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| ==Background==
| | ''Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space. Clinical approach differs by etiology — see the appropriate page below:'' |
| ===Pearls===
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| #Obtain GCS before intubation
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| #If intubate prevent hypertension (rebleeding)
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| ##Pretreatment
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| ###Lidocaine 1-1.5mg/kg (100mg) (blunts incr in BP)
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| ###Fentanyl 200mcg (sympatholytic)
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| ##Sedation
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| ###If pt has high BP - use propofol
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| ###If pt has good BP - use etomidate
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| #Treat pain
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| ##Prevents incr catacholamines/ incr BP
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| ===Epidemiology===
| | *[[Aneurysmal subarachnoid hemorrhage]] — spontaneous/non-traumatic SAH (most commonly ruptured cerebral aneurysm) |
| Of All pts in ED with c/o HA:
| | *[[Traumatic subarachnoid hemorrhage]] — SAH due to blunt or penetrating head trauma |
| * 1% will have SAH | |
| * 12% will have SAH if c/o worst HA of life
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| * 25% will have SAH if c/o worst HA of life + any neuro deficit
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| ===Risk Factors===
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| (in order of relative risk) | |
| # Genetics (polycystic kidney disease, Ehler-Danlos, family hx)
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| # Hypertension
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| # Atherosclerosis
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| # Cigarette smoking
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| # Alcohol
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| # Age > 85
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| # Cocaine use
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| # Estrogen deficiency
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| ==Clinical Manifestations==
| | [[Category:Neurology]] |
| # Sudden, severe headache (97% of cases)
| | [[Category:Critical Care]] |
| ## Sudden onset is more important finding than worst HA
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| # May be associated with syncope, seizure, nausea/vomiting, and meningismus
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| ## Meningismus may not develop until several hours after bleed (caused by blood breakdown > aseptic meningitis)
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| # Retinal hemorrhages
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| ## May be the only clue in comatose patients
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| # Approximately 30-50% will have sentinel bleed/HA 6-20 days before SAH
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| ==Diagnosis==
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| # Non-Contrast Head CT
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| ## 92% specific if performed w/in 24 hours of bleed
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| ## ~100% sensitive if performed w/in 12 hours of bleed
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| ## 91% sensitive in patients w/ normal neuro exam
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| ### Decreases to ~50% sensitive by day 5
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| ## Not as sensitive/specific for minor bleeds
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| ## SAH 2/2 aneurysm (90%) - look in cisterns (especially suprasellar cistern)
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| ## SAH 2/2 trauma - Look at convexities of frontal & temporal cortices
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| # Lumbar Puncture
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| ## Mandatory if there is a strong suspicion of SAH despite a normal head CT
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| ## Findings:
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| ### Elevated RBC count that doesn't decrease from tube one to four
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| #### (Decreasing RBCs in later tubes can occur in SAH; only reliable if RBC count in final tube is nl)
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| ### Opening pressure > 20 in 60% of patients with SAH
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| #### Can help differentiate from a traumatic tap (opening pressure expected to be normal)
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| #### Elevated opening pressure also seen in cerebral venous thrombosis, IIH
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| ### Xanthrochromia
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| #### May help differentiate between SAH and a traumatic tap
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| #### Takes at least 2 hours after the bleed to develop (beware of false negatives)
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| #### Sensitivity (93%) / specificity (95%) highest after 12 hours
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| ## If unable to obtain CSF consider CTA
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| ==Treatment ==
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| # Nimodipine
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| ## Associated with improved neuro outcomes and decreased cerebral infarction
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| ## Give 60mg q4hr PO or NGT only! (never IV)
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| # BP control
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| ## No consensus on HTN (incr BP may maintain CPP but may also increase rate of bleeding)
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| ### If pt is alert this means CPP is adequate so consider lowering sbp to 120-140
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| #### If pt has history of HTN consider lowering sbp to ~160
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| ### If pt is ALOC consider leaving BP alone as the ALOC may be 2/2 reduced CPP
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| ## If BP control is necessary use NICARDIPINE, LABETALOL, or ESMOLOL
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| ### Avoid vasodilators such as nitroprusside or NTG (increase cerebral blood volume > increased ICP)
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| # Discontinue/reverse all anticoagulation
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| ##Coumadin - give (prothrombin complex conc or FFP) and vit K)
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| ##Aspirin - give DDAVP
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| ##Plavix - give platelets
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| # Seizure prophylaxis
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| ## Controversial; 3 day course may be preferable
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| ## Phenytoin load
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| # Glucocorticoid therapy
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| ## Controversial; evidence suggests is neither beneficial nor harmful
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| # Glycemic control
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| ## Controversial; consider sliding scale if long pt stay in ED while awaiting ICU bed
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| # Avoid hypotension
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| ##Maintain MAP > 80
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| ###Give IVF
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| ###Give pressors if IVF ineffective
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| ==Complications==
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| # Rebleeding
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| ## Risk is highest within first 24 hours (2.5-4%), particularly within first 6 hours
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| ## Usually diagnosed by CT after acute deterioration in neuro status
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| ## Only aneurysm treatment is effective in preventing rebleeding
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| # Vasospasm
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| ## Leading cause of death and disability after rupture
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| ## Typically begins no earlier than day three after hemorrhage
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| ## Characterized by decline in neuro status
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| ## Aggressive treatment can only be initiated after the aneurysm has been treated (sx or intraluminal tx)
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| ### Triple-H therapy (hemodilution + induced hypertension (pressors) + hypervolemia)
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| # Cardiac abnormalities (?2/2 release of catecholamines due to hypoperfusion of hypothalamus)
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| ## Ischemia
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| ### Elevated troponin (20-40% of cases)
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| ### ST segment depression
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| ## Rhythm disturbances
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| ### Torsades, a fib, a flutter
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| ## QT prolongation
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| ## Deep, symmetric TWI
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| ## Prominent U waves
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| # Hydrocephalus
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| ## Consider ventricular drain placement for deteriorating LOC + no improvement within 24 hours
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| # Hyponatremia
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| ## Usually due to SIADH
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| ### Treat via isotonic, or if necessary, hypertonic saline (do not treat via water restriction!)
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| ==Grading (Hunt and Hess)==
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| Grade 0: Unruptured aneurysm
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| Grade 1: Asymptomatic or mild HA and slight nuchal rigidity
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| Grade 1a: No acute meningeal/brain reaction, with fixed neurological def
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| Grade 2: Moderate to severe headache, stiff neck, no neurologic deficit except cranial nerve palsy
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| Grade 3: Mild mental status change (drowsy or confused), mild focal neurologic deficit
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| Grade 4: Stupor or moderate to severe hemiparesis
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| Grade 5: Coma or decerebrate rigidity
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| ^Grade 1 or 2 have curable dz, if dx missed pts return w/ higher grade (ie 3 or 4), 2/3 will be dead or vegetative at 6 mos if grade 3 or 4!
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| ^Add one grade for serious sytemic dz (HTN, DM, severe stherosclerosis, COPD)
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| ==See Also==
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| Neuro: Intracranial Hemorrhage
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| ==Source==
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| 7/09 PANI (Adapted from Lampe, Birnbaumer), UpToDate, EB Emergency Medicine, July 2009
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| [[Category:Neuro]] | |
