Anaesthesia, 2009, 64, pages 1371–1383 .....................................................................................................................................................................................................................
Correspondence
National Patient Safety Agency surgical safety checklist and glycaemic control
The new National Patient Safety Agency (NPSA) guidelines [1] endorsing the World Health Organization (WHO) surgical safety checklist [2] are generally to be supported. At the eight hospitals piloting the checklist, overall inpatient deaths following major operations fell by more than 40% (from 1.5% to 0.8%) after introduction of the checklist, and the rate of major complications fell from 11% in the baseline period to 7% [3]. Despite these benefits we are concerned that the statement of ‘maintenance of glycaemic control’ to reduce surgical site infection is imprecise and not justified by the two references cited [4, 5]. The first reference was an observational study [4], in which the authors concluded that postoperative hyperglycaemia and an elevated glycosylated haemoglobin concentration were associated with a higher incidence of postoperative wound infection. This study failed to address the relationship between intervention and benefit, and thus by itself can not be used as evidence to justify the statement that maintenance of glycaemic control decreases surgical site infection. The second citation, Van den Berghe et al.’s study [5], concluded that inten-
sive insulin therapy to maintain blood glucose at or below 6.1 mmol.l)1 reduced morbidity and mortality amongst critically ill patients in the surgical intensive care unit. However, other investigators have failed to reproduce these findings. Indeed, some studies have actually reported a worse outcome when intensive insulin therapy was implemented in general intensive care units, with serious adverse incidents such as hypoglycaemia [6, 7]. Furthermore, the statement does not provide actual guidance on the maintenance of glycaemic control but merely suggests that ‘local guidelines on glycaemic control should be followed’. Concerns have been raised that current practice within the UK is inadequate [8]. The cornerstone of metabolic control of the diabetic patient in the peri-operative period is the administration of hypotonic intravenous glucose with potassium chloride and a variable insulin infusion [9]. Our unpublished data from 2007 showed that the local guidelines for the management of the diabetic adult patient undergoing surgery in 9 out of 11 acute hospitals in East Anglia recommended the use of hypotonic 5% or 10% glucose to be administered at a rate of 83–125 ml.h)1. Yet it is well known that hypotonic solutions predispose patients to hyponatraemia, fits and death [10–12]. The NPSA have already issued a safety alert highlighting the dangers of
hypotonic intravenous fluids in children [13]. A thorough review of guidelines for glycaemic control in the peri-operative period is required in the UK. We support the NPSA’s efforts to highlight the dangers of peri-operative hyperglycaemia; however, we are concerned that the lack of guidance on the management of glucose will lead to further instances of iatrogenic hypoglycaemia and hyponatraemia. N. Levy G. M. Hall West Suffolk Hospital Bury St Edmunds, UK St George’s University of London London, UK E-mail:
[email protected]
References 1 National Patient Safety Agency. Surgical Safety Checklist Alert. http:// www.npsa.nhs.uk/nrls/alerts-anddirectives/alerts/safer-surgery-alert/ (accessed 01 ⁄ 02 ⁄ 2009). 2 World Health Organisation. Surgical Safety Checklist. http://www.who.int/ patientsafety/safesurgery/tools_resources/ SSSL_Checklist_finalJun08.pdf (accessed 01 ⁄ 02 ⁄ 2009). 3 Haynes AB, Weiser TG, Berry WR, et al. A surgical safety checklist to reduce morbidity and mortality in a global population. The New England Journal of Medicine 2009; 360: 491–9.
A response to a previously published article or letter can be submitted to the Online Correspondence section at www.anaesthesiacorrespondence.com. All correspondence intended for publication in Anaesthesia should be submitted as an e-mail attachment to anaesthesia@nottingham. ac.uk. All correspondence submissions should be accompanied by a completed author declaration form as requested in the Guidelines to Authors which can be accessed at http://www.wiley.com/bw/submit.asp?ref=0003-2409. The author declaration form should be sent as an email attachment. Copy should be prepared in the usual style of the Correspondence section. Authors must follow the advice about references and other matters contained in the Author Guidelines at http://www.wiley.com/bw/submit.asp?ref=0003-2409&site=1. Correspondence presented in any other style or format will be returned to the author for revision.
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Correspondence Anaesthesia, 2009, 64, pages 1371–1383 . ....................................................................................................................................................................................................................
4 Latham R, Lancaster AD, Covington JF, Pirolo JS, Thomas CS. The association of diabetes and glucose control with surgical site infections among cardiothoracic surgery patients. Infection Control Hospital Epidemiology 2001; 22: 607–12. 5 Van den Berghe G, Wouters P, Weekers F, et al. Intensive insulin therapy in critically ill patients. New England Journal of Medicine 2001; 345: 1359–67. 6 Wiener RS, Wiener DC, Larson RJ. Benefits and risks of tight glucose control in critically ill adults: a meta-analysis. Journal of American Medical Association 2008; 300: 933–44. 7 Brunkhorst FM, Engel C, Bloos F, et al. Intensive insulin therapy and pentastarch resuscitation in severe sepsis. The German Competence Network Sepsis (SepNet). The New England Journal of Medicine 2008; 358: 125–39. 8 Simpson AK, Levy N, Hall GM. Peri-operative iv fluids in diabetic patients – don’t forget the salt. Anaesthesia 2008; 63: 1043–5. 9 Eldridge AJ, Sear JW. Peri-operative management of diabetic patients. Any changes for the better since 1985? Anaesthesia 1996; 51: 45–51. 10 Lobo DN, Stanga Z, Simpson JA, Anderson JA, Rowlands BJ, Allison SP. Dilution and redistribution effects of rapid 2-litre infusions of 0.9% (w ⁄ v) saline and 5% (w ⁄ v) dextrose on haematological parameters and serum biochemistry in normal subjects: a double-blind crossover study. Clinical Science (London) 2001; 101: 173–9. 11 Arieff AI. Hyponatraemia, convulsions, respiratory arrest and permanent brain damage after elective surgery in healthy women. New England Journal of Medicine 1986; 314: 1529–35. 12 Hoorn EJ, Lindemans J, Zietse R. Development of severe hyponatraemia in hospitalized patients: treatment related risk factors and inadequate management. Nephrology Dialysis Transplantation 2006; 21: 70–6. 13 National Patient Safety Agency. Patient Safety Alert 22. Reducing the Risk of Hyponatraemia When Administering Intravenous Infusions to
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Children. 28 March 2007; http:// www.npsa.nhs.uk/nrls/alerts-anddirectives/alerts/intravenous-infusions/ (accessed 01 ⁄ 02 ⁄ 2009).
World Health Organisation checklist and glycaemic control
The recent Safer Surgery Checklist, endorsed by the National Patient Safety Agency [1], incorporates a question asking if the surgical site infection bundle has been undertaken. This bundle includes glycaemic control suggesting that local guidelines should be followed. Our in-hospital audit performed in 2002 found that our guidelines were not being followed in 25% of cases and that there were episodes of both hypo- and hyperglycaemia, with the rate of hypoglycaemia running at 14%. After revising the guidelines and associated paperwork, and addressing education issues with both doctors and nurses, we repeated the audit in 2006 showing a good improvement (guidelines not being followed in 16% of cases and no incidents of hypoglycaemia). A further repeat of the audit in 2008 revealed some regression with episodes of hypoand hyperglycaemia re-emerging: hypoglycaemia now at 6%. This may have been caused by a combination of factors, including the admission of patients on the morning of surgery, change in junior doctors, working practices and movement to a ‘one-stop-shop’ preassessment process. We also looked for, and found, some evidence of postoperative hyponatraemia on our existing guidelines that included 5% glucose infusion at 83 ml.h)1. We are now looking to revise our guidelines for the peri-operative control of blood glucose in diabetic patients undergoing surgery but there is minimal guidance on optimal management. We are concerned that while the World Health Organization checklist has been shown to improve safety, in the absence of guidance on perioperative glycaemic control and glucose target levels, avoidable morbidity may continue because of loss of metabolic control.
S. Bhadresha K. M. Leyden S. L. Ellis Northampton General Hospital Cliftonville Northampton, UK E-mail:
[email protected]
Reference 1 http://www.npsa.nhs.uk/nrls/alertsand-directives/alerts/safer-surgeryalert/ (accessed 01 ⁄ 05 ⁄ 2009). Risk and outcome analysis of renal replacement therapies
We read with interest Hauer et al.’s paper [1] which aimed to identify risk factors for post-cardiac surgery renal failure when pre-operative renal function was normal. We commend their attempt to identify independent predictors and felt the paper raised some important questions. We would like to have known more about the patients’ comorbidities, the types of cardiac surgery performed and whether these were risk factors for renal failure. Previous revascularisation surgery, diabetes, hypertension, extracardiac vasculopathy and valvular ⁄ aortic surgery have all been previously identified as predictors of renal failure [2, 3], but this information was not presented. It would be interesting to know how closely the findings of earlier studies had been reproduced. Knowing more about the authors’ patient population would allow us to see how closely their findings relate to patients we encounter in our practice. We would be interested to learn more about the authors’ patient recruitment. How many patients were identified as suitable to take part in the study, and how many declined the opportunity to take part? If all 1574 patients were indeed recruited consecutively and no patients later withdrew consent or were lost to follow-up, then we must congratulate them on a considerable achievement. M. R. Edwards S. I. Jaggar Royal Brompton Hospital London, UK E-mail:
[email protected]
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