of community productivity and allows for selective intervention in the elderly.     

Haemodynamic effects of rocuronium during fentanyl anaesthesia: comparison with vecuronium

Haemodynamic variables were measured following administration of rocuronium 0.6 mg.kg-1 or vecuronium 0.08 mg.kg-1 (approximately equivalent to 2 x ED95 doses) in patients anaesthetized with fentanyl 50 micrograms.kg-1 and scheduled to undergo elective coronary artery bypass grafting. There were increases in stroke volume index (+15%) and cardiac index (+11%), and a decrease in pulmonary capillary wedge pressure (-25%) following administration of rocuronium (P < 0.05). The changes in heart rate (+7%), mean arterial pressure (-5%), systemic vascular resistance (-12%) and other measured or derived indices were insignificant. In comparison the administration of vecuronium was associated with decreases in heart rate (-7%), mean pulmonary artery pressure (-17%), central venous pressure (-15%) and the rate-pressure product (-9%) (P < 0.05). The changes in mean arterial pressure (-7%), cardiac index (-6%) and systemic vascular resistance (-8%) following vecuronium were insignificant. There were no differences in any of the variables between rocuronium and vecuronium. The absolute values of all variables were, however, within acceptable clinical limits. There was no evidence of histamine release in any patient. The present study shows that rocuronium 0.6 mg.kg-1 is associated with changes of only small magnitude in haemodynamic variables.     

The cardiovascular effects of diazepam and of diazepam and pancuronium during fentanyl and oxygen anaesthesia

A study of the physiological behaviour of the synthetic compound Orthonil (alpha-chloro-beta-(3-chloro-o-tolyl)-propionitrile revealed a strong auxin activity in higher plants. Otherwise, Orthonil appeared not to be a herbicide-auxin. It is metabolized intensively in plant tissues. Among the identified metabolites, two compounds were detected which also exert a high auxin activity. It is concluded that at least a part of the apparent auxin activity of Orthonil may be due to alpha-(3-chloro-o-tolyl) acetic acid, one metabolite of Orthonil. Although Orthonil strongly stimulates elongation growth, this growth is not accompanied by a stimulated ethylene evolution as is the case with other auxins. A possible metabolic pathway of Orthonil is discussed.     

Neuromuscular effects of rocuronium bromide (Org 9426) during fentanyl and halothane anaesthesia

The prevalence of hepatitis B virus (HBV) infection in the South African urban obstetric population, which consists of white, black, coloured and Asian patients from different socio-economic, cultural and geographical backgrounds, is unknown. Routine screening performed in 3,469 urban pregnant women revealed that 42 patients were HBV surface antigen-positive (a prevalence of 1.21%). Only 2 patients (4.6%) were hepatitis B e antigen (HBeAg)-positive (0.06% of the entire cohort), whereas the remaining 40 were identified as hepatitis B e antibody-positive. Despite a significant increase in the numbers of black patients, there has not been an accompanying increase in the number of HBV carriers. Replicative infection was equally distributed among white and black pregnant women. Because the low prevalence of HBeAg results in lack of perinatal transmission and the prevention of a single case of neonatal hepatitis B infection is costly, we conclude that in South African urban hospitals, routine screening for hepatitis B is not cost-effective.     

The effect of clonidine on intra-operative requirements of fentanyl during combined epidural/general anaesthesia

The study evaluates the analgesic effects of epidural clonidine in patients undergoing abdominal hysterectomy under combined epidural/general anaesthesia. Forty ASA 1-2 patients were divided into two groups who received epidurally either clonidine 300 micrograms (group 1) or placebo (group 2). Anaesthesia was maintained with oxygen/nitrous oxide, a midazolam infusion, vecuronium, and boluses of fentanyl 100 micrograms administered as needed to maintain cardiovascular stability. The mean (SD) intraoperative fentanyl requirements were 2.05 (0.18) and 3.66 (0.3) micrograms.kg-1.h-1 for groups 1 and 2 respectively (p < 0.001). Patients in Group 1 had a lower heart rate after tracheal intubation and surgical incision (p < 0.02). In the recovery room, pain intensity was lower in group 1 (p < 0.003) and the mean (SD) time until analgesia request was increased from 48.5 (8.4) min in group 2 to 235.7 (33.2) min in group 1 (p < 0.001). Our results demonstrate that epidural clonidine produces decreased fentanyl requirements, improved cardiovascular stability, reduced pain intensity and effective postoperative analgesia in the recovery room.     

Effect of anaesthesia with nitrous oxide in oxygen and fentanyl on renal function in the artificially ventilated dog

The effect on renal function of a large dose (25 micrograms kg-1) of fentanyl was investigated in 10 labrador dogs. The animals were anaesthetized with nitrous oxide in oxygen and a small supplement of fentanyl 0.4 microgram min-1 throughout the experiment, and muscular relaxation was provided by alcuronium, pulmonary ventilation being controlled. In the initial phase of each experiment, estimated renal plasma flow, glomerular filtration rate, urine volume, mean arterial pressure and renal vascular resistance were measured at 30-min intervals, three sets of samples being taken. Then the large dose of fentanyl was given over a 10-min period and the measurements were repeated at 30-min intervals for 90 min. Changes in renal function lasted for about 90 min; there was a significant decrease in estimated renal plasma flow (P less than 0.01), glomerular filtration rate (P less than 0.001), urine volume (P less than 0.01) and mean arterial pressure (P less than 0.001) together with an increase in renal vascular resistance (0.05 greater than P greater than 0.02). These changes were accompanied by bradycardia, but were still present when atropine was given.     

A meta-analysis of nausea and vomiting following maintenance of anaesthesia with propofol or inhalational agents

Methamphetamine (m-AMPH) administration injures both striatal dopaminergic terminals and certain nonmonoaminergic cortical neurons. Fluoro-Jade histochemistry was used to label cortical cells injured by m-AMPH in order to identify factors that contribute to the cortical cell body damage. Rats given four injections of m-AMPH (4 mg/kg) at 2-h intervals showed hyperthermia (mean = 40.0 +/- 0.10 degrees C) and increased behavioral activation relative to animals given saline (SAL). Three days later, m-AMPH-treated animals showed indices of injury to striatal DA terminals (depletion of tyrosine hydroxylase immunoreactivity) and parietal cortical cell bodies (appearance of Fluoro-Jade stained cells). Pretreatment with a dopamine (DA) D1, D2, or N-methyl-D-aspartate (NMDA) receptor antagonist, or administration of m-AMPH in a 4 degrees C environment, prevented or attenuated m-AMPH-induced hyperthermia, behavioral activation, and injury to striatal DA terminals and parietal cortical cell bodies. Animals pretreated with a DA transport inhibitor prior to m-AMPH showed hyperthermia, behavioral activation, and parietal cortical cell body injury, but they did not show striatal DA terminal injury. Pretreatment with a 5HT transport inhibitor failed to prevent m-AMPH-induced damage to striatal DA terminals or parietal cortical cell bodies. Animals given four injections of SAL in a 37 degrees C environment became hyperthermic, but showed no injury to striatal DA terminals or cortical cell bodies. The ability of the DA transport inhibitor to block m-AMPH-induced striatal DA damage, but not cortical injury, and the inability of hyperthermia alone to cause the cortical cell body injury suggests that m-AMPH-induced behavioral activation and hyperthermia may both be necessary for the subsequent parietal cortical cell body damage.     

Physiology of spinal anaesthesia and practical suggestions for successful spinal anaesthesia

There are numerous physiological effects of spinal anaesthesia. This chapter focuses on the physiological effects that are of clinical relevance to the anaesthesiologist, and provides suggestions for successful management of this simple and popular technique. The mechanisms and clinical significance of spinal-anaesthesia-induced hypotension, bradycardia and cardiac arrest are reviewed. The increasing popularity of ambulatory spinal anaesthesia requires knowledge that long-acting local anaesthetics, such as bupivacaine, impair the ability to void far longer than short-acting local anaesthetics, such as lidocaine. The importance of thermoregulation during spinal anaesthesia, and the clinical consequences of spinal-anaesthesia-induced hypothermia are reviewed. Effects of spinal anaesthesia on ventilatory mechanics are also highlighted. Lastly, the sedative and minimum-alveolar-concentration-sparing effects of spinal anaesthesia are discussed to reinforce the need for the judicious use of sedation in the perioperative setting.     

A comparison of 2% and 1% formulations of propofol for the induction and maintenance of anaesthesia in surgery of moderate duration

This study, conducted in 110 patients undergoing surgery of moderate duration, compared the pharmacodynamic equivalence, efficacy and safety of 1% and 2% formulations of propofol. Anaesthesia was induced with propofol 2 mg.kg-1 given over 40 s and supplementary bolus injections of propofol were given if needed. There were no significant differences between the groups in mean induction times, total induction doses of propofol, frequency and mean duration of apnoea, fentanyl requirements or mean recovery times (times to eyes opening and to orientation). Isolated statistically significant group differences in systolic and diastolic blood pressures and heart rates during induction were not considered clinically significant. Discomfort on injection occurred in 40% and 52% of those given 1% (n = 55) and 2% (n = 55) propofol, respectively; there was no statistically significant group difference in severity. No major adverse effects were reported. This study showed that the 2% formulation has a similar safety and pharmacodynamic profile to the 1% formulation.     

Transdermal fentanyl for severe cancer-related pain

This paper reports on the analysis of 332 otosclerosis revision operations. The results have been evaluated with reference to the type of the procedure at primary surgery, the alleged cause of failure and the applied technical solution. The need for revision surgery was found higher after primary total stapedectomy (3.4 per cent) than after partial stapedectomy (2.2 per cent) or stapedectomy (two per cent). The reason for revision varied according to the originally applied technique eg a migrated piston, a too short piston and a lateralized graft are almost exclusively found after total stapedectomies. The median hearing gain after revision of stapedectomy and partial stapedectomy was higher (20 dB and 18 dB respectively) than that after revision surgery for total stapedectomy (12 dB), but significantly lower than hearing gain after primary surgery (32 dB). Revisions yielded better results in the case of primary interventions with the use of a piston or pistonwire than in the case of primary interventions with a wire-type prosthesis. The risk for sensorineural loss (one per cent) was not higher than in primary surgery.     

Administration of a crystalloid fluid preload does not prevent the decrease in arterial blood pressure after induction of anaesthesia with propofol and fentanyl

Five oligosaccharide alpha1-phosphates and one sulfated glycopeptide have been isolated from the hemofiltrate of one patient with end-stage renal disease. Isolation of these compounds has been achieved using reverse osmosis, ion-exchange and size-exclusion chromatography and high performance liquid chromatography. The structures were predominantly elucidated by one- and two-dimensional 1H and 31P NMR spectroscopy. The chemical structures were determined to be: 1 NeuAc alpha2-3Gal alpha1-OPO3H2; 2 NeuAc alpha2-6Galbeta1-4GlcNAc alpha1-OPO3H2; 3 NeuAc alpha2-3Galbeta1-3GalNAc alpha1-OPO3H2; 4 NeuAc alpha2-3Galbeta1-3[NeuAc alpha2-6]GalNAc alpha1-OPO3H2 (proposed structure); 5 Fuc alpha1-2Galbeta1-4[Fuc alpha1-3]GlcNAc alpha1-OPO3H2; 6 HOSO3-4Fuc alpha1-6GlcNAcbeta1-NAsn. While 2 and 3 have been previously characterized as compounds of urine and hemofiltrate, the oligosaccharide alpha1-phosphates 1, 4, and 5 could be isolated--to our knowledge--for the first time from biological material. Compound 6 is the first glycopeptide reported to contain a 4-sulfated fucose residue.     

Aims and objectives for postgraduate learning in anaesthesia

This paper describes the statement of aims and objectives of postgraduate training for the Faculty of Anaesthetists of the Royal Australasian College of Surgeons. The objectives of the authors are that after study of this paper, the readers will: (a) Understand the importance of both "stated" and "informal" objectives in teaching and learning. (b) Understand the important terms used in the Faculty of Anaesthetists' Document on objectives. (c) Know the strategies using in writing the Faculty's Document of Objectives.     

Alfentanil-oxygen anaesthesia for coronary artery surgery

The anaesthétic properties of alfentanil were evaluated in 15 patients undergoing coronary artery bypass grafting operations. Alfentanil was infused at a rate of 3.0mg min-1 until the patients (breathing pure oxygen) became unconscious. Additional alfentanil 2.5-5.0mg i.v. was given if systolic arterial pressure increased by 15% or more from control values. Alfentanil produced unconsciousness in 75 +/- 18s, but muscle rigidity occurred in 27% of patients. Cardiovascular dynamics were minimally altered during the induction of anaesthesia and throughout most of the operation, although 60% of patients became hypertensive during sternotomy and 73% during sternal spread. Recovery from anaesthesia was rapid with patients regaining consciousness after 1.4 +/- 0.6h and fulfilling out criteria for extubation of the trachea 4.1 +/- 1.2h after operation. No patient was aware of laryngoscopy, endotracheal intubation or any aspect of the operation.     

Amethocaine gel for percutaneous local anaesthesia

Infection with varicella zoster virus is common in childhood and generally associated with few complications. Myopericarditis following varicella infection is rare but may result in severe rhythm disturbances and congestive cardiac failure. The case is presented of a 4-month-old infant presenting with a large pericardial effusion and cardiac tamponade 2 weeks after the onset of a varicella exanthem. Although Streptococcus was noted in the pericardial fluid, it could not be grown on bacterial culture and the subsequent clinical course was in keeping with a viral myopericarditis. CONCLUSION: Varicella infection in children may be complicated by myopericardial disease ranging from subclinical ECG changes to fulminant cardiac failure and/or cardiac tamponade. The clinical spectrum of this unusual complication is reviewed and the importance of early recognition emphasised.     

Etomidate: cardiovascular effects of a new intravenous anesthetic agent

The cardiovascular effects of intravenous Etomidate (0.2 mg/kg) were studied in 14 surgical patients with ages varying from 49 to 90. The anaesthetic induction occurs within 10 seconds and the mean duration of anaesthesia is from 6 to 8 minutes. I.V. Etomidate causes a slight lowering of the mean arterial pressure (8.5 per cent), a negligible increase of the heart rate (2.8 per cent) and an insignificant lowering of the mean pulmonary artery pressure (7 per cent). Cardiac output and stroke volume are respectively lowered by 7.6 per cent and 10 per cent. The peripheral vascular resistance is discreetly reduced by 3.8 per cent. From these results, we believe that Etomidate seems to induce sleep with the lightest hemodynamic disturbances in comparison with other agents commonly used. However, some undesirable side effects appeared in some of our patients which can become somewhat annoying, for example myoclonic movements and pain at the point of injection.