Does good glycaemic control benefit children after cardiac surgery?

The benefit of tight glycaemic control in the post-operative setting has come under increasing scrutiny of late. Initial small scale studies suggesting large clinical benefits have been followed by much larger multi-centre trials demonstrating neutral or even harmful effects of tight blood sugar control, with most investigators pointing towards the high occurrence of hypoglycaemia as being the main problem associated with therapy. These studies have been almost exclusively in adults but the role of tight glycaemic in critically ill children is less well understood. In this study, Agus et al examined whether tight glycaemic control reduces morbidity after paediatric cardiac surgery. In a two-centre, prospective, randomized trial, 980 children, 0 to 36 months of age, undergoing surgery with cardiopulmonary bypass were recruited. Participants were randomly assigned to either tight glycaemic control (with the use of an insulin-dosing algorithm targeting a blood glucose level of 4.4 to 6.1 mmol/l) or standard care in the cardiac intensive care unit. Continuous glucose monitoring was used to guide the frequency of blood glucose measurement and to detect impending hypoglycaemia. The primary outcome was the rate of health care-associated infections with secondary outcomes including mortality, length of stay, organ failure, and hypoglycaemia. A total of 444 of the 490 children assigned to tight glycaemic control (91%) received insulin versus 9 of 490 children assigned to standard care (2%). Although normoglycaemia was achieved earlier (6 hours vs. 16 hours, P<0.001) and was maintained for a greater proportion of the critical illness period (50% vs. 33%, P<0.001), tight control failed to show any benefit in the primary outcome (8.6 vs. 9.9 per 1000 patient-days, P=0.67), any of the secondary outcomes or in post-hoc analyses of high risk sub-groups. Due to the use of continuous glucose monitoring the rate of severe hypoglycaemia (<2.2 mmol/l) were very low occurring in only 3% of patients

Conclusions:

Tight glycaemic control can be achieved with a low hypoglycaemia rate after cardiac surgery in children, but does not significantly change the infection rate, mortality, length of stay, or measures of organ failure, as compared with standard care.

  • Agus MS, Steil GM, Wypij D, Costello JM, Laussen PC, Langer M, Alexander JL, Scoppettuolo LA, Pigula FA, Charpie JR, Ohye RG, Gaies MG; SPECS Study Investigators. Tight glycaemic control versus standard care after paediatric cardiac surgery. N Engl J Med. 2012 Sep 27;367(13):1208-19.