In this observational series: 204.<\/p>\n
This study describes the findings of 2,248 patients with \u201cheadache, suggestive of subarachnoid hemorrhage\u201d who underwent computed tomography, followed by lumbar puncture. CT is quite sensitive for aneurysmal hemorrhage in the few hours following onset, but fades with time. Spectrophotometric analysis of CSF is the gold standard for diagnosis in the United Kingdom, and was used by these facilities to describe positive, negative, and indeterminate results on LP.<\/p>\n
Of these 2,248 patients, LP were negative in 1,507, uninterpretable in 350, indeterminate in 299, and positive in 92. All patients with positive LP had follow-up CTA or MRA, and there were 9 vascular abnormalities. Then, a subset of the uninterpretable and indeterminate patients underwent CTA or MRA, as well, resulting in an additional two vascular abnormalities.<\/p>\n
Thus, 204.<\/p>\n
There are a few surprising bits regarding these data. The ~4% rate of \u201cSAH\u201d detected in this study is lower than most other observational series. Some of these, however, were neurosurgical referral centers, with much higher rates. Then, of course, the incidence will further depend on various definitions of positivity and the rate at which patients with lower pre-test likelihood are evaluated for SAH. Additionally, the rate of vascular abnormality in those with \u201cSAH\u201d was also quite low. In such a small sample, the confidence intervals are quite wide, so it\u2019s hard to estimate the generalizability of these findings.<\/p>\n
Regardless of the precise numbers, their overall conclusion is reasonable: CT + LP is extremely low yield for true pathology. There is a definite need for decision instruments with improved specificity to prevent such extensive resource utilization.<\/p>\n
\u201cAn Observational Study of 2,248 Patients Presenting With Headache, Suggestive of Subarachnoid Hemorrhage, Who Received Lumbar Punctures Following Normal Computed Tomography of the Head\u201d In this observational series: 204. This study describes the findings of 2,248 patients with \u201cheadache, suggestive of subarachnoid hemorrhage\u201d who underwent computed tomography, followed by lumbar puncture. CT is quite sensitive for aneurysmal hemorrhage in the few hours following onset, but fades with time. Spectrophotometric analysis of CSF is the gold standard for diagnosis in … Continue reading “How Many LPs Does It Take to Find SAH?”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[14],"tags":[],"class_list":["post-3212","post","type-post","status-publish","format-standard","hentry","category-neurology"],"jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p7KesJ-PO","jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=\/wp\/v2\/posts\/3212","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3212"}],"version-history":[{"count":0,"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=\/wp\/v2\/posts\/3212\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3212"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3212"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3212"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
http:\/\/www.ncbi.nlm.nih.gov\/pubmed\/26480290<\/a><\/p>\n\n