Tetanic stimulus of ulnar nerve as a predictor of heart rate response to skin incision in propofol remifentanil anaesthesia

Background: To study adequate antinociception during general anaesthesia,tetanic stimulus of 5–10 s duration has been used previouslyas a standardized nociceptive stimulus. However, such stimulihave been found to correlate poorly with intraoperative nociception.We hypothesized that an electrical tetanic stimulus of the ulnarnerve, lasting 30 s, would provide a reliable experimental painmodel. Methods: Thirty-three patients, undergoing open abdominal surgery, werestudied. Propofol and remifentanil were used for anaesthesia.Patients were randomized to receive remifentanil at three target-controlledinfusion levels (1, 3, or 5 ng ml^–1) during short (5 s,Tet5) and a long-lasting (30 s, Tet30) tetanic (50 mA, 50 Hz)stimulus and skin incision. RR intervals (RRI) were obtainedfrom the ECG and the mean RRI before each stimulus (Tet5, Tet30,incision) was compared with that after the stimulus. Results: At remifentanil level 1 ng ml^–1, the RRI responses totetanic stimuli and skin incision were prominent but with higherconcentrations (3 and 5 mg ml^–1), responses were verysmall. Tet30 (r²=0.780) was the best predictor of the RRI responseto skin incision when compared with Tet5 (r²=0.611), remifentanillevel (r²=0.340), or propofol level (r²=0.036). Conclusions: Long-lasting tetanic stimulus of ulnar nerve may provide a betterexperimental pain model for surgical pain during general anaesthesiathan shorter stimuli, which have been applied in earlier studies.     

Importance of the creatinine calibration in the estimation of GFR by MDRD equation.

Sir, We read with great interest the recent article by Van Biesenet al. [1] on the standardization of creatinine and the implicationsfor chronic kidney disease (CKD) management. We fully agreewith the general conclusions. However, we would     

No evidence for a role of cosmc-chaperone mutations in European IgA nephropathy patients

Background. Altered IgA1 galactosylation is involved in thepathogenesis of IgA nephropathy (IgAN). The galactosyltransferasecore-1 beta3-galactosyltransferase-1 (C1GALT1) and its chaperonecosmc are specifically required for O-galactosylation of theIgA1 hinge region. Mutations in the cosmc gene result in a secondaryloss of function of C1GALT1 with subsequent undergalactosylationof glycoproteins. Mosaic mutations of cosmc have been shownto result in autoimmune disease. We hypothesized that cosmcmutations might contribute to the altered IgA1 galactosylationin IgAN patients. Methods. We studied cosmc gene sequences in genomic DNA obtainedfrom male patients with biopsy-proven sporadic (n = 33) andfamilial IgAN (n = 6 patients from different families). To accountfor a potential mosaicism we sequenced cosmc in 10 differentperipheral blood mononuclear cell DNA clones of every patient.To specifically assess potential mosaic mutations in IgA-producingcells, cosmc mutations were also analysed in DNA isolated fromCD20+ B-lymphocytes from three male IgAN patients. Results. Despite our extensive genomic analysis, the data revealedno functionally relevant cosmc gene variants in sporadic orfamilial IgAN cases. A cosmc gene polymorphism, rs17261572,was identified in these IgAN patients in a similar frequencyas previously reported in healthy adults. A functional consequenceof this polymorphism has not yet been determined. Conclusion. Although decreased C1GALT1 activity has been implicatedin the IgAN pathogenesis and cosmc chaperone mutations can causeautoimmune disease, our data provide no evidence for a relevantrole of cosmc gene mutations in European patients with sporadicor familial IgAN.     

Reply

Sir, In response to the letter by Doi et al., we would like to highlightthe differences between the populations that we and Doi et al.studied, which might explain the     

Large volume N2O uptake alone does not explain the second gas effect of N2O on sevoflurane during constant inspired ventilation

Background. The second gas effect (SGE) is considered to besignificant only during periods of large volume N₂O uptake (VN₂O);however, the SGE of small VN₂O has not been studied. We hypothesizedthat the SGE of N₂O on sevoflurane would become less pronouncedwhen sevoflurane administration is started 60 min after thestart of N₂O administration when VN₂O has decreased to     

Effect of ascorbic acid supplementation on plasma isoprostanes in haemodialysis patients.

Sir, We would like to report the effect of ascorbic acid (AA) supplementationon plasma F₂-isoprostanes in haemodialysis patients with anaemiaand hyperferritinaemia. The F₂-isoprostanes, free-radical oxidationproducts of arachidonic acid, have been quantified in humanmodels of increased oxidative stress [1], including haemodialysispatients [2], and are a useful measure of in vivo lipid     

Oral calcium, sevelamer and vascular calcification in uraemic patients.

Sir, We have greatly appreciated the excellent, challenging reviewby Coladonato et al. [1] of the issue relating oral calciumload to artery calcifications and cardiovascular complications.We would like to add scientific works, which do not supportthis link, and stress shortcomings of the protocol design ofthe recently published ‘Treat to goal’ study [2]aimed at proving a causal relationship between oral calciumload and cardiovascular damage. As Coladonato et al. [     

Drug interaction between sevelamer and cyclosporin.

This letter was originally published in NDT volume 19, issue7, but without the Reply. The publisher would like to apologisefor this error and would now like to publish the paper againto include the Reply. Sir, We read with interest the original report     

Survey of cancellation rate of hypertensive patients undergoing anaesthesia and elective surgery

Hypertension is the commonest avoidable medical indication forpostponing anaesthesia and surgery. There are no universallyaccepted guidelines stating the arterial pressure values atwhich anaesthesia should be postponed. The aim of this studywas to determine the extent of variation across the South-Westregion of the UK in the anaesthetic management of patients presentingwith stage 2 or stage 3 hypertension. Each anaesthetist in theregion was sent a questionnaire with five imaginary case historiesof patients with stage 2 or stage 3 hypertension. They wereasked if they would be prepared to provide anaesthesia for eachpatient. The response rate was 58%. We found great variabilitybetween anaesthetists as to which patients would be cancelled.Departmental protocols may aid general practitioners and surgeonsin the preparation of patients for surgery, but such protocolsmay be difficult to agree in the light of such a wide variationin practice. Br J Anaesth 2001; 86: 789–93     

Some notes about the usage of the Charlson co-morbidity index.

Sir, We read with great interest the recent paper by Kalantar-Zadehet al. [1] based on a comparison of malnutrition–inflammationmarkers for outcome predictability. We appreciate its high levelin the matter of clinical usefulness and statistical power,but would like to add some critical notes. In our opinion, Kalantar-Zadeh et al. placed insufficient emphasison the significance     

Diagnosis and successful management of calciphylaxis in a pancreas-kidney transplant patient.

Sir, We would like to refer to a case of fatal calciphylaxis developed2 years after kidney transplantation published in the December2004 issue of Nephrology Dialysis Transplantation [1]. We report a case of a 49-year-old woman     

Myocardial protection with volatile anaesthetic agents during coronary artery bypass surgery: a meta-analysis

Previous studies have investigated the role of volatile anaestheticagents in myocardial protection during coronary artery bypassgraft (CABG) surgery, and some have identified beneficial effects.However, these studies have been too small to identify a significanteffect on myocardial infarction (MI) or mortality. We undertooka systematic overview and meta-analysis of all randomized trialscomparing volatile with non-volatile anaesthesia in CABG surgery.We identified 27 trials that included 2979 patients. There wasno significant difference in myocardial ischaemia, MI, intensivecare unit length of stay or hospital mortality between the groups(all P>0.05). Post-bypass, patients randomized to receivevolatile anaesthetics had 20% higher cardiac indices (P=0.006),significantly lower troponin I serum concentrations (P=0.002)and lesser requirement for inotropic support (P=0.004) comparedwith those randomized to receive i.v. anaesthetics. Durationof mechanical ventilation was reduced by 2.7 h (P=0.04), andthere was a 1 day decrease in hospital length of stay (P<0.001).Some of these outcomes were based on a smaller number of trialsbecause of incomplete data, largely because the individual trialsfocused on one or more surrogate endpoints. We found some evidencethat volatile anaesthetic agents provide myocardial protectionin CABG surgery, but larger adequately powered trials with agreed,defined outcomes need to be done to fully assess a possiblebeneficial effect of volatile anaesthetic agents on the riskof MI and mortality.     

ERRATUM

p. 608. In the correspondence of Raphael and Norton (third paragraph),"a large proportion of the patients studied would have requiredantagonism of neuromuscular block if mivacurium had been usedinstead of suxamethonium" should read "a large proportion ofthe patients studied would have been subject to an unnecessarilyprolonged neuromuscular block if mivacurium ..."     

Assessment instruments used during anaesthetic simulation: review of published studies

This review was undertaken to discover what assessment instrumentshave been used as measures of performance during anaesthesiasimulation and whether their validity and reliability has beenestablished. The literature describing the assessment of performanceduring simulated anaesthesia amounted to 13 reports publishedbetween 1980 and 2000. Only four of these were designed to investigatethe validity or reliability of the assessment systems. We concludethat the efficacy of methodologies for assessment of performanceduring simulation is largely undetermined. The introductionof simulator-based tests for certification or re-certificationof anaesthetists would be premature. Br J Anaesth 2001; 86: 445–50     

Editorial I: A fond farewell

Undoubtedly, it has been the greatest privilege of my professionallife to be Editor-in-Chief (EIC) of the British Journal of Anaesthesia(BJA). For nearly 8 yr, it has monopolized my waking hours.Yet it has been a highly rewarding, educational, and enjoyabletask. I would never have wanted to miss this huge challenge,and I am ambivalent about passing on the responsibility to mysuccessor, Professor Charles Reilly in Sheffield, UK. Part ofme would wish to undertake this burden forever. But, as withall living things, this journal needs continual stimulation,change, and renovation to keep it at the forefront of its specializedarea. No human being (or team of beings) can continue infinitelyto produce     

Current treatment options in secondary renal hyperparathyroidism.

Sir, We read with interest the editorial comment by H. Reichel onthe current treatment options in secondary renal hyperparathyroidism(SRHPT) and we totally agree with his conclusion that cinacalcetoffers a fundamentally different approach to SRHPT therapy whencompared with ‘active’ vitamin D derivative-basedapproach. However, we would like to make a few comments andraise the issue of the cost-effectiveness of this new treatment. The first comment concerns the current justification of theso called ‘active’ vitamin D metabolites. This adjectiveis actually a misnomer, since it is used for designating 1 OHvitamin D derivatives, which are the most potent vitamin D derivativesto increase intestinal absorption of calcium and phosphate andthe serum concentrations of these divalent ions, but not necessarilythe most ‘efficace’ at     

Malnutrition, chronic inflammation and atherosclerosis in dialysis patients

Sir, The supplement volume of Nephrology Dialysis Transplantationon chronic inflammation, atherosclerosis and immunointerventionin dialysis [1,2] has provided readers with an excellent reviewof this extremely important topic. We would like to contributetwo     

Successful defibrillation in the prone position

Early defibrillation provides the greatest chance of survivalafter ventricular fibrillation. Conventional cardiopulmonaryresuscitation and defibrillation requires the patient to bein the supine position. Electrical treatment of arrhythmiassuch as atrial fibrillation by means of a defibrillator backpaddle in patients receiving prone ventilation in intensivecare has been described. We report a case in which electricaldefibrillation was successfully performed in the prone positionin a patient undergoing complex spinal surgery. We suggest that,if defibrillation were required in ventilated patients positionedprone, defibrillation should be attempted in the prone position,as turning the patient supine would consume valuable minutesand reduce the chances of successful defibrillation. Br J Anaesth 2001; 87: 937–8