While supervising residents, one of the frequent diagnostic suggestions in undifferentiated febrile patients is: blood cultures. As an Emergency Physician, the utility of blood cultures \u2013 short of diagnosing endocarditis or another primary hematogenous source \u2013 is vanishingly small. After all, the source of infection is nearly universally somewhere else<\/i> \u2013 lung, urine, CSF, skin & soft tissue \u2013 and relying on the blood to give you the answer two days later is an unreliable and impractical proposition.<\/p>\n
This study is yet another attempt at identifying patients with high likelihood of bacteremia, retrospectively analyzing 5,499 patients at Odense University Hospital for whom blood cultures were drawn. This cohort, representing roughly half of all patients presenting to the Emergency Department, had positive blood culture results 7.6% of the time. CRP, temperature, and SIRS criteria were evaluated as potential predictive variables \u2013 and, unfortunately, the positive likelihood ratios of each were only between 2 and 3, and the negative likelihood ratios associated with each were all 0.4. The authors combine these criteria and promote their absence as a rule-out, with a negative predictive value of 99.5% \u2013 but, common sense ought obviate trying to diagnose bacteremia in an afebrile patient with no SIRS criteria, and the NPV performance is more related to the low prevalence of disease than the utility of their criteria.<\/p>\n
Really, the most interesting element of this study: the massive volume of blood cultures performed, with 92% of them true negative or false positive. Costs for blood cultures vary by facility, and range from $15-$50, with patient charges typically a significant multiplier beyond. A low yield might be important if the diagnoses were changing management and improving outcomes, but the vast majority of culture results are clinically unimportant. These authors have not described particularly strong positive predictors \u2013 but they\u2019ve illustrated the massive scope of the problem.<\/p>\n
\u201cHow do bacteraemic patients present to the emergency department and what is the diagnostic validity of the clinical parameters; temperature, C-reactive protein and systemic inflammatory response syndrome?\u201d<\/p>\n
While supervising residents, one of the frequent diagnostic suggestions in undifferentiated febrile patients is: blood cultures. As an Emergency Physician, the utility of blood cultures \u2013 short of diagnosing endocarditis or another primary hematogenous source \u2013 is vanishingly small. After all, the source of infection is nearly universally somewhere else \u2013 lung, urine, CSF, skin … Continue reading “Still Adrift in Ignorance Over Blood Cultures”<\/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":[9,22,12],"tags":[],"class_list":["post-3385","post","type-post","status-publish","format-standard","hentry","category-infectious-disease","category-screening","category-sepsis"],"jetpack_publicize_connections":[],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p7KesJ-SB","jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=\/wp\/v2\/posts\/3385","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=3385"}],"version-history":[{"count":0,"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=\/wp\/v2\/posts\/3385\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3385"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3385"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.emlitofnote.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3385"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}