A 50 y/o man with a history of CHF and COPD is brought in by ambulance in severe respiratory distress. He is sitting upright with a RR 30 and O2 saturation of 79% on room air.
Is this a CHF or COPD exacerbation?
This is a common dilemma faced in the ED. Fortunately there are likelihood ratios to help you risk stratify using a Bayes nomogram.
Note that the first table below (McCullough et al) enrolled ED patients WITH a known history of asthma or COPD. For the second table from JAMA (Wang et al), summative LRs for BNP are provided in ED patients with or without a history of asthma/COPD.
In the end, the most helpful positive findings which help you predict a CHF exacerbation causing dyspnea are (in descending order of LR):
- Exam: S3 heart sound
- CXR: Pulmonary edema
- Initial clinical judgment
- CXR: Cardiomegaly
- EKG: atrial fibrillation
- CXR: Pleural effusion
- EKG: Ischemic ST-T changes
- Exam: Jugular venous distension (JVD)
- History of atrial fibrillation
- Lab: BNP ≥ 100 pg/mL
- EKG: Q waves
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References
McCullough PA, Hollander JE, Nowak RM, et al; BNP Multinational Study Investigators. Uncovering heart failure in patients with a history of pulmonary disease: rationale for the early use of B-type natriuretic peptide in the emergency department. Acad Emerg Med. 2003 Mar;10(3):198-204. PubMed PMID: 12615582. Pubmed .
Wang CS, FitzGerald JM, Schulzer M, Mak E, Ayas NT. Does this dyspneic patient in the emergency department have congestive heart failure? JAMA. 2005 Oct 19;294(15):1944-56. PMID: 16234501. Pubmed .
Another tool that's useful in this clinical scenario is using ultrasound to see if there are b lines.
ReplyDeleteAnecdotally, it's helped me on more than one case
http://www.ncbi.nlm.nih.gov/pubmed/19183402
Agreed that Ultrasound B-lines are a great adjunct to help differentiate CHF from other causes for dyspnea. This JAMA article unfortunately is the most recent systematic review available (2005). Will take a few more years for US to really come into the mainstream for this purpose in the ED setting, I think.
Deletegreat post & review!
ReplyDeleteI would add that differentiating the etiology of severe dyspnea in the patient with both COPD & CHF may not be all that important. The mainstay of therapy for both is NIV -- if they are hypertensive, further reduce afterload with NTG; if they are wheezing (or even if they are not) add steroids and bronchodilators and consider antibiotics (GOLD criteria... even makes the mystery of superimposed pneumonia less of a problem). Loop diuretics won't help any of these patients acutely regardless.
Lastly, while some of these LRs are impressive, not only do many of them have broad confidence intervals, but I'm not sure I can call an S3 when the HR is 120 and the RR is 40 with crackles/wheezes/rhonchi all around (plus, of course, the noise from the NIV)
Good point. Even if they ARE wheezing, the article states that the neg LR ratio is not significant for ruling out CHF. So, with or without wheezing, you should still treat for CHF.
ReplyDeleteGood point about the S3 on exam!
Does anyone knows an App that has Fagan nomogram?
ReplyDeleteNo I don't. So, I have put one in my Dropbox and Evernote apps. Here's the link to the Dropbox nomogram. Feel free to use.
Deletehttps://dl.dropbox.com/u/5247611/Bayes%20Nomogram.jpg