#LIVES2025: Proactive vs Reactive Treatment of Hypotension During Surgery
- In ICU
- Tue, 28 Oct 2025
Intraoperative hypotension affects over 75% of surgical patients and is linked to serious complications, including myocardial ischaemia, kidney failure, and death. Despite this prevalence, uncertainty remains about optimal blood pressure management during surgery.
The PRETREAT (Proactive vs Reactive Treatment of Hypotension) trial tested whether stratified blood pressure targets adjusted to a patient's expected risk of intraoperative hypotension could reduce hypotension and improve outcomes.
The trial was conducted at two Dutch medical centres between June 2021 and February 2024. Adults undergoing elective noncardiac surgery with expected overnight hospital stays were randomised 1:1 to either proactive blood pressure management or usual care.
The trial employed an adaptive two-phase design, with the first phase allowing iterative adaptations of the intervention strategy and requiring at least 30% relative risk reduction in intraoperative hypotension to continue. The study was stopped early for futility after enrolling 3,522 of the planned 5,000 patients.
Patients were classified into low-, intermediate-, or high-risk groups using a preoperative prediction model, which determined their assigned mean arterial pressure (MAP) target. The intervention required maintaining:
- Low-risk patients: MAP ≥70 mm Hg
- Intermediate-risk patients: MAP ≥80 mm Hg
- High-risk patients: MAP ≥90 mm Hg
The control group received usual care targeting MAP ≥65 mm Hg, consistent with current guidelines. The median age was 59 years, 53.5% were female, and 97.3% received general anesthesia. Risk stratification classified 21% as low-risk, 56% as intermediate-risk, and 23% as high-risk for intraoperative hypotension.
The primary outcome was postoperative disability at 6 months, measured using the 12-item World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), which evaluates functional impairment across six domains, including cognition, mobility, self-care, interpersonal relationships, life activities, and participation. A 5-percentage-point difference was considered clinically meaningful.
Key Results
Functional Disability: The mean WHODAS score at 6 months was 17.7 in the intervention group versus 18.2 in the control group, with a between-group difference of -0.5% (95% credible interval: -1.9% to 0.9%). This represented no meaningful clinical benefit.
Treatment Implementation: The intervention successfully increased vasopressor use according to clinical guidelines (odds ratio: 3.73) with 100% posterior probability of superiority.
Hypotension Reduction: The intervention effectively reduced intraoperative hypotension, with the area under the threshold for MAP less than 65 mm Hg decreasing from 70.6 mm Hg × minutes in controls to 28.5 mm Hg × minutes in the intervention group—a 48.4% relative reduction. The effect was most pronounced in low-risk patients, showing a 58.3% reduction.
Blood Pressure Differences: The median average MAP was 86.9 mm Hg in the intervention group versus 81.1 mm Hg in controls. Any MAP below 65 mm Hg occurred in 47.7% of intervention patients versus 71.0% in controls.
Secondary Outcomes: There were no significant differences in any of the 23 secondary outcomes, including mortality, quality of life measures, intensive care admissions, hospital readmissions, or major complications like myocardial infarction, stroke, or acute kidney injury.
The trial demonstrated that proactively selecting MAP targets based on preoperative assessment of hypotension risk did not lead to clinically relevant improvements in functional disability at 6 months or any secondary outcome compared with standard blood pressure management.
These findings suggest that usual care, in which clinicians typically aim to prevent MAP below 65 mm Hg but often fail to fully avoid such episodes, does not result in worse outcomes than proactively maintaining higher intraoperative targets. However, the authors note that the safe lower limit of MAP remains uncertain.
Despite successfully reducing intraoperative hypotension by nearly 50%, risk-stratified, proactive blood pressure management did not improve 6-month functional disability compared with standard care in patients undergoing noncardiac surgery. This challenges the assumption that preventing intraoperative hypotension necessarily translates to better long-term patient outcomes.
Source: JAMA
Image Credit: iStock
