Performance of Hypotension Prediction Index for Prevention of Hypotension and Results on Biomarkers of Organ Injury and Oxidative Stress During Elective Non-Cardiac Surgery: A Randomized Controlled Trial

Background: Intraoperative hypotension is associated with increased postoperative morbidity and mortality. We tested whether the clinical application of an early warning system (EWS) in combination with an algorithm for hemodynamic management reduces the occurrence of intraoperative hypotension as well as decrease the degree of organ injury and oxidative stress. Methods: We randomly assigned patients undergoing major general surgery EWS and hemodynamic algorithm (intervention group, n=20) or standard care (n=20). The primary outcome was the difference in hypotension (defined as mean arterial pressure<65mmHg) evaluated as episodes, time and time-weighted average of hypotension. As secondary outcome we assessed surrogate markers of organ injury (neuron specific enolase -NSE), S100B protein, high-sensitive troponin, neutrophil gelatinase-associated lipocalin -NGAL) and oxidative stress (reduced glutathione). Results: The median number of hypotensive episodes was lower in the intervention group [-5.0 (95%CI:-9.0,-0.5);P<0.005], with lower time spent in hypotension [-12.8 minutes (95%CI:-38.0,-2.3 min);P<0.001], correspondent to -4.8% of total surgery time (95%CI: -12.7,0.01%; P<0.05). The median time-weighted average of hypotension was 0.12 mmHg (0.35) in the intervention group and 0.37 mmHg (1.11) in the control group, with a median difference of -0.25 mmHg (95%CI:-0.85, -0.01;P<0.05). NGAL was correlated with time-weighted average of hypotension (R=0.32;P<0.05) and S100B with all primary outcomes investigated (all P<0.001). The intervention group had lower NSE and higher reduced glutathione when compared to the control group. Conclusions: The use of an EWS coupled with an hemodynamic algorithm resulted in reduced intraoperative hypotension. This finding was coupled with a reduction of biomarkers of brain injury and oxidative stress. Trial Registration number and date: “Correlation Between Circulating Biomarkers of Organ Damage and Intraoperative Hypotension Management”, NCT03527758, registered on May 17, 2018.https://www.clinicaltrials.gov/ct2/show/NCT03527758?term=NCT03527758&draw=2&rank=1