Perioperative glycemic control with a computerized algorithm versus conventional glycemic control in cardiac surgical patients undergoing cardiopulmonary bypass with blood cardioplegia.

OBJECTIVE

In critical illness, hypoglycemia and hyperglycemia seem to influence outcome. While hypoglycemia can lead to organ dysfunction, hyperglycemia can lead to surgical site infections (SSI). In cardiac surgery, the use of blood cardioplegia is associated with high blood glucose levels. A computer-based algorithm (CBA) for guiding insulin towards normoglycemia might be beneficial. The authors' primary study end-point was the duration in a predefined blood glucose target range of 80 mg/dL to 150 mg/dL. Patients with conventional therapy served as controls.

DESIGN

Prospective, randomized trial.

SETTING

University hospital.

PARTICIPANTS

Seventy-five patients.

INTERVENTIONS

The start of therapy was the beginning of cardiopulmonary bypass. Group A: Therapy with CBA and measurement of blood glucose every 30 minutes. Group B: Measurement of blood glucose every 15 minutes using the identical CBA. Group C: Conventional therapy using a fixed insulin dosing scheme. End of therapy was defined as discharge from ICU.

MEASUREMENT AND MAIN RESULTS

Glucose administration during cardioplegia did not differ between groups (A: 33 ± 12 g; B: 32 ± 12 g; C: 38 ± 20 g). Glucose levels in groups A and B stayed significantly longer in the target interval compared with group C (A: 75 ± 20%; B: 72 ± 19%; C: 50 ± 34%, p < 0.01 n = 25, respectively). There were no significant differences regarding ICU stay and SSI rates.

CONCLUSIONS

Early computer-based insulin therapy allows practitioners to better achieve normoglycemia in patients undergoing major cardiac surgery with the use of blood cardioplegia.