The Use of the Hypotension Prediction Index Integrated in an Algorithm of Goal Directed Hemodynamic Treatment during Moderate and High-Risk Surgery

Abstract

(1) Background: The Hypotension Prediction Index (HPI) is an algorithm that predicts hypotension, defined as mean arterial pressure (MAP) less than 65 mmHg for at least 1 min, based on arterial waveform features. We tested the hypothesis that the use of this index reduces the duration and severity of hypotension during noncardiac surgery. (2) Methods: We enrolled adults having moderate- or high-risk noncardiac surgery with invasive arterial pressure monitoring. Participating patients were randomized 1:1 to standard of care or hemodynamic management with HPI guidance with a goal directed hemodynamic treatment protocol. The trigger to initiate treatment (with fluids, vasopressors, or inotropes) was a value of HPI of 85 (range, 0–100) or higher in the intervention group. Primary outcome was the amount of hypotension, defined as time-weighted average (TWA) MAP less than 65 mmHg. Secondary outcomes were time spent in hypertension defined as MAP more than 100 mmHg for at least 1 min; medication and fluids administered and postoperative complications. (3) Results: We obtained data from 99 patients. The median (IQR) TWA of hypotension was 0.16 mmHg (IQR, 0.01–0.32 mmHg) in the intervention group versus 0.50 mmHg (IQR, 0.11–0.97 mmHg) in the control group, for a median difference of −0.28 (95% CI, −0.48 to −0.09 mmHg; p = 0.0003). We also observed an increase in hypertension in the intervention group as well as a higher weight-adjusted administration of phenylephrine in the intervention group. (4) Conclusions: In this single-center prospective study of patients undergoing elective noncardiac surgery, the use of this prediction model resulted in less intraoperative hypotension compared with standard care. An increase in the time spent in hypertension in the treatment group was also observed, probably as a result of overtreatment. This should provide an insight for refining the use of this prediction index in future studies to avoid excessive correction of blood pressure.

Performance of the Hypotension Prediction Index May Be Overestimated Due to Selection Bias

“…Four randomized controlled trials have investigated the Hypotension Prediction Index's preventive effects on hypotension. 2,[15][16][17] Three of these trials, and an additional retrospective study, 18 showed less hypotension in the Hypotension Prediction Index guided group compared to a control group (the trials vary in their outcome definitions and precise management protocols, but the characteristics are beyond the scope of this analysis). 2,16,17 One trial also investigated the effect on postoperative hypotension and found no difference in their primary outcome between the Hypotension Prediction Index-guided group and the standard care group.…”

“…2,[15][16][17] Three of these trials, and an additional retrospective study, 18 showed less hypotension in the Hypotension Prediction Index guided group compared to a control group (the trials vary in their outcome definitions and precise management protocols, but the characteristics are beyond the scope of this analysis). 2,16,17 One trial also investigated the effect on postoperative hypotension and found no difference in their primary outcome between the Hypotension Prediction Index-guided group and the standard care group. 19 The fourth and largest study noted no difference between the Hypotension Prediction Index-guided group and the control group in the primary outcome variable: amount of hypotension (time-weighted average MAP less than 65 mmHg).…”

Prediction and Prevention of Intraoperative Hypotension with the Hypotension Prediction Index: A Narrative Review

“…After these initial results, four randomized controlled trials were published, comparing an HPI-guided hemodynamic treatment protocol group with a standard care control group [ 26 , 32 , 33 , 36 ]. The study by Wijnberge et al [ 26 ] involved 60 patients undergoing major high-risk surgery.…”

Applicability of hypotension prediction index to surgical patients

“…Table 1 shows the clinical trials for applying the HPI during various surgeries [6,9,[13][14][15][16][17][18][19]. However, the effectiveness of HPI is still controversial, and conflicting research results have been published [11,13,20,21].…”