Inclusion Criteria:

• Provision of signed and dated informed consent form.
• Stated willingness to comply with all study procedures and availability for the duration of the study.
• Male or female, aged ≥ 18 and ≤ 85 years.
• Admitted with a primary diagnosis of spontaneous, non-traumatic, subarachnoid hemorrhage within 48 hours of ictus hemorrhage.
• Disease-specific inclusion criteria:
  • Aneurysm identified as culprit of SAH;
  • Modified Fisher grade 1-4 (on admission imaging);
  • Hunt and Hess 1-3 or World Federation of Neurosurgeons grade 1-4 (on screening, included only if also fulfilling Glasgow Coma Scale verbal subscore≥ 4);
  • Minimum Glasgow Coma Scale verbal subscore of 4 (on screening).
• 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:
  • Stabilization period criteria:
    • Between 4-48 hours from clipping or coiling procedure (whichever applicable);
    • Successful treatment of culprit vascular lesion (i.e., ≥ 90% obliteration of aneurysm).
  • Requiring a minimum of 15mg OME prn during the 24-hour period immediately prior to enrollment.

Exclusion Criteria:

• 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;
  • 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 o Infected or wounded skin, or a skin lesion at the site of puncture for PPF-injection.
• Uncorrected coagulopathy:
  • platelet count < 50,000/μL, INR > 1.7;
  • requiring use of systemic anticoagulation, ticagrelor or dual antiplatelet therapy.
• 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 angiography (vasospasm defined as: moderate-tosevere arterial narrowing on digital subtraction angiography not attributable to atherosclerosis, catheter-induced spasm, or vessel hypoplasia, as determined by a neuroradiologist or neurointerventionalist).
• Standard pain regimen conditions:
  • Elevation of hepatic enzymes prohibiting use of scheduled acetaminophen (i.e., AST or ALT > 3 x upper limit level);
  • Chronic liver condition with absolute contra-indication for acetaminophen (even at lower maximum daily doses).
• Participation in a concurrent investigational/interventional study (observational studies allowed).
• 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).

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 7/17/2024. Questions regarding updates should be directed to the study team contact.