Hypotension During Surgery

Elderly patients are frequently burdened with age-associated comorbidities and frailty, accompanied by physiological changes such as vascular stiffening, cardiac dysfunction, and impaired autonomic regulation. These factors not only increase the risk of adverse perioperative outcomes but also heighten sensitivity to anesthetic agents, making elderly patients particularly susceptible to anesthesia-related complications, especially hypotension. Consequently, optimizing anesthesia strategies for this high-risk population has become a critical goal in perioperative management. Titrated anesthesia, which individualizes anesthetic drug delivery based on patient response to achieve predefined endpoints, offers a potential approach to mitigating anesthetic risks. Ciprofol, a novel intravenous anesthetic, has been associated with less hemodynamic suppression compared with traditional agents; however, higher single doses may still predispose patients to hypotension. Remifentanil, an ultra-short-acting opioid, exerts significant cardiovascular depressive effects, further contributing to perioperative hypotension. It is hypothesized that titrated administration of anesthetic agents during both the induction and maintenance phases, compared with conventional fixed-dose protocols, may reduce the incidence of perioperative hypotension in elderly patients.

Low blood pressure, also known as hypotension, is very common during major surgery under general anesthesia. Prolonged or severe hypotension can lead to complications such as kidney injury after surgery that slow down patient recovery. Anesthesiologists commonly administer medications called vasopressors to treat low blood pressure during surgery. These medications help raise the blood pressure back up to a safe range. Two vasopressor medications are commonly used for this purpose: norepinephrine and phenylephrine. Each of these medications has slightly different effects on the heart and blood vessels (cardiovascular system). It remains unknown which of these standard medications is better for treating low blood pressure during surgery. The goal of this clinical trial is to determine which of these two medications is better at preventing injury to the kidneys after major noncardiac surgery as well as other complications such as heart problems. Major surgeries are defined as those lasting at least two hours under general anesthesia. This trial will randomize about ten centers in North America to use either norepinephrine or phenylephrine as the primary medication to treat low blood pressure in adults undergoing major noncardiac surgery. Each hospital will prioritize one of the drugs each month, and the assigned drug will rotate each month at each hospital. No further participant involvement will be required as de-identified data are collected as part of standard medical care.

Background: Acute circulatory failure, often presenting as arterial hypotension, is a major contributor to postoperative morbidity and mortality. Accurate blood pressure (BP) monitoring is essential for timely therapeutic intervention, particularly in patients undergoing major surgery. Among invasive BP measurement sites, the radial artery is commonly used due to its accessibility and ease of catheterization. However, physiologically, the radial artery may underestimate central arterial pressure compared to the femoral artery, especially in patients receiving vasopressors or in critical conditions. This discrepancy can lead to overtreatment with vasopressors and associated complications. Current literature on the accuracy of radial versus femoral BP monitoring is outdated and based solely on observational studies. There is a lack of high-quality randomized data to inform clinical guidelines. Hypothesis: Femoral arterial pressure monitoring, by offering more accurate hemodynamic data, reduces the need for vasopressor support, particularly norepinephrine, compared to radial artery monitoring. Primary Objective: To compare the effect of femoral versus radial invasive BP monitoring on the proportion of patients requiring norepinephrine from anesthetic induction to postoperative day 7 (D7) following elective cardiac surgery. Norepinephrine treatment is defined by continuous intravenous administration of norepinephrine for more than 1 minute. Secondary Objectives : To compare the following outcomes between the two strategies within the first 7 postoperative days: incidence of acute kidney injury (AKI) according to KDIGO criteria, incidence of cardiac complications (arrhythmias requiring treatment, myocardial injury (troponin \>99th percentile or \>20% rise from baseline), myocardial infarction, cardiogenic shock, cardiac arrest), vaso-inotropic score (VIS), duration of any vasopressor therapy (days), ICU and hospital length of stay (days), all-cause mortality at day 7 and day 30, total duration (hours/days) and maximal dose of norepineprhine therapy, intraoperative hypotension episodes (MAP\<65 mmHg \> 5 min), incidence of arterial catheter-related complications (hematoma, bleeding, infection, thrombosis, arterial occlusion, malfunction, dislodgement). Primary Endpoint: The proportion of patients receiving continuous intravenous norepinephrine from anesthesia induction to postoperative day 7. Secondary Endpoints: AKI occurrence or need for renal replacement therapy; cardiac complications: atrial/ventricular arrhythmias requirinf treatment, myocardial injury (troponin \>99th percentile or \>20% rise from baseline), myocardial infarction (biomarker elevation + ECG or echocardiographic abnormalities), cardiogenic shock, cardiac arrest; maximum VIS in the OR, ICU admission, and day 1; intraoperative hypotension episodes (MAP\<65 mmHg \> 5 min); total norepinephrine support duration (in hours); duration of any vasopressor therapy; arterial line complications: malfunction, dislodgement, hematoma, thrombosis, infection, bleeding, arterial occlusion; ICU and hospital length of stay (days); all-cause mortality at day 7 and day 30 Study Design: A prospective, multicenter (Besançon and Dijon University Hospitals), randomized, superiority, single-blind, intention-to-treat clinical trial in adults undergoing elective cardiac surgery. Patients are randomized to femoral or radial artery catheterization for continuous BP monitoring. Sample Size: Based on an expected norepinephrine use rate of 70%, a 15% absolute risk reduction, α = 0.05, and power = 90%, 162 patients per group are required. Accounting for 5% data loss, 340 patients will be enrolled. Study Arms: Radial group: invasive BP monitoring via radial artery catheterization Femoral group: invasive BP monitoring via femoral artery catheterization The arterial line is placed under ultrasound guidance in the operating room and maintained postoperatively in the ICU or critical care unit until no longer clinically indicated. Eligibility Criteria Inclusion: adults patients ≥18 years undergoing elective on-pump cardiac surgery with informed consent. Exclusion: emergency surgery, use of dual arterial lines, heart transplantation, mechanical circulatory support, contraindications to radial/femoral catheterization, legal or ethical inability to consent. Study Timeline Inclusion period: 36 months Patient follow-up: 7 days post-surgery Total study duration: 36 months Data Collection: Clinical data are collected by research staff using an electronic case report form (e-CRF) via CleanWeb™ software. Expected Impact: There are currently no guidelines specifying the optimal site for invasive BP monitoring. This study aims to provide robust evidence on whether femoral BP monitoring improves clinical outcomes, reduces vasopressor use, and minimizes adverse events. Positive findings could inform future practice guidelines and lead to broader investigations in other clinical settings.

Randomized, multi-site, study assessing the feasibility of lower limit of autoregulation targeted mean arterial pressure (MAP) vs. standard MAP management in neonates undergoing cardiac surgery with cardiopulmonary bypass. After eligibility screening and consent, subjects will be randomized to either the intervention (study) or control group.

The goal of this randomized clinical trial is to compare different types of advanced hemodynamic monitoring in patients undergoing major abdominal surgery. Participants undergoing major abdominal surgery will receive anesthesia with two different types of hemodynamic monitoring - group A will receive arterial pressure cardiac output algorithm with the FloTrac sensor and group B will receive hemodynamic monitoring with the Hypotension Prediction Index. The main question the study aims to answer is: • will the hypotension prediction index algorithm reduce the rate of hypotension in comparison to arterial pressure cardiac output algorithm.

The perioperative period poses a heightened risk of complications for patients, including hypotension. While the issue of intraoperative hypotension is well-documented in medical literature, the occurrence and causes of hypotension in the post-anesthesia care unit often receive less attention. This phase of postoperative care, however, is vital for ensuring patient stability and preventing severe consequences. Failure to identify and manage a drop in blood pressure can lead to hypoperfusion of critical organs, increasing the risk of morbidity and mortality. The aim of this study is to examine the frequency of hypotension in the post-anesthesia care unit-defined as systolic blood pressure \<90 mmHg or a drop of more than 20% from baseline-and to identify factors contributing to its development.

The goal of this prospective observational study is to externally validate the prediction algorithm using non-invasive monitoring device for intraoperative hypotension. The main question it aims to answer is: Does the prediction algorithm predict intraoperative hypotension effectively?

Perioperative anesthesiologists can benefit from easily obtainable hemodynamic variables detecting or quantifying the lack of an adequate compensatory capacity of the cardiovascular system in order to optimize patient management and improve patient outcomes. Parameters of the Pressure Recording Analytical Method (PRAM; Vygon, Padua, Italy) of the MostCare system, specifically cardiac cycle efficiency has been proposed as such variables. Yet, their value in anesthesia and especially in hypertensive patients is not studied. The goal of the PRAM-in-HYPO study is to prospectively evaluate the relationship between cardiac reserve and efficiency and cardiovascular risk factors in patients wo will undergo major surgical procedures using the state-of-the-art hemodynamic monitors. Also the investigators aim to build a predictive model to identify patients with decreased cardiac reserve due to hypertension and other cardiovascular risk factors, who are susceptible to post-induction hypotension. The investigators seek to include high-risk patients or patients presenting for major surgery, who are monitored with an advanced hemodynamic monitor to adequately evaluate the differences in cardiac reserve and cardiac efficiency.

Adequate free flap perfusion during Deep Inferior Epigastric Perforator (DIEP) flap breast reconstruction surgery requires maintaining blood pressure above 100 mmHg and avoiding excessive fluid administration. This study aims to determine whether the use of a measurement of preload dependency (Pulse Pressure Variation = PPV), can guide fluid therapy and if it decreases the risk of flap oedema. For this purpose, two fluid management strategies will be compared: * Static intraoperative fluid management: Administration of crystalloid fluids is limited to 5ml/kg/h * Dynamic intraoperative fluid management: Crystalloid fluids are only administered if PPV exceeds 12% The purpose of this study is to compare the static and dynamic (= targeted) fluid strategy and to evaluate the effect on flap oedema and flap perfusion.

In this prospective, randomized, single-blind study, we aim to compare the effects of general anesthesia and spinal anesthesia on postoperative myocardial injury in elderly patients undergoing hip surgery. Cardiovascular events are a leading cause of mortality and morbidity following non-cardiac surgery, with myocardial injury after non-cardiac surgery (MINS) being a significant concern. MINS, characterized by asymptomatic elevation of troponin levels without accompanying ECG findings, is closely associated with postoperative mortality. With the increasing prevalence of comorbidities in the elderly population and the rising frequency of non-cardiac surgeries in this demographic, understanding the effects of different anesthesia types on postoperative myocardial injury is crucial.