Higher Blood Pressure Targets During Surgery Cut Delirium Risk, Major Review Finds

Raising a patient’s blood pressure targets during noncardiac surgery may lower the risk of two important postoperative complications—delirium and surgical site infection—but does not appear to protect the heart or kidneys, according to a new systematic review and meta-analysis published in Anesthesiology and Perioperative Science. The analysis pooled data from 18 randomized controlled trials involving 16,573 adults and represents the most comprehensive synthesis to date of how aggressively anesthesiologists should manage blood pressure in the operating room.

Current guidelines recommend keeping mean arterial pressure, or MAP, at or above 60 to 65 mmHg during surgery to avoid hypotension. What has remained controversial is whether pushing targets higher—either with a fixed elevated threshold such as MAP of 75 to 80 mmHg, or with an individualized target tailored to each patient’s preoperative baseline blood pressure—translates into fewer major complications after the operation ends. The new review, registered prospectively in PROSPERO, set out to answer that question by comparing intensive management against standard care across randomized trials only.

The researchers searched PubMed, Embase, the Cochrane Library and Web of Science from inception to November 4, 2025, with an updated search in May 2026. The included trials, published between 2017 and 2026, ranged in size from 98 to 7,490 patients and were conducted largely in China and Germany, with additional trials from France, Italy, the Netherlands, Switzerland and one large multinational study, the POISE-3 trial. The populations consisted primarily of elderly patients undergoing noncardiac surgery, many classified as ASA physical status III or IV, indicating a high baseline clinical risk, and many with preexisting hypertension. Seven trials used a fixed higher-target strategy and eleven used an individualized strategy.

The headline finding concerns postoperative delirium. Across 10 studies covering 5,478 patients, intensive blood pressure management was associated with a lower risk of delirium, with a pooled risk ratio of 0.72 (95% confidence interval 0.55 to 0.93; P = 0.019) and low heterogeneity. Trial sequential analysis, a technique that controls for random error and tests whether the accumulated evidence is large enough to be conclusive, supported this benefit: the cumulative evidence crossed the monitoring boundary for benefit and reached the required information size under the prespecified assumption of a 30 percent relative risk reduction. The certainty of this evidence was nonetheless downgraded to moderate by the GRADE framework, because a leave-one-out sensitivity analysis showed the result was fragile—removing one small trial by Hu and colleagues rendered the overall effect statistically non-significant.

The second positive finding was surgical site infection. In five studies enrolling 3,649 patients, the intensive group had a markedly lower infection incidence, with a risk ratio of 0.64 (95% confidence interval 0.53 to 0.76; P = 0.002), no heterogeneity, and stability in leave-one-out analysis. The authors graded this evidence as moderate certainty and framed it as hypothesis-generating, noting that infection ascertainment likely varied across studies and that wound outcomes are strongly influenced by perioperative factors other than blood pressure. They speculate that higher pressures may improve peripheral tissue perfusion and oxygenation, enhancing wound healing and inhibiting bacterial colonization.

The neutral results may matter even more for surgical practice. Postoperative myocardial injury, assessed across 9 studies and 14,606 patients, showed no difference between strategies (risk ratio 1.02, 95% confidence interval 0.92 to 1.13), with zero heterogeneity. Acute kidney injury, reported in 13 studies and 15,143 patients, was likewise unaffected (risk ratio 0.92, 95% confidence interval 0.79 to 1.06). Trial sequential analysis showed that the accrued information size reached 256 percent of the required size for myocardial injury, and exceeded the threshold for kidney injury, indicating that a benefit of the prespecified magnitude—a 20 percent relative risk reduction—is unlikely, although smaller effects cannot be excluded. Mortality, stroke, pneumonia, heart failure, acute respiratory distress syndrome, intensive care admission and hospital length of stay also showed no significant differences between groups.

Subgroup analyses added a nuance: the reduction in delirium appeared within the individualized higher-target subgroup (risk ratio 0.62 across six studies), while the fixed higher-target subgroup showed no significant difference (risk ratio 0.79 across four studies). However, the test for subgroup differences was not statistically significant, so the authors caution against concluding that one strategy type is definitively superior. Physiologically, they note, the lower limit of cerebral autoregulation varies between individuals and tends to shift rightward in patients with chronic hypertension, meaning a fixed elevated target might still fall below the ischemic threshold for some elderly patients, whereas an individualized target calibrated to preoperative baseline pressure may better preserve patient-specific cerebral perfusion.

The authors also offer a candid explanation for why the intensive strategy failed to protect the heart and kidneys. Reviewing hemodynamic data from the included trials, they found a lack of substantial separation between groups: despite very different protocol-defined targets, the achieved between-group MAP differences were only about 6 to 7 mmHg in some landmark trials, and patients in standard-care groups received closely monitored care with limited exposure to severe hypotension. The neutral results may therefore reflect the small achieved difference in blood pressure rather than a true absence of effect. A further complication is that raising blood pressure does not necessarily improve tissue perfusion: pursuing higher targets typically required greater vasopressor exposure, which can induce microcirculatory vasoconstriction and offset the benefit of improved perfusion pressure.

The study has limitations the authors acknowledge. Blinding anesthesiologists to the intervention is inherently difficult, introducing unavoidable risk of bias; the risk-of-bias assessment rated 12 trials at low risk, three with some concerns and three at high risk. Trials varied in outcome assessment and protocol thresholds, determinants of intervention intensity such as vasopressor and fluid use were reported too sparsely to synthesize, several secondary outcomes rested on few trials and events, and only English-language studies were included. The neurocognitive analysis was restricted to delirium, leaving longer-term cognitive outcomes unexamined.

For clinicians, the practical message is measured. The authors conclude that for most patients undergoing noncardiac surgery, the standard target of MAP at or above 65 mmHg is sufficiently safe and effective, and that because benefits are limited to delirium and surgical site infection—both of moderate certainty—with no effect on myocardial injury, kidney injury or mortality, intensive targets increase treatment burden for an uncertain net benefit. The decision to pursue higher targets, they argue, is better individualized to the patient and the hemodynamic context than applied uniformly. They call for definitive large-scale trials with postoperative neurocognitive outcomes as primary endpoints, and for greater emphasis on holistic perioperative care, including judicious management of preoperative antihypertensive medications and vigilant control of postoperative hypotension, alongside mechanism-directed interventions that address the underlying cause of low blood pressure rather than simply raising the number on the monitor.

Subject of Research: Effects of intensive versus standard intraoperative blood pressure management on postoperative outcomes in noncardiac surgery

Article Title: Intraoperative blood pressure management strategies and postoperative outcomes in patients undergoing noncardiac surgery: a systematic review and meta-analysis

Article References: Zhang, Z.-X., Han, Y., Chen, C., Li, T.-X., Sun, Q.-R., Zhuang, H.-J., & Yu, H. (2026). Intraoperative blood pressure management strategies and postoperative outcomes in patients undergoing noncardiac surgery: a systematic review and meta-analysis. Anesthesiology and Perioperative Science, 4(1), Article 43. https://doi.org/10.1007/s44254-026-00188-9

Image Credits: AI Generated

DOI: 10.1007/s44254-026-00188-9

Keywords: intraoperative blood pressure, noncardiac surgery, postoperative delirium, surgical site infection, acute kidney injury, myocardial injury, meta-analysis, trial sequential analysis, mean arterial pressure, anesthesia, GRADE evidence, perioperative care