Tight Glycemic Control Versus Standard Care After Pediatric Cardiac Surgery

Study Questions:

Does tight glycemic control reduce morbidity after pediatric cardiac surgery?

Methods:

SPECS, a prospective, randomized trial was performed at two high-volume pediatric cardiac intensive care units (ICUs). Children 0-36 months of age admitted to the ICU after cardiac surgery with cardiopulmonary bypass were included. Exclusion criteria included pre-existing diabetes or inadequate vascular access. Patients were randomly assigned to either tight glycemic control with a goal blood glucose level of 80-110 mg/dl or standard care in the ICU. Continuous glucose monitoring was performed to guide the frequency of blood glucose monitoring and to detect impending hypoglycemia. Continuous insulin infusion was performed by the bedside nurse using an insulin-dosing algorithm. The primary outcome was the number of health care-associated infections, including pneumonia, blood stream, urinary tract, and surgical-site infections. Secondary outcomes included mortality, duration of mechanical ventilation, ICU length of stay, proportion of children with hypoglycemia, and measures of organ failure.

Results:

A total of 980 children were enrolled. Of the 490 children assigned to tight glycemic control, 444 (91%) received insulin, as compared with 9 of 490 (2%) children assigned to standard care. Normoglycemia was achieved earlier with tight control (6 hours vs. 16 hours, p < 0.001) and was maintained for a greater portion of the critical illness period (50% vs. 33%, p < 0.001). No difference was seen for the primary outcome of health care-associated infections (8.6 per 1,000 patient-days in the tight control group, as compared with 9.9 per 1,000 days in the standard care group, p = 0.67), or in any of the secondary outcomes. Severe hypoglycemia (blood glucose <40 mg/dl) occurred in 3% of patients assigned to tight glycemic control, as compared with 1% of patients in the standard care group (p = 0.03).

Conclusions:

Tight glycemic control does not significantly change the infection rate, mortality, length of stay, or measures of organ failure, as compared with standard of care. Attainment of tight control is feasible with a low rate of hypoglycemia.

Perspective:

Since Van den Bergh and colleagues demonstrated improved outcomes in adult ICU patients with intensive insulin therapy (N Engl J Med, 2001), there has been significant interest in investigating this approach in additional patient populations. Infants and children undergoing surgery for congenital heart disease have a high rate of postoperative hyperglycemia. This is the first study to prospectively investigate the role of tight glycemic control specifically in a large population of patients following surgery for congenital heart disease. This study used a realistic blood glucose management plan revolving around a sophisticated insulin algorithm administered by the bedside nurse. The incidence of serious hypoglycemia was lower than previously reported studies in children, and may have been related to continuous blood glucose monitoring. No improvement in morbidity or mortality was seen in the patients receiving tight control of blood glucose levels. In a field where prospective data with large patient numbers are often lacking, this study again demonstrates that prospective trials in congenital heart disease are feasible and can help to answer important clinical questions.

Clinical Topics: Cardiac Surgery, Congenital Heart Disease and Pediatric Cardiology, Invasive Cardiovascular Angiography and Intervention, Cardiac Surgery and CHD and Pediatrics, Congenital Heart Disease, CHD and Pediatrics and Interventions, CHD and Pediatrics and Prevention, Interventions and Structural Heart Disease

Keywords: Hyperglycemia, Pneumonia, Heart Defects, Congenital, Morbidity, Respiration, Artificial, Hypoglycemia, Length of Stay, Heart Diseases, Child, Uterine Cervical Dysplasia, Blood Glucose, Intensive Care Units, Pediatric, Hypoglycemic Agents, Cardiopulmonary Bypass, Cardiac Surgical Procedures, Diabetes Mellitus


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