A Phase 4 interventional study of Phenylephrine hydrochloride infusion and Norepinephrine bitartrate infusion in Spine Surgery, Intraoperative Hypotension and Tissue Perfusion, sponsored by Mayo Clinic. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-02.
Sponsored by Mayo Clinic · Phase 4, Interventional, and Treatment
The purpose of this research is to compare two commonly used medications, phenylephrine and norepinephrine, that are used to treat low blood pressure during complex spine surgery. The goal is to determine whether one medication better maintains blood flow to the body's organs during surgery and whether it leads to better recovery and fewer complications after surgery.
885 studies on the registry are indexed under Hypotension; 195 are open to participants now.
This study's planned enrollment of 50 is below the median of 87 across 590 interventional studies indexed under Hypotension.
Browse Hypotension studies →Mayo Clinic is the lead sponsor of 3,269 studies on the registry; 672 are open to participants now.
Of its 452 completed or terminated interventional studies of FDA-regulated products, 321 (71%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants assigned to this group will undergo elective complex spine surgery with intraoperative blood pressure support managed using phenylephrine as the assigned first-line vasopressor strategy.
Drug: Phenylephrine hydrochloride infusion
Participants assigned to this group will undergo elective complex spine surgery with intraoperative blood pressure support managed using norepinephrine as the assigned first-line vasopressor strategy.
Drug: Norepinephrine bitartrate infusion
Phenylephrine hydrochloride will be prepared at a concentration of 40 mcg/mL and initiated at 0.2 mcg/kg/min. The infusion will be titrated intraoperatively to maintain MAP greater than 85 mmHg from surgical manipulation of vertebrae until final wound closure.
Norepinephrine bitartrate will be prepared at a concentration of 16 mcg/mL, equivalent to 8.47 mcg/mL norepinephrine base, and initiated at 0.02 mcg/kg/min. The infusion will be titrated intraoperatively to maintain MAP greater than 85 mmHg from surgical manipulation of vertebrae until final wound closure.
Peak Intraoperative Serum Lactate
Highest intraoperative serum lactate concentration measured during surgery. Serum lactate will be analyzed as a continuous marker of tissue perfusion.
Time frame: Intraoperatively, from initiation of lactate monitoring through final wound closure
Incidence of Elevated Intraoperative Serum Lactate
Number of patients with presence of serum lactate greater than 2.0 mmol/L at any time during surgery.
Time frame: Intraoperatively, from initiation of lactate monitoring through final wound closure
Postoperative Myocardial Injury After Noncardiac Surgery
Presence of postoperative myocardial injury after noncardiac surgery, defined as cardiac troponin greater than the 99th percentile of the upper reference limit and not attributable to a nonischemic cause.
Time frame: Within 30 days after surgery
Postoperative Acute Kidney Injury
Number of patients to be diagnosed with new acute kidney injury during postoperative hospitalization, based on KDIGO creatinine, urine output, renal replacement therapy, or hemodialysis criteria as specified in the protocol.
Time frame: During postoperative hospitalization, up to 30 days after surgery
Proportion of Intraoperative Hypotension
Duration of intraoperative MAP less than 85 mmHg divided by total surgical length, expressed as a percentage.
Time frame: Intraoperatively, from surgical incision to turnover to anesthesia
Volume of Blood Transfusion
Total volume of blood transfusion, stratified by packed red blood cells, fresh frozen plasma, cryoprecipitate, platelets, and cell saver.
Time frame: During surgery and within 24 hours postoperatively
Length of ICU Stay
Postoperative time during which the participant requires ICU-level care, reported in days.
Time frame: From ICU admission to discharge from ICU-level care, up to 30 days after surgery
Length of Hospital Stay
Time from anesthesia end until discharge to inpatient rehabilitation, skilled nursing facility, or home, reported in days.
Time frame: From anesthesia end to hospital discharge, up to 30 days after surgery
Quality of Recovery 15 (QoR-15) Score
QoR-15 is an instrument that uses 15 questions regarding patient support, comfort, emotions, physical independence, and pain. Participants rate each question on a scale of 0 (none of the time) to 10 (all of the time).
Time frame: 14 days post-operatively
30-Day Readmission Rate
Number of patients to be readmitted to the hospital for any reason on or before postoperative day 30.
Time frame: Within 30 days after surgery
30-Day All-Cause Mortality
Incidence of death from any cause within 30 days of surgery
Time frame: Within 30 days after surgery
Plan to share: No
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This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Norepinephrine