|
| |
| Subarachnoid Hemorrhage
(SAH) |
| Overview |
 | 6-16 per 100,000 / year |
| Risk of SAH increases with age and peaks at 50 years |
| Risk factors for SAH:
 | Smoking |
| Putative factors: increasing age, female gender, black race, alcohol abuse, and binge drinking. |
| There appears to be an inverse relationship between body-mass index and the incidence of SAH. |
|
|
| Spontaneous intracranial hemorrhages: 77% caused by aneurysms.
| Types: saccular, mycotic & fusiform |
|
| Other causes of SAH
| Trauma |
| Vascular malformations of brain & spinal cord |
| Blood dyscrasias |
| Less common causes: tumors, infection, and vasculopathies. |
|
| Autopsy prevalence of aneurysm: 1% |
| 10% died and never reached the hospital |
|
| Signs & Symptoms |
| Headache: sudden onset and very severe |
| Meningeal signs |
| A warning leak may occur in up to 50% of the patients several days or weeks prior to the hemorrhage. |
|
| Diagnosis |
| CT head without contrast detects 80-90% of the SAH in first 24 hours. |
| The longer the interval between onset of symptom and scan, less likely CT
will show the bleed. |
| At 3 weeks after bleed, almost 0%. |
| If the history is right, CT head negative, consider LP. |
| MRI may be more sensitive in detecting SAH for onset > 4 days ago. |
| 20% of patient may have multiple aneurysms. |
| 20-25% of cases, Angiogram negative, recommended that a repeat study be
performed in 2 weeks. |
|
| Fischer Grading System of CT scan |
| Grading:
| No clot seen |
| A diffuse thin layer of blood less than 1 mm thick |
| A localized clot or diffusely distributed hemorrhage greater than or equal to 1 mm in thickness |
| An intraventricular or intraparenchymal hemorrhage |
|
| Grade 3 appears to carry the greatest risk of subsequent vasospasm. |
|
| General Care |
| Admit to intensive care unit |
| Routine lab and coagulation profile |
| Quiet environment on bed rest. |
| Consider central and arterial line, Foley catheter and pneumatic
boots. |
| Consider anticonvulsants, corticosteroids and H2 blockers. |
| Nimodipine 60 mg q 4 h |
| Antihypertensive agents, such as Labetalol to control blood pressure. |
| Reversible analgesics, such as narcotics, are used to control both blood pressure and agitation. |
| Antifibrinolytic agents are now used less commonly.
| Bleeding risk reduced by 50% |
| Risk of diarrhea in 24%, hydrocephalus in 25%, and an increased rate of ischemic injury. |
|
| Placement of a ventricular catheter might also be required in patients who are drowsy and demonstrate ventriculomegaly on their CT scan. |
|
| Recurrent Bleed |
| 4% chance of recurrent hemorrhage within the first 24 hours |
| 1.2% chance each day during the first 2 weeks. |
| Total 20% risk for rebleeding within 14 days. |
|
| Hunt-Hess grading system |
| Grade 0: asymptomatic and have unruptured aneurysms. |
| Grade 1: mildly symptomatic with headache. |
| Grade 2: severe headache associated with nuchal rigidity and possibly a
cranial nerve deficit. |
| Grade 3: drowsy or confused and may have a mild focal neurologic deficit.
|
| Grade 4 : stuporous with a moderate to severe hemiparesis and possibly
early decerebrate rigidity. |
| Grade 5: comatose with decerebrate rigidity or flaccidity. |
| Surgical risk increases with the clinical grade, which is predictive for
eventual neurologic outcome. |
|
| Prognosis |
| For those that reach the hospital:
| 1/3 comatose |
| 1/3 develop neurologic deterioration |
| 1/3 good recovery possible |
|
|
| Further reading |
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|
Differentiate between traumatic tap and SAH
| CSF characteristic |
Traumatic tap |
True SAH |
| Color gets lighter with subsequent tubes |
yes |
no |
| RBC count in first & last tube |
count decrease |
stay constant |
| Clotting of blood in CSF |
yes |
no |
Xanthochromia in supernatant
(CSF needs to be centrifuged immediately, & examined by spectrophotometry) |
rare with RBC count less than 200,000 |
present within 4 hours of SAH, maximum at 1
week, persists for about 3 weeks |
CT finding and possible implications
| CT scan findings |
Possible implications |
| Blood in basal cisterns |
nonspecific |
| Blood in Sylvian fissure |
MCA aneurysm |
| Blood in cavum septum pellucidum, interhemisphere fissure |
Anterior communicating aneurysm |
| Isolated intraventricular blood |
anterior communicating or basilar artery aneurysm |
| Intracerebral blood in temporal lobe or basal ganglion |
middle cerebral or internal carotid aneurysm |
| Intracerebral blood in frontal lobe |
anterior cerebral artery aneurysm |
| Finding on initial CT after aneurysm
rupture |
| Normal |
8.3% |
| Decreased density |
1.1% |
| Intracerebral hematoma |
17.4% |
| Subdural hematoma |
1.3% |
| SAH |
85.2% |
Classification of SAH and plan for treatment
| Hunt & Hess |
Clinical presentation |
Timing for surgery |
| I |
asymptomatic or mild headache |
May benefit from early surgery |
| II |
headache, stiff neck, no focal deficit other than cranial
nerve deficit |
| III |
Drowsy, mild focal deficit |
Timing of surgery unclear, with less favorable
outcome |
| IV |
Stupor, hemiparesis |
| V |
Deep coma, decerebration |
Management of SAH
| Conditions |
Management Options |
| Prevent vasospasm? |
| Nimodipine 60 mg q4 po or NG |
| ? 3% NaCl iv 50ml tid |
| Maintain electrolyte balance |
|
| Delayed vasospasm |
| Discontinue Nimodipine, antihypertensive & diuretic |
| 5% Albumen 250 ml iv |
| Swan-Ganz placement, titrate to keep wedge pressure 12-14 mm Hg |
| Maintain cardiac index about 4L/min/sq. meter |
| Dobutamine 2-15 ug/kg/min |
|
| Airway |
| Intubate to protect airway if drowsy |
|
| Fluid |
| 0.9% NaCl 2-3 liter/day |
|
| Elevated BP |
| ?Keep mean arterial BP <125 |
| If > 125, use
| Labetolol 20 to 80 mg every 10 min, drip 0.5-2mg/min
|
| Vasotec 1.25-2.5 mg iv q 6 hr |
| Nicardipine 5mg/hr, increase by 1-2.5mg/hr, up to 15 mg/hr |
|
|
| Pain |
| Tylenol with codeine or Morphine 1-2 mg iv |
|
Prevent stress ulcer
|
| Especially for pt on NSAID, history of ulcer or on ventilator:
Pepcid 20 mg iv bid or Zantac 50 mg iv bid
Sucrafate 1 g in 20 ml water tid |
|
| Agitation |
| Midazolam 0.06-1.1mg/kg/hr
Propofol 3-10mg/kg/hr |
|
| Hyponatremia |
| If severe, e.g. <120, consider Fludrocortisone
0.2 mg bid po/NG |
|
| Miscellaneous |
| Anticonvulsants |
| Stool softener, pneumatic compression devices |
| Positioning, turning |
| Nutritional support |
| Treat infection |
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Further Reading
e
Medicine
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