#236 Physical Exam Series: Approach to Shortness of Breath

October 12, 2020 | By Justin Berk

Common CardioPulmonary Exam Maneuvers and Which Ones Actually Matter

Learn which exam maneuvers are worthwhile and which ones are worthless in your approach to shortness of breath. In our evidence based series on the physical exam, we discuss the approach to the dyspneic patient with Dr. Brian Garibaldi (Hopkins, SBM), associate professor of pulmonary and critical care medicine at Johns Hopkins, and co-president of the Society of Bedside Medicine. We discuss the physical exam’s effect on our differential diagnosis, maneuvers that are commonly taught, and some simple tests with great data that may go overlooked. Be prepared, this episode may take your breath away!

Listeners can claim Free CE credit through VCU Health at http://curbsiders.vcuhealth.org/ (CME goes live at 0900 ET on the episode’s release date).

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Credits

• Written and Produced by: Justin Berk, MD, MPH, MBA and Sam Masur, MD 
• Infographic: Sam Masur, MD, Beth Garbitelli
• Cover Art: Beth Garbitelli
• Hosts: Stuart Brigham, MD; Matthew Watto, MD, FACP; and Paul Williams, MD, FACP
• Editor:Justin Berk MD; Clair Morgan of nodderly.com
• Guest(s): Brian Garibaldi, MD

Sponsor

National Internal Medicine Day

Help ACP celebrate National Internal Medicine Day on October 28th. Visit https://www.acponline.org/NIMD20 to learn how you can show your internal medicine pride. Be sure to tag @ACPInternists and use the hashtags #NationalInternalMedicineDay, #IMProud, and #IMEssential.

VCU Health CE

The Curbsiders are partnering with VCU Health Continuing Education to offer FREE continuing education credits for physicians and other healthcare professionals. Visit curbsiders.vcuhealth.org and search for this episode to claim credit. See info sheet for further directions. Note: A free VCU Health CloudCME account is required in order to seek credit.

How to Claim VCU CME Credit

Time Stamps

• Sponsor – National Internal Medicine Day, The American College of Physicians
• Sponsor – VCU Health Continuing Education
• 00:00 Intro, disclaimer, guest bio
• Sponsor – National Internal Medicine Day, The American College of Physicians
• 03:47 Introduction to evidence-based exam, pre-test probability, and likelihood ratios
• 05:29 Case from Kashlak Memorial 
• 06:51 Dr. Garibaldi’s initial maneuvers for the dyspneic patient
• 11:33 Recapping the exam maneuvers
• 14:05 Likelihood ratios for common maneuvers
• 18:25 Over 6/Under 6 maneuvers
• 25:30 Recap of Dr. Garibaldi’s go-to maneuvers
• 28:19 Role of labs and diagnostic imaging
• 31:03 Role of point-of-care ultrasound (POCUS)
• 34:10 Friday at 5pm
• 36:31 Take home points
• 39:25 Outro
• Sponsor – VCU Health Continuing Education

1. Physical Exam Series: Approach to Shortness of Breath Clinical Pearls

   1. By the time we put the stethoscope on the chest, we should be confirming what we already suspect based on prior exam maneuvers, history, and observation.
   2. Time is a diagnostic tool. It can be used to adjust the pre-test probability
   3. Most maneuvers on the Over 6/Under 6 List for Dyspnea are not auscultation
   4. It is important to look at both the positive and negative likelihood ratios. For many tests, such as displaced PMI, they can be useful if positive, but their absence does not rule out the diagnosis. 
   5. Practice. Dr. Garibaldi recommends being intentional with practice, including performing the maneuver on patients with and without positive findings.
   6. Dr. Garibaldi recommends asking others for their thoughts. Ask colleagues to come perform their exam maneuvers and compare notes.
   7. If interested in a certain part of the body, we must look at it completely. For example, don’t drop the stethoscope down someone’s shirt, hoping it will land on the heart.

PE: Dyspnea Show Notes 

Maneuvers for the Dyspneic Patient

• Observation: Dr. Garibaldi meets the patient in the waiting room. As the patient gets up to move toward the exam room, he can see what happens when the system is stressed.

• • • Snoring?
    • Can the patient stand up on his/her own?
    • Dyspnea worse while walking?
    • How is the gait?
    • Asymmetric chest wall expansion?
    • How do the hands look? Any sign of palmar crease pallor, arthritis, splinter hemorrhages or clubbing?

• Respiratory Rate: predictor of worsening disease. Respiratory rates greater than 22 predict early clinical deterioration (Mochizuki 2017)

• Heart Failure Specific Exam: direct check for lower extremity edema, carotid exam, jugular venous distention, displaced point-of-maximal impulse, and listening for extra heart sounds

• Percussion: Dr. Garibaldi looks for any type of asymmetry for any focal process. He will also percuss the anterior chest wall for loss of dullness

• Lung Auscultation: listening for diminished breath sounds, crackles, or wheezes

• • Kashlak Pearl: By the time we put the stethoscope on the chest, we should be confirming what we already suspect based on prior exam maneuvers, history, and observation.

Evidence-Based Likelihood Ratios

Definitions

Pre-test/Post-test Probability: 

• Pre-test and post-test probabilities are the probabilities of a specific diagnosis before and after a test. 
• When we see a patient in front of us, we base our pre-test probability for that specific diagnosis on prevalence in the community, initial clinical information, and gestalt
• Dr. Garibaldi says pre-test probability is vital to performing the correct maneuvers for a focused physical exam.

Likelihood Ratios: 

• Each exam maneuver is a clinical test, with its own characteristics, such as sensitivity and specificity for a given diagnosis. 
• Using these characteristics, we can calculate a likelihood ratio, which can be used to adjust our post-test probability for that diagnosis. 
• A positive likelihood ratio measures how much a positive test affects the probability of a specific diagnosis. 
• A negative likelihood ratio measures how much a negative test affects the probability of that diagnosis.
• Using Fagan’s Nomogram for likelihood ratios
  • LR > 10 will change post test probability by 50% or more
  • LR > 5 will change post test probability by 40%

Table of Likelihood Ratios for Dyspnea

Dr. Garibaldi’s Take on Likelihood Ratios

• Likelihood ratios are not as sensitive as we would expect due to physiology. For example, patients with chronic heart failure may have hypertrophied lymphatics, and so fluid may not be audible in the lungs for all volume overloaded CHF patients
• Limitations of the evidence may be the variability of skill in each examiner, often based on time practicing. For example, if we compared physical exam and ultrasound in a practitioner who got 6 months of dedicated ultrasound training, but no specific exam training, it’s like comparing apples and oranges.
• Kashlak Pearl: Most maneuvers on the Over 6/Under 6 list are not auscultation. Rather they are observation or a stress-response maneuver
• Some maneuvers may have great likelihood ratios, but require significant practice to be able to perform, such as the Valsalva maneuver for heart failure, which make them much less practical.
• Hepatojugular reflux is a useful maneuver to confirm high filling pressures in the heart. But it may not be useful if you can already identify jugular venous distention. Dr. Garibaldi uses it as a confirmatory maneuver
• Kashlak Pearl: It is important to look at both the positive and negative likelihood ratios. For many tests, such as displaced PMI, they can be useful if positive, but their absence does not rule out the diagnosis. 
• If positive, some of these maneuvers are not only diagnostic, but also prognostic. For example, an S3 on auscultation can be diagnostic for heart failure, but also prognostic for cardiovascular and all-cause mortality (JACC Heart Failure 2014)
• Additionally, per Dr. Garibaldi, +LR for absent cardiac dullness is 16 and -LR 0.8 for diagnosing COPD in patients with a history of smoking or self-reported COPD (Sarkar et al)

Labs and Diagnostic Imaging

Why do a physical exam if we’re just going to order a chest xray, echocardiogram, and blood work anyway?

• • Context is key. Labs and imaging may not be easily available in outpatient clinics
  • Labs are not always helpful. For example, positive LR of BNP (4.6) is lower than a combined laterally displaced PMI (5.8), visible JVD (3.9), and S3 (3.9) for heart failure
  • Lab tests may be more useful to rule out diseases, as some of our high positive LRs do not have good negative LRs. For example, although JVD(+3.9/-0.7) and audible S3 (+3.9/-0.8) each have a positive LR of 3.9 for heart failure, their absence does not rule out heart failure. But with a negative chest XR (0.11), and we can be relatively confident the patient does not have a heart failure exacerbation
  • In the hospital, we are often using readily available labs in place of the physical exam, rather than to augment it

• Kashlak Pearl: Remember time is a diagnostic tool. It can be used to adjust the pre-test probability

What’s the role of Point of Care Ultrasound (POCUS)?

• Although sensitivity/specificity can reach 90% with our physical exam, ultrasound can get even higher into the 90s. For example, ≥3 B lines in bilateral lung zones on ultrasound has a sensitivity/specificity of 94%/92% respectively for cardiogenic pulmonary edema, with a positive LR of 12 (al Deeb et al)
• Ultrasound is a fantastic test for effusions, including small amounts of fluid anywhere. For example, the positive LR for a pleural effusion using ultrasound is 47 with a sensitivity of 94% and specificity of 98% (Yousefifard et al)
• Dr. Garibaldi recommends POCUS for looking at cardiac ejection fraction. The positive LR for visually reduced ejection fraction in heart failure exacerbation is 4.1 (Martindale et al)
• Ultrasound will never completely replace stethoscope because “you can’t see wheeze”

Take Home Points

• Dr. Garibaldi recommends being intentional with practice, including performing the maneuver on patients with and without positive findings.

• Dr. Garibaldi recommends asking others for their thoughts. Ask colleagues to come perform their exam maneuvers and compare notes.
• If interested in a certain part of the body, we must look at it completely. For example, don’t drop the stethoscope down someone’s shirt, hoping it will land on the heart.

Looking to learn how to perform a maneuver we just discussed?

Check out the Stanford 25 and Society of Bedside Medicine’s 5 Minute Moment!

Links*

1. Stanford 25: Teaching and promoting bedside exam skills to students, residents and healthcare professionals both in person and online
2. The 5 Minute Moment at the Society of Bedside Medicine
3. The POCUS Atlas: Evidence Based Point of Care Ultrasound

Goal

Listeners will feel confident how to optimally use the physical exam to guide clinical decision-making in patients presenting with dyspnea.

Learning objectives

After listening to this episode listeners will…  

1. Describe the effectiveness of the exam when it comes to aiding diagnosis in a patient with dyspnea
2. Identify specific exam maneuvers that can aid clinical decision-making 
3. Identify exam maneuvers that may not offer more information compared to imaging such as POCUS

Disclosures

This episode was made with assistance from the Society of Bedside Medicine and funding from the New York Academy Medicine.  Dr Garibaldi reports no relevant financial disclosures. The Curbsiders report no relevant financial disclosures.

Citation

Masur S, Garibaldi BT, Watto M, Williams P, Brigham S, Berk J.  #236 Physical Exam Series: Approach to Shortness of Breath. The Curbsiders Internal Medicine Podcast. https:/www.thecurbsiders.com/episode-list. Original Air Date October 12,  2020.

References

1. Mochizuki K et al. Importance of respiratory rate for the prediction of clinical deterioration after emergency department discharge: a single-center, case-control study. Acute Med Surg. Nov 2016. doi:10.1002/ams2.252
2. Sarkar M et al. Physical signs in patients with chronic obstructive pulmonary disease. Lung India. 2019. doi:10.4103/lungindia.lungindia_145_18
3. Fagan TJ. Letter: Nomogram for Bayes theorem. N Engl J Med. 1975;293(5):257. doi:10.1056/NEJM197507312930513
4. Simel, David, et al. Rational Clinical Examination, McGraw-Hill Professional Publishing, 2009. ProQuest Ebook Central 
5. McGee, Steven. Evidence-based physical diagnosis [4th edition] Elsevier, 2018. Clinical Key
6. Benbassat, J., Baumal, R. Narrative Review: Should Teaching of the Respiratory Physical Examination Be Restricted Only to Signs with Proven Reliability and Validity?. J GEN INTERN MED 25, 865–872 (2010). https://doi.org/10.1007/s11606-010-1327-8
7. Al Deeb M et al. Point-of-care ultrasonography for the diagnosis of acute cardiogenic pulmonary edema in patients presenting with acute dyspnea: a systematic review and meta-analysis. Acad Emerg Med. 2014;21(8):843-852. doi:10.1111/acem.12435
8. Yousefifard et al. Screening Performance Characteristic of Ultrasonography and Radiography in Detection of Pleural Effusion; a Meta-Analysis. Emerg (Tehran). 2016;4(1):1-10.
9. Martindale et al. Diagnosing Acute Heart Failure in the Emergency Department: A Systematic Review and Meta-analysis. Acad Emerg Med. 2016;23(3):223-242. doi:10.1111/acem.12878
10. Caldentey et al. Prognostic value of the physical examination in patients with heart failure and atrial fibrillation: insights from the AF-CHF trial (atrial fibrillation and chronic heart failure). JACC Heart Fail 2014.. doi:10.1016/j.jchf.2013.10.004