Clinical Research Directory

Effects of Ephedrine, Phenylephrine, Norepinephrine and Vasopressin on Contractility of Human Myometrium and Umbilical Vessels: An In-vitro Study

Hypotension is one of the most common adverse effects of spinal anesthesia for cesarean deliveries, affecting as many as 55-90% of mothers. Hypotension during cesarean deliveries can have detrimental effects on the mother and neonate. Various vasopressors, such as ephedrine, phenylephrine and more recently norepinephrine, have been used for the prevention and treatment of hypotension at cesarean deliveries. Ephedrine was historically considered as the gold standard vasopressor for the management of hypotension during cesarean deliveries. This was based on studies in animal models that showed preserved uteroplacental circulation with ephedrine and not with phenylephrine. However, multiple studies in the past several decades have shown that phenylephrine compared with ephedrine results in a more favorable fetal acid-base status. Consequently, the use of phenylephrine for blood pressure management during cesarean deliveries increased. Recently, norepinephrine was introduced in the obstetrical practice for the management of hypotension at cesarean deliveries, due to its ability to maintain maternal cardiac output better than phenylephrine. Studies have also investigated the use of vasopressin to limit hypotension during CD. There have been case reports of successful vasopressin usage to treat post-spinal hypotension after CD in patients with advanced idiopathic pulmonary arterial hypertension as well as severe mitral stenosis with pulmonary hypertension. Its effect was associated with hemodynamic stability without evidence of harm to the mother or child. However, much controversy still exists surrounding the choice of vasopressor in the obstetric population, in large part due to their varying efficacies, and maternal and fetal effects. Vasopressors used for the treatment of hypotension during cesarean deliveries can have significant direct or indirect effects on the perfusion of uteroplacental and umbilical vessels. Reduction of uteroplacental perfusion and constriction of umbilical vessels can result in fetal acidosis, however, the mechanisms for these effects are unclear. The investigators hypothesize that ephedrine, phenylephrine and norepinephrine and vasopressin have variable effects on the contractility of pregnant myometrium and umbilical arteries due to their variable actions on adrenergic alpha (α) and beta (β) receptors, as well as vasopressin1 and vasopressin2 receptors located in these tissues.

Intraoperative Hypotension in Pancreatoduodenectomy: A Randomized Trial of General Versus Combined Anesthesia

This randomized clinical trial compares the hemodynamic effects of general anesthesia versus combined general anesthesia (thoracic epidural) in patients undergoing pancreatoduodenectomy. The primary aim is to assess the incidence of intraoperative hypotension and related adverse events. Secondary outcomes includes vasopressor requirements, transfusion needs, postoperative complications, intensive care unit admission, hospital length of stay, and mortality.

"Effect of Pre-Spinal Mindfulness-Based Breathing Exercise on Hemodynamic Response in Elective Cesarean Section"

Spinal anesthesia-induced hypotension is one of the most frequent and clinically significant complications of obstetric anesthesia, occurring in up to 50-80% of parturients undergoing elective cesarean section. Preoperative anxiety has been shown to potentiate hemodynamic instability through autonomic nervous system activation, thereby increasing susceptibility to spinal hypotension. This prospective, randomized, controlled trial aims to evaluate the effect of a standardized 5-minute mindfulness-based breathing exercise administered immediately prior to spinal anesthesia on the hemodynamic response in pregnant women scheduled for elective cesarean section. Eligible participants will be randomized in a 1:1 ratio into two parallel groups: the Mindfulness-Based Breathing Exercise Group and the Control Group receiving standard preoperative care. The breathing intervention consists of slow diaphragmatic breathing at a rate of approximately 6 breaths per minute (4-second inhalation through the nose, 6-second exhalation through the mouth), guided by a standardized script delivered by a trained anesthesiologist or nurse. Participants in the intervention group will be instructed to silently repeat the phrase "My body is relaxing as I exhale" with each exhalation, incorporating a mindfulness component. The primary outcome is the maximum decrease in systolic arterial pressure (SAP) within the first 10 minutes following spinal anesthesia induction. Secondary outcomes include preoperative state anxiety scores (STAI-5), early spinal hypotension incidence, heart rate changes, and vasopressor requirements. The study will be conducted at Atatürk University Faculty of Medicine, Department of Anesthesiology and Reanimation, Erzurum, Turkey, in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines.

Predicting Spinal Hypotension in Cesarean Section

This prospective observational study investigates the predictive value of anthropometric and hemodynamic indices for spinal anesthesia-induced hypotension (SAIH) during cesarean section. While spinal anesthesia is preferred for its rapid onset, SAIH remains a frequent complication risking maternal and fetal safety. The study enrolled parturients at Erciyes University, excluding those with hypertension or extreme weight/height. Preoperative measurements included BMI, waist circumference (WC), body roundness index (BRI), and modified shock index (MSI). Following standardized spinal anesthesia with hyperbaric bupivacaine (Harten's dosage), hemodynamic parameters and sensory block levels were monitored. This research aims to determine whether BRI and WC offer superior predictive utility compared with conventional markers such as BMI and MSI to enhance individualized risk assessment in obstetric anesthesia.

Skin Conductance for Predicting Spinal Anesthesia-Induced Hypotension in Geriatric Urologic Oncology Patients

Spinal anesthesia-induced hypotension is a common and clinically significant complication in elderly patients undergoing oncologic surgery. Early identification of patients at risk for hemodynamic instability remains a major challenge in perioperative management. Skin conductance reflects sympathetic nervous system activity and may provide a noninvasive indicator of autonomic responses. This prospective observational study aims to evaluate whether skin conductance measurements can predict the development of hypotension following spinal anesthesia in geriatric oncology patients undergoing urologic surgery. The findings may contribute to improved perioperative monitoring and early risk stratification in this vulnerable patient population.

Vasopressor Impact on Brain Circulation, Organ Blood Flow and Tissue Oxygenation During Anesthesia

The optimal vasopressor for ensuring organ blood flow and tissue oxygen delivery during surgery remains undetermined. This study aim to compare the effects of noradrenaline vs. phenylephrine infusion on blood flow and oxygen delivery to the brain and various other organs in anesthetized neurosurgical patients.

Frequency of Electrical Acupoint Stimulation on Hypotension During Induction

Within 30 minutes before anesthesia, acupoint electrical stimulation at different frequencies were applied at Neiguan and Jian Shi. The changes in blood pressure during the anesthesia induction period were compared between the high-frequency group and the low-frequency group.

Comparing Fluid Responsiveness Assessment Methods in Patients With Impaired Consciousness

Hypotension is a significant precursor to unfavorable clinical outcomes. To determine whether infusion therapy can positively impact the management of hypotension, several evaluative tests can be utilized. These include assessing the collapsibility and distensibility indices of the inferior vena cava, conducting a passive leg raising (PLR) test, and performing a fluid challenge (FC). Technologically advanced methods leveraging dynamic testing are capable of real-time prediction of a patient's response to infusion therapy. Nonetheless, the use of systolic pressure variability (SPV), pulse pressure variability (PPV), and stroke volume variability (SVV) is often limited by the prohibitive costs of the necessary equipment. In contrast, the PLR test and FC are not subject to this limitation. Despite being deemed unreliable by numerous clinical protocols, static measurements of central venous pressure (CVP) or pulmonary capillary wedge pressure (PCWP) persist in usage among certain traditionalists within the medical community. It must be noted that the patient's baseline state and the unique clinical context are pivotal in determining the precision of these methodologies. For example, the PLR test may yield limited information in fully conscious patients, and the prognostic value of CVP measurements is significantly diminished in cases of pneumothorax and hydrothorax. Regrettably, there is a paucity of data on the prognostic utility of these tests in patients with altered levels of consciousness, despite their growing presence in intensive care units. This gap underscores the necessity for comprehensive studies that evaluate the predictive efficacy of infusion therapy responsiveness in patients with concurrent hypotension and impaired consciousness. Purpose of the study: to investigate the sensitivity and specificity of methods for assessing fluid responsiveness in patients with hypotension and decreased level of consciousness.

The Effect of Frailty on Hypotension After Anesthesia Induction

Frailty is defined as a state of weakness resulting from a decrease in physiological reserves due to physiological changes, diseases, and/or malnutrition associated with advancing age. Frail older adults face increased mortality, morbidity, and healthcare costs when exposed to stressors, making this issue increasingly important. The FRAIL Scale, developed by Morley et al. , is a 5-item measure that assesses frailty. The FRAIL Scale has been validated in many countries and has been proven to be an effective method for detecting frailty. This scale assesses the patient's fatigue, resistance, mobility, weight loss, and other diseases. In the 5-item FRAIL scale, patients receive 0 or 1 point based on their answers, and a total of 0 points is considered non-frail, 1-2 points is considered pre-frail, and \>2 points is considered frail. Frailty is associated with a higher risk of postoperative complications. Rothenberg and colleagues reported in a study involving more than 400,000 patients that frailty doubles the risk of postoperative complications . Hypotension following anesthesia induction is a common complication in geriatric patients. Decreased cardiopulmonary reserve with age leads to an exaggerated drop in blood pressure during induction . In this study, the investigators aimed to determine the effect of frailty level in geriatric patients on hypotension observed after anesthesia induction.

Clinical Trial of Digital Therapeutics (One.Dr) for Suspected Orthostatic Hypotension Patients

Participants who meet the inclusion/exclusion criteria in the Screening visit are randomly assigned 1:1 to the treatment group or the sham control group. The two-week period after Screening is the Run-in period, and the participant performs self-measured blood pressure monitoring, records data using the One.Dr application, and records symptoms and events related to orthostatic hypotension such as dizziness in the application. Only those who have completed the Run-in period will enter the Intervention period (for 6 weeks at 3-8 weeks), and according to each allocation group, non-pharmaceutical treatment education is provided for the treatment group and general health knowledge education is provided for the sham control group.

Comparative Analysis Of Dexmedetomidine And Dexamethasone As An Adjuvant To 0.5%Ropivacaine On Onset Of Ultrasound Guided Supraclavicular Brachial Plexus Block In Patients Undergoing Upper Limb Surgeries

To compare the efficacy of dexmedetomidine and dexamethasone as an adjuvant to 0.5%ropivacaine on onset of ultrasound guided supraclavicular brachial plexus block in patients undergoing upper limb surgeries. Ropivacaine hydrochloride, a long acting local anesthetic, is commonly used for supraclavicular block owing to its favorable safety profile especially in terms of minimal cardiotoxicity and less motor block. Dexmedetomidine, a highly selective alpha-2 adrenergic agonist, enhances the quality of supraclavicular block by providing sedation and analgesia while potentially prolonging the duration of block through hyperpolarization of nerve fibers. While, Dexamethasone, a synthetic corticosteroid with potent anti-inflammatory and immunosuppressive properties, prolongs duration of analgesia by reducing perineural inflammation and inhibiting nociceptive signal transmission. Supraclavicular brachial plexus block offers dense anesthesia for surgical procedures at or distal to the elbow with relatively high success rate, once described as "spinal of the arm". Moreover, supraclavicular brachial plexus block is an excellent alternative to general anesthesia in upper limb surgeries.

Hypotension Prediction Index: Correlations Between Invasive and Non-invasive Pressure Points.

To evaluate the clinical performance of the Hypotension Prediction Index obtained from the continuous, non-invasive Clear Sight monitor.

Efficacy and Safety Evaluation of Non-invasive Temporal Interference Stimulation for Blood Pressure Regulation

The primary objective of this research is to study the efficacy and safety of temporal interference stimulation for regulating the blood pressure.

Comparison of EOSP Between Usg Guided S-FICB vs USG Guided PENG Block in Pts Undergoing Femur Fracture Surgery

To compare the immediate and postoperative analgesic efficacy of S-FICB and PENG block will be the objective. The use of ultrasonography in anesthesia has helped the anesthetist to see the nerve, needle and the distribution of the drug, thereby enhancing the chances of a favorable outcome of the nerve block. Grade A recommendation for an ultrasound guided approach to the peripheral nerve blocks is supported by level Ib evidence for a shortened time for the onset of sensory block, decreased performance time and lower drug doses10. Although individually both the blocks have been studied, there are only a handful of studies comparing both techniques under ultrasound guidance for making patient positioning for spinal anesthesia easy. And no local data is available comparing these blocks. So, we want to compare the analgesic efficacy of USG PENG block with USG S-FICB block in patients with fracture femur in reducing pain associated with positioning (sitting) for subarachnoid block, duration of analgesia, opioid sparing effect and complications. So that procedure with better analgesic efficacy and less complications will be included in our local guidelines as a part of multimodal analgesia.

Continuous Infusion of Norepinephrine vs Phenylephrine During Spinal Anesthesia for Cesarean Section (INPEACE)

The goal of this clinical trial is to compare norepinephrine and ephedrine in maintaining blood pressure during spinal anaesthesia for elective cesarean delivery. The main questions it aims to answer are: * Do phenylephrine and norepinephrine administered as manually controlled continuous infusion during elective cesarean delivery have different effects on neonatal outcome ? * Do phenylephrine and norepinephrine administered as manually controlled continuous infusion during elective cesarean delivery have different effects on maternal hemodynamics? Participants will receive either phenylephrine or norepinephrine infusion, at the time of performing spinal anesthesia, the infusion rate will be adjusted manually depending on maternal arterial pressure.

Spinal Cord Transcutaneous Stimulation Effect on Blood Pressure in Acute Spinal Cord Injury (SCI)

The goal of this clinical trial is to evaluate the effect of transcutaneous spinal cord stimulation on blood pressure in individuals with an acute spinal cord injury (within 30 days of injury). Blood pressure instability, specifically orthostatic hypotension (a drop in blood pressure when moving lying flat on your back to an upright position), appears early after the injury and often significantly interferes with participation in the critical rehabilitation time period. The main questions it aims to answer are: 1. Can optimal spinal stimulation increase blood pressure and resolve orthostatic symptoms (such as dizziness and nausea) when individuals undergo an orthostatic provocation (a sit-up test)? Optimal stimulation and sham stimulation (which is similar to a placebo treatment) will be compared. 2. What are the various spinal sites and stimulation parameters that can be used to increase and stabilize blood pressure to the normal range of 110-120 mmHg? Participants will undergo orthostatic tests (lying on a bed that starts out flat and then moved into an upright seated position by raising the head of bed by 90° and dropping the base of the bed by 90° from the knee) with optimal and sham stimulation, and their blood pressure measurements will be evaluated and compared.

The Effect of Transcutaneous Stimulation on Blood Pressure in Spinal Cord Injury (SCI)

This project will investigate the effect of spinal cord transcutaneous stimulation on blood pressure in individuals with a chronic spinal cord injury who experience blood pressure instability, specifically, orthostatic hypotension (a drop in blood pressure when moving from lying flat on your back to an upright position). The main questions it aims to answer are: 1. What are the various spinal sites and stimulation parameters that normalize and stabilize blood pressure during an orthostatic provocation (70 degrees tilt)? 2. Does training, i.e., exposure to repeated stimulation sessions, have an effect on blood pressure stability? Participants will undergo orthostatic tests (lying on a table that starts out flat, then tilts upward up to 70 degrees), with and without stimulation, and changes in their blood pressure will be evaluated.

The Effect of Two Different Doses of Noradrenaline on Hypotension Caused by Spinal Anesthesia for Cesarean Section

To compare two infusion rates of norepinephrine for prophylaxis against post-spinal hypotension during caesarean delivery.

Use of Ultrasonography to Determine Fluid-responsiveness for Shock in a Population of Intensive Care Unit Patients

The objective of our study is to determine the correlation of transthoracic ultrasonographic indices of fluid responsiveness to changes in direct measures of cardiac output and to compare them to other established predictors of fluid responsiveness such as central venous pressure variation, systolic arterial pressure variation and pulse pressure variation in a broad population of patients. Hypothesis: There will be a significant difference in the inferior vena cava respiratory variation and subclavian vein respiratory variation between responders and non-responders to intravenous fluid challenge in a broad population of patients with shock.

The Effect of phoSPHocreatine on mEdical Emergency Team (Met) tREated Patients

Unexpected deaths and unplanned intensive care unit (ICU) admissions are common during hospital stay and are often preceded by warning abnormalities in patients' vital signs. These abnormalities trigger Medical Emergency Team (MET) activation and up to 15% of patients visited by the MET is admitted to the ICU with an overall hospital stay after the MET intervention of approximately 2 weeks. Phosphocreatine (PCr) is a natural energy-buffering molecule associated with signals of mortality reduction in patients with acute cardiac conditions (according to meta-analytic finding from our group) and with encouraging beneficial effects on other acute organ failures (e.g. brain). The investigators designed a multi-center, randomized, placebo-controlled trial to confirm the promising beneficial effects of PCr in hospitalized patients. The investigators expects a reduction in hospital stay (measured as an increase in days alive and out of hospital at 30 days) when PCr is added to standard treatment in patients requiring MET intervention.

The Hypotension Prediction Index in Free Flap Transplant in Head and Neck Surgery.

The aim of the current study is to evaluate the effects of the Hypotension Prediction Index (HPI) on the degree of intraoperative hypotension in patients undergoing free flap surgery. The hypothesis is that implementation of the HPI algorithm will reduce the time-weighted average (TWA) intraoperative hypotension below a threshold of 65 mmHg (16), and to reveal the relationship between the episodes of hypotension and free flap viability and function.

PeRsonalized Blood prEssure Management on Postoperative Complications and Mortality in hIgh-risk Patients Undergoing Major Non-cardiac Surgery

High-risk populations, particularly elderly individuals and patients with cardiovascular comorbidities, exhibit markedly elevated incidences of postoperative myocardial injury (MINS), acute kidney injury (AKI), and mortality. Intraoperative hypotension (IOH), a pervasive clinical phenomenon affecting 40%-90% of surgical cases, Substantial observational evidence links IOH severity/duration to ischemic organ injuries (MINS, AKI) and long-term morbidity.Nevertheless, inherent limitations of observational designs-particularly residual confounding-preclude definitive causal inferences. Notably, randomized controlled trials (RCTs) investigating goal-directed hemodynamic interventions demonstrate inconsistent clinical benefits, underscoring the imperative to clarify causal mechanisms between IOH and organ injury. This causal ambiguity arises from two unresolved scientific questions: (1) Threshold personalization deficit; (2) Therapeutic strategy limitations. In light of current evidence, perioperative hypotension management demands personalized strategies, the investigators propose a multicenter randomized controlled trial (RCT) that aims to clarify the clinical benefits of individualized blood pressure management.

Noninvasive Continuous BP Monitoring in Newborns Based on Pulsatile Signal Morphological Features Using NIRS

The goal of this study is to evaluate if a novel near-infrared spectroscopy (NIRS) device can accurately estimate blood pressure in newborns at risk for unstable blood pressure. The main questions it aims to answer are: * Can NIRS accurately estimate blood pressure when compared to the gold standard, arterial line blood pressure * Can NIRS accurately estimate blood pressure when compared to infants with cuff blood pressure monitoring Researchers will compare NIRS-based estimates to arterial line blood pressure readings and manual cuff measurements to optimize and validate the FlexNIRS device for neonates to accurately estimate blood pressure continuously and noninvasively. Participants will wear a small, noninvasive NIRS sensor on the forehead.

Early Initiated Vasopressor Therapy in the Emergency Department

The goal of this pragmatic, multi-center, superiority, randomized clinical trial is to compare early treatment with peripheral (through a vein) infused noradrenaline (a natural hormone that increases blood pressure) with fluid only therapy in patients with hypotensive and shock in the Danish and Swedish Emergency Departments (ED). The main questions it aims to answer are: If early initiated noradrenaline in non-bleeding hypotensive patients presenting in the ED can * Improve time to shock control. * Reduce the need for ICU admittance. * Decrease mortality. Participants will be included by the clinical staff and treated urgently with either noradrenaline or usual treatment during their Emergency Department stay. After completion of the treatment in the Emergency Department, patient data will be extracted from the bed-side measurements, electronic health records and national registers. Patients will be contacted by the research staff 1 year after study inclusion to answer brief questions about their daily physical function and ability to care for themselves. Researchers will compare with patients receiving fluid therapy only, as this is the usual standard of care in Danish and Swedish Emergency Departments.