Pressure Recording Analytical Method Parameters and Their Relationship With Hypotension in Hypertensive Patients

Study Overview
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Brief Summary
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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.

Detailed Description
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Untreated hypertension decreases the cardiac reserve through several mechanisms, which are augmented by other cardiovascular risk factors such as diabetes mellitus and coronary artery disease. Perioperative stress on top of these overlapping diseases causes wide variations in the arterial blood pressure. From the anesthesiologist's point of view, this translates into a wide variation in response to surgical stress among patients with seemingly similar cardiovascular risk factors. The cardiac reserve may be measured by cardiac catheterization or echocardiography, none of which are feasible during a surgery. Recently, some parameters of the Pressure Recording Analytical Method (PRAM) were shown to be affected by hypertension or intraoperative events such as pneumoperitoneum and position changes. This suggests that PRAM may be used to evaluate the risk of adverse hemodynamic events in newly diagnosed, untreated hypertensive patients. The investigators hypothesized that there is a relationship between hypertension, diabetes mellitus and decreased cardiac reserve and efficiency and that PRAM parameters may identify this. Also, the static or dynamic PRAM parameters may predict pre-incision hypotension in patients wo will undergo major surgical procedures. In order to test these hypothesis, a prospective cohort study was planned, as the outcome has a very short latency and the intent is to observe the outcome, not to prevent or treat it. The investigators aim to collect high quality hemodynamic data from normotensive, hypertensive, and untreated hypertensive patients. In order to obtain sufficient relevant data, only patients scheduled for major surgeries will be included. Patients who are planned to be monitored with the MostCare hemodynamic monitor, and who need a passive leg raising test will be included in the study. Hypertension is the most prevalent of cardiovascular risk factors, namely diabetes mellitus, coronary artery disease, smoking, obesity, and dyslipidemia, which may present as either the mediator or cofounder of hypertension. Therefore a detailed medical history including information relevant to these conditions will be collected.

Official Title
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Observational Study to Evaluate the Pressure Recording Analytical Method Parameters in Patients Susceptible to Post-induction Hypotension Due to Hypertension, Diabetes Mellitus, Cardiovascular Risk Factors, or Major Surgery

Conditions
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Cardiovascular Diseases, Surgery, Hypotension, Hypotension on Induction, Hypotension During Surgery

Intervention / Treatment
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* Diagnostic Test: Passive leg raising


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age at least 18 years Undergoing major surgery under general anesthesia Expected surgery time >2 h Expected length of postoperative stay >2 d Invasive blood pressure (radial or femoral) and Mostcare monitoring Indication for a passive leg raising test: risk of hypovolemia (preoperative fasting, bowel preparation, loss of appetite, limited access to water) or expected major surgery, expected blood loss, cardiovascular comorbidity (hypertension, diabetes mellitus, coronary artery disease, peripheral artery disease, hyperlipidemia, morbidity, active smoking). Recruitment after booking for surgery with sufficient time to read, understand and question study patient information prior to attending for surgery. Ability and willingness to provide informed consent Exclusion Criteria: Refuse to consent to the study Arterial wave form distortion Cardiac arrhythmia Inappropriate identification of the dicrotic notch for any reason Planned intraoperative mean arterial blood pressure < 65 mmHg Hemodynamic instability defined as mean arterial blood pressure < 65 mmHg Preoperative requirement of inotrope/vasopressor infusion Preoperatively receiving vasoactive drugs Patients fitted with an intra-aortic balloon pump Patients fitted with Extracorporeal Membrane Oxygenation Critically ill patients requiring preoperative intensive care unit Presence of intraabdominal hypertension New York Heart Association Class 3-4 heart failure Congestive heart failure with ejection fraction < 35% Glomerular filtration rate < 30 ml/min/1.73 m2 Ongoing renal replacement therapy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Low cardiac reserve/efficiency<br>Patients who were identified as having low cardiac reserve and efficiency, based on PRAM parameters. | Diagnostic Test: Passive leg raising<br>* All patients who met the inclusion criteria will be placed head down flat and feet up at a 45° angle for 30 seconds. Hemodynamic parameters and analysis by pressure recording analytical method obtained with the MostCare will be collected before, during and after the test until the end of the surgery. The total duration of the intervention (passive leg raising) is 30 seconds. The total duration of hemodynamic parameters recording is expected to be 60-600 minutes.<br>|
| Normal cardiac reserve/efficiency<br>Patients who were identified as having normal cardiac reserve and efficiency, based on PRAM parameters. | Diagnostic Test: Passive leg raising<br>* All patients who met the inclusion criteria will be placed head down flat and feet up at a 45° angle for 30 seconds. Hemodynamic parameters and analysis by pressure recording analytical method obtained with the MostCare will be collected before, during and after the test until the end of the surgery. The total duration of the intervention (passive leg raising) is 30 seconds. The total duration of hemodynamic parameters recording is expected to be 60-600 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference of mean CCE, dP/dt, SVI, CPI, Ea by hypertension and diabetes mellitus | Difference in baseline PRAM parameters between patients who have hypertension, diabetes mellitus and other cardiovascular diseases and those who have none. | From the start of surgery until the end of surgery | 
| Difference of mean CCE, dP/dt, SVI, CPI, Ea at the 30th second of passive leg raising by hypertension and diabetes mellitus | Difference in the magnitude of the changes observed in PRAM parameters after a passive leg raising test between patients who have hypertension, diabetes mellitus and other cardiovascular diseases and those who have none. | From the start of passive leg raising test until the end of the test | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Mean Arterial Blood Pressure < 65 mmHg Within 5 Minutes Following Tracheal Intubation | Hypotension, defined as mean arterial blood pressure < 65 mmHg, within 5 minutes after tracheal intubation. | From the start of surgery until the end of surgery | 
| Number of Participants With Mean Arterial Blood Pressure < 65 mmHg Between Tracheal Intubation and Surgical Incision | Hypotension, defined as mean arterial blood pressure < 65 mmHg, between 5 minutes after tracheal intubation and surgical incision. | From the start of surgery until the end of surgery | 
| Number of Participants With Mean Arterial Blood Pressure < 65 mmHg During the Surgery | Hypotension, defined as mean arterial blood pressure < 65 mmHg, between surgical incision and end of surgery. | From the start of surgery until the end of surgery | 
| Predictive factors of hypotension | Identification of patient characteristics and arterial pressure waveform parameters associated with hypotension. A multiple logistic regression analysis will be performed. | From the start of surgery until the end of surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Mostcare, Pressure Recording Analytical Method, Pulse contour analysis, Hemodynamic monitoring, Effective arterial elastance, Cardiac cycle efficiency, Cardiac power output, Myocardial contraction, Cardiac output, Stroke volume, Systemic vascular resistance