Arterial Hypotension During Cardiopulmonary Bypass and Postoperative Lung Injury in Patients Undergoing Urgent...

To determine whether intraoperative arterial hypotension during cardiopulmonary bypass (CPB) is associated with postoperative lung injury (PLI) in patients undergoing emergency surgery for acute type A aortic dissection (ATAAD).

Single-center retrospective cohort study with propensity score matching and sensitivity analyses.

A tertiary academic cardiovascular intensive care unit in France.

A total of 150 adult patients who underwent emergency ATAAD repair between January 2018 and December 2020. Patients with refractory low cardiac output syndrome or requiring extracorporeal life support were excluded.

No therapeutic intervention was applied. Intraoperative arterial pressure was continuously recorded during CPB to evaluate exposure to hypotension.

PLI was defined as a PaO₂/FiO₂ ratio ≤200 mmHg for more than 24 consecutive hours within the first 10 postoperative days. The primary exposure was mean arterial pressure <50 mmHg sustained for more than 10 minutes during CPB. After propensity score matching (n = 144), PLI occurred in 54.2% of hypotensive patients versus 27.8% in nonhypotensive patients (odds ratio 3.07, 95% confidence interval [1.54-6.15], p < 0.001). Sensitivity analyses demonstrated a dose-response association with deeper and longer hypotension, including a significant association for mean arterial pressure <55 mmHg lasting >10 minutes (odds ratio 2.35, 95% confidence interval [1.11-4.99], p = 0.03). This analysis examining pulmonary outcomes was performed on one of the largest single-center ATAAD surgical cohorts to date.

The current findings suggest that both the depth and duration of intraoperative hypotension during CPB are associated with PLI. This highlights intraoperative blood pressure as a potentially modifiable factor, but confirmation in prospective interventional studies is required.