Closed-loop versus manual vasopressor titration for blood pressure control in surgical and critically ill patients: A systematic review and meta-analysis of randomised trials.

BACKGROUND

Perioperative hypotension is associated with myocardial injury, acute kidney injury, and mortality, yet manual vasopressor titration frequently results in suboptimal blood pressure (BP) control. Closed-loop vasopressor (CLV) systems use automated feedback algorithms to maintain predefined BP targets and may reduce haemodynamic variability while decreasing provider workload.

METHODS

We conducted a PRISMA-guided systematic review and meta-analysis on PubMed, CENTRAL, EMBASE, and Web of Science from inception to June 2025. Randomised controlled trials of adults receiving CLV or manual vasopressor titration in perioperative and critical care settings were included. The primary outcome was time below target; secondary outcomes included time within and above target, time in hypotension (MAP <65 mmHg), vasopressor consumption, and length of stay.

RESULTS

Eight trials with 640 patients were analysed, including five trials conducted in the operating room and three trials in the ICU. Compared with manual titration, CLV significantly reduced time below target (mean difference [MD] = -15.81%; 95% CI = -20.38 to -11.25%; p < 0.001; n = 176), increased time in target (MD = 30.18%; 95% CI = 21.91 to 38.44%; p < 0.001; n = 216), reduced time in hypotension (SMD = -0.90; 95% CI = -1.64 to -0.17; p = 0.02; I2 = 79%), and hospital length of stay (MD = -1.12 days; 95% CI = -2.21 to -0.04 days; p = 0.04; I2 = 0%; n = 158). The length of post-anaesthesia care unit-intensive care unit stay (MD = -0.05 min, 95% CI = -1.10 to 1.00 min; p = 0.93; I2 = 0%; n = 198) did not differ between the two groups.

CONCLUSION

In surgical and critically-ill patients, closed-loop systems were associated with improved adherence to predefined blood pressure targets with reduced time below target and increased time in target compared to manual vasopressor titration. Whether these haemodynamic improvements translate into beneficial impact on patient outcomes will require confirmation in large multicentre randomised trials.

SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD420251000124).