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

Nina Gentile, MD 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

Nina Gentile, MD 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%

Nina Gentile, MD Case Example 49 year old male with sudden onset of severe headache followed by syncope at work EMS found him awake but confused No PMH and on no medications

Nina Gentile, MD 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

Nina Gentile, MD 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

Nina Gentile, MD Warning or “Sentinel” Bleeds 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.

Nina Gentile, MD Outcome of Patients Initially Misdiagnosed and Correctly With SAH OutcomeMisdiagnosis (n=45) Correct Diagnosis (n=75) Excellent/good 24 (53)* 68 (91)* Fair 5 (11) 4 (5) Poor/vegetative/dead16 (36)* 3 (4)* Values are number (%) in each clinical grade category. P<.001 Stroke 1996;27: Misdiagnosis of SAH

Nina Gentile, MD Computed Tomography Sensitive for blood –day of the bleed 95% –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%

Nina Gentile, MD Computed Tomography Characteristic hemorrhage after aneurysmal rupture

Nina Gentile, MD Lumbar puncture and CSF Exam in SAH CSF should be examined if the CT is negative, equivocal, or technically inadequate Within the first 8 hours will show frank blood or red blood cells on microscopy Delayed CSF examination may show only xanthochromia or an inflammatory reaction

Nina Gentile, MD Initial Treatment AirwayIntubate 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

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

Nina Gentile, MD Vasospasm Appears after 3-4 days and peaks at 7-10 days Factors released at time of bleeding induce vasoconstriction with decreased perfusion New headache, seizures, or change in mentation New focal neurologic signs suggesting ischemia

Nina Gentile, MD Prevent Ischemic Complications of Vasospasm Avoid Dehydration and Hypotension Manage High Intracranial Pressure (CPP=MAP-ICP) Calcium Channel Blocker –Nimodipine -- neuroprotection

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

Nina Gentile, MD 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