Limb Occlusion Pressure Tourniquets for Surgery Recovery

(LOP Trial)

Overseen By Haley Goble, MHA

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: The Methodist Hospital Research Institute

Must not be taking: Prescription pain medications

Disqualifiers: Fistulas, PVD, Prior trauma, others

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

Compensation: Varies

Number of Visits: 5

400 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether Limb Occlusion Pressure (LOP), a lower tourniquet pressure based on a patient's blood pressure, can reduce pain and the need for opioids after orthopedic surgery. Standard tourniquet pressures often cause side effects such as muscle weakness and pain. Participants will be divided into two groups: one using traditional tourniquet pressure and the other using the experimental LOP, a new potential method for applying tourniquets. The trial seeks healthy adults undergoing specific surgeries, such as carpal tunnel release or knee replacement, who are not on chronic pain medications. As an unphased trial, it offers participants the chance to contribute to innovative research that could enhance surgical recovery.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but if you are on prescription pain medications for chronic conditions, you may not be eligible to participate.

What prior data suggests that this technique is safe for surgery recovery?

Research has shown that Limb Occlusion Pressure (LOP) tourniquets are generally safe for surgeries. Unlike standard tourniquets, which use high pressure, LOP adjusts based on a patient's blood pressure, with a small safety margin added. This adjustment usually results in much lower pressure.

Studies have found that LOP reduces the need for high pressures, which can cause side effects like muscle weakness and pain after surgery. By using lower pressure, LOP helps prevent these issues.

Previous research has demonstrated that LOP decreases the risk of side effects. It is designed to stop blood flow with the least pressure needed, making it a safer choice for patients. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the limb occlusion pressure technique because it offers a potentially safer and more comfortable alternative to the standard pneumatic tourniquet pressure used during surgeries. Unlike conventional methods that apply higher pressure, this approach uses a precisely controlled lower pressure, reducing the risk of tissue damage and discomfort. By fine-tuning the pressure based on the limb's specific needs, this method aims to improve recovery outcomes and enhance patient safety.

What evidence suggests that using limb occlusion pressure is effective for reducing post-operative pain?

This trial will compare Limb Occlusion Pressure (LOP) tourniquets with standard pneumatic tourniquet pressure during surgery. Research has shown that LOP can reduce pain and complications after surgery compared to higher pressures. Specifically, studies have found that LOP results in less pain and better outcomes by using lower pressure tailored to each patient's blood pressure, with a small safety margin. This method decreases discomfort during surgeries and improves the surgical area. Additionally, LOP is associated with fewer side effects, such as muscle weakness, and reduces the need for painkillers after surgery. These findings suggest that LOP effectively improves recovery after orthopedic surgeries. ^{1 2 3 4 6}

Who Is on the Research Team?

Patrick McCulloch, MD

Principal Investigator

The Methodist Hospital Research Institute

Are You a Good Fit for This Trial?

This trial is for healthy adults over 18 who are having certain orthopedic surgeries like knee replacements or carpal tunnel release. It's not for those on long-term pain meds, with past trauma/surgery in the limb to be operated on, or with blood vessel issues that prevent tourniquet use.

Exclusion Criteria

I have been on prescription pain medication for a chronic condition for more than 6 weeks.

Patients who cannot use a tourniquet (e.g. certain patients with fistulas or PVD, certain patients with Peripheral Vascular Disease)

I have had surgery or an injury to the limb being examined.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

1 visit (in-person)

Pre-operative

Consent obtained and baseline questionnaires completed during a pre-operative office visit

1 day

1 visit (in-person)

Surgery

Participants undergo orthopedic surgery with either standard or limb occlusion pressure tourniquet

1 day

1 visit (in-person)

Post-operative Monitoring

Participants keep a daily pain and opioid consumption diary for two weeks after surgery

2 weeks

Daily self-reporting

Follow-up

Participants complete outcome questionnaires to assess recovery and outcomes

8 weeks

2 visits (in-person or virtual)

What Are the Treatments Tested in This Trial?

Interventions

• Experimental - Limb Occlusion pressure

Trial Overview The study tests if using Limb Occlusion Pressure (LOP), which is lower than standard tourniquet pressure and based on patient's blood pressure, can reduce post-surgery pain and opioid need, potentially improving recovery outcomes.

How Is the Trial Designed?

Group I: Experimental - Limb occlusion pressure Experimental Treatment 1 Intervention

This group receives a slightly lower tourniquet pressure than they would during standard of care. This lowered limb occlusion pressure is determined by the tourniquet device.

Group II: Control - Standard pneumatic tourniquet pressure Active Control 1 Intervention

This group receives the standard pneumatic tourniquet pressure during surgery like they would during standard of care.

Who Is Running the Clinical Trial?

The Methodist Hospital Research Institute

Lead Sponsor

Trials

299

Recruited

82,500+

Published Research Related to This Trial

In a study of 44 patients undergoing orthopedic hand/wrist surgery, using limb occlusion pressure (LOP) instead of standard tourniquet pressure (STP) significantly reduced post-operative pain medication usage by 50% in the first week.

Patients in the LOP group experienced 80% less pain at the tourniquet site compared to those in the STP group, while both groups reported similar pain levels at the surgical site.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Limb Occlusion Pressure Versus Standard Pneumatic Tourniquet Pressure in Open Carpal Tunnel Surgery - A Randomized Trial. Morehouse, H., Goble, HM., Lambert, BS., et al.[2022]

The arterial occlusion pressure (AOP) estimation method effectively sets tourniquet inflation pressures in lower limb surgeries, resulting in excellent or good performance in 97.76% of cases across 198 operations involving 224 lower extremities.

Using the AOP method allowed for lower tourniquet pressures (average 173.3 mmHg) than previously recommended, while still achieving a bloodless surgical field, and no complications were reported during or after the procedures.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical utilization of arterial occlusion pressure estimation method in lower limb surgery: effectiveness of tourniquet pressures. Tuncalı, B., Boya, H., Kayhan, Z., et al.[2018]

Using the limb-occlusion-pressure (LOP) method significantly lowered the tourniquet cuff pressure during total knee arthroplasty compared to the standard method, which could help reduce the risk of complications.

While there were no significant differences in postoperative pain or complications between the LOP and control groups, patients with a cuff pressure of 225 mm Hg or lower experienced no infections and fewer wound complications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Lower tourniquet cuff pressure reduces postoperative wound complications after total knee arthroplasty: a randomized controlled study of 164 patients. Olivecrona, C., Ponzer, S., Hamberg, P., et al.[2022]

In a study of 115 patients undergoing upper limb surgeries, using an arterial occlusion pressure estimation method for setting tourniquet pressure resulted in effective bloodless surgical fields, with 100% effectiveness reported by the surgical team at the end of procedures.

This method allowed for lower tourniquet pressures (mean maximum of 175.5 mmHg) without any observed complications, suggesting it is a safe and practical approach for minimizing pressure-related issues during surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy of arterial occlusion pressure estimation-based tourniquet pressure settings in upper limb surgery. Tuncali, B., Kokten, G., Boya, H., et al.[2022]

Tourniquet use during extremity surgery is generally safe, but requires careful assessment of patient history and understanding of risks to prevent complications.

Knowledge of the physiological effects of tourniquets, including their impact on skin, vascular health, and postoperative pain, is essential for improving surgical outcomes and ensuring safe perioperative care.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Understanding and Optimizing Tourniquet Use During Extremity Surgery. Jensen, J., Hicks, RW., Labovitz, J.[2020]

In a study of 244 patients undergoing foot and ankle surgery, an automated tourniquet system that measured limb occlusion pressure (LOP) resulted in significantly lower tourniquet pressures (198.5 mmHg) compared to the control group (259.6 mmHg), indicating a more efficient method for setting pressure.

The use of LOP measurement not only reduced the required tourniquet pressure but also improved the quality of the surgical field, suggesting that this method could enhance surgical outcomes while minimizing potential complications associated with higher pressures.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Automated cuff occlusion pressure effect on quality of operative fields in foot and ankle surgery: a randomized prospective study. Younger, AS., Manzary, M., Wing, KJ., et al.[2014]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10386602/

Limb occlusion pressure versus standard tourniquet ... The RTP significantly reduced tourniquet related pain and discomfort during minor hand surgeries. It provided better motionless operative field and adequate ...

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11943322/

A Systematic Review and Meta-Analysis of Tourniquet ... The primary outcome was the adequacy and quality of the bloodless field achieved at lower tourniquet occlusion pressures. The limb occlusion ...

3. withpower.com withpower.com/trial/phase-3-2018-2b8d6

Limb Occlusion Pressure Tourniquets for Surgery Recovery Research shows that using limb occlusion pressure (LOP) to set tourniquet pressures can reduce postoperative pain and complications compared to standard ...

4. clinicaltrials.gov clinicaltrials.gov/study/NCT04390425

Limb Occlusion Pressure Tourniquets to Decrease Pain ... High tourniquet pressure had been associated with adverse side effects such as ischemia, muscle weakness, and post operative pain. Limb Occlusion Pressure, LOP, ...

5. sciencedirect.com sciencedirect.com/science/article/pii/S2666061X2500032X

Perioperative Arthroscopic Tourniquet Usage: Practices ... Among the 58% of surgeons who do apply such techniques, 62% rely on blood pressure and 48% rely on the limb circumference size to determine their desired ...

6. frontiersin.org frontiersin.org/journals/surgery/articles/10.3389/fsurg.2023.1104603/full

Optimization of surgical tourniquet usage to improve ... Personalized tourniquet pressure based upon LOP is typically substantially lower than standard tourniquet pressures currently used, which can reduce the risks ...