Using Information to Solve Clinical Problems: The Patient With Chest Pain

1
Using Information to Solve Clinical Problems The
Patient With Chest Pain

• Family Medicine Clerkship
• 2000-2001

2
Goals and objectives

• Upon completion the learner will be able to
• identify the types of information necessary for
  clinical care
• using a clinical scenario identify areas where
  information should be sought
• when given a clinical problem be able to identify
  resources useful for delivering optimum care

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Information at the point of care

• A physician seeing patients in an office setting
  will generate 15 questions per day
• 33 related to treatment
• 25 to diagnosis
• 15 to pharmacotherapeutics
• Resource utilization varies
• Textbooks
• Human
• PDR

4
Information at the point of care

• Why arent more of these questions answered?
• Convenience
• Time
• Inability to formulate answerable questions

5
Should we consider these issues?

• Current system doesnt work
• Decisions based on dated information
• CME not effective
• Adult learning theory
• Learning takes place
• in context of patient care
• when questions are answered
• the issues are applicable to work
• when it doesnt take too much time

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Model for information needs
Unrecognized information needs
Attitude
New Medical Knowledge
Recognized information needs
Implemented information needs

• Attitude
• Importance of question
• Knowledge of resources
• Environment

• Environment
• Importance of question

Pursued information needs
Satisfied information needs
Skill
Knowledge of resources
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What do you need to practice effective medicine?

• Personal skills
• ability to critically reflect on your practice
• ability to formulate questions
• skills, time, and resources to answer questions
  with evidence
• ability to implement answers in the care of
  patients

8
Using evidence in practice

• Consider alternatives to Medline searches
• Be able to recognize relevant, patient- oriented
  valid studies
• Use computers at point of care

9
Getting started on a lifetime of practice

• Reflect on patient care on a regular basis
• Inquire about the best approach for patients,
  dont advocate a plan
• Feel good about not knowing everything
• Learn to ask a focused clinical question
• Let someone else do the heavy lifting
• Learn to use a computer

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Ms. P. J.

• 48 year old female with mid sternal discomfort
  occurring on exertion but mostly at rest
  intermittently for 6 months, relieved by TUMS
• HTN, DM, Hyperlipidemia
• Father with MI at 68

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Knowledge base

• Unstable angina causes
• Increase in oxygen demand
• exertion
• Reduced supply of oxygen
• anemia, thrombus, spasm
• Most common cause unstable coronary plaque
• Variant angina, non-Q wave MI, post MI angina
  also in this definition

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Medical knowledge base

• Presentation
• Symptoms of angina at rest
• New onset exertional angina of Canadian
  Cardiovascular Association Class III
• Recent acceleration of angina as reflected by an
  increase in severity to class III

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Posing a clinical question

• Try to avoid patient specific questions
• What do I do about this patient?
• Frame the question in a manner that will generate
  pertinent answers
• How and where should I evaluate chest pain in
  patients without ongoing pain but with risk
  factors?
• What studies will either increase or decrease my
  suspicion that a female patient with atypical
  pain but multiple risk factors has angina?

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Searching for information

• Formulate the question
• Search secondary sources
• Critique the information
• Are the results relevant?
• Is the information going to change my practice?
• Is the information valid?

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Where to find the information?

• http//www.fammed.usouthal.edu
• http//www.guideline.gov/

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Three principal presentations of unstableangina

• Rest angina
• Angina occurring at rest and
  usually prolonged 20 minutes
• occurring within a week of
  presentation.
• New onset angina
• Angina of at least CCSC III
  severity with onset within 2 months of
• initial presentation.
• Increasing angina
• Previously diagnosed angina that
  is distinctly more frequent, longer in duration,
  or lower in threshold (i.e., increased by at
  least one CCSC class within 2 months of initial
  presentation to at least CCSC III severity).

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Grading of angina pectoris by the
CanadianCardiovascular Society classification
system

• Class Description of
  stage Class I Ordinary physical
  activity does not cause angina, such as walking,
  climbing stairs. Angina occurs with
  strenuous, rapid, or prolonged exertion at work
  or recreation. Class II Slight
  limitation of ordinary activity. Angina occurs on
  walking or climbing stairs rapidly,
  walking uphill, walking or stair climbing after
  meals, or in cold, or in wind, or under
  emotional stress, or only during the few hours
  after awakening. Walking more than two
  blocks on the level and climbing more
  than one flight of ordinary stairs at a normal
  pace and in normal condition. Class III
  Marked limitations of ordinary physical
  activity. Angina occurs on walking one
  to two blocks on the level and climbing one
  flight of stairs in normal conditions
  and at a normal pace. Class IV
  Inability to carry on any physical activity
  without discomfort -- angina symptoms
  may be present at rest.

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Diagnosing the patient with chest pain

• Likelihood of syndrome being cardiac in nature
  dependent on
• history obtained by the physician
• evidence of prior MI or other evidence of CAD
• Age, sex, DM, HTN, smoking, lipids
• Other factors
• Cocaine, prior variant angina, etc.

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Characterizing chest pain

• Not angina
• Pleuritic pain
• Mid-epigastric pain
• Point tenderness
• Reproducible chest wall pain
• Episodes lasting seconds
• Pain radiating into the lower extremities

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Characterizing chest pain

• Not angina?
• 22 of patients presenting to ED had sharp pain
  and 13 had pleuritic pain
• 7 of those had ischemic pain on follow-up

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Making the Dx Physical exam

• Commonly normal
• Findings of note
• Transient S3 or S4, mitral regurgitation murmer,
  or precordial lift during episode
• Bruits or other evidence of PVD

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Making the Dx EKG

• Findings suggestive of CAD
• ST elevation or depression
• T-wave inversions across precordium
• Changes during pain

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Unstable angina Prognosis

• Risk of death between that of stable angina and
  acute MI
• Improves after 2 months
• Change in character or tempo often presage
  adverse event
• Prolonged pain also considered high risk

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Unstable angina Prognosis

• Worrisome physical exam findings
• CHF, MR murmur, hypotension with pain
• EKG
• Dramatic ST changes

25
Factors predicting survival

• LV function
• Extent of obstruction
• Age
• Co-morbid conditions

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Risk stratification

• Physician performance
• Computer enhancement

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Management of Chest Pain Syndrome

• Telephone presentation
• Should be seen with rare exception
• Those with known CAD should go to ER

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Management of Chest Pain Syndrome

• Unstable angina with symptoms less than 20
  minutes, hemodynamic instability or LOC should go
  to ED
• Others can be evaluated in office with EKG
  capability
• 98.5 stable following transport
• EKG with elevations PPV 79
• NPV 64

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Chest pain syndrome Management

• Not angina
• Possible unstable angina
• Probable Unstable angina without ongoing ischemia
• Unstable Angina with ischemic changes or ongoing
  pain

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Chest pain syndrome Management

• Not angina
• Discontinue cardiac work-up
• Look for other causes
• Return for changes in symptoms

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Chest pain syndrome Management

• Further risk stratification
• Evidence of ongoing ischemia
• Prior cardiac work-up including LV function,
  anatomy, revascularization, medications
• Current history

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Chest pain syndrome Management

• Unstable angina
• Pain similar to prior ischemic event
• Known CAD or CHF with pain
• Pain on maximal medical management
• Pain 20 minutes, worsening of symptoms two
  classes

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Chest pain syndrome Management

• Intermediate risk for unstable angina
• No known disease but high likelihood based on
  history
• Known disease but weak history
• Low risk but unreliable

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Chest pain syndrome Management

• Low risk for unstable angina
• No ongoing pain or EKG changes
• Consider other causes
• Consider outpatient work-up

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Unstable Angina

• Give ASA
• Consider precipitating factors
• Anemia, thyroid disease, pneumonia, infection,
  valvular disease
• Consider other diagnoses
• Acute MI, aortic dissection, ruptured aneurysm,
  pericarditis, pneumothorax, PTE

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Unstable Angina

• Treatment
• ICU, bed rest, oxygen if hypoxic
• ASA, heparin, nitrates, beta-blockers, morphine
• Rule-out myocardial infarction, lipids
• EKG at 24 hours or with pain
• CXR, ECHO
• For ongoing pain, cardiologist is provider of
  choice

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Unstable angina

• Monitoring heparin
• 80 units/kg bolus and infusion of 18
  units/kg/hour Check after 6 hours and make
  adjustments
• H and H every day for three days and platelets
• LMWH is alternative
• 1mg/kg BID
• Advantage is no laboratory monitoring of
  anticoagulation, but still need to monitor for
  bleeding

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Intermediate risk of unstable angina

• Consider admission to monitored bed
• Anticoagulation, ASA, NTG as indicated

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Low risk of unstable angina

• Therapeutic trial with nitrates, beta-blockers,
  ASA
• Exercise or pharmacologic stress test

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Ms. P. J.

• Evidence suggested that patients with risk
  factors but a story inconsistent with angina
  could be managed in an outpatient setting
• Female patients with multiple risk factors should
  have studies other than a plain stress test to
  evaluate their chest pain

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Ms. P. J.

• Patient was placed on ASA and Atenolol and
  scheduled for an outpatient cardiolyte GXT which
  was positive
• She was cathed as an outpatient which revealed a
  single vessel lesion which was opened
• She is now on aggressive risk factor management
  (but that is the subject of another talk)