subarachnoid hemorrhage diagnosis-what to do j. stephen huff, md fourth-year student elective...

Subarachnoid hemorrhage

diagnosis-what to do

J. Stephen Huff, MD

Fourth-Year student elective director

Professor of Emergency Medicine and Neurology

University of Virginia

Virginia College of Emergency PhysiciansHot Springs, Virginia 2016

Corey Heitz, MDDirector, Undergraduate

Medical Education

Assistant Professor of Emergency MedicineVirginia Tech Carilion

Disclosures

none

Objectives

Rule out SAH without performing an LP every time!

What are we looking for?

Aneursymal SAH

or

Non-aneurysmal SAH

Aneurysmal SAH

High morbidity and mortality

Possibility of “sentinel bleeding”

Non-aneurysmal SAH

Aka perimesencephalic SAH

Usually venous

Minimal long term effects

Point #1:

We aren’t just looking for blood, we are looking for aneurysmal bleeding

Testing algorithm

POSITIVE: NO LP

NEGATIVE, LP POSITIVE

NEGATIVE, LP NEGATIVE

CT

CT

CT

angio

angio

done

Proposed revision

POSITIVE

NEGATIVE*

NEGATIVE*

CT

CT

CT

Angio (CTA)

DONE

Angio (CTA)

Let’s talk about LP

Invasive

Sometimes painful

Complications

Doesn’t diagnose aneurysm!

But if it’s a good test…

2 true positives in 302 patients

~1 in 200 after negative head CT

Risk/Benefit

NND: 150-200

NNH: 10-20

Point #2:

LPs are low yield, high adverse effects

But is CT good enough?

Perry et al 2011:953 patients CTed within 6 hours:

all SAHs diagnosed

Backes et al 2012: validated sens/spec of 100%

But is CT good enough?

Dubosh 20168907 patients13 missed SAH on CT1.46 per 1000 CTs

LR- for CT: 0.010 (0.003-0.034)

NND for LP: 700

Proposed revision

POSITIVE

NEGATIVE*

NEGATIVE*

CT

CT

CT

Angio (CTA)

DONE

Angio (CTA)

Summary

LPs are low yield and fair # of complications

CT within 6 hours is excellent

Positives go to angio anyway

700 LPs to diagnose 1 missed bleed? Insane

subarachnoid hemorrhage diagnosis-what to do j. stephen huff, md fourth-year student elective...

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