Clinical reasoning lessons learned from pharyngitis
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Clinical reasoning: lessons learned from pharyngitis!. Robert M. Centor, MD, FACP Dean, HRMC, UAB. Roadmap. Clinical reasoning System 1 – Intuitive (FAST) System 2 – Analytic (SLOW) My evolving problem representation and illness scripts Adult sore throats – morbidity & mortality And why?

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Clinical reasoning: lessons learned from pharyngitis!

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Clinical reasoning lessons learned from pharyngitis

Clinical reasoning: lessons learned from pharyngitis!

  • Robert M. Centor, MD, FACP

  • Dean, HRMC, UAB


Roadmap

Roadmap

  • Clinical reasoning

    • System 1 – Intuitive (FAST)

    • System 2 – Analytic (SLOW)

  • My evolving problem representation and illness scripts

  • Adult sore throats – morbidity & mortality

  • And why?

  • Take home lessons


Goals

Goals

  • Understand dual-process theory of clinical reasoning

  • Understand why we should expand the pharyngitis paradigm

  • Understand red flags in pharyngitis (changing the illness script)

  • Understand when to invoke analytic reasoning


Why clinical reasoning

Why clinical reasoning

  • Kassirer:

    • Academic Medicine July, 2010 “Teaching Clinical Reasoning”

  • WAR research

    • Value of attendings sharing their thought processes


The tyranny of a term

The tyranny of a term

  • 29-year-old woman c/o of fever and cough

  • Abnormal CXR

  • Treated for CAP with azithromycin


1 week later

1 week later

  • CXR has worsened

  • Admitted for CAP

  • Treated with moxifloxacin

  • D/C’ed after 4 days


2 weeks later

2 weeks later

  • Fever and cough have not subsided

  • ID consult takes a history:

    • 2 months of fever and cough

    • 9 pound weight loss

    • True night sweats daily

    • Lives in a home for former drug abusers


Diagnostic errors

Diagnostic errors

  • Patient has TB

  • The label encouraged “premature closure”

  • The physicians used intuitive decision making

  • Never moved to analytic decision making

  • They never “slowed down”


The tyranny of a term1

The tyranny of a term

  • CAP

  • CHF

  • “Just a sore throat”


Dual process reasoning

Dual-process reasoning


Intuitive or automatic

Intuitive or automatic

  • Problem representation (should include context)

  • Illness scripts

  • Often involves pattern recognition

  • Contextual cues


Expertise vs experienced non experts

Expertise vs. experienced non-experts

  • Refining problem representation

  • Refining illness scripts

  • Knowing when to invoke analytic reasoning

    • Slowing down when you should: a new model of expert judgment

    • Moulton Acad Med 2007 vol. 82 (10 Suppl) pp. S109-16


Cap revisited

CAP revisited

  • Physicians used intuitive reasoning

  • Their illness script for CAP:

    • Fever

    • Cough

    • Abnormal CXR

  • Consultant had an expanded illness script

  • “Slowed down” and switched to analytic reasoning


My pharyngitis evolution

My pharyngitis evolution

  • How my problem representation and illness scripts evolved over 30 years

  • The following cases tell a cautionary tale


Clinical reasoning lessons learned from pharyngitis

1981

  • Problem representation:

    • Does the adult pharyngitis ER patient have a strep throat?

  • Context:

    • No rapid tests yet

    • Minimal chance for follow-up

  • Illness script

    • Treat strep throat patients to prevent acute rheumatic fever

    • Strep throat patients look sicker (on average)


Group a strep prediction model

Group A Strep Prediction Model

  • 286 consecutive adult ED patients

  • 2 throat swab cultures – with specific typing of groups (A,B,C and G)

  • Logistic regression model developed

Centor. MDM – 1981.


The model

The MODEL

  • Four factors, equally weighted

    • Tonsillar exudates

    • Swollen, tender anterior cervical nodes

    • Lack of cough

    • Fever


Probability estimates

  • History of fever

  • Tonsillar exudates

  • Swollen, tender, anterior cervical nodes

  • Lack of cough

Probability Estimates


Clinical reasoning lessons learned from pharyngitis

2000

  • Problem representation:

    • Provide the four clinical factors

  • Context:

    • Want to treat strep throat – several reasons

    • But we may also want to treat group C strep


Illness script 2000

Illness script 2000

  • Use the score to estimate strep probability

  • We should give strep throat patients penicillin

    • To prevent acute rheumatic fever

    • To decrease peritonsillar abscess

    • To decrease symptom duration

    • To decrease contagion


Clinical reasoning lessons learned from pharyngitis

2000


An eponym

Adios pharyngitis – 1993

Eponym first used 2000

The prevailing paradigm

An eponym


The current early 21 st century paradigm illness script

The current (early 21st century) paradigm (illness script)


The current paradigm

The current paradigm


The current paradigm1

The current paradigm


The current paradigm2

The current paradigm


Clinical reasoning lessons learned from pharyngitis

2001


Clinical reasoning lessons learned from pharyngitis

  • Pharyngitis Guideline (CDC & AAFP)

    • Reassure 0 + 1

    • Test 2

    • Test or treat 3 + 4


Clinical reasoning lessons learned from pharyngitis

2002


Clinical reasoning lessons learned from pharyngitis

  • Pharyngitis guideline

    • Reassure 0 + 1

    • Test 2, 3 & 4

    • I become enraged with this quote


Clinical infectious diseases 2002

Clinical Infectious Diseases 2002

  • “We must conclude, therefore, that the algorithm based strategy proposed in the ACP-ASIM Guideline would result in the administration of antimicrobial treatment to an unacceptably large number of patients with nonstreptococcal pharyngitis.”


Why are the conclusions different

Why are the conclusions different?

  • Different focus of illness scripts

  • ACP – more outpatient generalist focused, therefore treating the patient is the clear priority

  • IDSA – more societal focused – worried about creating antibiotic resistance


Stimulus for blog new interest

Stimulus for blog & new interest


Clinical reasoning lessons learned from pharyngitis

2005


A malpractice lawyer calls

a Malpractice Lawyer calls

  • Father of 2 boys w/ documented group A strep c/o sore throat

  • Negative rapid test -> no Rx

  • Patient dies 2 days later of group A strep septicemia

  • Do they have a case?


Mistakes made 1

Mistakes Made #1

  • Ignored the concept of pretest probability

  • This is a contextual error

  • He used intuitive diagnosis and treatment, but should have invoked analytical reasoning

  • But this care does follow a guideline…

  • So probably no malpractice case


Clinical reasoning lessons learned from pharyngitis

2006


Clinical reasoning lessons learned from pharyngitis

Morning Report Presentation

Symptomatic treatment

both times

Severe (10/10) throat pain, high fever, and hoarseness

Returns to ER

Worsening symptoms –

Negative Rapid Test

Presents to ER Negative Rapid Test

30 yo WF

Day 1

ER Visit

Day 5

ER Visit

Day 3

ER Visit

Day 9


Case continued

Case Continued

  • Physical examination

    • T: 101° HR: 101 RR: 18 BP: 122/78

    • Prominent exudates, non-displaced uvula

    • Anterior cervical nodes

    • Diffuse anterior neck edema

    • Diffuse moderate ant neck tenderness

  • Pharyngitis score = 4


Laboratory data

Laboratory Data

  • Negative rapid test

  • Negative mono spot test

  • CT of neck


Enlarged palatine tonsils

Enlarged Palatine tonsils


Diagnostic studies

Diagnostic Studies

  • Culture – negative GC & chlamydia

  • Rapid flu test

  • EBV and CMV titers -

  • HIV -

  • Throat culture grew group C strep

  • Full recovery with 7 days of antibiotics


Differential of worsening pharyngitis

Differential of worsening pharyngitis

  • False negative rapid test

    • Sensitivity in practice - ~75%

  • NGA strep (group C > group G)

  • GC pharyngitis

  • Infectious Mononucleosis

  • Acute HIV infection

Shah. JGIM – 2007.


Differential continued

Differential continued

  • Peritonsillar abscess

  • Lemierre’s syndrome

  • F necrophorumbacteremic pharyngitis


Mistakes made 2

Mistakes Made #2

  • First ER visit acceptable – used intuition

  • Second ER visit – context should have triggered analytic reasoning

  • Decisions based on test results

  • Rather than patient presentation


Lesson learned from case 2

Lesson learned from Case #2

  • No previous illness script for “worsening pharyngitis”

  • Worsening pharyngitis is no longer “just a sore throat” AND

  • It REQUIRES analytic reasoning


Increasing interest in lemierre

Increasing interest in Lemierre

  • Repeated blog entries

  • Many comments including the mother of a Lemierre syndrome survivor

  • Multiple emails

  • Multiple newspaper links


Clinical reasoning lessons learned from pharyngitis

2008


Justin rodgers

Justin Rodgers

  • Day 1 – sore throat

  • Day 2 – doc started Z-pack

  • Day 3-6 – fevers to 102 pain & swelling Right neck


Justin rodgers1

Justin Rodgers

  • Admitted for metastatic lung abscesses

  • Day 9 – blood grew Fusobacterium

  • He died after 3 weeks in the ICU


Lemierre s syndrome

Lemierre’s Syndrome

  • Syndrome known since the early 1900s

  • 1936 Lancet by A. Lemierre

  • Bacillus funduliformis in 1930

  • Fusobacterium necrophorum (@ least 80%)

Lemierre. Lancet – 1936.


Lemierre s presentation

Lemierre’s Presentation

Sore throat


Lemierre s presentation1

Sore throat

4-5 days

Fever & rigors

Lemierre’s Presentation


Lemierre s presentation2

Sore throat

4-5 days

Fever & rigors

Lemierre’s Presentation

Repeated rigors


Lemierre s presentation3

Sore throat

4-5 days

Fever & rigors

Lemierre’s Presentation

Repeated rigors


Lemierre s presentation4

Sore throat

4-5 days

Fever & rigors

Lemierre’s Presentation

Repeated rigors

Metastatic abscesses


Mistakes made 3

Mistakes Made #3

  • Used azithromycin rather than penicillin

  • Primary physician stayed in automatic mode despite:

    • worsening course

    • neck swelling

    • bacteremicsymptoms


Tyranny of a term

Tyranny of a term

  • “just a sore throat”

  • Never considered switching to analytic reasoning


The danish experience 90 95

The Danish Experience 90-95

  • Incidence of necrobacillosis

    • 1.5 / million / yr

  • Incidence of Lemierre’s

    • 0.8 / million / yr

  • All 24 patients with Lemierre’s were young and previously healthy

  • Pre-hospital delay = increased morbidity

Hagelskjaer. Eur J Clin Microbiol Infect Dis - 1998.


The danish experience 98 01

The Danish Experience 98-01

  • 3 yr prospective study

  • 58 patients with Lemierre’s

  • 3.6 cases / million / yr

  • 14.4 cases / million / yr (or 1 in 70,000) for the age group 15-24

Hagelskjaer. Eur J Clin Microbiol Infect Dis - 2008.


Time for analytic reasoning

Time for analytic reasoning!


Illness script

Illness script

  • Is our illness script wrong?

  • Should we add fuso pharyngitis to our illness script?


Clinical reasoning lessons learned from pharyngitis

Is Fuso pharyngitis as dangerous as strep pharyngitis?


What data did i need

What data did I need?

  • Relative prevalence of strep and fuso pharyngitis

  • Risk of ARF from strep

  • Risk of Lemierre from fuso

  • Outcomes of ARF & Lemierre


Fusobacterium necrophorum

Fusobacterium necrophorum

  • Deduction –> F. necrophorum causes pharyngitis

  • Lemierre’s follows sore throats

  • 4 studies support F. necrophorum -> endemic pharyngitis

  • But no clinical data


Fusobacterium pharyngitis

Fusobacterium pharyngitis

  • Likely cause of endemic pharyngitis

  • More common in adolescents and young adults - ~ 10% incidence

  • Possible synergistic action with

    • EBV

    • Group C

  • No current diagnostic test

  • Differential for worsening pharyngitis


Clinical reasoning lessons learned from pharyngitis

2009


Lemierre s risk for adolescents

Lemierre’s Risk for adolescents

6% pharyngitis


Lemierre s risk for adolescents1

6% pharyngitis

60,000/

1 million

Lemierre’s Risk for adolescents


Lemierre s risk for adolescents2

6% pharyngitis

60,000/

1 million

Lemierre’s Risk for adolescents

6000

F. necro /

1 million


Lemierre s risk for adolescents3

60,000/

1 million

Lemierre’s Risk for adolescents

14.4 Lemierre’s/

1 million

6000

F. necro /

1 million

6% pharyngitis


Lemierre s risk for adolescents4

6% pharyngitis

60,000/

1 million

Lemierre’s Risk for adolescents

14.4 Lemierre’s/

1 million

6000

Fuso /

1 million

1/400 F. pharyngitis ->

Lemierre’s


Lemierre s mortality estimate

Lemierre’s mortality estimate


Why expand the pharyngitis paradigm

Why expand the pharyngitis paradigm!


Take home points

Take home points

  • F necrophorum causes endemic pharyngitis

  • Avoid macrolides for empiric treatment

  • Pharyngitis normally resolves in 3-5 days

  • Red flags

    • Neck swelling

    • High fever, rigors, night sweats

  • For bacteremic symptoms :

    • penicillin and metronidazole

    • clindamycin


Pharyngitis illness script 2011

Pharyngitis illness script 2011

  • Pharyngitis score probably indicates bacterial pharyngitis

    • Around 75% of 3s & 4s are strep A or C

  • Both strep A & C and fuso pharyngitis deserve antibiotics

  • When symptoms worsen, switch to analytic reasoning

  • We need to revise guidelines to consider more than GAS


Clinical reasoning

Clinical reasoning

  • Expand illness scripts and therefore

  • Problem representation

  • Understand the context of the illness scripts

  • Know when to “slow down” and analyze


References

References

  • Slides and references available upon request

  • [email protected]


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