Permissive Hypotension for Surgery

(PHACS Trial)

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Massachusetts General Hospital

Disqualifiers: Severe shock, Renal dysfunction, Cirrhosis, Stroke, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

Duration: 2 to 3 days

80 Participants Needed

Trial Summary

What is the purpose of this trial?

The objective of this pilot randomized controlled trial is to demonstrate the feasibility of implementing a pragmatic clinical trial randomizing patients to permissive hypotension versus usual care and to determine the impact of permissive hypotension on vasopressor exposure, ICU length of stay, markers of end organ perfusion, and clinically relevant patient outcomes. The data collected from this pilot study will be used as preliminary data for study design and grant applications for a larger multicenter randomized controlled trial.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment Permissive Hypotension for Surgery?

A study on individualized blood pressure management during major abdominal surgery showed that patients who had their blood pressure carefully managed experienced fewer negative outcomes after surgery compared to those who received standard care. This suggests that managing blood pressure, including allowing it to be lower in a controlled way, can be beneficial during surgery. ^{1 2 3 4 5}

Is permissive hypotension generally safe for humans?

Research shows that managing blood pressure during surgery can reduce complications, but lowering blood pressure too much may lead to negative outcomes like stroke. It's important to carefully control blood pressure to avoid these risks. ^{4 6 7 8 9}

How is the treatment Permissive Hypotension Therapy different from other treatments for managing blood pressure during surgery?

Permissive Hypotension Therapy is unique because it deliberately lowers blood pressure during surgery to reduce blood loss and improve surgical conditions, unlike standard treatments that aim to maintain normal blood pressure levels. This approach requires careful monitoring to ensure vital organs receive enough blood flow, making it different from typical blood pressure management strategies. ^{2 7 8 10 11}

Eligibility Criteria

This trial is for patients who have low blood pressure following cardiac surgery. The study aims to include individuals who can safely participate in a comparison of permissive hypotension versus usual care post-surgery.

Inclusion Criteria

I am scheduled for a planned heart surgery.

Exclusion Criteria

Rapidly increasing pressors within 60 mins of arrival

I was admitted to the ICU in severe shock needing high doses of specific heart medications.

I have a brain condition that requires controlling my blood pressure.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

1 day

1 visit (in-person)

Treatment

Participants are randomized to either permissive hypotension or usual care, with monitoring of hemodynamics and vasopressor use

2 to 3 days

Continuous monitoring in ICU

Follow-up

Participants are monitored for safety and effectiveness after treatment, including cognitive assessment and survival to hospital discharge

1 week

Daily assessments in hospital

Treatment Details

Interventions

• Permissive Hypotension

Trial Overview The trial is testing the approach of allowing lower than normal blood pressure (permissive hypotension) after heart surgery, compared to the standard treatment. It will look at how this affects the need for drugs that raise blood pressure, ICU stay duration, organ function, and overall patient outcomes.

Participant Groups

Group I: Permissive hypotension Intervention Experimental Treatment 1 Intervention

In addition to the regular care provided to cardiac surgery patients, those in the permissive hypotension intervention arm will have a MAP target \> 60mmHg.

Group II: Standard of Care Active Control 1 Intervention

Patients randomized to the standard of care arm will receive the regular care provided to cardiac surgery patients.

Who Is Running the Clinical Trial?

Massachusetts General Hospital

Lead Sponsor

Trials

3,066

Recruited

13,430,000+

Findings from Research

Perioperative hypertension is common and requires careful management by anaesthetists to make informed decisions about antihypertensive therapy and surgical risk assessment.

Management strategies must consider the potential impacts of left ventricular diastolic dysfunction and reduced coronary reserve on patient outcomes during surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Perioperative hypertension: new strategies for management. Skarvan, K.[2019]

Intra-arterial blood pressure monitoring in 4342 patients undergoing noncardiac surgery was associated with a higher incidence of peri-operative myocardial injury (38.7%) compared to noninvasive monitoring (25.7%), indicating a potential increased risk of morbidity.

Even after adjusting for various patient and surgical factors, intra-arterial monitoring remained linked to a greater risk of myocardial injury, suggesting that this method may not improve outcomes and could warrant further investigation in future studies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mode of blood pressure monitoring and morbidity after noncardiac surgery: A prospective multicentre observational cohort study. Abbott, TEF., Howell, S., Pearse, RM., et al.[2023]

Continuing antihypertensive therapy up to the date of surgery significantly reduces perioperative risks for patients with hypertension, highlighting the importance of managing blood pressure before and during surgical procedures.

Effective collaboration among internists, surgeons, and anesthesiologists is crucial for safely managing hypertensive patients during operations, ensuring careful selection of anesthetics and continuous patient monitoring.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Hypertension and surgical risk]. Hoffmann, D.[2007]

An automated closed-loop vasopressor administration device successfully maintained mean arterial pressure (MAP) within 5 mmHg of the target 80 mmHg for 98% of the intraoperative period in a swine model of induced hypotension.

This study demonstrates that norepinephrine can be accurately titrated using this automated system, suggesting a potential for improved management of intraoperative hypotension and reduced risk of postoperative complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Automated Titration of Vasopressor Infusion Using a Closed-loop Controller: In Vivo Feasibility Study Using a Swine Model. Joosten, A., Delaporte, A., Alexander, B., et al.[2020]

Effective management of perioperative hypertension is crucial as it significantly reduces the risk of serious complications such as stroke, acute coronary syndrome, and renal dysfunction, which can lead to increased morbidity and mortality.

Continuing chronic antihypertensive medications during the perioperative period has been shown to improve patient outcomes, highlighting the importance of maintaining blood pressure control before, during, and after surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Isolated perioperative hypertension: clinical implications & contemporary treatment strategies. Dodson, GM., Bentley, WE., Awad, A., et al.[2019]

A new preoperative risk model called the HEART score was developed to predict intraoperative hypotension or bradycardia in patients undergoing elective noncardiac surgery, based on data from 193 patients.

The HEART score, which includes factors like preoperative heart rate, hypotension, age, medication use, and type of surgery, was found to be moderately predictive of these adverse events, helping to better stratify patient risk and guide perioperative management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Predictors of intraoperative hypotension and bradycardia. Cheung, CC., Martyn, A., Campbell, N., et al.[2022]

Deliberate reduction of blood pressure during surgery has been controversial for 30 years, with many studies lacking rigorous control standards.

The article reviews the impact of blood pressure reduction on organ perfusion and provides recommendations on the safe application and limitations of this technique based on the summarized results.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Deliberate hypotension in head and neck surgery. Ward, CF., Alfery, DD., Saidman, LJ., et al.[2019]

In a meta-analysis of 10 randomized trials involving 9359 patients, permissive management of intraoperative blood pressure (mean arterial pressure ≤60 mm Hg) did not increase mortality compared to targeted management (mean arterial pressure >60 mm Hg).

Permissive blood pressure management was associated with a lower incidence of atrial fibrillation and a shorter length of hospital stay, suggesting potential benefits beyond mortality rates.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intraoperative hypotension and postoperative outcomes: a meta-analysis of randomised trials. D'Amico, F., Fominskiy, EV., Turi, S., et al.[2023]

Tight blood pressure control during major non-cardiac surgery significantly increased the mean arterial pressure (MAP) above 85 mm Hg and reduced instances of hypotension compared to routine management, indicating a potential safety benefit.

Delaying the restart of chronic antihypertensive medications until the third postoperative day did not adversely affect postoperative systolic blood pressure, suggesting that this approach may be safe and feasible in the context of tight blood pressure management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Tight perioperative blood pressure management to reduce complications: a randomised feasibility trial. Li, K., Hu, Z., Li, W., et al.[2023]

Deliberate hypotension can effectively reduce blood loss during surgery and improve the surgical field, but it must be carefully managed to avoid risks of inadequate blood flow to vital organs, especially in patients with a history of hypertension.

For most patients, maintaining systolic arterial pressure above 80 torr is safe during induced hypotension, while careful monitoring of vital signs and blood gases is crucial to ensure patient safety and successful outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Deliberate hypotension. Ewards, MW., Flemming, DC.[2019]

Perioperative hypertension is common and can lead to serious complications like infarctions and strokes if not treated, but aggressive treatment is generally not necessary as most cases are hypertensive urgencies rather than emergencies.

For managing hypotension during surgery, the recommended approach includes reducing anesthesia depth, administering intravenous fluids, and using vasopressors like ephedrine or phenylephrine when mean arterial pressure drops below 60 mm Hg.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cardiovascular anesthetic complications and treatment in oral surgery. Adlesic, EC.[2013]

References

1. United States pubmed.ncbi.nlm.nih.gov

Perioperative hypertension: new strategies for management. [2019]

2. England pubmed.ncbi.nlm.nih.gov

Mode of blood pressure monitoring and morbidity after noncardiac surgery: A prospective multicentre observational cohort study. [2023]

3. Germany pubmed.ncbi.nlm.nih.gov

[Hypertension and surgical risk]. [2007]

4. United States pubmed.ncbi.nlm.nih.gov

Automated Titration of Vasopressor Infusion Using a Closed-loop Controller: In Vivo Feasibility Study Using a Swine Model. [2020]

5. United Arab Emirates pubmed.ncbi.nlm.nih.gov

Isolated perioperative hypertension: clinical implications & contemporary treatment strategies. [2019]

6. United States pubmed.ncbi.nlm.nih.gov

Predictors of intraoperative hypotension and bradycardia. [2022]

7. United States pubmed.ncbi.nlm.nih.gov

Deliberate hypotension in head and neck surgery. [2019]

8. England pubmed.ncbi.nlm.nih.gov

Intraoperative hypotension and postoperative outcomes: a meta-analysis of randomised trials. [2023]

9. England pubmed.ncbi.nlm.nih.gov

Tight perioperative blood pressure management to reduce complications: a randomised feasibility trial. [2023]

10. United States pubmed.ncbi.nlm.nih.gov

Deliberate hypotension. [2019]

11. United States pubmed.ncbi.nlm.nih.gov

Cardiovascular anesthetic complications and treatment in oral surgery. [2013]