Robert M Centor MD FACP Regional Dean HRMC of UAB Chair ACP BOR Philip Tumulty The Effective Clinician Acknowledgements Castiglioni Roy and colleagues WAR research The CPS team ID: 775456
Download Presentation The PPT/PDF document " Learning (& teaching) to think like..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Learning (& teaching) to think like a clinician
Robert M.
Centor
, MD, FACP
Regional Dean, HRMC of UAB
Chair, ACP BOR
Slide2Philip Tumulty
The Effective Clinician
Slide3Slide4Slide5Acknowledgements
Castiglioni
, Roy and colleagues – WAR research
The CPS team
Groopman
,
Kahneman
,
Gladwell
, Klein for their books
Society to improve diagnosis in medicine
Slide6A recent patient presentation
41-year-old Hispanic man (left Mexico 7
yrs
ago) presents with 4 day h/o progressive dyspnea and fevers
No previous illness
Clear sputum with occasional blood streaks
Feels well other than dyspnea
Denies orthopnea or PND
Slide7Physical Exam
T 101 P 140 BP 140/85 RR 22 O
2
sat 91%
Decreased breath sounds on the right
Heart exam – tachycardia, no murmurs, rubs or gallops
No peripheral edema
Slide8Routine labs
CBC
WBC13kHgb10.4Hct31.2Plt32584% N, 10% L
BMP
135
97
12
128
4.1
27
0.8
8.6
Slide9CXR
Slide10Diagnosis?
How would you treat the patient?
Do you need more information?
Slide11Why clinical reasoning
Kassirer
:
Academic Medicine July, 2010 “Teaching Clinical Reasoning”
WAR research
Value of
attendings
sharing their thought processes
Slide12Diagnosis is Job #1
Slide13Requires thinking
Slide14Problem Representation
…
early step is the creation of the
mental
abstraction or
“
problem
representation
,
”
usually
as a one-
sentence summary
defining
the specific case in
abstract terms
Slide1547-year-old man presents to emergency department with right elbow painNo PMH, no medsWent to bed at 10:30 pm, awoke at 2:17 am with severe right elbow pain, elbow hot and exquisitely tenderNo previous similar episodesArthrocentesis: 140k WBC with no organisms on gram stain
The patient’s story
Patient #1
Slide16Senior resident
47-year-old man with a hot, right elbow and pus in the joint.
Attending physician
Two problem representations
Slide17Senior resident
47-year-old man with a hot, right elbow and pus in the joint.
47-year-old man with SUDDEN ONSET of a hot, right elbow and pus in the joint, but a negative gram stain.
Attending physician
Two problem representations
Slide18Illness scripts
Features present (or absent) that we use to match against our problem representation
Example – CAP – productive cough, fever, sweats &/or rigors, abnormal chest exam, typical CXR – short duration
Slide19Senior resident
47-year-old man with a hot, right elbow and pus in the joint.Therefore – septic arthritis
Attending physician
Implications from problem representation
Slide20Senior resident
47-year-old man with a hot, right elbow and pus in the joint.Therefore – septic arthritis
47-year-old man with SUDDEN ONSET of a hot, right elbow and pus in the joint, but a negative gram stain.Therefore, must consider crystalline arthritis.
Attending physician
Implications from problem representation
Slide21The patient had pseudogout.The resident focused solely on the synovial fluid WBCHe did not believe that crystalline arthritis could cause that high WBCThe attending focused on the negative gram stain and sudden onset. The WBC did not influence decision making.Both used system 1, the attending had a more refined illness script
Denouement
Slide2256-year-old man admitted for 4 days of progressive dyspneaMinimal cough – 2 episodes of clear pink tinged sputumDenies fever, rigors, has felt chillyNo upper respiratory tract symptomsRoutine labs unremarkableCXR:
Illness patient script #2
Slide23Slide24Emergency Dept
56-year-old man with progressive dyspnea and a left upper lobe infiltrate
56-year-old man with progressive dyspnea, but no purulent sputum, no fever and no rigors
Internal Medicine Team
Two problem representations
Slide25Community acquired pneumoniaMedical team remained skepticalproBNP = 900Echocardiogram order
Admission diagnosis
Slide26Left ventricular ejection fraction ~ 30 %Increased pulmonary artery pressure
Echocardiogram
results
Slide27LVEF = 20% with dilated cardiomyopathyMild CAD – approximately 40% in each arteryLeft atrial enlargementPCWP = 30PAP = 64/38
Cardiac catheterization
Slide28When questioned 36 hours later – patient told us that he had had progressive dyspnea on exertion for at least 2 monthsHistory of hypertension – untreatedCardiac exam – loud summation gallop
Further history & physical
Slide29Incomplete data collection – proper history not takenRadiologist read the X-ray as infiltrate – did not notice the cardiomegalyInadequate physical exam skillsDiagnostic inertia
Why such dx errors?
Slide30BE SKEPTICAL – do not believe the “label” the patient carriesAsk yourself if the story (problem representation) fits the illness script for the diagnosisIf not – start from the beginning!
How to avoid
such errors
Slide31In making diagnoses (really diagnostic decisions) we start with system 1When we think that system 1 is failing, we resort to system 2So what do we mean by system 1 and system 2
The Dual Process theory of cognition
Slide32System 1 - ExperientialIntuitiveTacit ExperientialPattern recognitionMatching against illness script
Dual process theory
Slide33System 1 - ExperientialIntuitiveTacit ExperientialPattern recognitionMatching against illness script
System 2 - AnalysisAnalyticDeliberateRationalCareful analysisConsider a wide differential
Dual process theory
Slide34Not Independent!!!
Slide3550-year-old male veteran presents with chest pain. Sent for stress test, but the lab finds that he has tachycardia. Labs include Calcium of 11.5.The patient is volume contracted because of 5 liters daily ileostomy losses (colectomy while in service for Crohn’s colitis)With repeated testing patient consistently has an elevated Calcium
Hypercalcemia
patient
Slide3650-year-old man with chest pain, tachycardia, markedly increased ileal output (ileostomy) and an elevated calcium level
Problem representation
Slide37Many students and residents just guess – usually focus on the hypercalcemia and pick cancer related or hyperparathyroidism – common causesUnfortunately, they do not develop problem representation They focus on one lab test, rather than the entire patient
System 1 thinking
Slide38This diagnosis is obtuse. Most correct answers come from a careful consideration of the entire differential diagnosisAs one goes through the differential diagnosis, the correct answer (hyperthyroidism) becomes a considerationFew if any learners include hyperthyroidism in their initial differential diagnosisWe need system 2 when the correct diagnosis not clear.
System 2 thinking
Slide39Most diagnostic decisions represent system 1 thinkingWe only move to system 2 when we mustExperts do more with system 1 than can experienced non-experts
Going back and forth
Systems 1 & 2
Slide40Illness scripts with greater granularityMore attention to “red flags”
System 1 for experts
Slide41Kahneman and TverskySkeptical attitude towards expertise and expert judgmentFocuses more on errorsHeuristic – shortcuts or “rules of thumb”While heuristics often work, they do have risks
Challenges – Heuristics and Biases
Slide42Anchoring heuristic – focusing too much on 1 piece of informationThe synovial fluid WBC in our patientAvailability heuristic – influenced by the last patient you saw, or a particularly memorable patientMy estimate of risk of allopurinol causing TENPremature closureOften related to anchoring heuristic
Classic heuristics that lead to errors
Slide43You
have a solution that you like, but you are choosing to ignore anything that you see that doesn't comply with it." – from the Blind Banker – Sherlock Season 1 Episode 2
Slide44The Naturalistic Decision Making movement
Sources of Power – Gary Klein
Now for a different construct
Slide45How do experts get it right?Especially high stakes, uncertainty and time pressureFirefighter studies
Naturalistic decision making
Slide46Approach 1 – use pattern recognition to match the problem representation with an illness scriptExperts note “red flags” or discomforts when 1 or more key features do not matchExperts have more completely developed illness scripts
RPD
Recognition-Primed Decision Making
Slide47NSTEMI or not: a 59-year-old man with chest pain and troponin elevationExpert discussant worries about a missing physical findingThe story:Severe chest painRadiation to legLow BPST elevationElevated troponin
JGIM April 2013
The patient with chest pain
Slide48Approach 1 – use pattern recognition to match the problem representation with an illness scriptExperts note “red flags” or discomforts when 1 or more key features do not matchExperts have more completely developed illness scriptsApproach 2 – related to hypothesis testingSearch for missing dataExample – examine synovial fluid for crystalsMore system 2 – but then reverts to system 1 when data collected
RPD
Recognition-Primed Decision Making
Slide49Approach 3 – mentally simulate the consequences of adopting the diagnosisKlein calls this a “premortem” examinationMental simulation can highlight concerns – and sometimes leads to re-evaluationAnalogous to – what diagnosis can we not afford to miss!
More RPD
Slide50Low BP but no mention of BP in the other armAdmitting resident describes an early diastolic blowing murmur II/VIExpert’s “pre-mortem” thinking caused him to worry about anti-coagulationWhen a nurse finally gave BP in both arms, the puzzle pieces all fit
Our chest pain patient
Slide5129-year-old female – fever and coughCXR
The Tyranny of a Term
An example
Slide52Slide53Azithromycin for presumed community acquired pneumonia
Treatment
Slide54No improvementAdmitted to hospitalTreated for CAP with moxifloxacinCXR
One week later
Slide55Slide56Continued cough and feverID consultedRepeat CXR
2 weeks after discharge
Slide57Slide582 months of symptomsNight sweats9 pound weight lossLives in a recovery home for drug abusersAnother resident has a bad cough
TAKES a good HISTORY
ID consultant
Slide59Anchoring – premature closureIncomplete illness scriptInadequate data collection
Diagnosis = TB
Errors
Slide60Learners want to learn how and why we make decisionsFacts are retrievableTherefore we must teach diagnostic reasoning every day on rounds, consults and in the clinicWisdom trumps knowledge
Understanding cognition and medical education
Slide61Remember that experts have more refined illness scripts and problem representationTherefore, we are trying to help our learners know when System 1 is adequate and when to move to System 2As learners progress they should spend more time in System 1They will get there faster if we are explicit in explaining the clues and cues
What should we be teaching?
Slide62Treated initially for community acquired pneumoniaNo clinical improvementID switched antibiotics 2 times10 days later we get these Xrays
Back to our patient
Slide63Xrays
10 days later
Slide64Comparison of PA films
Slide65Other clues
Hgb
slowly decreasing and after 10 days is less than 8
Patient is expectorating blood
Iron deficiency anemia
Slide66Bronchoscopy result
Fresh RBC
BAL RBC 206 million
BAL WBC 14 million
Slide67Urinalysis
Not originally obtained
180 RBC no casts
Slide68Audience participation
What is the new differential diagnosis?
What errors did we make?
Slide69Final diagnosis
Granulomatosis
with
polyangiitis