Protective ventilation measures improve outcomes during major vascular surgery

Abstract

Background: In major endovascular and open vascular surgery cases, pulmonary complications remain persistently high and the most prevalent. Despite strong evidence from intensive care unit (ICU) practices demonstrating benefits of ventilation management with low tidal volume and high positive end expiratory pressure (PEEP), no consensus exists regarding protective ventilation use intraoperatively. Methods: A single institute, patient and surgeon blinded, prospective, randomized study design was used. Patients undergoing major vascular surgery (vascular surgery scheduled for >120 minutes and requiring general anesthesia) from 2015-2016 were randomized to pre-defined control (n = 14) or intervention (n =19) intraoperative ventilation arms. As described later, intervention consisted of a combination of low tidal volume, optimized positive end expiratory pressure (PEEP) and low intraoperative FiO2. Primary outcomes included all-cause mortality, myocardial infarction (MI) and reintubation within 7 post-operative days (POD). Secondary outcomes included atelectasis, pulmonary function measures, hospital length of stay and post-operative complications of re-intubation, pneumonia, sespsis, unplanned readmission or return to operating room, and/or mortality. Results: The intervention arm had significantly reduced post-operative atelectasis ((p <0.02) and increased post-operative SpO2 (p< 0.02). The intervention arm also had a significantly lower length of hospital stay (6.9±5.5 vs 3.3±1.8, p < 0.016). This was corroborated by a multivariate regression analysis that showed therapy was independently correlated with decreased length of stay (p<0.007). Conclusion: Our data indicate a combination of low tidal volumes, optimized PEEP and low FiO2 improves outcomes of patients undergoing major vascular surgery. Importantly, our study demonstrates that these study parameters for evaluation of intraoperative ventilation management are feasible in a busy academic center and a larger clinical trial is worthy. Protective intraoperative ventilation measures could have significant effects on vascular surgery outcomes.