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1
Evidence-Based Physical Diagnosis
Steve McGee, MD
Professor, University of Washington
Alaska ACP and AKOMA 2016
March 31, 2016
Diagnosis today:
Bedside diagnosisTechnology
Evolution of Diagnostic Standard
Diagnosis historically:
Diagnosis today:
Bedside diagnosisTechnology
Evolution of Diagnostic Standard
Dermatologic diagnosisCellulitisZosterPsoriasis
Neurologic diagnosisParkinson’s diseaseBell’s palsyAmyotrophic lateral sclerosis
Musculoskeletal diagnosisCardiologic diagnosis
PericarditisMitral valve prolapse
Ophthalmologic diagnosisDiabetic retinopathy
Psychiatric diagnosis
Diagnosis historically:
2
Diagnosis today:
Bedside diagnosisTechnology
Evolution of Diagnostic Standard
Evidence-BasedPhysical Diagnosis
essential here
Dermatologic diagnosisCellulitisZosterPsoriasis
Neurologic diagnosisParkinson’s diseaseBell’s palsyAmyotrophic lateral sclerosis
Musculoskeletal diagnosisCardiologic diagnosis
PericarditisMitral valve prolapse
Ophthalmologic diagnosisDiabetic retinopathy
Psychiatric diagnosis
Diagnosis historically:
Traditional Measure: Sensitivity and Specificity
Patients with suspected ascites:
Finding Sensitivity(%)
Specificity(%)
INSPECTION
Bulging flanks 73-93 44-70
Edema 87 77
PALPATION AND PERCUSSION
Flank dullness 80-94 29-69
Shifting dullness 60-87 56-90
Fluid wave 50-80 82-92
Better Measure: Likelihood Ratio (LR)
Probability of finding in patients with disease
Probability of finding in patients without disease
LR =
3
How Accurate is the Fluid Wave?
In 100 patients referred with abdominal distension and suspected ascites:
- 50% with ascites have a positive fluid wave
- 10% without ascites have a positive fluid wave
Therefore:
How Accurate is the Fluid Wave?
Probability of finding in patients with disease
Probability of finding in patients without disease
= = =50%
10%5.0
In 100 patients referred with abdominal distension and suspected ascites:
- 50% with ascites have a positive fluid wave
- 10% without ascites have a positive fluid wave
Therefore:
0.1 0.2 0.5 1 2 5 10
LRs = Diagnostic Weights
0 ∞
4
0.1 0.2 0.5 1 2 5 10
LRs = Diagnostic Weights
0 ∞
Increase probability
Decreaseprobability
No change in probability
0.1 0.2 0.5 1 2 5 10
LRs = Diagnostic Weights
0 ∞
+45%+30%+15%-15%-30%-45%
No changein probability
0.1 0.2 0.5 1 2 5 10
LRs = Diagnostic Weights
0 ∞
+45%+30%+15%-15%-30%-45%
No changein probability
5
Ascites
Finding Likelihood ratio if finding:
Present Absent
INSPECTION
Bulging flanks 1.9 0.4
Edema 3.8 0.2
PALPATION AND PERCUSSION
Flank dullness NS 0.3
Shifting dullness 2.3 0.4
Fluid wave 5.0 0.5
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Ascites
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Fluid wave
Absence of bulging flanksAbsence of shifting dullness
Flank tympanyAbsence of edema
Shifting dullnessEdema
Ascites
Absence of fluid waveBulging flanks
Flank dullness
6
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Fluid waveFlank tympany
Absence of edemaEdema
Ascites
4 Clinical Questions:
Does my patient with chest pain or dyspnea have a increased left atrial filling pressure?
Does my patient with lymphadenopathy have serious disease?
Does my patient with a systolic murmur have significant valvular heart disease?
Does my patient with acute respiratory complaints have pneumonia?
Congestive Heart Failure: Increased Left Heart Filling Pressure
“The patient cannot breathe in a horizontal position…the pulse is frequent and weak...the veins are swollen in the neck...the strokes of the heart extend farther… there is swelling of the feet and ankles…”
J. N. Corvisart, 1812
7
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Heart rate >100/minCracklesElevated neck veins
S3 gallopDisplaced apical impulse
EdemaS4 gallop
Abdominojugular test
Congestive Heart Failure: Increased Left Heart Filling Pressure
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Heart rate >100/minCracklesElevated neck veins
S3 gallopDisplaced apical impulse
EdemaS4 gallop
Abdominojugular test (positive or negative)
Congestive Heart Failure: Increased Left Heart Filling Pressure
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Heart rate >100/min
Elevated neck veinsS3 gallop
Displaced apical impulse
(i.e., Not Significantly different from 1.0)
EdemaS4 gallop
Crackles
Negative abdominojugular test Positive abdominojugular test
Congestive Heart Failure: Increased Left Heart Filling Pressure
NS
8
Finding Likelihood ratio if finding:
Present Absent
Heart rate > 100/min 5.5 NS
Crackles NS NS
Elevated jugular venous pressure 3.9 NS
Positive abdominojugular test 8.0 0.3
Supine apical impulse lateral to MCL 5.8 NS
S3 gallop 3.9 NS
S4 gallop NS NS
Edema NS NS
Congestive Heart Failure: Increased Left Heart Filling Pressure
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Heart rate >100/min
Elevated neck veinsS3 gallop
Displaced apical impulse
Crackles
Negative abdominojugular test Positive abdominojugular test
Congestive Heart Failure: Increased Left Heart Filling Pressure
NS
Characteristics of Crackles
Fine Coarse
EarlyInspiratory
LateInspiratory
Chronic obstructive lung disease
Congestive heart failure
Interstitial fibrosis
Pneumonia
Timing ofcrackles
9
Peripheral Lymphadenopathy
*Serious disease: malignancy, granuloma
Setting No. patients(no. studies)
Seriousdisease, %
Family practice 249 (1) 1
Lymph Node clinics 1049 (3) 25
Surgical series 2174 (8) 56
Bubonic plague (Boccaccio’s Decameron, 1348)‘there appeared at the beginning of the malady, certain swellings, either on the groin or under the armpits…named plague-boils…a very certain token of coming death”
Peripheral Lymphadenopathy
*Serious disease: malignancy, granuloma
Setting No. patients(no. studies)
Seriousdisease, %
Family practice 249 (1) 1
Lymph Node clinics 1049 (3) 25
Surgical series 2174 (8) 56
Bubonic plague (Boccaccio’s Decameron, 1348)‘there appeared at the beginning of the malady, certain swellings, either on the groin or under the armpits…named plague-boils…a very certain token of coming death”
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Lymphadenopathy
Age of patient
Weight lossPalpable spleen
Lymph node size
Supraclavicular nodesFixed lymph nodes
Hard nodes
10
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Lymphadenopathy
Age of patient
Palpable spleen
Lymph node size
Supraclavicular nodesFixed lymph nodes
Hard nodes
Weight loss
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Lymphadenopathy
Age < 40 years
Weight loss
Palpable spleen
Lymph node size ≥ 9 cm2
Supraclavicular nodes
Fixed lymph nodes
NS
Hard nodes
Lymphadenopathy
Finding Likelihood ratio if finding:
Present Absent
Age ≥ 40 years 2.4 0.4
Weight loss 3.4 0.8
Supraclavicular location 3.2 0.8
Generalized lymphadenopathy NS NS
Lymph node size< 4 cm2
4-8.99 cm2
≥ 9 cm2
0.4NS8.4
Hard texture 3.2 0.6
Lymph node tenderness 0.4 1.3
Fixed lymph nodes 10.9 NS
Palpable spleen NS NS
11
Systolic Murmurs:
A Treatise on the Diseases of the Heart and Great Vessels
James Hope, 1832
Increased AV velocity Aortic stenosis Increased AV flow without obstruction
Mitral regurgitation
Tricuspid regurgitation
Location of sound: Important landmark
Aortic valve
Boundary of all systolic murmurs
Mitral valve
3rd left parasternal space
Systolic Murmurs: 4 (of 6) Basic Patterns
Above and below landmark:“Broad apical-base”
12
Systolic Murmurs: 4 (of 6) Basic Patterns
Above and below landmark:“Broad apical-base”
ECHO:
• Increased aortic velocity (98%)
• 2/3 aortic stenosis
• 1/3 increased flow (no stenosis)
Systolic Murmurs: 4 (of 6) Basic Patterns
Above and below landmark:
Entirely above landmark:
“Broad apical-base”
“Isolated base”
Systolic Murmurs: 4 (of 6) Basic Patterns
Above and below landmark:
Entirely above landmark:
“Broad apical-base”
“Isolated base”
ECHO:
• Normal!
13
Systolic Murmurs: 4 (of 6) Basic Patterns
Above and below landmark:
Entirely above landmark:
Entirely below landmark:“Broad apical-base” “Left lower sternal”
“Isolated base”
Systolic Murmurs: 4 (of 6) Basic Patterns
Above and below landmark:
Entirely above landmark:
Entirely below landmark:“Broad apical-base” “Left lower sternal”
“Isolated base”
ECHO:
• Moderate/severe TR (65%)
• Increased AV flow (40%)
Systolic Murmurs: 4 (of 6) Basic Patterns
Above and below landmark:
Entirely above landmark:
Entirely below landmark:“Broad apical-base” “Left lower sternal”
“Broad apical”“Isolated base”
14
Systolic Murmurs: 4 (of 6) Basic Patterns
Above and below landmark:
Entirely above landmark:
Entirely below landmark:“Broad apical-base” “Left lower sternal”
“Broad apical”“Isolated base”
ECHO:
• Moderate/severe MR (63%)
• Plus mod/severe TR (34%)
Systolic Murmurs: 4 (of 6) Basic Patterns
Above and below landmark:
Entirely above landmark:
Entirely below landmark:“Broad apical-base” “Left lower sternal”
“Broad apical”“Isolated base”
Systolic Murmurs and Valvular Disease
Murmur pattern Aortic stenosis*
Mitral regurg†
Tricuspid regurg†
Broad apical-base 9.7 NS NS
Isolated base NS NS NS
Left lower sternal NS NS 8.4
Broad apical 0.2 6.8 2.5
No murmur 0.05 0.4 0.6* Peak aortic velocity ≥ 2.5 M/sec†Moderate or worse
15
Pneumonia
“Using my new invention, the clinician can detect acute pneumonia in every possible case”
René Laennec, 1821
“It is high time to strip the stethoscope of the extravagant pretensions thrust upon it”
Thomas Addison,1846
Pneumonia
“Using my new invention, the clinician can detect acute pneumonia in every possible case”
René Laennec, 1821
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Percussion dullness
Pneumonia
Egophony
Cachexia
Crackles
Vital sign abnormalities
Diminished breath soundsBronchial breath sounds
Wheezes
16
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Percussion dullness
Pneumonia
Egophony
Cachexia
Crackles
Vital sign abnormalities
Diminished breath soundsBronchial breath sounds
Wheezes
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Percussion dullness
Pneumonia
Egophony
Cachexia
Crackles
Vital sign abnormalities
Diminished breath soundsBronchial breath sounds
Wheezes
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Percussion dullness
Pneumonia
CracklesDiminished breath sounds
Wheezes
EgophonyCachexia
O2 saturation <95%Bronchial breath sounds
1.8
17
Pneumonia
Finding Likelihood ratio if finding:
Present Absent
Cachexia 4.0 NS
O2 saturation <95% 3.1 0.7
Percussion dullness 3.0 NS
Diminished breath sounds 2.2 0.8
Bronchial breath sounds 3.3 NS
Egophony 4.1 NS
Crackles 2.3 0.8
Wheezing 0.8 NS
Do combinations of findings increase accuracy?
SUSPECTED PNEUMONIA:The clinician scores 1 point for each of the following findings:
Temperature > 37.8 Heart rate > 100/min Crackles Diminished breath sounds Absence of asthma
Heckerling and others. Ann Intern Med 1990;113:664-670
Finding Likelihood ratio if finding:
Present Absent
0 or 1 findings 0.3 …
2 or 3 findings NS …
4 or 5 findings 8.2 …
Pneumonia
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
EgophonyCachexia
O2 saturation <95%Bronchial breath sounds
18
Pneumonia
Heckerling score, 4-5Heckerling score, 0-1
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
EgophonyCachexia
O2 saturation <95%Bronchial breath sounds
Do combinations of findings increase accuracy?
Finding Points
Age > 40 years +5
Lymph Node Tenderness -5
Lymph Node Size< 1 cm2
1 – 3.99 cm2
4 – 8.99 cm2
9 cm2 or more
0+4+8+12
Generalized pruritus +4
Supraclavicular nodes present +3
Lymph node hard +2
Correction factor -6
Vassilakopoulos and others. Medicine 2000: 79: 338-347
For example, a 55-year-old asymptomatic patient with nontender but hard supraclavicular adenopathy 6 cm2:
5 + 8 + 3 + 2 – 6 = 12
LYMPHADENOPATHY:
Finding LR
- 3 or less 0.04
-2 or -1 0.1
0 to 4 NS
5 or 6 5.1
7 or more 21.9
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Lymphadenopathy
Weight lossLymph node size ≥ 9 cm2
Supraclavicular nodes, or hard nodes
Fixed lymph nodes
19
0.1 0.2 0.5 1 2 5 10 LRsLRs
-45% -30% -15% +15% +30% +45%
Probabilitydecrease increase
Lymphadenopathy
Weight lossLymph node size ≥ 9 cm2
Supraclavicular nodes, or hard nodes
Fixed lymph nodesLymph node score ≥ 7Lymph node score -3 or less
Lymph node score -2 or -1
Findings With Surprising Accuracy
Conjunctival rim pallor, detecting Hb < 11 gm/dL
LR = 16.7
Absence of percussion dullness, detecting pleural effusion
LR = 0.1
Characteristic diastolic murmur of ARMurmur present, LR = 9.9 (mild AR or worse)Murmur absent, LR = 0.1 (moderate AR or worse)
Pulsus paradoxus, detecting cardiac tamponadeParadox present, LR = 5.9Paradox absent, LR = 0.03
Summary: Modern Role of Physical Diagnosis
For entire areas of clinical medicine, bedside diagnosis remains the diagnostic standard
Bedside diagnosisTechnology
20
Summary: Modern Role of Physical Diagnosis
For entire areas of clinical medicine, bedside diagnosis remains the diagnostic standard
If technology is diagnostic standard, 3 Approaches to Physical Diagnosis Accept it all, “lock, stock, and barrel” Toss the entire enterprise out
Bedside diagnosisTechnology
Summary: Modern Role of Physical Diagnosis
For entire areas of clinical medicine, bedside diagnosis remains the diagnostic standard
If technology is diagnostic standard, 3 Approaches to Physical Diagnosis Accept it all, “lock, stock, and barrel” Toss the entire enterprise out Use an EVIDENCE-BASED approach
Evidence-Based Physical Diagnosis essential here
Bedside diagnosisTechnology
Summary: Modern Role of Physical Diagnosis
For entire areas of clinical medicine, bedside diagnosis remains the diagnostic standard
If technology is diagnostic standard, 3 Approaches to Physical Diagnosis Accept it all, “lock, stock, and barrel” Toss the entire enterprise out Use an EVIDENCE-BASED approach
Best measure of accuracy = Likelihood ratio Ascites Increased left heart filling pressure Lymphadenopathy Systolic murmurs Pneumonia
Evidence-Based Physical Diagnosis essential here
Bedside diagnosisTechnology
21
Thanks!