[Prolonged mechanical ventilation after isolated coronary artery bypass grafting]

Following coronary bypass surgery, postoperative intensive care plays a central role in the subsequent course of the illness. It is well known that patients with prolonged mechanical ventilation have an increased risk of developing numerous secondary organ complications and consequently have higher morbidity and mortality. The objective of this study was to validate established risk factors for prolonged postoperative mechanical ventilation after isolated coronary bypass surgery in a recent, representative patient collective.

In this retrospective, single-center study, all patients who underwent isolated coronary bypass surgery in 2024 and subsequently received interdisciplinary intensive care at the Ulm University Clinic were included.

The 312 patients included in the study were between 45 and 85 years old; 84% (n = 262) were male. The median ventilation time for all patients was 15 h (Q1 = 11 h; Q3 = 21 h), whereby 19.5% (n = 61) required prolonged mechanical ventilation (PMV). In the multiple logistic regression analysis, intraoperative perfusion time (OR = 1.01; 95% CI 1.0-1.02; p = 0.04) and postoperative peak lactate (OR = 1.26; 95% CI 1.12-1.41; p < 0.001) were significant independent risk factors for PMV. The PMV group also had significantly lower oxygenation indices (Horovitz index = p_aO₂/F_iO₂), more positive fluid balances on the first and cumulatively on the second postoperative day, longer ischemia and surgical times, and higher European System for Cardiac Operative Risk Evaluation (EuroSCORE) scores. Hospital mortality was significantly higher at 8.2% (n = 5) in the PMV group than in the non-PMV group at 0.8% (n = 2).

A comprehensive risk profile for prolonged mechanical ventilation is an essential component of intensive care risk stratification and treatment planning. It enables a differentiated assessment of severity and complexity of underlying diseases and thereby associated organ dysfunction. Against this backdrop, necessary intensive care interventions can be initiated early and potentially contribute to improve treatment outcomes.