06/07/2025
# # # 🚨 Subarachnoid Haemorrhage (SAH) in the ED: Know What You're Handling 🚨
We often come across patients with **suspected SAH**, but how much do we *actually* know about the condition? Understanding the pathophysiology, diagnostic timelines, and early interventions makes a significant difference—not just for the referral process, but for the patient’s outcome.
Let’s unpack this.
---
# # # 📊 **Epidemiology & The Big Picture**
* **SAH** accounts for \~5% of all strokes, yet it carries **high morbidity and mortality**.
* Majority (\~85%) are due to **ruptured intracranial aneurysms**.
* Peak incidence: **40–60 years**, slightly more common in females.
* Mortality remains high (35–50%), and nearly half of patients die before reaching hospital.
---
# # # 💥 **Ruptured vs Unruptured Aneurysms**
* **Ruptured Aneurysms:**
* Present with a **sudden, severe headache**—described as a "thunderclap" (reaches maximal intensity in 7 mm, posterior circulation location, and family history increase rupture risk.
---
# # # 🧠 **Diagnosis Pathway**
1. **CT Head – Non-contrast**
* Sensitivity highest if done within **6 hours** of headache onset (\~98–100%).
* Sensitivity falls significantly after that—down to \~85% at 12 hours.
2. **Lumbar Puncture**
* If CT is negative but clinical suspicion remains, **LP is warranted**.
* Best performed **≥12 hours after symptom onset** to detect **xanthochromia** (bilirubin breakdown from haemoglobin).
* Remains valid and can detect xanthochromia for up to **2 weeks post-onset**.
* Spectrophotometry is the gold standard; avoid relying on visual inspection alone.
---
# # # 🛏️ **Initial ED Management – Suspected or Confirmed SAH**
While waiting for neurosurgical advice, early interventions matter.
# # # # ✅ **If Suspected SAH (prior to CT or LP):**
* Document the working diagnosis and differential clearly.
* Prescribe **laxatives** to prevent straining.
Encourage fluid po intake
* Analgesia
# # # # ✅ **If CT Confirms SAH:**
* **BP monitoring is critical** – both hypotension and surges are harmful.
* Target:
* **SBP 90 mmHg**
* Avoid dips in MAP to ensure adequate cerebral perfusion.
* If needed, use **metaraminol peripherally** to maintain MAP.
* **Maintain euvolaemia**:
* Aim for isotonic fluid at **125 ml/hour** (Plasmalyte or Hartmann’s – local protocol dependent).
* Start **Nimodipine 60 mg orally/NG every 4 hours** (or IV if NBM) to reduce delayed cerebral ischemia.
* Keep patient **strictly flat**, encourage **bed rest**.
* **CTA ** should be arranged urgently to identify the aneurysm.
---
# # # 🧬 **Grading Systems in NS Communication**
You’ll often see references to SAH grading in neurosurgical feedback—here’s what they mean:
1. **WFNS Grade** – Based on **GCS and motor deficits**, ranges from Grade I (mild) to Grade V (coma). Used for prognosis and triaging urgency.
2. **Fisher Grade** – CT-based grading reflecting the **volume and distribution of blood**. Higher grades indicate higher vasospasm risk.
