What is a significant risk factor for sternal wound infection after cardiac surgery?

Prolonged cardiopulmonary bypass (CPB) is indeed a significant risk factor for sternal wound infection following cardiac surgery. This is because extended duration on CPB can lead to a number of physiological changes, including increased inflammation, compromised immune response, and alterations in coagulation, all of which can significantly impair wound healing. Additionally, longer surgery times can increase the chances of contamination and create more tissue trauma. Understanding these risks is crucial for clinicians when planning surgery and implementing preventive measures to reduce the likelihood of sternal wound infections.

While age over 50, having hypertension, and a history of smoking might contribute to overall patient risk, they do not directly correlate with the mechanical and biological factors influenced by prolonged CPB in the same way that it does with sternal wound infections. The association of these other factors is often more generalized and less directly impactful on the surgical outcome compared to the physiological stresses imposed by prolonged CPB.