senior with oxygen maskA 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 Fagan nomogram.

Note that there are 3 tables:

  1. All-comer Emergency Department (ED) patients1
  2. ED patients WITH a known history of asthma or COPD2
  3. Summative LRs for BNP are provided in ED patients with or without a history of asthma/COPD1

See the blue font for the likelihood ratios ≥ 3.0.

PV Card: Does Your Dyspneic Patient Have CHF?

Adapted from [1, 2] Go to ALiEM (PV) Cards for more resources.



  1. Wang C, FitzGerald J, Schulzer M, Mak E, Ayas N. Does this dyspneic patient in the emergency department have congestive heart failure? JAMA. 2005;294(15):1944-1956. [PubMed]
  2. McCullough P, Hollander J, Nowak R, et al. 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;10(3):198-204. [PubMed]
Michelle Lin, MD
ALiEM Founder and CEO
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg SF General. ALiEM Founder @aliemteam #PostitPearls at Bio:
Michelle Lin, MD