| Identifier |
esr_interpretation_correction_lee |
| Title |
Erythrocyte Sedimentation Rate (ESR) Interpretation and Correction |
| Creator |
Andrew G. Lee, MD; Alicia Chen |
| Affiliation |
(AGL) Chairman, Department of Ophthalmology, The Methodist Hospital, Houston, Texas; Professor of Ophthalmology, Weill Cornell Medicine, New York City, New York; (AC) Class of 2023, Baylor College of Medicine, Houston, Texas |
| Subject |
ESR; Red Blood Cells |
| Description |
Summary: • Typical clinical scenario: elderly patient with an erythrocyte sedimentation rate (ESR) of 100 mm/hr > temporal artery biopsy to evaluate for giant cellarteritis o Do general exam, urine analysis, chest x-ray, serum protein electrophoresis, CBC, etc. o ESR is not specific but if >100 mm/hr, then something's usually wrong o Also, correct for age and hematocri t• Two ESR corrections to make, based on: o Age > Men: age/2 > Women: (age+10)/2 > Example: For a 70 year old female, 40 mm/hr is the starting point for ESR, not 0 mm/hr. o Hematocrit > Especially if moderate or severe anemia (a mild anemia will not change ESR to a clinically significant degree) > Use the Fabry equation: corrected ESR = Westergren sed rate * 15 / (55-hematocrit) • Use the ESR in combination with C reactive protein and platelet count o If all 3 are in the same direction (e.g. all elevated), then sensitivity and specificity of ESR is increased o If ESR is elevated, CRP is normal, and platelet count is normal, ESR could be elevated due to some other globulin or some other reason to have fibrinogen increase other than temporal arteritis. |
| Transcript |
So if you're interested in the erythrocyte sedimentation rate and its uses in neuro-ophthalmology, you should watch that video. This video is about the sed rate by itself and how it can cause a problem for you as an ophthalmologist. The typical consultation is going to be an elderly patient and they're going to be admitted to the hospital and then their sed rate is part of their routine screening and it's all of sudden is 100 millimeters per hour and they want you to do a temporal artery biopsy and evaluate the patient for giant cell arteritis, which is a very common clinical scenario. And one of the things that you need to know is this sedimentation rate is not specific. When you have a sed rate that's over a hundred though, it usually means something's wrong with the patient, and you can look on the video for all the causes of the sedimentation rate to be elevated. Today we're just talking about making a correction and there's two corrections that you need to make. The first is based on age, so if you look in the laboratory the sed rate normal is going to be some crazy number like zero to ten, or zero to twenty, and basically we don't want to use the laboratory normals of the sedimentation rate because we're not using it in the same way that other specialties are using it. We're using it for giant cell arteritis and so the age correction is an empiric formula -- it's different for men and women. So for men it's just their age divided by 2, and for women it's their age plus 10 divided by 2. So already in this 70-year-old even though a hundred seems high for a 70-year-old, age plus 10 80 divided by 2, 40 is actually the starting point, not zero. The second correction that we have to make is for the hematocrit and under normal circumstances a mild anemia, or even a moderate anemia, will not change the sed rate to a clinically significant degree. But when you start getting sed rates that are a hundred and you have an anemia where the hematocrit is 21 or 22 or 23, this level of hematocrit can definitely alter what the corrected sedimentation rate should be and so we use the Fabry equation to help us correct for the anemia. And so you're going to do a Westergren sedimentation rate and we multiply that by 15 and then divide that number by 55 minus their hematocrit. And so that Fabry formula, just like the age formula, is an empiric formula. So in this particular example, we've got 70 is the age -- we're already thinking about 40 as the target. The Westergren sed rate in this case was 100 times 15 is gonna be 1500. 55 minus the hematocrit, so we'll make the number easy, we'll make it 25. So 55 minus 25 is gonna be 30, and so when we take that number, the 15 minus, the 55 minus the hematocrit, this number here is gonna end up being 50. So a 50 sed rate is very close to the 40 and so if you just add anything on to this 70-year-old diabetes, chronic kidney disease, a urinary tract infection, pneumonia -- suddenly this 50 is not as scary as it was when it was a hundred and in the absence of symptoms of giant cell arteritis, we're gonna be asking the primary services to look for another cause for the sed rate to be elevated. And so one of the other things you need to know is we use the sed rate in combination with two other things: the C reactive protein and the platelet count. And so if all three indices are going the same direction -- elevated sed rate, elevated CRP, elevated platelets, thrombocytosis -- then we'll feel more confident in any one of the numbers and so the sensitivity and the specificity of the test sed rate is increased if you use it in combination with the CRP and the platelet count. So if you've got a sed rate that's elevated but you're thinking it's not giant cell, if you have a normal CRP and a normal platelet count that is suggesting that whatever is causing this sed rate to be elevated is not actually the acute phase reactants of inflammation but it's something else in their blood, some other globulin or some other reason to have fibrinogen increase other than temporal arteritis. So in every patient who has a sed rate that's over a hundred you need to look for a cause that usually means a general exam, urine analysis, chest x-ray, serum protein electrophoresis, CBC and you're going to be looking for common things, common infections, common inflammations, and common malignancies. You're going to correct for age, you're going to correct for the hematocrit. In general, it doesn't matter if the hematocritis mildly decreased but once you start getting moderate to severe anemia, you need to make that correction with the Fabry equation. |
| Date |
2021-04 |
| Language |
eng |
| Format |
video/mp4 |
| Type |
Image/MovingImage |
| Collection |
Neuro-Ophthalmology Virtual Education Library: Andrew G. Lee Collection: https://novel.utah.edu/Lee/ |
| Publisher |
North American Neuro-Ophthalmology Society |
| Holding Institution |
Spencer S. Eccles Health Sciences Library, University of Utah |
| Rights Management |
Copyright 2019. For further information regarding the rights to this collection, please visit: https://NOVEL.utah.edu/about/copyright |
| ARK |
ark:/87278/s6n0744h |
| Setname |
ehsl_novel_lee |
| ID |
1680599 |
| Reference URL |
https://collections.lib.utah.edu/ark:/87278/s6n0744h |
