Cerebral oximetry in high-risk surgical patients: where are we?

PURPOSE OF REVIEW: This review aims to summarize the latest evidence on the role of near-infrared spectroscopy (NIRS) in monitoring cerebral oxygenation in high-risk surgical patients, including both cardiac and noncardiac surgeries, and to present a new algorithm for its application. RECENT FINDINGS: NIRS effectively measures brain oxygen saturation noninvasively, proving valuable in cardiac surgeries to reduce neurological complications, though its impact on nonneurological outcomes is less clear. In noncardiac surgeries, NIRS can help prevent complications like postoperative cognitive dysfunction, particularly in high-risk and major surgeries. Studies highlight the variability of cerebral oxygenation impacts based on surgical positions, with mixed results in positions like the beach chair and sitting positions. A structured algorithm for managing cerebral desaturation has been proposed to optimize outcomes by addressing multiple factors contributing to blood oxygen content and delivery. SUMMARY: Despite its limitations, including spatial resolution and interindividual variability, NIRS is a useful tool for intraoperative cerebral monitoring. Further studies are needed to confirm its broader applicability in noncardiac surgeries, but current evidence supports its role in reducing postoperative complications especially in cardiac surgeries.

Hypotension prediction index guided goal-directed therapy to reduce postoperative acute kidney injury during major abdominal surgery: study protocol for a multicenter randomized controlled clinical trial.

BACKGROUND: Acute kidney injury (AKI) is a significant postoperative complication associated with increased mortality and hospital costs. Hemodynamic strategies, such as goal-directed therapy, might reduce AKI risk. Predicting and proactively managing intraoperative hypotension may be helpful. This trial aims to investigate if a preemptive hemodynamic strategy guided by the hypotension prediction index (HPI) can decrease the incidence of moderate-to-severe AKI within 30 days following major elective abdominal surgery. METHODS: This is an open-label, controlled, multicenter, randomized clinical trial that involves daily patient follow-up until hospital discharge. Inclusion criteria are patients aged over 65 and/or categorized as ASA III or IV physical status, undergoing major elective abdominal surgery (general, urological, or gynecological procedures) via laparoscopic or open approach under general or combined anesthesia. INTERVENTION: In the intervention group, hemodynamic management will be based on the HPI and the advanced functional hemodynamic variables provided by the Hemosphere platform and the AcumenIQ® sensor (Edwards Lifesciences). The primary outcome is the incidence of moderate-to-severe AKI within 7 days post-surgery. Secondary outcomes include postoperative complications and 30-day mortality. DISCUSSION: This study explores the potential of HPI-guided hemodynamic management in reducing AKI after major elective abdominal surgery, with implications for postoperative outcomes and patient care. TRIAL REGISTRATION: ClinicalTrials.gov NCT05569265. Registered on October 6, 2022.

Restrictive versus liberal transfusion strategy for red blood cell transfusion in critically ill patients and in patients with acute coronary syndrome: a systematic review, meta-analysis and trial sequential analysis.

INTRODUCTION: The risks and benefits of transfusing critically ill patients continue to evoke controversy. Specifically, the critically ill patients with active ischemic cardiac disease continue to represent a "gray area" in the literature. EVIDENCE ACQUISITION: Meta-analysis of the effects of lower versus higher hemoglobin thresholds on mortality in critically ill patients was carried out using PRISMA methodology. A systematic research was performed in PubMed, Embase, and the Cochrane Library (last update, December 2014). INCLUSION CRITERIA: Anemic critically ill adult patients admitted to intensive care units and/or anemic patients with acute coronary syndrome in which a restrictive vs. liberal transfusion therapy was compared. PRIMARY ENDPOINT: mortality. Included studies were subjected to quantifiable analysis, predefined subgroup analysis, trial sequential analysis and predefined sensitivity analysis. EVIDENCE SYNTHESIS: Thirty RCT's were initially identified; 6 fulfilled the inclusion criteria, including 2156. There were no differences in mortality between the restrictive and liberal groups (RR: 0.86, 95% CI 0.70-1.05 P=0.14), neither in patients with chronic cardiovascular disease subgroup (RR: 1.13, 95% IC 0.88-1.46 P=0.34). However, there is a trend towards decreased mortality in the subgroup critically ill (RR: 0.86, 95% CI 0.73-1.01 P=0.06); while in the subgroup of patients with acute myocardial infarct seems like it might be a non-significant trend towards increased mortality (RR: 3.85, 95% CI 0.82-18.0 P=0.09). CONCLUSIONS: Restrictive strategy is at least as effective to liberal strategy in critically ill patients. Nevertheless, there is insufficient evidence to recommend a restrictive strategy for patients with acute coronary syndrome.