subarachnoid hemorrhage
Bleeding into the subarachnoid space, where the cerebrospinal fluid circulates.
SAH pathophysiology
Most often arise at the bifurcation of the major arteries in the circle of Willis --aka Berry aneurysms -- 2% of the population has them
Conditions that predispose someone to SAH
- PCKD- HTN- Smoking- Ehlers-Danlos Syndrome- Neurofibromatosis Type 1
subarachnoid hemorrhage S/S
1. HA (often described as the worse HA of their life)2. LOC (about 40% will lose consciousness)3. N/V 4. Nuchal rigidity5. Fever6. Third cranial nerve palsy (mydriasis)
SAH Delayed neuro injury
1. reRupture (early coiling is the best intervention)2. Hydrocephalus (manifests as change in LOC)3. Delayed cerebral ischemia (aka Vasospasm can occur 2 days to 3 weeks)4. Hyponatremia (CSW)
SAH LIT
- Non con head CT (95% accurate)- LP (CSF will be yellow)- Ottawa SAH scale
SAH management
1. Surgical coiling or clipping 2. Nimodipine for vasospasm prophy (60 mg q4hr)3. If patient becomes obtunded or decrease in LOC= EVD & Osmotic therapy4. Hyponatremia= Hypertonic saline
How fast can you correct Na+?
No more than 12 mEq/24 hours