ID Miscellany|physical Exam|Signs|Humanities #idmesh

๐™๐™š๐™ข๐™ฅ๐™š๐™ง๐™–๐™ฉ๐™ช๐™ง๐™š-๐™ฅ๐™ช๐™ก๐™จ๐™š ๐™™๐™ž๐™จ๐™จ๐™ค๐™˜๐™ž๐™–๐™ฉ๐™ž๐™ค๐™ฃ (๐™๐™–๐™œ๐™š๐™ฉ& #39;๐™จ ๐™จ๐™ž๐™œ๐™ฃ)

1/11
For every 1 deg F rise in temp, HR incrementally increases by 8-10 bpm (๐“›๐“ฒ๐“ฎ๐“ซ๐“ฎ๐“ป๐“ถ๐“ฎ๐“ฒ๐“ผ๐“ฝ๐“ฎ๐“ปโ€™๐“ผ ๐“ป๐“พ๐“ต๐“ฎ) https://academic.oup.com/qjmed/article/os-20/78/205/1515205">https://academic.oup.com/qjmed/art...
2/11
This is a physical sign that may have become less popular now because of more sophisticated methods of diagnosing infections.

But knowing its application can expand our clinical reasoning toolkit and enhance bedside diagnosis and teaching.
3/11
There are a couple of ways to determine whether ๐™๐™š๐™ข๐™ฅ๐™š๐™ง๐™–๐™ฉ๐™ช๐™ง๐™š-๐™ฅ๐™ช๐™ก๐™จ๐™š ๐™™๐™ž๐™จ๐™จ๐™ค๐™˜๐™ž๐™–๐™ฉ๐™ž๐™ค๐™ฃ is present.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> using a math equation to derive a cut-off HR below which, a diagnosis of "relative bradycardia" can be made

https://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> applying a set of criteria
4/11
Ostergaard, et al proposed a calculation to determine โ€œrelativeโ€ bradycardia" -- a pulse rate lower than 95% CI for the patientโ€™s temp (determined among 673 patients https://abs.twimg.com/emoji/v2/... draggable="false" alt="๐Ÿ‘‡" title="Rรผckhand Zeigefinger nach unten" aria-label="Emoji: Rรผckhand Zeigefinger nach unten">):

Men: if HR <10.2 x T0C โ€“ 333
Women: if HR <11 x T0C โ€“ 359

https://www.sciencedirect.com/science/article/pii/S0163445396922252?via%3Dihub">https://www.sciencedirect.com/science/a...
5/11
On the other hand, Cunha proposed a more permissive criteria to determine relative bradycardia https://abs.twimg.com/emoji/v2/... draggable="false" alt="๐Ÿ‘‡" title="Rรผckhand Zeigefinger nach unten" aria-label="Emoji: Rรผckhand Zeigefinger nach unten">, based on:

https://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> a set of inclusion/exclusion criteria
https://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> set of expected HRs per given temp

https://www.sciencedirect.com/science/article/pii/S1198743X14637393?via%3Dihub">https://www.sciencedirect.com/science/a...
5/11On the other hand, Cunha proposed a more permissive criteria to determine relative bradycardia https://abs.twimg.com/emoji/v2/... draggable=, based on:https://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> a set of inclusion/exclusion criteriahttps://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> set of expected HRs per given temp https://www.sciencedirect.com/science/a..." title="5/11On the other hand, Cunha proposed a more permissive criteria to determine relative bradycardia https://abs.twimg.com/emoji/v2/... draggable="false" alt="๐Ÿ‘‡" title="Rรผckhand Zeigefinger nach unten" aria-label="Emoji: Rรผckhand Zeigefinger nach unten">, based on:https://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> a set of inclusion/exclusion criteriahttps://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> set of expected HRs per given temp https://www.sciencedirect.com/science/a..." class="img-responsive" style="max-width:100%;"/>
6/11
Whatever method you use, once you determine that โ€œrelative bradycardiaโ€ is present, you can look at a list and be familiar with the many conditions (infectious and non-infectious) that it has been traditionally associated with https://abs.twimg.com/emoji/v2/... draggable="false" alt="๐Ÿ‘‡" title="Rรผckhand Zeigefinger nach unten" aria-label="Emoji: Rรผckhand Zeigefinger nach unten">

https://www.sciencedirect.com/science/article/pii/S1198743X14637393?via%3Dihub">https://www.sciencedirect.com/science/a...
7/11
The exact sensitivity and specificity of the Fagetโ€™s sign is unknown. But data seems to show its diagnostic value in the following infections:

https://abs.twimg.com/emoji/v2/... draggable="false" alt="1โƒฃ" title="Tastenkappe Ziffer 1" aria-label="Emoji: Tastenkappe Ziffer 1"> Legionella
https://abs.twimg.com/emoji/v2/... draggable="false" alt="2โƒฃ" title="Tastenkappe Ziffer 2" aria-label="Emoji: Tastenkappe Ziffer 2"> Chlamydia
https://abs.twimg.com/emoji/v2/... draggable="false" alt="3โƒฃ" title="Tastenkappe Ziffer 3" aria-label="Emoji: Tastenkappe Ziffer 3"> Salmonella typhi (typhoid fever)
https://abs.twimg.com/emoji/v2/... draggable="false" alt="4โƒฃ" title="Tastenkappe Ziffer 4" aria-label="Emoji: Tastenkappe Ziffer 4"> Dengue
8/11
Among close to 700 patients, relative bradycardia had no predictive value regarding most likely infection but found only in specific diseases:

https://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> typhoid fever (but NOT non-typhi Salmonella)
https://abs.twimg.com/emoji/v2/... draggable="false" alt="โ–ช๏ธ" title="Schwarzes kleines Quadrat" aria-label="Emoji: Schwarzes kleines Quadrat"> Legionella & Chlamydia pneumonia (but NOT Mycoplasma) https://www.sciencedirect.com/science/article/pii/S0163445396922252?via%3Dihub">https://www.sciencedirect.com/science/a...
10/11
Case control study (N=70) in Singapore, relative bradycardia was a significant feature of dengue but not other causes of infection (p < 0.001))

https://wwwnc.cdc.gov/eid/article/13/4/06-1212_article">https://wwwnc.cdc.gov/eid/artic...
11/11
So next time you see a febrile patient (e.g. patient coming w/ CAP, returned traveler), try to see if you can apply the ๐™๐™–๐™œ๐™š๐™ฉ& #39;๐™จ ๐™จ๐™ž๐™œ๐™ฃ.

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