Does This Adult Patient Have Acute Meningitis? Welcome to the Education Guides portion of The Rational Clinical Examination series. Teaching tips and notes for making sessions relevant and interactive will be included in the notes pages of selected slides. Throughout the Education Guides, the following ABC’S may be highlighted in the notes pages: A: Slide contains animation geared to increase interactivity. B: Slide contains basic principles related to teaching diagnosis. These slides are part of a uniform set that will be used throughout the Education Guides. C: Slide contains an opportunity to increase relevance and interactivity through use of cases or by asking the learners to commit to a specific answer that can be used for discussion and for anchoring their responses. One easy, inexpensive, and fun strategy is to hand out blank file cards at the start of the session and have learners use them to write down their numeric guesses of probabilities. These cards can be passed around the room in order to “blind” the process. Once the learners have written down their estimates, they can pass the cards around the room so that no one is holding their own card and can report on what is in front of them without identifying their own answers. This contributes to a safe learning environment in which learners are not afraid to make honest guesses. S: Slide contains a stumbling block.

Case Scenario 1 30-year-old man presents to emergency department (ED) 24-hour history of chills and a stiff neck Afebrile with normal mental status Full neck flexion but with cervical pain Kernig and Brudzinski signs absent

Impact on Likelihood of Disease LR: Impact on Likelihood of Disease LR = 0.3 Less Likely LR = 0.2 LR = 0.1 LR = 0.01 LR = 3 More Likely LR = 5 LR = 10 LR = 100  Increasing impact increasing impact LR = 1 No Impact on Likelihood of Disease B: Slide contains a basic principle related to teaching diagnosis: Likelihood Ratio. A: Slide uses animation to graphically illustrate the concept that LR has greater impact on pretest probability as it moves away from the central line of LR = 1, where the test result will not differentiate disease from no disease. Note that animation in this slide is fully automated (ie, you do not need to do anything) and is used to provide a different way of describing how to interpret LRs that may appeal to visual learners.

Test Characteristics: Examination Likelihood Ratios From Prospective Studies Finding LR+ (95% CI) LR– (95% CI) Fever 0.82 (0.62-1.1) 1.2 (0.94-1.5) Kernig sign (Thomas) 0.97 (0.27-3.6) 1.0 (0.94-1.1) Kernig sign (Uchihari) 4.2 (0.23-77) 0.92 (0.81-1.0) Brudzinski sign 0.97 (0.26-3.5) Jolt accentuation 2.4 (1.4-4.2) 0.05 (0.01-0.35) S: This slide presents a frequent stumbling block. This slides shows selected LRs from Table 30-6 pertaining to the physical examination. What is most noteworthy about this slide is consistency with this the classic findings are not useful. With the exception of jolt accentuation test (which has been evaluated in only 1 study), all of the clinical findings your learners are likely using in practice have LRs that are near 1 and/or have confidence intervals that include 1. The Kernig and Brudzinski signs are widely used by trainees and practitioners, yet they lack helpful diagnostic test characteristics. Although the test characteristics of jolt accentuation are promising, further studies would be needed to increase our level of confidence in this test and the test properties reported. You can ask your learners 2 questions in the context of this slide: 1) do they think they should continue to use the Kernig and/or Brudzinski signs in evaluations of patient for meningitis, and 2) how many of them have ever heard of, let alone performed, the jolt accentuation test.

Likelihood Ratio Jolt accentuation test LR– = 0.05 If negative, posttest probability < 0.1% Jolt accentuation test LR+ = 2.4 1% Pretest probability in population presenting to ED If positive, posttest probability = 2% Estimating prior probability: The single prospective US cohort estimated that the prevalence of acute meningitis in populations presenting to the ED was ~1%. This slide illustrates the effect of a jolt accentuation test if a prior probability of 1% is assumed. If the jolt accentuation test is negative, the posttest probability is quite low (<0.1%). Most practitioners would consider this below their threshold for performing an LP and might choose not to perform additional testing. If the jolt accentuation test is positive, the posttest probability would be approximately 2%. One would have to decide whether this prior probability was high enough to warrant additional testing (ie, LP). We also have to acknowledge that the jolt accentuation test has only been studied in a single setting and should be validated in more studies.

Terms of Use: The Rational Clinical Examination Education Guides PowerPoint Usage Guidelines JAMAevidence users may display, download, or print out PowerPoint slides and images associated with the site for personal and educational use only. Educational use refers to classroom teaching, lectures, presentations, rounds, and other instructional activities, such as displaying, linking to, downloading, printing, and making and distributing multiple copies of said isolated materials in both print and electronic format. Users will only display, distribute, or otherwise make such PowerPoint slides and images from the applicable JAMAevidence materials available to students or other persons attending in-person presentations, lectures, rounds, or other similar instructional activities presented or given by User. Commercial use of the PowerPoint slides and images are not permitted under this agreement. Users may modify the content of downloaded PowerPoint slides only for educational (non-commercial) use; however, the source and attribution may not be modified. Users may not otherwise copy, print, transmit, rent, lend, sell, or modify any images from JAMAevidence or modify or remove any proprietary notices contained therein, or create derivative works based on materials therefrom. They also may not disseminate any portion of the applicable JAMAevidence site subscribed to hereunder through electronic means except as outlined above, including mail lists or electronic bulletin boards.