General SurgeryGUARDIANNCT04789733
The GUARDIAN Pilot Trial
A study testing Tight pressure management and Routine pressure management in people with General Surgery, run by The Cleveland Clinic at 1 site in China.
Trial summary
The treatments will be: 1) norepinephrine or phenylephrine infusion to maintain intraoperative MAP ≥85 mmHg, delayed resumption of chronic antihypertensive medications, and a target ward MAP ≥80 mmHg (tight pressure management); or, 2) routine intraoperative blood pressure management and prompt resumption of chronic… Read more about this study
- Who is it for?
- Ages 45 years and older
- Conditions the study is for
- General Surgery
- What is being tested?
- Tight pressure management and Routine pressure management
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 1 siteChina
- Study dates
- 27 Apr 2021to 31 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 45 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- ≥45 years old
- Scheduled for major noncardiac surgery expected to last at least 2 hours;
- Having general endotracheal, neuraxial anesthesia, or the combination;
- Expected to require at least overnight hospitalization;
- Are designated ASA physical status 2-4 (ranging from mild systemic disease through severe systemic disease that is a constant threat to life);
- Chronically taking at least one anti-hypertensive medication;
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- Expected to have direct blood pressure monitoring with an arterial catheter;
- Cared for by clinicians willing to follow the GUARDIAN protocol;
- Subject to at least one of the following risk factors:
- History of peripheral arterial surgery;
- History of coronary artery disease;
- History of stroke or transient ischemic attack;
- Serum creatinine >175 µmol/L (>2.0 mg/dl);
- Diabetes requiring medication;
- Current smoking or 15 pack-year history of smoking tobacco;
- Scheduled for major vascular surgery;
- Body mass index ≥35 kg/m2;
- Preoperative high-sensitivity troponin T >14 ng/L or troponin I equivalent;
- B-type natriuretic protein (BNP) >80 ng/L or N-terminal B-type natriuretic protein (NT-ProBNP) >100 ng/L
Who cannot join
- Are scheduled for carotid artery surgery;
- Are scheduled for intracranial surgery;
- Are scheduled for partial or complete nephrectomy;
- Are scheduled for pheochromocytoma surgery;
- Are scheduled for liver transplantation;
- Require preoperative intravenous vasoactive medications;
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- Have a condition that precludes routine or tight blood pressure management such as surgeon request for relative hypotension;
- Require beach-chair positioning;
- Have end-stage renal disease requiring dialysis or estimated glomerular filtration rate (eGFR) <30 ml/min;
- Have a documented history of dementia;
- Have language, vision, or hearing impairments that may compromise cognitive assessments;
- Have contraindications to norepinephrine or phenylephrine per clinician judgement;
- Have previously participated in this trial.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Tight Perioperative Blood Pressure Management to Reduce Serious Cardiovascular, Renal, and Cognitive Complications: The GUARDIAN Pilot Trial
The treatments will be: 1) norepinephrine or phenylephrine infusion to maintain intraoperative MAP ≥85 mmHg, delayed resumption of chronic antihypertensive medications, and a target ward MAP ≥80 mmHg (tight pressure management); or, 2) routine intraoperative blood pressure management and prompt resumption of chronic antihypertensive medications (routine pressure management).
Read the detailed description
Consenting patients who take either angiotensin converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), or calcium channel blockers will be asked not to take the medications on the morning of surgery, and instead bring them with them to the hospital. Qualifying patients will be randomized 1:1, with random-sized blocks.
Randomization will be implemented by clinicians in collaboration with research personnel. Arterial catheter transducers will be positioned at the level of the right atrium, and adjusted as necessary if patient position is changed.
The treatments will be: 1) norepinephrine or phenylephrine infusion to maintain intraoperative MAP ≥85 mmHg, delayed resumption of chronic antihypertensive medications, and a target ward MAP ≥80 mmHg (tight pressure management); or, 2) routine intraoperative blood pressure management and prompt resumption of chronic antihypertensive medications (routine pressure management).
Tight pressure management: In patients assigned to tight pressure management, angiotensin converting enzyme inhibitors and angiotensin receptor blockers will not be given the morning of surgery. Other chronic antihypertensives will only be given as necessary to treat hypertension. Clinicians will be encouraged to insert the required arterial catheter before anesthetic induction because much hypotension occurs shortly after anesthetic induction.
A norepinephrine or phenylephrine infusion (in the preferred local concentration) will be prepared, connected to an intravenous catheter, and activated at a low rate. Norepinephrine can be safely given through a central catheter or peripherally.
General anesthesia will be induced with propofol or etomidate which will be given in repeated small boluses or target-controlled infusion in an effort to keep mean arterial pressure ≥85 mmHg. Clinicians will be encouraged to use etomidate when rapid-sequence inductions are required. Simultaneously, the vasopressor infusion will be adjusted with the same goal. Anesthetic dose, fluid administration, and vasopressor administration will be adjusted with the goal of maintaining the individual designated baseline mean arterial pressure. Invasive or non-invasive advanced hemodynamic monitoring is not required, but should be used when practical. Clinicians should use available information to optimize vascular volume, afterload, and inotropy.
Resumption of chronic anti-hypertensive medications will be delayed until the third postoperative day unless deemed necessary to treat hypertension or for some other clear indication (e.g., preventing atrial fibrillation in a chronic beta-blocker user) because >90% of MINS occurs within 48 hours after surgery. When necessary to treat hypertension, chronic antihypertensive or new medications can be used per clinician preference. Clinicians will make what efforts they can to maintain postoperative mean arterial pressures ≥80 mmHg during the initial three postoperative days by maintaining adequate hydration, using inotropic and chronotropic drugs, and vasopressor as necessary. This protocol specifies the blood pressure target but leaves implementation to clinical judgement.
Routine pressure management: In patients assigned to routine pressure management, ACEIs, ARBs, and/or calcium channel blockers can be given the morning of surgery if deemed appropriate by the attending anesthesiologist. The arterial catheter will be inserted before or after induction of anesthesia per clinician preference. General anesthesia will be induced and maintained per routine. Blood pressure will not be deliberately reduced, but per routine clinicians will presumably not intervene until MAP is <65 mmHg. As usual, chronic anti-hypertensive medications will be restarted shortly after surgery unless contraindicated by hypotension.
In both groups, other aspects of anesthetic management will be at the discretion of the responsible anesthesiologist, including the types and volumes of various fluids. Volatile or intravenous anesthesia is permitted.
There will be no limitation on ancillary vasoactive, chronotropic, and inotropic drugs. Clinicians will be free to use advanced hemodynamic monitoring (e.g., pulse-wave analysis, esophageal Doppler, etc.). Blood products will be given per routine. Similarly, postoperative analgesic management will be per routine and clinician preference. Neuraxial and peripheral nerve blocks are permitted, but epidural catheters should not be activated until surgery is nearly finished.
Because patients must be fairly sick to qualify for GUARDIAN, some will go to directly from surgery to critical care units, or much less often, become unstable and require transfer from a routine ward to an ICU. In either case, every effort will be to maintain randomized treatments and blood pressure targets.
In all cases, good judgement will predominate. Clinicians should always act in their patients' best interests, irrespective of the GUARDIAN protocol
- Conditions
- General Surgery
- Being tested
- Tight pressure management, Routine pressure management
- Keywords
- Blood pressure, major adverse cardiac events, Delirium, Acute kidney injury
- Medical subject headings
- Cardiovascular Diseases, Delirium, Acute Kidney Injury
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Tight pressure managementOther
Norepinephrine or phenylephrine infusion to maintain intraoperative MAP ≥85 mmHg, delayed resumption of chronic antihypertensive medications, and a target ward MAP ≥80 mmHg (tight pressure management)
Routine pressure managementOther
Routine intraoperative blood pressure management and immediate restart of antihypertensive medications.
| Study group | Role | What they receive |
|---|---|---|
| Tight pressure management | Experimental | Patients assigned to tight blood pressure control angiotensin converting enzyme inhibitors and angiotensin receptor blockers will not be given the morning of surgery. Other chronic antihypertensives will only be given as necessary to treat hypertension. Norepinephrine or phenylephrine infusion will be infused at a rate sufficient to maintain intraoperative MAP ≥ 85 mmHg.
Resumption of chronic anti-hypertensive medications will be delayed until the third postoperative day unless deemed necessary to treat hypertension or for some other clear indication.
The target for postoperative systolic arterial pressures ≥110 mmHg during the initial three postoperative days. Receives: Other: Tight pressure management |
| Routine pressure management | Other | ACEIs, ARBs, and/or calcium channel blockers can be given the morning of surgery if deemed appropriate by the attending anesthesiologist. Intraoperative blood pressure will be managed per clinical routine. As usual, chronic anti-hypertensive medications will be restarted shortly after surgery unless contraindicated by hypotension. Receives: Other: Routine pressure management |
What is being measured
The primary outcome is the main question the study is designed to answer.
Intraoperative blood pressure management
The fraction of time when intraoperative MAP is <65 mmHg and ≥85 mmHg during surgery.
Measured: Intraoperative
Postoperative blood pressure management
Time to restarting routine antihypertensive medications.
Measured: First 3 postoperative days
Secondary outcomes (2)
Intraoperative pressure
Time-weighted mean-arterial pressure
Measured: Intraoperative
Postoperative pressure
Time-weighted systolic pressure
Measured: Initial 3 postoperative days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Mar 2021
- Study start27 Apr 2021
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for General SurgeryStudies of the same condition, open and under way.
- More trials run by The Cleveland ClinicThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Parallel group randomized trial.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- The Cleveland Clinic
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04789733
- Sponsor's protocol ID
- The GUARDIAN pilot trial
- Acronym
- GUARDIAN
- Status last verified
- Mar 2026
- First submitted
- 14 Jan 2021
- Last updated
- 17 Mar 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Li K, Hu Z, Li W, Shah K, Sessler D. Tight perioperative blood pressure management to reduce complications: a randomised feasibility trial. BMJ Open. 2023 Nov 17;13(11):e071328. doi: 10.1136/bmjopen-2022-071328.
PubMed 37977865
Study at a glance
From the registry record, last updated by the sponsor on 17 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Tight Perioperative Blood Pressure Management to Reduce Serious Cardiovascular, Renal, and Cognitive Complications: The GUARDIAN Pilot Trial
- ClinicalTrials.gov ID
- NCT04789733
- Acronym / sponsor ID
- GUARDIAN / The GUARDIAN pilot trial
- Conditions
- General Surgery
- Keywords
- Blood pressure, major adverse cardiac events, Delirium, Acute kidney injury
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- The Cleveland ClinicUniversity, hospital or other
- Study start
- 27 Apr 2021 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 10 Mar 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The treatments will be: 1) norepinephrine or phenylephrine infusion to maintain intraoperative MAP ≥85 mmHg, delayed resumption of chronic antihypertensive medications, and a target ward MAP ≥80 mmHg (tight pressure management); or, 2) routine intraoperative blood pressure management and prompt resumption of chronic antihypertensive medications (routine pressure management).
Detailed description
Consenting patients who take either angiotensin converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), or calcium channel blockers will be asked not to take the medications on the morning of surgery, and instead bring them with them to the hospital. Qualifying patients will be randomized 1:1, with random-sized blocks.
Randomization will be implemented by clinicians in collaboration with research personnel. Arterial catheter transducers will be positioned at the level of the right atrium, and adjusted as necessary if patient position is changed.
The treatments will be: 1) norepinephrine or phenylephrine infusion to maintain intraoperative MAP ≥85 mmHg, delayed resumption of chronic antihypertensive medications, and a target ward MAP ≥80 mmHg (tight pressure management); or, 2) routine intraoperative blood pressure management and prompt resumption of chronic antihypertensive medications (routine pressure management).
Tight pressure management: In patients assigned to tight pressure management, angiotensin converting enzyme inhibitors and angiotensin receptor blockers will not be given the morning of surgery. Other chronic antihypertensives will only be given as necessary to treat hypertension. Clinicians will be encouraged to insert the required arterial catheter before anesthetic induction because much hypotension occurs shortly after anesthetic induction.
A norepinephrine or phenylephrine infusion (in the preferred local concentration) will be prepared, connected to an intravenous catheter, and activated at a low rate. Norepinephrine can be safely given through a central catheter or peripherally.
General anesthesia will be induced with propofol or etomidate which will be given in repeated small boluses or target-controlled infusion in an effort to keep mean arterial pressure ≥85 mmHg. Clinicians will be encouraged to use etomidate when rapid-sequence inductions are required. Simultaneously, the vasopressor infusion will be adjusted with the same goal. Anesthetic dose, fluid administration, and vasopressor administration will be adjusted with the goal of maintaining the individual designated baseline mean arterial pressure. Invasive or non-invasive advanced hemodynamic monitoring is not required, but should be used when practical. Clinicians should use available information to optimize vascular volume, afterload, and inotropy.
Resumption of chronic anti-hypertensive medications will be delayed until the third postoperative day unless deemed necessary to treat hypertension or for some other clear indication (e.g., preventing atrial fibrillation in a chronic beta-blocker user) because >90% of MINS occurs within 48 hours after surgery. When necessary to treat hypertension, chronic antihypertensive or new medications can be used per clinician preference. Clinicians will make what efforts they can to maintain postoperative mean arterial pressures ≥80 mmHg during the initial three postoperative days by maintaining adequate hydration, using inotropic and chronotropic drugs, and vasopressor as necessary. This protocol specifies the blood pressure target but leaves implementation to clinical judgement.
Routine pressure management: In patients assigned to routine pressure management, ACEIs, ARBs, and/or calcium channel blockers can be given the morning of surgery if deemed appropriate by the attending anesthesiologist. The arterial catheter will be inserted before or after induction of anesthesia per clinician preference. General anesthesia will be induced and maintained per routine. Blood pressure will not be deliberately reduced, but per routine clinicians will presumably not intervene until MAP is <65 mmHg. As usual, chronic anti-hypertensive medications will be restarted shortly after surgery unless contraindicated by hypotension.
In both groups, other aspects of anesthetic management will be at the discretion of the responsible anesthesiologist, including the types and volumes of various fluids. Volatile or intravenous anesthesia is permitted.
There will be no limitation on ancillary vasoactive, chronotropic, and inotropic drugs. Clinicians will be free to use advanced hemodynamic monitoring (e.g., pulse-wave analysis, esophageal Doppler, etc.). Blood products will be given per routine. Similarly, postoperative analgesic management will be per routine and clinician preference. Neuraxial and peripheral nerve blocks are permitted, but epidural catheters should not be activated until surgery is nearly finished.
Because patients must be fairly sick to qualify for GUARDIAN, some will go to directly from surgery to critical care units, or much less often, become unstable and require transfer from a routine ward to an ICU. In either case, every effort will be to maintain randomized treatments and blood pressure targets.
In all cases, good judgement will predominate. Clinicians should always act in their patients' best interests, irrespective of the GUARDIAN protocol
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- Parallel group randomized trial.
| Arm | Type | Receives |
|---|---|---|
| Tight pressure management | Experimental | Other: Tight pressure managementPatients assigned to tight blood pressure control angiotensin converting enzyme inhibitors and angiotensin receptor blockers will not be given the morning of surgery. Other chronic antihypertensives will only be given as necessary to treat hypertension. Norepinephrine or phenylephrine infusion will be infused at a rate sufficient to maintain intraoperative MAP ≥ 85 mmHg. Resumption of chronic anti-hypertensive medications will be delayed until the third postoperative day unless deemed necessary to treat hypertension or for some other clear indication. The target for postoperative systolic arterial pressures ≥110 mmHg during the initial three postoperative days. |
| Routine pressure management | Other | Other: Routine pressure managementACEIs, ARBs, and/or calcium channel blockers can be given the morning of surgery if deemed appropriate by the attending anesthesiologist. Intraoperative blood pressure will be managed per clinical routine. As usual, chronic anti-hypertensive medications will be restarted shortly after surgery unless contraindicated by hypotension. |
Who may qualify
- Ages
- 45 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (19 listed)
- ≥45 years old
- Scheduled for major noncardiac surgery expected to last at least 2 hours;
- Having general endotracheal, neuraxial anesthesia, or the combination;
- Expected to require at least overnight hospitalization;
- Are designated ASA physical status 2-4 (ranging from mild systemic disease through severe systemic disease that is a constant threat to life);
Key exclusion criteria (13 listed)
- Are scheduled for carotid artery surgery;
- Are scheduled for intracranial surgery;
- Are scheduled for partial or complete nephrectomy;
- Are scheduled for pheochromocytoma surgery;
- Are scheduled for liver transplantation;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Tight pressure managementNorepinephrine or phenylephrine infusion to maintain intraoperative MAP ≥85 mmHg, delayed resumption of chronic antihypertensive medications, and a target ward MAP ≥80 mmHg (tight pressure management) | Other | Tight pressure management |
| Routine pressure managementRoutine intraoperative blood pressure management and immediate restart of antihypertensive medications. | Other | Routine pressure management |
Primary outcome
Intraoperative blood pressure management
Time frame: Intraoperative
The fraction of time when intraoperative MAP is <65 mmHg and ≥85 mmHg during surgery.
Postoperative blood pressure management
Time frame: First 3 postoperative days
Time to restarting routine antihypertensive medications.
2 secondary outcomes
Intraoperative pressure
Time frame: Intraoperative
Postoperative pressure
Time frame: Initial 3 postoperative days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Mar 2026.
- Derived from this study: PubMed 37977865Li K, Hu Z, Li W, Shah K, Sessler D. Tight perioperative blood pressure management to reduce complications: a randomised feasibility trial. BMJ Open. 2023 Nov 17;13(11):e071328. doi: 10.1136/bmjopen-2022-071328.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Tight pressure management and Routine pressure management in people with General Surgery, run by The Cleveland Clinic at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 19 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 17 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Intraoperative blood pressure management (time frame: Intraoperative). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04789733, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Mar 2026.