Postoperative Hyperglycemia Affects Two-Thirds of Cardiac Surgery Patients, Linked to Higher Risk of Complications: Study

“Postoperative hyperglycemia (PHG) was observed in 65.3% of patients undergoing cardiopulmonary bypass and was significantly associated with a higher risk of several postoperative complications,” the researchers reported in Frontiers in Cardiovascular Medicine. Patients with PHG had increased rates of acute kidney injury (12.6% vs. 4.0%), delirium (9.5% vs. 3.4%), and pulmonary infections (12.0% vs. 5.1%) when compared to those without PHG.

The researchers further identified several independent risk factors for developing PHG, including pre-existing diabetes (odds ratio [OR] 13.1), pulmonary infection (OR 1.91), elevated intraoperative blood glucose levels (OR 1.51), and female sex (OR 1.38). In addition to heightened complication rates, patients with PHG also faced prolonged ICU stays and longer overall hospitalization.

Postoperative hyperglycemia is commonly observed following cardiac surgery involving cardiopulmonary bypass (CPB) and is associated with increased morbidity and mortality. Yuping Xiang, Department of Critical Care Medicine, West China Hospital, Sichuan University/West China School of Nursing, Sichuan University, Chengdu, Sichuan, China, and colleagues aimed to assess the incidence of PHG in such patients, identify its independent risk factors, and explore its impact on clinical outcomes.

For this purpose, the researchers conducted a retrospective observational study at West China Hospital of Sichuan University, analyzing patients who underwent cardiac surgery with cardiopulmonary bypass between January 2023 and March 2024. 1,008 consecutive patients admitted to the cardiac surgery ICU were categorized into PHG and non-PHG groups. Blood glucose levels were monitored immediately after surgery and every 3–4 hours daily for 10 days or until ICU discharge. Patients with PHG received intravenous insulin therapy.

Based on the study, the researchers reported the following findings:

• Postoperative hyperglycemia (PHG), defined as random blood glucose ≥180 mg/dL on two occasions within 24 hours, was observed in 65.28% of patients undergoing cardiac surgery.
• Older age was associated with a higher risk of PHG (OR 1.054).
• Female patients were more likely to develop PHG (OR 1.380).
• Diabetes was a strong predictor of PHG (OR 13.101).
• Pulmonary infection increased the risk of PHG (OR 1.918).
• Longer aortic cross-clamp time was linked to PHG (OR 1.007).
• Higher intraoperative glucose levels were independently associated with PHG (OR 1.515).
• Patients with PHG had a higher incidence of acute kidney injury compared to those without PHG (12.61% vs. 4.00%).
• The rate of delirium was higher in the PHG group (9.57% vs. 3.43%).
• Pulmonary infection occurred more frequently in PHG patients (12.01% vs. 5.14%).
• The duration of mechanical ventilation was longer in the PHG group (19 vs. 14 hours).
• The length of ICU stay was extended among PHG patients (74 vs. 58 hours).
• Hospital stay was also prolonged in PHG cases (13 vs. 11 days).
• Self-discharge or death was more common in PHG patients compared to non-PHG patients (3.95% vs. 0.57%).

The study revealed that postoperative hyperglycemia commonly occurs after cardiac surgery with cardiopulmonary bypass and is independently associated with risk factors like older age, female sex, diabetes, pulmonary infections, longer aortic cross-clamp time, and high intraoperative glucose levels. PHG is linked to poorer outcomes, including higher rates of kidney injury, delirium, infections, prolonged ventilation, extended ICU and hospital stays, and increased risk of self-discharge or death.

"These findings highlight the need for timely detection and effective management of PHG to enhance postoperative recovery," the authors concluded.

Reference:

Xiang, Y., Luo, T., & Zeng, L. (2025). Risk factors and clinical outcome of postoperative hyperglycemia after cardiac surgery with cardiopulmonary bypass. Frontiers in Cardiovascular Medicine, 12, 1479922. https://doi.org/10.3389/fcvm.2025.1479922