ebm physical exam series introduction and systolic murmurs

EBM Physical Exam Series

Samuel Lai, MD Assistant Clinical Professor UCI Internal Medicine Hospitalist Program

Introduction and Systolic Murmurs

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Introduction

1. How did we get here? a) Educational grant background

b) My interest in studying the physical exam

2. Where are we going from here? a) An EBM series focused on the physical exam

b) Topics for consideration

a) Aortic stenosis

b) CHF

c) Cardiac Tamponade

d) Others

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Introduction – EBM PE Series Goals

• Identify the evidence-based medicine behind our physical exam

• Employ EBM knowledge to our daily practice

• Share an open, low-stakes environment for skills practice

• Create a forum for collegial exchange

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Introduction – Series Session Outline

Series Goals Session Goals

Identify the evidence-based medicine behind our physical

exam Power-Point Lecture

Employ EBM knowledge to our daily practice

Share an open, low-stakes environment for skills practice

Audio Review Video Review

Live Demonstration

Create a forum for collegial exchange

Interactive sessions (group work, low-stakes quizzing,

gamification)

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EBM PE Series: Session 1 Introduction to Statistics and Systolic Murmur Overview

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Question for the Group

Inpatient wards

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Additional Thoughts

1. Appropriate Use, ACC, 2017: “TTE is an appropriate test among patients with unexplained murmur or abnormal heart sounds, reasonable suspicion for VHD, history of rheumatic heart disease, known disease associated with VHD, first-degree relatives of patients with bicuspid aortic valve, or exposure to medications that could result in VHD.”

2. VHD Guidelines, AHA, 2014: “A TTE should be performed to correlate findings with initial impressions based on initial clinical evaluation”

3. VHD Management, MKSAP 17: If a systolic murmur is greater than 2/6, then a TTE is warranted

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What physical exam findings for murmurs are helpful?

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Likelihood Ratios – A Necessary Sidebar

• What is a likelihood ratio (LR)?

• “The LR of a test/sign is the proportion of patients with disease who have a particular finding, divided by the proportion of patients without disease who also have the same finding”

• The proportion of patients with an MI that have a troponin of 1, divided by the proportion of patient without an MI who also have a troponin of 1.

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Likelihood Ratios – The Equations

“Positive” Likelihood Ratio

Sensitivity/(1-Specificity)

“Negative” Likelihood Ratio

(1-Sensitivity)/Specificity

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Likelihood Ratios – Easier Ways to Think About This

• If a LR is > 1, then the odds of having the disease increases

• If a LR is < 1, then the odds of having the disease decreases

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Likelihood Ratios – Why Use These Versus Others?

1. Simplistic

2. Accurate

3. Able to Combine

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Likelihood Ratios – Simplicity Exercise

Simplicity Exercise

45 y/o white male with atypical chest pain (pretest 51%)

Stress Test: Specificity 90%, Sensitivity 75%

Without using likelihood ratios, how much does a positive test affect your pre-test probability?

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Likelihood Ratios – Accuracy Exercise

Accuracy Exercise

45 y/o white male with typical chest pain (pretest 70%)

A. TEST A: Specificity 95%, Sensitivity 10%

B. TEST B: Specificity 90%, Sensitivity 40%

C. TEST C: Specificity 85%, Sensitivity 70%

Which test would you order? Why?

LR 2

LR 4

LR 4.6

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Likelihood Ratios – Combination Exercise

Combination Exercise

45 y/o white male with SOB. You are concerned about CHF. Pretest probability is 50%.

Physical Exam Findings

• Positive hepatojugular reflux (LR 5)

• Bilateral lower lobe crackles (LR 6)

• S3 present (LR 10)

Can we add these findings together?

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Likelihood Ratios – Everyday Utilization

Do you utilize LRs during rounds?

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Previous Example

CHF pre-test probability:

50%

Positive hepatojugular reflux

(LR 5)

Post-test probability?

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Previous Example

Pre-test probability: 50%

Positive hepatojugular reflux (LR 5)

Post-Test Probability: 80%

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Previous Example

Pre-test probability: 50%

Positive hepatojugular

reflux (LR 5)

Post-Test Probability: 80%

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Likelihood Ratios – Ending the Sidebar

Questions?

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Murmurs and VHD: An Overview

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Murmurs and VHD: Characteristic Murmurs

Characteristic Murmurs

• Aortic stenosis

• Mitral regurgitation

• Tricuspid regurgitation

• Ventricular septal defect

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Murmurs and VHD: Steve McGee’s Murmur Patterns

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Murmurs and VHD: Comparison of LRs

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Murmurs and VHD: A Teaser

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EBM Series: Session 1 – Take Home Points

1. Likelihood ratios: simplistic, accurate, able to be combined

2. Remember 15-30-45% rule for LRs of 2, 5 and 10

3. Consider utilizing the broad-apical-base pattern for AS

4. Consider utilizing the broad-apical pattern for MR

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EBM Series: Session 1 – The End

Questions, concerns or thoughts?

ebm physical exam series introduction and systolic murmurs

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