Is a Mean Arterial Pressure Less Than 65 mm Hg an Appropriate Indicator of the Quality of Anesthesia Care?

Individualized Perioperative Hemodynamic Management Using Hypotension Prediction Index Software and the Dynamics of Troponin and NTproBNP Concentration Changes in Patients Undergoing Oncological Abdominal Surgery

INTRODUCTION

Abdominal oncologic surgeries pose significant risks due to the complexity of the surgery and patients' often weakened health, multiple comorbidities, and increased perioperative hazards. Hypotension is a major risk factor for perioperative cardiovascular complications, necessitating individualized management in modern anesthesiology.

AIM

This study aimed to determine the dynamics of changes in troponin and NTproBNP levels during the first two postoperative days in patients undergoing major cancer abdominal surgery with advanced hemodynamic monitoring including The AcumenTM Hypotension Prediction Index software (HPI) (Edwards Lifesciences, Irvine, CA, USA) and their association with the occurrence of postoperative cardiovascular complications.

METHODS

A prospective study was conducted, including 50 patients scheduled for abdominal cancer surgery who, due to the overall risk of perioperative complications (ASA class 3 or 4), were monitored using the HPI software. Hypotension was qualified as at least one ≥ 1 min episode of a MAP < 65 mm Hg. Preoperatively and 24 and 48 h after the procedure, the levels of NTproBNP and troponin were measured, and an ECG was performed.

RESULTS

We analyzed data from 46 patients and found that 82% experienced at least one episode of low blood pressure (MAP < 65 mmHg). However, the quality indices of hypotension were low, with a median time-weighted average MAP < 65 mmHg of 0.085 (0.03-0.19) mmHg and a median of 2 (2-1.17) minutes spent below MAP < 65 mmHg. Although the incidence of perioperative myocardial injury was 10%, there was no evidence to suggest a relationship with hypotension. Acute kidney injury was seen in 23.9% of patients, and it was significantly associated with a number of episodes of MAP < 50 mmHg. Levels of NTproBNP were significantly higher on the first postoperative day compared to preoperative values (285.8 [IQR: 679.8] vs. 183.9 [IQR: 428.1] pg/mL, p < 0.001). However, they decreased on the second day (276.65 [IQR: 609.4] pg/mL, p = 0.154). The dynamics of NTproBNP were similar for patients with and without heart failure, although those with heart failure had significantly higher preoperative concentrations (435.9 [IQR: 711.15] vs. 87 [IQR: 232.2] pg/mL, p < 0.001). Patients undergoing laparoscopic surgery showed a statistically significant increase in NTproBNP.

CONCLUSIONS

This study suggests that advanced HPI monitoring in abdominal cancer surgery effectively minimizes intraoperative hypotension with no significant NTproBNP or troponin perioperative dynamics, irrespective of preoperative heart failure.

Targeting Higher Intraoperative Blood Pressures Does Not Reduce Adverse Cardiovascular Events Following Noncardiac Surgery

BACKGROUND

Intraoperative arterial hypotension is strongly associated with postoperative major adverse cardiovascular events (MACE); however, whether targeting higher intraoperative mean arterial blood pressures (MAPs) may prevent adverse events remains unclear.

OBJECTIVES

This study sought to determine whether targeting higher intraoperative MAP lowers the incidence of postoperative MACE.

METHODS

This single-center randomized controlled trial assigned adult patients at cardiovascular risk undergoing major noncardiac surgery to an intraoperative MAP target of ≥60 mm Hg (control) or ≥75 mm Hg (MAP ≥₇₅). The primary outcome was acute myocardial injury on postoperative days 0-3 and/or 30-day MACE/acute kidney injury (AKI) (acute coronary syndrome, congestive heart failure, coronary revascularization, stroke, AKI, and all-cause mortality). The secondary outcome was 1-year MACE.

RESULTS

In total, 458 patients were randomized (intention-to-treat population: 451). The cumulative intraoperative duration with MAP <65 mm Hg was significantly shorter in the MAP ≥₇₅ group (median 9 minutes [interquartile range: 3 to 24 minutes] vs 23 minutes [interquartile range: 8-49 minutes]; P < 0.001). The primary outcome incidence was 48% for MAP ≥₇₅ and 52% for control (risk difference -4.2%; 95% CI: -13% to +5%), the primary contributor being AKI (incidence 44%). Acute myocardial injury occurred in 15% (MAP ≥₇₅) and 19% (control) of patients. The secondary outcome incidence was 17% for MAP ≥₇₅ and 15% for control (risk difference +2.7; 95% CI: -4% to +9.5%).

CONCLUSIONS

These findings do not support universally targeting higher intraoperative blood pressures to reduce postoperative complications. Despite a 60% reduction in hypotensive time with MAP <65 mm Hg, no significant reductions in acute myocardial injury or 30-day MACE/AKI could be found. (Biomarkers, Blood Pressure, BIS: Risk Stratification/Management of Patients at Cardiac Risk in Major Noncardiac Surgery [BBB]; NCT02533128).