High-dose vecuronium neuromuscular block: a comparison of arrhythmias and onset of block during sufentanil anaesthesia

This study compared the heamodynamic effects of sufentanil with those observed following concomitant sufentanil and highdose vecuronium administration to determine whether vecuronium induces bradyarrhythmias. Sixty coronary artery bypass patients were stratified into beta blocker (n = 30) or non-beta blocker (n = 30) groups and following induction with sufentanil (9 ± 3 μg · kg^?1) and midazolam (0.07 ± 0.04 mg · kg^?1), received either succinylcholine 1 mg · kg^?1 (SxCh), vecuronium 0.3 mg · kg^?1 (Vec 0.3), or vecuronium 0.5 mg · kg^?1 (Vec 0.5). Using a Holter ECG monitor, bradyarrhythmias were classified as mild (HR 46–50), moderate (HR 40–45) or severe (HR < 40). In the pre-induction period, there were no differences in the incidence of mild, moderate or severe bradyarrhythmias among the SxCh, Vec 0.3 or Vec 0.5 groups, in either the beta blocker or non-beta blocker groups. Following induction, there were similar reductions in mean heart rate and mean arterial pressure in all three muscle relaxant groups in both the beta and the non-beta blocker groups; however, there was no difference in the incidence of mild, moderate or severe bradyarrhythmias among the SxCh, Vec 0.3 or Vec 0.5 groups. The Vec 0.5 beta blocker group had a higher incidence of mild bradyarrhythmias (32 ± 36%) than the Vec 0.5 non-beta blocker group (2 ± 3% P = 0.017). Using EMG recording, the onset time of maximal neuromuscular block for the Vec 0.3 group (108 ± 17 sec) was longer (P < 0.05) than the SxCh (76 ±21 sec) and Vec 0.5 (82 ± 13 sec) groups, which were similar. We conclude: (i) vecuronium does not affect HR or the incidence of bradyarrhythmias following sufentanil administration and that the observed reduction in HR and mean arterial pressure were due to sufentanil administration, (ii) vecuronium (0.5 mg · kg^?1) provides an onset time of neuromuscular block similar to SxCh, and (iii) patients taking beta blockers preoperatively are more prone to develop bradyarrhythmias during sufentanil administration.     

Variation in the diagnosis of vesicoureteric reflux using micturating cystourethrography

  Variability in the interpretation of micturating cystourethrography by paediatric radiologists for the diagnosis of vesicoureteric reflux in children was evaluated. All 265 micturating cystourethrograms (MCUs) that were available from 304 consecutive children aged 0.5 – 61 months  –  who were investigated after their first urine infection between 1993 and 1995 as part of a prospective cohort study  –  were selected for interpretation. Three experienced paediatric radiologists from the same department independently interpreted the MCUs according to the grading system of the International Reflux Study in Children, from grades 0 to V, with the presence of intrarenal reflux also noted. Apart from being informed that urine infection was the indication for the MCU, no other clinical information was given to the radiologists. The indices of variability used were the percentage of agreement and the kappa statistic, expressed as a percentage. Both measures were weighted with integers representing the number of categories from perfect agreement. Disagreement was analysed for children and kidneys. For the diagnosis of vesicoureteric reflux in individual patients, including grade, the percentage of agreement was 96% – 97% (kappa 90% – 91%) and the weighted percentage of agreement was 96% – 98% (weighted kappa 93% – 94%). The same high level of agreement was present for individual kidneys, with a percentage of agreement of 97% – 98% (kappa 89% – 92%) and a weighted percentage of agreement of 98% – 99% (kappa 94% – 95%). There was near perfect agreement in the interpretation of radiological micturating cystourethrography among three experienced paediatric radiologists for the diagnosis and grade of vesicoureteric reflux. Any variations in the medical care of children suspected of having vesicoureteric reflux are not explained by differences in the reporting of this diagnostic test. Received June 19, 1996; received in revised form November 1, 1996; accepted December 6, 1996     

Cognitive behaviour therapy approach to disputing automatic thoughts: a two-stage model

Research shows that clients with automatic thoughts (dysfunctional thinking) often do not think of alternative explanations in relation to negative events. Furthermore, these automatic thoughts are characterized by a broad global, self-evaluative and ambiguous nature that could make disputing (or changing the ways they think) the most difficult part of the therapeutic process. This paper proposes a two-stage practise-based disputing model, guided by research, that aims to 'bring' an automatic thought to a specific, objective, quantifiable and concrete level at which not only is the particular aspect(s) of the automatic thought that causes emotional disturbances finely focused, but the disputing is also likely to be effective and manageable. Furthermore, it will also generate alternative explanations that are helpful in reducing emotional disturbances and in facilitating problem solving approach. In this paper, the authors use a case example to discuss the rationale that underpins the conceptualization of the model and to illustrate the process in which the strategies of the model are effectively used.     

Post-streptococcal glomerulonephritis in Hong Kong.

Of 74 paediatric inpatients with acute glomerulonephritis, 58 (78%) had a raised (greater than 1/200) antistreptolysin O titre. Serum C3 concentration was low in 73, but returned to normal within six weeks. Streptococcal infection remains the commonest cause of acute nephritis in children in Hong Kong, possibly due to overcrowded living conditions.     

Arterial and Venous Pharmacokinetics of Ropivacaine with and without Epinephrine after Thoracic Paravertebral Block

Background: Animal and volunteer studies indicate that ropivacaine is associated with less neurologic and cardiac toxicity than bupivacaine. Ropivacaine may offer advantages when used for thoracic paravertebral block. This study was designed to describe the pharmacokinetics of ropivacaine after thoracic paravertebral block.

Methods: Twenty female patients undergoing elective unilateral breast surgery were randomly assigned to receive a single bolus thoracic paravertebral injection of 2 mg/kg ropivacaine, with or without 5 [mu]g/ml epinephrine. Simultaneous arterial and venous blood samples were obtained for plasma ropivacaine assay. Data were analyzed with NONMEM, using two possible absorption models: conventional first-order absorption and absorption following the inverse gaussian density function.

Results: Epinephrine reduced the peak plasma concentrations and delayed the time of peak concentration of ropivacaine in both the arterial and venous blood. The time course of drug input into the systemic circulation was best described by two inverse gaussian density functions. The median bioavailability of the rapid component was approximately 20% higher when epinephrine was not used. The mean absorption times were 7.8 min for the rapid absorption phase and 697 min for the slow absorption phase, with wide dispersion of the absorption function for the acute phase. The half-time of arterial-venous equilibration was 1.5 min.     

RESULTS OF OPEN CARPAL TUNNEL RELEASE: A COMPREHENSIVE,RETROSPECTIVE STUDY OF 188 HANDS

Background : Many recent reports of the results of decompression of the median nerve in the carpal tunnel have concentrated on only one aspect of recovery (numbness, grip etc.), and there are no reports of a comprehensive study of outcome. The aim of the present study was to review comprehensively the results of the direct visualization method of decompression of the carpal tunnel and to compare them with the published results of endoscopic release. Methods : Patients' perceptions of the severity of pain, numbness and paraesthesiae due to carpal tunnel syndrome (CTS), before and after open carpal tunnel release (CTR) in 188 hands were reviewed retrospectively at a minimum time of follow-up of 18 months. Motor and sensory testing, provocation testing and measurement of scar tenderness in 135 hands were performed at a clinical review. Results : Subjective results showed that 70% experienced a reduction in the severity of pain after CTR, 78% of hands experienced a reduction in the severity of paraesthesiae and 77% experienced a reduction in the severity of numbness. A total of 49% had improvements in all three symptoms after CTR. At the clinical review, sensory testing revealed that 59% of hands had normal or slightly diminished light touch, 35% had normal static two-point discrimination and 61% had normal dynamic two-point discrimination. Results for Tinel's test, Phalen's test and pressure provocation testing were positive in 10% of hands. There was no scar tenderness in 38%, no persisting thenar atrophy in 90%. Normal grip strength was found in 93% and 91% had normal pinch strength. Conclusions : It was concluded that open carpal tunnel release remains a safe and reliable treatment for carpal tunnel syndrome. The very low incidence of serious complications from the open technique of CTR, when compared with endoscopic CTR as published by different authors in the literature, and the comparable clinical results, appears to make the open technique a safer and preferable option. However, a properly controlled trial of both techniques is necessary to compare them.