What’s better than a champagne tap? Not having to do an LP in the first place.
Why Use It
+~100% sensitive for SAH + The only wellvalidated calc for SAH rule-out
– Strict inclusion criteria, so only applicable to small number of patients
– 40 years or older? (a.k.a. every patient in the ED) automatic fail
× Underinvestigation: failure to act on neck painor stiffness
× Overinvestigation: interpretation of “thunderclap” headache; don’t apply rule if you’re not suspicious for SAH
DERIVATION: 1,999 pts, 5 Canadian centers, prospectively enrolled, 3 different CDRs with sens 100%, spec 28-39%
VALIDATION: 2,131 pts, 10 Canadian centers, prospective external cohort, sens 100%, spec 15%
1. Perry JJ, Stiell IG, Sivilotti ML, et al. High risk clinical characteristics for subarachnoid haemorrhage in patients with acute headache: prospective cohort study. BMJ. 2010;341:c5204.
2. Perry JJ, Stiell IG, Sivilotti ML, et al. Clinical decision rules to rule out subarachnoid hemorrhage for acute headache. JAMA. 2013;310(12):1248-55.