Heart surgery with protective barrier

Cardiac Surgery and Steroids: Unveiling the Risks of Surgical Site Infections

Kai Mendoza in Health & Wellness November 2025 • 5 min read.

"A deep dive into the factors that increase the likelihood of postoperative infections, helping patients and healthcare providers stay informed and proactive."

Undergoing cardiac surgery is a significant health event, and while it can be life-saving, it's crucial to be aware of potential complications. Postoperative infections, especially surgical site infections (SSIs), are a major concern. These infections can lead to increased morbidity, mortality, and healthcare costs. Identifying risk factors associated with these infections is essential for targeted prevention strategies.

A comprehensive study, 'Steroids in Cardiac Surgery Trial: A Substudy of Surgical Site Infections,' delved into these risk factors using data from a large, multi-center randomized controlled trial. The original trial, known as SIRS (Steroids in Cardiac Surgery), investigated the effects of intraoperative methylprednisolone (a steroid) administration during cardiac surgery. While the initial trial found no impact on mortality or major morbidity from steroid use, this substudy focused specifically on identifying risk factors for SSIs.

This analysis provides valuable insights that empower both patients and healthcare providers. Understanding these risks allows for better preparation, preventative measures, and ultimately, improved outcomes after cardiac surgery.

What Factors Increase Your Risk of Surgical Site Infections After Cardiac Surgery?

The study analyzed data from 7,406 patients who underwent cardiac surgery, excluding those who died intraoperatively or within 48 hours post-operation. Researchers tracked the occurrence of surgical site infections within the first 30 days after surgery and employed a statistical model to pinpoint significant risk factors. Here’s what they discovered:

Several factors significantly increased the risk of developing a surgical site infection:

Diabetes Managed with Insulin: Patients whose diabetes was managed with insulin had a higher risk (adjusted odds ratio [aOR]: 1.55; 95% confidence interval [CI]: 1.13 to 2.12).
Oral Hypoglycemics or Diet-Controlled Diabetes: Similar risks were observed for those managing diabetes with oral medications (aOR 1.60; 95% CI 1.18 to 2.16) or diet alone (aOR 1.81; 95% CI 1.16 to 2.83).
Female Sex: Being female was associated with an increased risk (aOR 1.34; 95% CI 1.05 to 1.71).
Renal Failure: Both with (aOR 2.03; 95% CI 1.06 to 3.91) and without dialysis (aOR 1.50; 95% CI 1.04 to 2.14), renal failure increased infection risk.
Prolonged Cardiopulmonary Bypass (CPB) Time: Surgeries requiring longer CPB times (over 96 minutes) elevated risk (aOR 1.84; 95% CI 1.44 to 2.35).
Body Mass Index (BMI): Both underweight (BMI < 22.3, aOR 0.44; 95% CI 0.28 to 0.71) and obese (BMI > 30, aOR 1.49; 95% CI 1.17 to 1.89) individuals faced heightened risk.
Elevated Blood Glucose Levels: Higher peak blood glucose levels in the intensive care unit (ICU) were also a factor (aOR 1.02 per mmol·L¯¹; 95% CI 1.00 to 1.04).
Coronary Artery Bypass Grafting (CABG): Undergoing CABG was riskier than other types of cardiac surgeries (aOR 2.59; 95% CI 1.87 to 3.59).

Interestingly, the study also found that being underweight (BMI less than 22.3) also increased the risk of surgical site infections. This highlights the importance of maintaining a healthy weight, whether that means gaining or losing weight, to optimize surgical outcomes.

Taking Steps to Minimize Your Risk

While some risk factors, like sex and the type of surgery needed, are unavoidable, many others can be managed through proactive measures. By understanding these risks and working closely with your healthcare team, you can significantly reduce your chances of developing a surgical site infection and improve your overall recovery after cardiac surgery. Make sure to have open and honest conversations with your doctor about your individual risk factors and the best strategies for managing them.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1007/s12630-018-1253-5, Alternate LINK

Title: Steroids In Cardiac Surgery Trial: A Substudy Of Surgical Site Infections

Subject: Anesthesiology and Pain Medicine

Journal: Canadian Journal of Anesthesia/Journal canadien d'anesthésie

Publisher: Springer Science and Business Media LLC

Authors: Graham R. Mcclure, Emilie P. Belley-Cote, John Harlock, Andre Lamy, Michael Stacey, P. J. Devereaux, Richard P. Whitlock

Published: 2018-12-10

Everything You Need To Know

What are the primary risk factors for surgical site infections (SSIs) identified in the Steroids in Cardiac Surgery Trial Substudy following cardiac surgery?

The 'Steroids in Cardiac Surgery Trial: A Substudy of Surgical Site Infections' identified several factors that increase the risk of Surgical Site Infections (SSIs) after cardiac surgery. These include diabetes managed with insulin, oral hypoglycemics, or diet; being female; renal failure (with or without dialysis); prolonged cardiopulmonary bypass (CPB) time; being underweight or obese based on Body Mass Index (BMI); elevated blood glucose levels in the ICU; and undergoing coronary artery bypass grafting (CABG). These risk factors were determined through the analysis of data from over 7,400 patients, highlighting the significance of each factor in postoperative infection rates.

How does the management of diabetes (with insulin, oral hypoglycemics, or diet) impact the risk of surgical site infections (SSIs) after cardiac surgery, according to the Steroids in Cardiac Surgery Trial Substudy?

The Steroids in Cardiac Surgery Trial Substudy indicates that individuals with diabetes, regardless of whether it's managed through insulin, oral medications, or diet alone, face a higher risk of surgical site infections (SSIs) following cardiac surgery. The adjusted odds ratios (aORs) for each management method are significant, suggesting that the underlying metabolic conditions associated with diabetes—such as impaired immune function and wound healing—contribute to this increased risk. While the study identifies this correlation, it does not explore specific interventions beyond general risk management. Further research could investigate targeted glycemic control strategies to mitigate SSI risk in diabetic patients undergoing cardiac surgery.

Why are both underweight and obese individuals at a higher risk of developing surgical site infections (SSIs) following cardiac surgery, as indicated by the Steroids in Cardiac Surgery Trial Substudy?

The Steroids in Cardiac Surgery Trial Substudy found that both underweight (BMI < 22.3) and obese (BMI > 30) individuals are at increased risk of Surgical Site Infections (SSIs) after cardiac surgery. While obesity's link to SSIs is often attributed to factors like increased subcutaneous fat and impaired blood supply, the increased risk in underweight individuals may relate to compromised immune function and nutritional deficiencies. This finding underscores the importance of optimizing nutritional status before cardiac surgery, whether through weight gain or weight loss, to mitigate infection risks. Further research could explore specific nutritional interventions to improve surgical outcomes for patients at both ends of the BMI spectrum.

How does prolonged cardiopulmonary bypass (CPB) time during cardiac surgery influence the likelihood of surgical site infections (SSIs), based on the findings from the Steroids in Cardiac Surgery Trial Substudy?

The Steroids in Cardiac Surgery Trial Substudy found that surgeries requiring longer Cardiopulmonary Bypass (CPB) times (over 96 minutes) are associated with an elevated risk of Surgical Site Infections (SSIs). Prolonged CPB can lead to increased inflammation, immunosuppression, and tissue damage, creating an environment more conducive to infection. While the study identifies CPB duration as a risk factor, it doesn't delve into specific strategies to mitigate this risk. Future studies could explore interventions such as modified CPB techniques or pharmacological agents to reduce inflammation and improve immune function during prolonged surgeries, potentially lowering SSI rates.

What specific characteristics of Coronary Artery Bypass Grafting (CABG) might contribute to a higher risk of surgical site infections (SSIs) compared to other cardiac surgeries, as suggested by the Steroids in Cardiac Surgery Trial Substudy?

The Steroids in Cardiac Surgery Trial Substudy identifies undergoing Coronary Artery Bypass Grafting (CABG) as a risk factor for Surgical Site Infections (SSIs) compared to other types of cardiac surgeries. The higher risk associated with CABG could be related to the complexity and duration of the procedure, the extent of tissue trauma, and the potential for more extensive wound sites, all of which can increase susceptibility to infection. While the study highlights this association, it doesn't explore specific differences in surgical techniques or patient characteristics that might explain the increased risk. Further research could investigate these factors to identify targeted strategies for reducing SSI rates in CABG procedures.