Intraoperative Hypotension

Intraoperative hypotension is commonly treated with fluid administration; however, excessive fluid therapy may contribute to postoperative pulmonary complications. This randomized double-blind controlled trial evaluates whether proactive administration of fixed low-dose norepinephrine reduces intraoperative crystalloid administration while maintaining hemodynamic stability in high-risk patients undergoing laparoscopic abdominal surgery. One hundred and thirty patients will be randomized to receive either norepinephrine infusion (0.03 µg/kg/min) or placebo from induction until skin closure within a protocolized hemodynamic strategy guided by mean arterial pressure and pulse pressure variation.

The internal jugular vein (IJV) collapsibility index has been proposed as a practical alternative of of the inferior vena cava collapsibility index (IVC-CI), as it is easily accessible using bedside ultrasonography. Several studies have demonstrated a correlation between IJV collapsibility and central venous pressure as well as right atrial pressure.

Prospective double blind randomized controlled trial. By randomizing patients undergoing kidney transplantation into a conventional catecholamine drug (dobutamine) blood pressure maintenance group and a terlipressin-complexed dobutamine group, the investigators compared the effect of intraoperative blood pressure maintenance and the dosage of the vasoactive drug, postoperative graft function, delayed graft function, and other related complications between the two groups, in order to demonstrate whether the use of terlipressin for blood pressure regulation during kidney transplantation is superior to the existing treatments.

This observational study aims to learn whether changes in the internal jugular vein during anesthesia induction can help predict low blood pressure and kidney injury after surgery. The main questions it aims to answer are: 1. Can the internal jugular vein collapsibility index before anesthesia predict low blood pressure during induction? 2. Can the change in internal jugular vein collapsibility from before to just after anesthesia predict low blood pressure during surgery and acute kidney injury after surgery? Participants will have routine ultrasound scans of the neck before anesthesia and again shortly after they fall asleep for surgery. Researchers will also record blood pressure during surgery and measure kidney function after surgery using routine blood tests. and again shortly after they fall asleep for surgery. Researchers will also record blood pressure during surgery and measure kidney function after surgery using routine blood tests.

Intraoperative hypotension is commonly treated with fluid administration; however, excessive fluid therapy may contribute to postoperative pulmonary complications. This randomized double-blind controlled trial evaluates whether proactive administration of fixed low-dose norepinephrine reduces intraoperative crystalloid administration while maintaining hemodynamic stability in high-risk patients undergoing laparoscopic abdominal surgery. One hundred and thirty patients will be randomized to receive either norepinephrine infusion (0.03 µg/kg/min) or placebo from induction until skin closure within a protocolized hemodynamic strategy guided by mean arterial pressure and pulse pressure variation.

This study investigates if the Hypotension Prediction Index (HPI) combined with the Assisted Fluid Management (AFM) software can improve perioperative hemodynamic management in adult patients undergoing general anesthesia. The main question is : Does the HPI and AFM software reduce the incidence and duration of intraoperative hypotension? Does the HPI and AFM software optimize fluid and vasopressor administration? Does the HPI and AFM software improve perioperative outcomes? Participants will be randomly allocated to either an experimental group receiving goal directed hemodynamic therapy guided by HPI and AFM or a control group receiving conventional hemodynamic management.

Intraoperative hypotension, defined as a drop in blood pressure during surgery, is a frequent event in patients undergoing general anesthesia. Even brief episodes of low blood pressure may reduce blood flow to vital organs such as the brain, heart, and kidneys, and have been associated with an increased risk of postoperative complications, prolonged recovery, and worse clinical outcomes. Despite its clinical importance, the management of intraoperative hypotension is often based on general guidelines and individual clinician experience rather than patient-specific physiological mechanisms. Low blood pressure during surgery can occur for different underlying reasons, including reduced circulating blood volume, excessive vasodilation caused by anesthetic agents, impaired heart contractility, or abnormalities in heart rate. In routine practice, these mechanisms are not always clearly distinguished, and similar treatment strategies may be applied to patients with different physiological causes of hypotension. As a result, the response to treatment can vary widely between patients. This prospective observational study aims to improve the understanding of intraoperative hypotension by collecting detailed hemodynamic data during surgery and analyzing these data using machine learning methods. The study is designed to observe current clinical practice without altering or interfering with routine patient care. All decisions regarding anesthesia management and treatment of hypotension will be made by the attending anesthesiologists according to standard clinical practice. The research team will not provide treatment recommendations during surgery. Adult patients undergoing elective surgery under general anesthesia with continuous invasive arterial blood pressure monitoring will be included. During the intraoperative period, blood pressure, heart rate, cardiac output, stroke volume, systemic vascular resistance, and other advanced hemodynamic parameters will be continuously recorded at regular intervals. When hypotension occurs, the onset, duration, and severity of the episode will be documented, along with the treatment applied, such as fluid administration, vasopressor agents, or inotropic medications. The time required for blood pressure to recover to an acceptable level will also be recorded. The collected data will be analyzed using machine learning techniques to identify distinct subtypes of intraoperative hypotension based on physiological patterns. These subtypes may reflect different underlying mechanisms, such as hypovolemia, vasodilation, myocardial depression, or heart rate-related causes. In addition, the study will evaluate how different treatment strategies perform across these hypotension subtypes and how quickly hemodynamic stability is restored. Patient-related factors such as age, sex, body mass index, physical status classification, and comorbid conditions will also be examined to determine their relationship with the occurrence, severity, and treatment response of hypotension episodes. By combining patient characteristics, physiological data, and treatment responses, the study aims to generate data-driven insights into personalized hypotension management. The ultimate goal of this research is to support the development of individualized treatment recommendations for intraoperative hypotension based on objective physiological data rather than a one-size-fits-all approach. The findings of this study are expected to provide a strong scientific foundation for future clinical decision-support systems that can assist anesthesiologists in selecting the most appropriate treatment strategy for each patient. By improving the precision of blood pressure management during surgery, this approach has the potential to enhance patient safety and perioperative outcomes while maintaining standard clinical workflows.

This proof-of-concept randomized controlled trial evaluates a reinforcement learning (RL)-based clinical decision support system for intraoperative hemodynamic management during non-cardiac surgery. Background: Intraoperative hypotension is common during general anesthesia and is associated with adverse outcomes including acute kidney injury, myocardial injury, and increased mortality. Current hemodynamic management relies on the individual anesthesiologist's clinical judgment, which can vary in consistency and timeliness. An RL-based system that learns optimal vasoactive agent dosing strategies from clinical data may help standardize and improve real-time hemodynamic decision-making. Purpose: The primary objective is to evaluate whether the RL-based decision support system can learn intraoperative hemodynamic management decisions comparable to those of experienced anesthesiologists, as measured by the mean absolute error (MAE) between RL-recommended and clinician-executed vasoactive agent doses. The secondary objective is to assess whether RL-guided management improves clinical hemodynamic outcomes, including the time-weighted average of hypotension and the percentage of time with mean arterial pressure within the target range. Participants: Adult patients (aged 18 to 85 years, ASA I-IV) scheduled for elective non-cardiac surgery under general anesthesia with continuous invasive arterial blood pressure monitoring. Procedures: Participants will be randomly assigned (1:1) to one of two groups. In the RL-guided group, the anesthesiologist will receive real-time vasoactive agent dosing recommendations from the decision support system displayed on a bedside screen; the anesthesiologist retains full clinical autonomy over all final decisions. In the standard care group, the anesthesiologist will manage hemodynamics according to institutional standard practice without input from the system. The patient and the outcomes assessor will be masked to group assignment. Data collection covers the intraoperative period and 30-day postoperative follow-up.

The PROST-BP trial is a prospective, single-center, randomized, patient-blinded, non-inferiority trial investigating whether intermittent oscillometric blood pressure monitoring is non-inferior to continuous intraarterial blood pressure monitoring in reducing intraoperative hypotension in patients having robot-assisted radical prostatectomy.

The effect of noradrenaline infusion versus standard blood pressure management on perioperative HYPotension in NOn-caRdiac surgery. The study aims to determine whether perioperative noradrenaline infusion is superior to standard blood pressure management for the occurrence of perioperative hypotension.

The study aims to assess whether the transverse diameter of the right common femoral vein (RCFV) in the inguinal region could reflect the degree of post-spinal hypotension during elective orthopedic surgery.

The prevention of intraoperative hypotension could reduce postoperative organ injury and mortality, particularly in elderly patients receiving long-term renin-angiotensin system inhibitors. Previous meta-analyses suggest that ciprofol, a novel intravenous anesthetic agent, may provide improved hemodynamic stability compared to propofol; however, its precise effects on perioperative hemodynamics remain unclear. The study will assess whether ciprofol improves perioperative hemodynamic stability in elderly patients receiving renin-angiotensin system inhibitors.

The goal of this observational study is to learn the how to determine the mean arterial pressure(MAP) or blood pressure level to be maintained during non-cardiac surgery for optimal brain health in patients above the age of 60 undergoing major non-cardiac surgery. The main question\[s\] it aims to answer are: * Is there a way to tailor the blood pressure to be maintained in such patients during surgery for optimal brain health using non-invasive monitors that check the brains electrical activity, the electroencephalogram(EEG) monitor, and the brain's blood oxygen levels, the cerebral oximetry(CO) monitor? * How much does this optimal blood pressure level vary between patients? Participants will be asked to: * Complete a questionnaire at the time they enroll into the study, as well as a daily questionnaire to help determine their level of thinking and brain health. This questionnaire will be administered by a member of the study team. * They will also have an EEG and CO monitoring sticker placed on their foreheads. This will be connected to a monitor that will collect this data just before, during, and after their surgery. The data collected through these monitors will help us with our study goals.

This study is a randomized, controlled trial. A total of 92 patients will be randomized to receive sufentanil or remifentanil during extracranial-intracranial bypass surgery.

Postoperative acute kidney injury (AKI) is a serious complication often linked to low blood pressure during surgery. This study aims to better protect patients' kidneys by personalizing how blood pressure is managed during an operation. The project has two main goals: First, researchers will analyze data from over 44,000 past surgeries to identify which specific blood pressure measurements are the most critical warning signs for kidney damage. Second, using this knowledge, they will build a smart tool (a machine learning model) to predict a unique, safe blood pressure target for each individual patient before their surgery begins. This personalized approach is intended to give doctors a specific target to maintain during surgery, helping to prevent kidney injury and improve patient safety.

Perioperative hypotension is a risk factor for perioperative complications. Advances in machine learning and artificial intelligence have produced an algorithm that predicts the occurrence of hypotension episodes by analyzing an arterial pressure waveform. This technology has not been validated in thoracic surgical patients undergoing lung resections with the use of one-lung ventilation (OLV). We planned an observational, prospective multi-centre cohort validation study of the Hypotension Prediction Index (HPI) in patients undergoing lung resection procedures with the use of one-lung ventilation and a lung-protective strategy.

Acute renal injury (AKI) is a common complication after cardiac surgery and is associated with worse outcomes. It is now realized that intraoperative hypotension is an important risk factor for the development of AKI. In a recent randomized controlled trial of patients undergoing major noncardiac surgery, intraoperative individualized blood-pressure management reduced the incidence of postoperative organ dysfunction. The investigators hypothesize that, for patients undergoing off-pump CABG, targeted blood-pressure management during surgery may also reduce the incidence of postoperative AKI.

In order to reduce the incidence of IOH, various goal-directed therapy (GDT) protocols have already been introduced with success regarding the reduction of postoperative AKI and MINS. However, these studies used an invasive hemodynamic monitoring which offered a continuous surveillance of the blood pressure. In contrast, standard non-invasive blood pressure monitoring results in a blind gap between two measurements (mostly three or five minutes). In order to address this limitation, different continuous non-invasive blood pressure monitoring devices have been introduced. The next evolutional step of non-invasive cardiac output monitoring was to prevent IOH before their onset by using the Hypotension Prediction Index (HPI). Based on the Edward ́s monitoring platform, HPI is a monitoring tool which aims to predict IOH (defined as MAP\<65 mmHg for at least one minute) up to 15 min before its onset. The underlying machine learning based algorithm uses analyses features from the pressure waveform and was first calculated from a large retrospective data set of surgical patients and subsequently validated in a prospective cohort. In this study HPI showed a sensitivity of 88% and specificity of 87% for predicting IOH 15 min before its onset. Since then, own and studies of other working groups confirmed the effective prevention of IOH by the use of HPI-based GDT. Until today the arterial waveform analysis was dependent on invasive arterial measurement but since Edwards Lifesciences already promoted the start of the HPI on the ClearSight platform a non-invasive measurement will soon be possible. Further, until now it has not yet been proven that the perioperative use of a continuous non-invasive blood pressure monitoring has a beneficial effect on the patient´s outcome. Study objectives The aim of the study is to investigate whether a hemodynamic protocol based on continuous non-invasive cardiac output monitoring (ClearSight system) compared to standard care can reduce the incidence of IOH, postoperative AKI, and MINS in patients undergoing major trauma and orthopedic surgery.

This study aim to implement intraoperative hemodynamic monitoring and management guided with HPI algorithm in frail patients undergoing elective abdominal surgery. Investigators hypothesize that the use of this algorithm will alter treatment of hypotension and reduces the amount of hypotension as measured by the time weighted average (TWA) during non-cardiac surgery and to anticipate a reduction of postoperative AKI incidents, to explore the clinical benefits of impact of Acumen guided algorithm hemodynamic management in postoperative intestinal function recovery, and postoperative cardiac complications.