BLOCK-SAH

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)

Inclusion Criteria:

In order to be eligible to participate in this study, an individual must meet all of the

Following criteria:

1. Provision of signed and dated informed consent form

2. Stated willingness to comply with all study procedures and availability for the duration of the study

3. Male or female, aged ≥18 and ≤ 85 years

4. Admitted with a primary diagnosis of spontaneous, non-traumatic, subarachnoid hemorrhage within 48 hours of ictus hemorrhage

5. Disease-specific inclusion criteria:

   1. Aneurysm identified as culprit of SAH

   2. Modified Fisher grade 1-4 (on admission imaging)

   3. Hunt and Hess 1-3 or World Federation of Neurosurgeons grade 1-4 (on admission, included only if also fulfilling Glasgow Coma Scale verbal subscore≥4)

   4. Minimum Glasgow Coma Scale verbal subscore of 4 (on screening)

6. Able to verbalize pain scale scores according to 11-point numeric pain scale In order to be enrolled and undergo randomization in this study, an individual must

Meet all of the additional criteria:

1. Stabilization period criteria:

   1. A minimum of 4 hours from clipping or coiling procedure (whichever applicable)

   2. Successful treatment of culprit vascular lesion (i.e., ≥90% obliteration of aneurysm)

2. Requiring a minimum of 15mg OME prn for headache analgesia during any 24-hour period during eligibility period

Exclusion Criteria:

An individual who meets any of the following criteria will be excluded from participation

In this study:

1. Premorbid conditions:

   • Pre-existing neurologic, psychiatric, or other condition that would confound neurologic assessment or would make difficult/impossible to accurately assess neurologic and/or functional outcome

   • Pre-existing diffuse flow-limiting narrowing of arteries in the Circle of Willis, regardless of etiology (e.g., atherosclerosis, vasculitis, Moya-Moya syndrome)

   • Prior use of opioid or barbiturate analgesics for at least two-thirds of the days in previous month, regardless of indication

   • Diagnosis of substance use disorder in the previous year

   • Infected or wounded skin, or a skin lesion at the site of puncture for PPF-injection

2. Uncorrected coagulopathy

   • Platelet count < 50,000/μL, International Normalized Ratio (INR) > 1.7

   • Requiring use of systemic anticoagulation and antiplatelet therapy (except for aspirin monotherapy).

3. SAH-specific:

   • Head trauma as etiology of SAH

   • Infection as cause for aneurysm or SAH (i.e., mycotic aneurysms)

   • Inability to successfully treat culprit vascular lesion

   • Diffuse vasospasm on initial diagnostic CTA or digital subtraction angiography (DSA). Vasospasm is defined as moderate-to-severe arterial narrowing on DSA or CTA not attributable to atherosclerosis, catheter-induced spasm, or vessel hypoplasia, as determined by a neuroradiologist or neurointerventionalist

4. Standard pain regimen conditions

   • Elevation of hepatic enzymes prohibiting use of scheduled acetaminophen (i.e., AST or ALT > 3x upper limit level)

   • Chronic liver condition with absolute contra-indication for acetaminophen (even at lower maximum daily doses)

5. Participation in a concurrent investigational/interventional study (observational studies allowed)

6. Known to be pregnant, or with a positive pregnancy test

7. Allergy or intolerance to the medications used in the PPF-block (i.e., ropivacaine, dexamethasone) or standard pain regimen (acetaminophen)

8. Vulnerable populations such as, prisoners and inmates (abiding GCP per the study IRB)

9. Unable to receive first PPF-injection within 96 hours of ictus hemorrhage