Title: Spotlight Case January 2004
1Spotlight Case January 2004
- Crushing Chest Pain A Missed Opportunity
2Source and Credits
- This presentation is based on the Jan. 2004 AHRQ
WebMM Spotlight Case - See the full article at http//webmm.ahrq.gov
- CME credit is available through the Web site
- Commentary by Mark Graber, MD, State University
of New York at Stony Brook - Editor, AHRQ WebMM Robert Wachter, MD
- Spotlight Editor Tracy Minichiello, MD
- Managing Editor Erin Hartman, MS
3Objectives
- At the conclusion of this educational activity,
participants should be able to - Appreciate the challenges of diagnosing aortic
dissection - Describe the Bayesian approach to diagnosis
- Understand the benefits and limitations of
heuristic thinking - List the cardinal dimensions of clinical
decision-making
4Case Crushing Chest Pain
- A 62-year-old female presented with 12 hours of
crushing chest pain. Her blood pressure was
140/90, heart rate 110, and respiratory rate 16.
An EKG revealed left ventricular hypertrophy with
strain. Review of the chest x-ray in the
emergency department (ED) revealed no
abnormalities. She was treated for an acute
coronary syndrome (ACS) with heparin, aspirin,
morphine, and a nitroglycerin drip. Cardiac
enzymes were drawn.
5Case (cont.) Crushing Chest Pain
- The patient was admitted to the cardiac care
unit. Seven hours after admission, the patient
became hypotensive, with a systolic blood
pressure in the 80s and a heart rate in the 120s.
A repeat EKG revealed no significant changes.
Right-sided leads showed no evidence of right
ventricular infarct. The first set of cardiac
enzymes was equivocal, and a CPK-MB was minimally
elevated.
6Chest Pain in the Emergency Dept.
- Chest pain is a common complaint in the ED
- Correct and timely diagnosis is critical and
linked to morbidity and mortality in many
diagnoses - Acute coronary syndrome
- Pulmonary embolism
- Aortic dissection
.
7Diagnosis of Chest Pain in the ED
von Kodolitsch Y, et al. Arch Intern Med.
20001602977-82.
8Three Different Approaches to Medical
Decision-Making
- Use of heuristics
- Bayesian approach
- Application of algorithms
Elstein AS. Acad Med. 199974791-4.
9Examples of Medical Decision-Making Using
Heuristics
- AvailabilityDiagnosis springs to mind because
clinician has seen such patients before - RepresentativenessMental match between patients
symptoms and characteristic symptoms of disease
stored in clinicians memory
Elstein AS. Acad Med. 199974791-4.
10Benefits and Risks of Using Heuristics
- AdvantageCan reach correct diagnosis rapidly
- DisadvantageCan lead to diagnostic error when
correct diagnosis not considered
Elstein AS. Acad Med. 199974791-4.
11This Case Approached Using Heuristics
- Clinician knows
- Acute Coronary Syndrome is the most common cause
of chest pain in the emergency room - Clinician thinks
- Diagnosis must be ACS
12Medical Decision-Making Using Bayesian Approach
- List all diagnostic possibilities
- Determine likelihood of each
- Gather pertinent clinical data
- Adjust initial probabilities based on clinical
data using Bayesian calculations
Sox HC Jr, et al. Medical decision making.1988.
13Is this ACS? Bayesian Approach
Nomogram
14Medical Decision-Making Using Bayesian Approach
- After adjusting pretest probability by clinical
data available in this case (lack of ECG
findings, lack of rales, hypotension, etc.), the
overall likelihood of ACS is less than 17 - CONSIDER ALTERNATIVE DIAGNOSIS!
15Medical Decision-Making Using Algorithmic Approach
- Use of algorithms can simulate expert thinking
- Multiple decision models available
- Algorithms improve sensitivity and specificity of
diagnosing cardiac ischemia when compared with
clinical judgment
Panju AA, et al. JAMA. 19982801256-63. Goldman
L, et al. N Engl J Med. 1988318797-803. Pozen
MW, et al. N Engl J Med. 19843101273-8.
16Medical Decision-Making Using Algorithmic Approach
- Use of a formula based on 7 clinical variables to
predict cardiac ischemia results in a likelihood
of ACS of 7 - Use of a derived prediction rule using 4 clinical
variables (hx MI, diaphoresis, ST elevation, q
waves) results in a likelihood of 2 of ACS in
this patient - CONSIDER ALTERNATIVE DIAGNOSIS!
Pozen MW, et al. N Engl J Med. 19843101273-8.
Tierney WM, et al. Crit Care Med.
198513526-31.
17Case (cont.) Crushing Chest Pain
- The team re-reviewed the chest x-ray and
discovered an abnormality in the aorta a 1-cm
separation between the intimal calcification and
the adventitial outline of the descending aorta
(the calcium sign), consistent with aortic
dissection.
18Chest X-ray with Calcium Sign (arrow)
19Aortic Dissection
- Mortality rates approach 1 per hour
- Diagnosis is missed in 25-50 of patients
- Survival exceeds 90 with prompt diagnosis and
management
Spittell PC, et al. Mayo Clin Proc.
199368642-51. Klompas M. JAMA.
20022872262-72. Nienaber CA, et al. N Engl J
Med. 19933281-9.
20Aortic Dissection
- Classic presentation includes acute-onset, severe
chest/back pain described as tearing or
ripping - Atypical presentations are common
- 15 of patients report NO pain
- Supportive findings include pulse deficit, new
aortic regurgitation, tamponade, and focal
neurological deficits - Majority of patients have no specific physical
findings
Spittell PC, et al. Mayo Clin Proc.
199368642-51. Hagan PG, et al. JAMA.
2000283897-903.
21Aortic Dissection Physical Exam Findings
Klompas M. JAMA. 20022872262-72.
22Aortic Dissection
- 90 of patients with aortic dissection have an
abnormal CXR - Abnormal aortic contour and widened mediastinum
are the most common findings - A NORMAL CXR DOES NOT RULE OUT AORTIC DISSECTION!
Spittell PC, et al. Mayo Clin Proc.
199368642-51. Hagan PG, et al. JAMA.
2000283897-903.
23Aortic Dissection CXR Findings
Klompas M. JAMA. 20022872262-72.
24Case (cont.) Crushing Chest Pain
- A transesophageal echocardiogram revealed an
ascending aortic dissection. Anticoagulation
therapy was discontinued, beta-blocker therapy
was initiated, and cardiothoracic surgery was
called. The patient was transported to the
operating room. Upon arrival in the operating
room, the patient became progressively
hypotensive, coded, and died. Post-mortem autopsy
revealed hemorrhage into the pericardium.
25Transesophageal Echocardiography of Aortic
Dissection
Video
26What Went Wrong?
- The patients death may be result of errors in
each of the cardinal dimensions of clinical
decision-making - Data gathering
- Hypothesis generation/synthesis
- Verification
27Errors in Clinical Decision-Making
- Data gathering
- Staff not trained to recognize the calcium sign
- Synthesis
- Diagnosis of ACS assigned despite low likelihood
- An alternative diagnosis was not initially
entertained - Verification
- Premature closure CCU team accepted diagnosis of
ACS without re-examining the facts - Framing Team biased by how case was presented
- Anchoring Team fixated on an early diagnosis
Rosman HS, et al. Chest. 1998114793-5. Elstein
AS. In Clinical reasoning in the health
professions. 199549-59. Kassirer JP, Kopelman
RI. Am J Med. 198986433-41. Graber M, et al.
Acad Med. 200277981-92.
28Avoiding Errors in Clinical Decision-Making
- Consider diseases you cannot afford to miss
- Supplement diagnostic skills using a bayesian
approach or established algorithms - Consider tests that will help rule in an
alternative diagnosis rather than pursue a test
for a diagnosis already in doubt - Be aware of common cognitive biasesavoid
premature closure by re-examining the facts - Ask yourself, What else could this be?
Rosman HS, et al. Chest. 1998114793-5. Elstein
AS. In Clinical reasoning in the health
professions. 199549-59. Kassirer JP, Kopelman
RI. Am J Med. 198986433-41. Graber M, et al.
Paper presented October 20, 2002 Baltimore, MD.