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

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