National Patient Safety Agency surgical safety checklist and glycaemic control

Abstract

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 intensive 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 Our unpublished data from 2007 showed that the local guidelines for the management of the diabetic adult patient undergoing surgery in 9 out of 11 acute hospitals in East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.