Blood Pressure Targets During General Anaesthesia in High-Risk Patients-A Randomised Clinical Feasibility Trial

There is limited high-quality evidence to guide haemodynamic and respiratory management during general anaesthesia. The goal of this trial was to test the feasibility of testing different ventilatory settings and blood pressure targets. Previous trials on blood pressure targets have suffered from poor adherence and limited between-group separation. This manuscript focuses on the overall feasibility, as well as blood pressure targets.

This was a multicentre, randomised, factorial, clinical trial conducted at eight hospitals in Denmark. 483 patients ASA 3-5, scheduled for major surgery under general anaesthesia, were included. Patients were randomised to a minimum mean arterial blood pressure (MAP) target of 60, 70 or 80 mmHg, or 90% of baseline systolic blood pressure. The primary outcomes focused on feasibility, while secondary outcomes included intra- and postoperative complications, hospital length of stay, quality of life and recovery and mortality.

Out of 1690 eligible patients, 483 (29%) were randomised, below the goal of 50%. Separation in blood pressure was achieved and blood pressure during vasoactive treatment was within predefined target ranges. There was no difference in most of the postoperative outcomes. Some complications, including acute kidney injury (OR 4.74, 95% CI 1.17; 31.8) and cardiac arrhythmias (OR 8.13, 95% CI 1.35; 156), were more common in the MAP-80-mmHg group compared to the MAP-60-mmHg group. The MAP-80-mmHg group had fewer days alive and out of hospital within 30 days (median difference -1.88 days, 95% CI -3.50; -0.26).

While not all feasibility goals were achieved, separation in blood pressure and adherence to targets were adequate. Larger trials are needed to determine the optimal blood pressure target during general anaesthesia.

Clinicaltrials.gov: NCT06047119.