case-based teaching didactic component: subarachnoid hemorrhage department of neurology university...
TRANSCRIPT
Case-Based TeachingDidactic Component:
Subarachnoid Hemorrhage
Department of Neurology
University of Miami School of Medicine
Subarachnoid HemorrhageLearning Objectives
• Describe the clinical presentation of a pt with SAH
• Describe the diagnostic evaluation of a pt with suspected SAH
• List the 6 major complications of aneurysmal SAH and describe their inpatient management
Clinical Presentation
• Aneurysmal subarachnoid hemorrhage– first, worst, different, or persistent headache– meningeal signs– signs of intracranial hypertension
Also be aware of:1) CN 3 palsies w/ PCOM aneurysms &
2) “sentinel bleeds”
Correlation of Lesion Localization & Clinical Findings
• Meninges– neck stiffness (AP direction) & pain– photophobia
• Intracranial hypertension– headache– nausea, vomiting– subhyaloid (preretinal) hemorrhage
(associated with sudden ICP)– lethargy (bicerebral dysfunction)
Subhyaloid hemorrhages appear round when the patient is supine and crescent shaped (like a “U”)
when the patient is upright.
Hunt & Hess ScaleChoose the single most-appropriate grade
• Grade I: asx; mild HA; slight nuchal rigidity• Grade II: moderate-to-severe HA; nuchal rigidity;
no neuro deficit other than CN palsy• Grade III: drowsiness/confusion; mild focal deficit• Grade IV: stupor; moderate-to-severe hemiparesis• Grade V: coma; decerebrate posturing
Prognostic value in SAH pts:Grades I-III better prognosis & surgical candidates
Differential Diagnosis of Patient with Signs of Intracranial Hypertension +/- Meningeal Signs
• Subarachnoid hemorrhage– aneurysm, AVM, tumor– bleeding diathesis, anticoagulant
• Intracerebral hemorrhage– esp. caudate w/ IVH or midline cerebellum
• Subdural hematoma
• Meningitis
Evaluation
• CT scan of brain w/o contrast– if CT nondiagnostic: perform lumbar puncture
• cells 1st & last tubes (but may take 4-12 h for RBCs to reach lumbar cistern)
• xanthochromia
(occurs 4 h to 2 wks after bleed)
– if CT shows SAH:
perform 4-vessel
cerebral arteriography
CT Brain
SAH in interhemispheric fissure & Sylvian fissures.Prominent interhemispheric SAH is characteristic
of anterior communicating artery aneurysms.
Blood ininter-
hemisphericfissure
Blood in Sylvianfissures
4-Vessel Cerebral Arteriography
• 7-mm anterior communicating artery aneurysm (straight black arrow)
• smaller incidental L MCA aneurysm also seen (curved black arrow)
AP view of LICA angiogram
ACAs
LMCA
LICA
Aneurysmal SAH:Common Locations of Cerebral Aneurysms
Management
• Consult neurosurgeon immediately for aneurysmal clipping to eliminate rebleeding risk
• Begin monitoring &/or treating major complications of aneurysmal SAH– Rebleeding—esp. 1st 24-48 hrs, resolves w/ clipping– Vasospasm—days 4-14, nimodipine + triple-H therapy– Seizures—prophylactic fosphenytoin/phenytoin– Hyponatremia—due to central salt-wasting syndrome; give NS– Hydrocephalus—after 1-2 wks, ventriculostomy– Cardiac arrhythmias/MI (non-Q wave)—monitor in unit
Management
• NOTE: The most important thing to monitor is the patient’s LOC, since most SAH complications affect it– Rebleeding– Vasospasm (= delayed cerebral ischemia)– Seizures– Hyponatremia– Hydrocephalus
Management:Therapy begun preop, continued postop
• Supportive care– dark, quiet room in ICU; HOB > 30 degrees– ECG monitoring, frequent neuro checks– stool softener, antiemetic, narcotic, sedative– IV NS, H-2 blocker (not cimetidine), SCDs– fosphenytoin/phenytoin
Management:Delayed Cerebral Ischemia (DCI) of Vasospasm
• Nimodipine 60 mg q4h po (x 21 d) begun preop– Do not use a higher dose (if BP too low, DCI worse)
• Monitor w/ TCD at least daily– treat d velocities, even before signs or sxs
• Start with triple-H therapy in this order:1. Hypervolume: IV NS 150 cc/h2. Hyperosmolarity: albumin 5% 250 cc IV q4h3. Hypertension: dopamine (monitor CVP or PAWP)
• Angioplasty if triple-H therapy fails
CT Scan:Consequences of Delayed Cerebral Ischemia
CT scan of bilateral ACA infarcts (dark areas) due to vasospasm in pt with ruptured anterior communicating artery aneurysm
Note blood in the Sylvian and interhemispheric fissures
Counseling
• Recurrence not likely with clipped aneurysm• Resume previous activities when able• Likely safest not to undergo MRI in the future• Cigarette smoking increases risk of SAH• Familial condition more likely if:
– polycystic kidney disease in pt or family– more than two relatives have cerebral aneurysm
• Asymptomatic aneurysms > 7 mm have increased risk of rupture
The End
Department of Neurology
University of Miami School of Medicine