Abstract
Summary
Introduction
Intra‐operative hypotension is common during general anaesthesia, but its association with postoperative pneumonia remains uncertain, partly because hypotension has been defined using different thresholds. We evaluated whether absolute thresholds or relative reductions from baseline mean arterial pressure were associated more strongly with postoperative pneumonia after non‐cardiac surgery.
Methods
We conducted a retrospective multicentre cohort study of 151,036 adults undergoing non‐cardiac surgery under general anaesthesia at three Chinese hospitals. Intra‐operative hypotension was assessed using 12 metrics across nine thresholds, including absolute mean arterial pressure thresholds of
Results
Of 151,036 patients, postoperative pneumonia occurred in 3486 (2.3%). Relative reductions in mean arterial pressure were more consistently associated with postoperative pneumonia than absolute thresholds. At a 20% reduction from baseline, the number of intra‐operative hypotension episodes was associated with postoperative pneumonia (subdistribution hazard ratio (sHR) 1.079, 95%CI 1.050–1.109, p c
e of intra‐operative hypotension (sHR 1.108, 95%CI 1.068–1.149, p
Discussion
Intra‐operative hypotension was associated with postoperative pneumonia when defined as a relative reduction from baseline mean arterial pressure, whereas conventional absolute thresholds were less informative. These findings suggest that maintaining intra‐operative blood pressure close to baseline may be more relevant to pulmonary risk than relying on fixed absolute thresholds alone.