What pain medications can be given to a patient with a subarachnoid hemorrhage?

Pain Management in Subarachnoid Hemorrhage

For patients with subarachnoid hemorrhage, use acetaminophen (paracetamol) as first-line analgesia, with cautious addition of opioids (morphine or gabapentin) when needed, while strictly avoiding NSAIDs due to bleeding risk.

First-Line Analgesic Approach

Acetaminophen (Paracetamol) is the safest initial choice:

• Dose: 500-1000 mg every 6 hours 1, 2
• Maximum daily dose: 4000 mg 3
• No antiplatelet effects or bleeding risk 3
• Hepatotoxicity is the primary concern at excessive doses 3

Second-Line Options for Moderate to Severe Pain

Opioids remain the standard for severe SAH headache despite concerns:

• Morphine is the most commonly used opioid in SAH patients 2
• Start with low doses and titrate to effect 3
• Subcutaneous or intravenous routes are preferred over intramuscular 3, 2
• Patient-controlled analgesia (PCA) can be considered for appropriate patients 2

Important caveat: Many centers (37%) express reluctance to use opioids in SAH due to concerns about masking neurological examination and causing sedation 2. However, untreated severe pain can worsen outcomes through hypertension and patient distress.

Emerging Alternative: Gabapentin

Gabapentin shows promise as a narcotic-sparing agent:

• Dosing: Start 300 mg three times daily, rapidly escalate to 900-1200 mg three times daily 4, 5
• Well-tolerated with only 6% experiencing nausea and 1.8% requiring discontinuation 5
• May reduce opioid requirements, though evidence is limited to small studies 4, 5
• Particularly useful for persistent post-SAH headache with neuropathic features 4

Critical Medications to AVOID

NSAIDs are contraindicated in acute SAH:

• 75% of neurosurgical centers avoid NSAIDs in SAH patients 2
• Risk of bleeding complications outweighs analgesic benefit 3
• This includes ibuprofen, ketorolac, diclofenac, and aspirin 3

Pain Assessment Strategy

Use validated pain scales consistently:

• Numeric rating scales (0-10) or visual analog scales for conscious patients 3, 4
• For comatose or sedated patients, use behavioral pain scales 2
• Reassess pain intensity regularly, especially after interventions 3

Blood Pressure Management During Pain Control

Balance analgesia with hemodynamic goals:

• Maintain systolic blood pressure <160 mmHg to prevent rebleeding 3, 1
• Adequate pain control helps achieve blood pressure targets 1
• Use titratable antihypertensive agents (nicardipine, labetalol) alongside analgesics 3

Common Pitfalls to Avoid

• Over-sedation masking neurological deterioration: Use the minimum effective opioid dose and consider gabapentin as adjunct 2, 5
• Inadequate pain assessment in obtunded patients: Many centers fail to assess pain in comatose SAH patients; use behavioral scales 2
• NSAID use: Despite their efficacy for headache, the bleeding risk is unacceptable in acute SAH 2
• Delayed analgesia: Pain should be managed during diagnostic evaluation, not after 3

Practical Algorithm

1. Immediate: Acetaminophen 1000 mg IV/PO every 6 hours 1, 2
2. If pain persists (NRS >4): Add morphine 2-4 mg IV every 2-4 hours as needed, or consider PCA 2
3. For persistent headache beyond 48 hours: Add gabapentin 300 mg TID, escalate to 900-1200 mg TID over 3-5 days 4, 5
4. Avoid: All NSAIDs, aspirin, and antiplatelet agents until aneurysm is secured 2
5. Monitor: Pain scores every 4 hours, neurological examination, blood pressure 3, 1