1. Subarachnoid Hemorrhage Nina T
Subarachnoid Hemorrhage Nina T. Gentile, MD Associate Professor Division of Emergency Medicine Temple University School of Medicine Philadelphia, PA 54 1 54

2. Teaching Objectives
Emphasize the importance of early detection of both large and “sentinel” SAH
Understand the value and the limitations of CT and LP to diagnose the disease
Describe the therapies used to manage or prevent
The acute effects of the hemorrhage
Vasospasm and subsequent ischemic stroke

3. Aneurysmal Subarachnoid Hemorrhage: Introduction
30,000 Americans suffer non-traumatic SAH each year
Overall mortality rates are 35 to 40%
Up to 12% of patients die before reaching medical attention
Another 25% die in subsequent 3 months
Morbidity among survivors is 50%

4. Case Example
49 year old male with sudden onset of severe headache followed by a syncopal episode at work
Colleagues called EMS who found him awake but confused
No PMH and on no medications

5. Symptoms of Subarachnoid Hemorrhage
Sudden, unusually severe or “thunderclap” headache
Pain in neck, back, eye, or face
Loss of or change in consciousness
Nausea, vomiting, photophobia, or phonophobia

6. Signs of Subarachnoid Hemorrhage
Abnormal vital signs
Respiratory changes, hypertension, cardiac arrhythmias
Meningismus
Focal neurologic signs
III nerve palsy – IC/PCA aneurysm
Paraparesis – ACA aneurysm
Hemiparesis, aphasia – MCA aneurysm
Ocular hemorrhages

7. Symptoms and Signs of Subarachnoid Hemorrhage
Roughly half of all patients with SAH have “typical” presentations
However, patients presenting with less severe headache without a change in mentation, meningismus or a focal neurologic deficit are likely to be misdiagnosed

8. Warning or “Sentinel” Bleeds
Diagnosis of “sentinel” hemorrhage is often made retrospectively
Up to 50% of patients with SAH report having had a distinct, severe headache in the days to weeks before the index bleed
half will have seen a doctor
Screen patients with “sentinel” headaches before a full-blown hemorrhage occurs.

9. Misdiagnosis of SAH
Outcome of Patients Initially Misdiagnosed and Correctly With SAH
Outcome Misdiagnosis (n=45) Correct Diagnosis (n=75)
Excellent/good (53)* 68 (91)*
Fair (11) (5)
Poor/vegetative/dead 16 (36)* (4)*
Values are number (%) in each clinical grade category.
P<.001
Stroke 1996;27:

10. Suspected SAH Unenhanced CT
LP (+)
LP (-)
No SAH
Subspecialty
Consultation

11. Computed Tomography Sensitive for blood Sensitivity drops when
day of the bleed %
within 12 hours of symptom onset as high as 98%.
Sensitivity drops when
symptoms are days in duration
amount of bleeding is small
study is difficult to interpret
Patients with small or “sentinel” bleeds are more likely to receive an incorrect clinical diagnosis and are more likely to have a false negative CT
85%

12. Computed Tomography
Characteristic hemorrhage after aneurysmal rupture

13. Lumbar puncture and CSF Exam in SAH
CSF should be examined if the CT is negative, equivocal, or technically inadequate
LP early after symptom onset will show frank blood or red blood cells on microscopy.
Delayed CSF examination may show only xanthochromia or an inflammatory reaction

14. Initial Treatment Airway Intubate to prevent aspiration Breathing
Beware of deteriorating mentation and signs of rising ICP
Elevated BP
Keep mean arterial BP <125
If > 125, use:
Labetalol 10 IVP mg every 10 min, drip 2-8 mg/min Vasotec mg iv q 6 hr

15. Cardiac Complications of Subarachnoid Hemorrhage
ECG abnormalities are common in SAH
ST segment elevation or depression and deep T waves are the most common.
Are usually benign
Cardiac damage can occur
CK-MB elevated in 20 to 50%
Echo shows LV abnormalities (especially with severe SAH)

16. Vasospasm Appears after 3-4 days and peaks at 7-10 days
Caused by a release of factors at time of bleeding that induce vasoconstriction and decreased blood flow
New headache, seizures, or decreased alertness
New focal neurologic signs suggesting ischemia

17. Prevent Ischemic Complications of Vasospasm
Avoid Dehydration, Correct Hyponatremia and Hypotension
Manage High Intracranial Pressure (CPP=MAP-ICP)
Early Use of Calcium Channel Blocker
Nimodipine 60 mg q4 po or NG

18. Returning to our Case Example…
Patient’s CT scan showed SAH.
With neurosurgical input, oral nimodipine was started while in the ED.
Angiography revealed a ruptured right posterior communicating artery aneurysm.
He underwent aneurysm clipping and developed symptomatic vasospasm on post-op day 4.
After rehab, he was left with only a mild right hemiparesis.

19. Teaching Points SAH is often misdiagnosed
CT is sensitive but not fool-proof
LP for patients with normal or equivocal CT
Early angiography and neurosurgical consultation to facilitate surgical intervention
Treat to:
Avoid aspiration, hypertension, and neurogenic cardiac injury
Control seizure and increased ICP
Prevent recurrent hemorrhage and ischemic stroke from vasospasm