Nerve Block for Subarachnoid Hemorrhage

(BLOCK-SAH Trial)

Recruiting at 11 trial locations

Overseen By Ralisa Pop

Age: 18+

Sex: Any

Trial Phase: Phase 2

Sponsor: University of Florida

Must be taking: Opioids

Must not be taking: Opioids, Barbiturates, Anticoagulants, Antiplatelets

Disqualifiers: Neurologic, Psychiatric, Substance use, others

Prior Safety Data This treatment has passed at least one previous human trial

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 2

195 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

BLOCK-SAH is a phase II, multicenter, randomized, double-blinded, placebo-controlled clinical trial with a sequential parallel comparison design (SPCD) of bilateral pterygopalatine fossa (PPF) injections with 20mg ropivacaine + 4mg dexamethasone (active, PPF-block) compared to saline (placebo) for headache in survivors of aneurysmal subarachnoid hemorrhage (SAH), while monitoring intracranial arterial mean flow velocities with transcranial Doppler (TCD) peri-intervention (intervention = PPF-injections: active or placebo)

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

The trial does not specify if you need to stop your current medications, but it excludes those requiring systemic anticoagulation and antiplatelet therapy (except aspirin) and those with prior opioid or barbiturate use. It's best to discuss your specific medications with the trial team.

Is the pterygopalatine fossa nerve block generally safe for humans?

Research suggests that pterygopalatine fossa nerve blocks, especially when guided by ultrasound, are generally considered safe, though there is a risk of injury to nearby structures like the maxillary artery, which could lead to complications such as bleeding. ^{1 2 3 4 5}

How is the Pterygopalatine Fossa Nerve Block with Ropivacaine and Dexamethasone treatment different from other treatments for subarachnoid hemorrhage?

This treatment is unique because it involves a nerve block (a procedure to block pain signals) in the pterygopalatine fossa, which is a specific area in the skull, using a combination of ropivacaine (a local anesthetic) and dexamethasone (a steroid to reduce inflammation). It is administered via an ultrasound-guided approach, which is considered safe and precise, and is different from standard treatments that may not target this specific area or use this combination of drugs. ^{1 3 4 5 6}

What data supports the effectiveness of the treatment Pterygopalatine Fossa Nerve Block with Ropivacaine and Dexamethasone for subarachnoid hemorrhage?

The research indicates that nerve blocks in the pterygopalatine fossa are used for managing pain in facial surgeries and headaches, suggesting potential effectiveness in pain management. However, specific data on its use for subarachnoid hemorrhage is not provided. ^{1 3 4 5 6}

Are You a Good Fit for This Trial?

This trial is for adults aged 18-85 who've had a non-traumatic subarachnoid hemorrhage (SAH) from a brain aneurysm within the past 48 hours. They must be able to communicate pain levels, have certain scores on neurological scales, and consent to all study procedures.

Inclusion Criteria

Provision of signed and dated informed consent form

My aneurysm caused a type of stroke known as SAH.

Modified Fisher grade 1-4 (on admission imaging)

Exclusion Criteria

I cannot take acetaminophen due to a chronic liver condition.

Known to be pregnant, or with a positive pregnancy test

I am allergic or intolerant to ropivacaine, dexamethasone, or acetaminophen.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Double-Blinded Treatment

Participants receive bilateral pterygopalatine fossa (PPF) injections with either active PPF-block or placebo, monitored with transcranial Doppler (TCD)

48 hours

2 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment, including incidence of radiographic vasospasm

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Placebo Pteryogpalatine Fossa Injection
• Pterygopalatine Fossa Nerve Block with Ropivacaine and Dexamethasone

Trial Overview The BLOCK-SAH trial tests if injections in the pterygopalatine fossa with ropivacaine and dexamethasone can reduce headache after SAH compared to saline placebo. It's double-blinded, meaning neither participants nor researchers know who gets which treatment.

How Is the Trial Designed?

Group I: Group 2 - Placebo - Active Experimental Treatment 2 Interventions

Subjects randomized to Group 2 will receive a placebo PPF-injection in Stage 1 followed by an active PPF nerve block in Stage 2 of the Double-Blinded Trial Phase

Group II: Group 1 - Active - Active Active Control 1 Intervention

Subjects randomized to Group 1 will receive an active PPF nerve block in Stage 1 followed by an active PPF nerve block in Stage 2 of the Double-Blinded Trial Phase

Group III: Group 3 - Placebo - Placebo Placebo Group 1 Intervention

Subjects randomized to Group 3 will receive a placebo PPF-injection in Stage 1 followed by a placebo PPF-injection in Stage 2 of the Double-Blinded Trial Phase

Pterygopalatine Fossa Nerve Block with Ropivacaine and Dexamethasone is already approved in United States for the following indications:

Approved in United States as PPF Block for:

• Post-SAH Headache

Who Is Running the Clinical Trial?

University of Florida

Lead Sponsor

Trials

1,428

Recruited

987,000+

National Institute of Neurological Disorders and Stroke (NINDS)

Collaborator

Trials

1,403

Recruited

655,000+

New York University

Collaborator

Trials

249

Recruited

229,000+

Massachusetts General Hospital

Collaborator

Trials

3,066

Recruited

13,430,000+

Published Research Related to This Trial

In a study of 833 pterygopalatine fossa nerve blocks (PPFBs) performed on 411 adults, only minor oozing at the injection site was reported as a side effect, indicating a high safety profile for this ultrasound-guided technique.

Although there were significant changes in systolic blood pressure, heart rate, and oxygen saturation before and after the procedure, no clinically significant adverse effects were identified, suggesting that PPFBs are a safe and effective pain management option.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ultrasound-Guided Suprazygomatic Nerve Blocks to the Pterygopalatine Fossa: A Safe Procedure. Smith, CR., Dickinson, KJ., Carrazana, G., et al.[2023]

The suprazygomatic approach for injecting local anesthetics into the pterygopalatine fossa was found to be the safest option, with a 100% safety rate, although it was not always feasible, being successful in 96.5% of cases.

In contrast, the anterior infrazygomatic approach, while always feasible, posed the highest risk of maxillary artery puncture at 14.7%, making it the least safe option among the approaches studied.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the feasibility and safety of infrazygomatic and suprazygomatic approaches to pterygopalatine fossa using virtual reality. Jerman, A., Umek, N., Cvetko, E., et al.[2023]

In a study of 16 patients undergoing radical maxillary sinusotomy, those who received a continuous maxillary nerve block required significantly less sevoflurane during surgery compared to those who did not receive the block.

Patients with the maxillary nerve block also consumed significantly less diclofenac sodium for pain relief after surgery, indicating effective postoperative analgesia from this technique.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A new method of continuous maxillary nerve block with an indwelling catheter. Kohase, H., Miyamoto, T., Umino, M.[2019]

In a study of 90 pediatric patients aged 0 to 18 years, it was found that the distance from the suprazygomatic skin to the foramen rotundum increases significantly with age, indicating that older children require deeper needle insertion for the suprazygomatic maxillary nerve block.

Despite the increased depth needed for older patients, the angles of needle re-orientation for accessing the pterygopalatine fossa remain clinically similar across age groups, varying by only up to 3 degrees, which suggests that the technique can be consistently applied regardless of age.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of age on the anatomy of the pediatric pterygopalatine fossa and its relationship to the suprazygomatic maxillary nerve block. Marston, AP., Merritt, G., Morris, JM., et al.[2018]

A study analyzing 61 CT angiographies found that using a 35-mm needle for maxillary nerve block has a high probability (79%) of successfully reaching the inferior orbital fissure, while maintaining a low risk of serious complications, such as skull base injury (2%) and optical nerve damage (0%).

The anatomical measurements indicated that distances from the puncture point to key landmarks (like the optic canal and foramen rotundum) increase with patient height, suggesting that individual anatomical variations should be considered when performing maxillary nerve blocks.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Anatomical landmarks for maxillary nerve block in the pterygopalatine fossa: A radiological study. Carrier, S., Castagneyrol, B., Beylacq, L., et al.[2019]

A previously unidentified nerve was discovered between the pterygopalatine ganglion (PPG) and the ophthalmic nerve in all five human cadaver specimens studied, which may explain the unexpected pain relief observed after PPG blockage.

The presence of nitric oxide synthase (NOS)-containing nerve fibers suggests that this nerve likely contains sensory fibers, providing a potential anatomical basis for the broader pain relief experienced in the ophthalmic area following PPG interventions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A previously undescribed branch of the pterygopalatine ganglion. Oomen, KP., Ebbeling, M., de Ru, JA., et al.[2013]

Citations

1. England pubmed.ncbi.nlm.nih.gov

Ultrasound-Guided Suprazygomatic Nerve Blocks to the Pterygopalatine Fossa: A Safe Procedure. [2023]

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

Comparison of the feasibility and safety of infrazygomatic and suprazygomatic approaches to pterygopalatine fossa using virtual reality. [2023]

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

A new method of continuous maxillary nerve block with an indwelling catheter. [2019]

4. Ireland pubmed.ncbi.nlm.nih.gov

Impact of age on the anatomy of the pediatric pterygopalatine fossa and its relationship to the suprazygomatic maxillary nerve block. [2018]

5. France pubmed.ncbi.nlm.nih.gov

Anatomical landmarks for maxillary nerve block in the pterygopalatine fossa: A radiological study. [2019]

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

A previously undescribed branch of the pterygopalatine ganglion. [2013]