Relationship of perioperative hyperglycemia and major infections in cardiac surgery patients

Abstract

Two of the major infectious complications of cardiac surgery are pneumonia and surgical site infections of the sternum and graft harvest site. These postoperative adverse events significantly increase patient morbidity, mortality and cost associated with coronary artery bypass graft operations. Pre-existing diabetes mellitus is commonly considered one of the primary risk factors for development of these major infections. However, most of the previous cardiac surgery risk factor studies have not considered the role perioperative stress hyperglycemia may play in initiating these complications. The primary hypothesis of this retrospective descriptive cohort study was that perioperative stress hyperglycemia (defined as either perioperative serum glucose threshold ≥250 mg/dL or perioperative serum glucose change ≥50 mg/dL) is an independent risk factor for the composite outcome of postoperative infections, including pneumonia and surgical site infections of the sternum and harvest site. The relationship of stress hyperglycemia to the individual infection outcomes was also examined. The secondary study hypothesis was that stress hyperglycemia increases resource utilization as excess days of care. The setting was a tertiary care federal medical facility in the southwestern United States, and the study cohort involved 1285 male military veterans.