PowerPoint Presentation: Evaluation of Dyspnea
Slide 1: Definition and Clinical Significance
Dyspnea is a subjective experience of breathing discomfort that varies in intensity and accounts for 1 in 4 ambulatory patient encounters. 1
- Chronic dyspnea is defined as shortness of breath lasting >4 to 8 weeks 1
- Approximately 85% of cases are attributable to congestive heart failure, myocardial ischemia, or COPD 1
- More than 30% of cases are multifactorial 1
- Dyspnea is a predictor for all-cause mortality 2
Slide 2: Pathophysiology - Two Primary Mechanisms
Mechanism 1: Increased Respiratory Drive
Increased afferent input to respiratory centers from multiple sources: 1
Stimulation of pulmonary receptors (irritant, mechanical, vascular):
- Interstitial lung disease, pleural effusion, pulmonary embolism, congestive heart failure 1
Chemoreceptor stimulation:
Mechanism 2: Impaired Ventilatory Mechanics
Reduced afferent feedback for a given efferent output (corollary discharge mismatch): 1
- Airflow obstruction: Asthma, COPD, laryngospasm (increased resistive load from airway narrowing and elastic load from hyperinflation) 1
- Muscle weakness: Myasthenia gravis, Guillain-Barré, spinal cord injury, myopathy 1
- Decreased chest wall compliance: Severe kyphoscoliosis, obesity, pleural effusion 1
Key concept: In most cardiopulmonary diseases, both mechanisms coexist in varying degrees. 1
Slide 3: MCQ #1 - Pathophysiology
Case: A 68-year-old woman with known COPD presents with worsening dyspnea. She describes her breathing as "My breath doesn't go out all the way" and "My breathing requires work." Spirometry shows FEV1/FVC ratio of 0.65 with hyperinflation.
Question: Which pathophysiologic mechanism(s) best explain her dyspnea?
A) Increased respiratory drive from chemoreceptor stimulation only
B) Impaired ventilatory mechanics from airflow obstruction and hyperinflation only
C) Both increased respiratory drive (from increased dead space/hypercapnia) and impaired mechanics (from obstruction/hyperinflation)
D) Stimulation of pulmonary vascular receptors only
Answer: C - COPD produces dyspnea through combined mechanisms: airflow obstruction creates increased resistive and elastic loads from hyperinflation (impaired mechanics), while increased dead space and potential hypercapnia increase respiratory drive. 1
Slide 4: Quality of Dyspnea - Diagnostic Clues
The words patients use to describe dyspnea provide insight into underlying pathophysiology: 1
"Chest Tightness"
- Relatively specific for bronchoconstriction (asthma, COPD exacerbation) 1, 3, 4
- Most frequent descriptor in asthma patients (45.8%) 5
"Air Hunger" and "Inability to Get a Deep Breath"
- Suggests restrictive mechanics: heart failure, pulmonary fibrosis, dynamic hyperinflation 1, 3, 4
- Combined effects of increased drive to breathe and limited tidal volume 1
- Most frequent descriptor in CHF patients (24.4% for "hunger for more air") 5
"My Breathing Requires Work" / "My Breath Doesn't Go Out All the Way"
- Suggests obstructive disease: COPD (46.3% and 29.6% respectively) 5
- Reflects increased effort from airflow obstruction 5
"Effort," "Suffocation," "Rapid Breathing"
Important caveat: Linguistic and cultural differences exist in how patients characterize symptoms. 1
Slide 5: MCQ #2 - Quality of Dyspnea
Case: A 45-year-old woman presents to the ED with acute dyspnea. She describes "chest tightness" and "I feel that my airway is obstructed." She has a history of seasonal allergies. Examination reveals diffuse expiratory wheezing. Oxygen saturation is 92% on room air.
Question: Based on the quality of her dyspnea, what is the most likely diagnosis?
A) Acute myocardial infarction
B) Pulmonary embolism
C) Asthma exacerbation
D) Panic attack
Answer: C - "Chest tightness" is relatively specific for bronchoconstriction and is the second most frequent descriptor in asthma patients (45.8%). 1, 5 The descriptor "I feel that my airway is obstructed" is also highly associated with asthma (40.7%). 5
Slide 6: Differential Diagnosis - Cardiac Causes
Heart Failure (Systolic and Diastolic Dysfunction)
- Elevated left atrial pressures → pulmonary congestion → stimulation of pulmonary receptors
- Restrictive mechanics from pulmonary edema → limited tidal volume
- Patients describe "air hunger" and "inability to get a deep breath" 3, 4
- "My breathing is heavy" is most frequent descriptor (74.4%) 5
Key clinical features: 3
- Orthopnea, paroxysmal nocturnal dyspnea, peripheral edema
- Diastolic dysfunction causes dyspnea primarily with exercise rather than at rest 4
Coronary Artery Disease
Pathophysiology: 3
- Myocardial oxygen supply does not meet demand
- Decreased cardiac output → chemoreceptor stimulation 1
- May present as exercise-induced dyspnea 4
Valvular Disease
Pathophysiology: 3
- Mitral stenosis or regurgitation → elevated left atrial pressures → pulmonary congestion
Arrhythmias
Pathophysiology: 4
- Exercise-induced arrhythmias and chronotropic incompetence
- Abnormal heart rate response patterns on cardiopulmonary exercise testing
Slide 7: MCQ #3 - Heart Failure
Case: A 72-year-old man with hypertension presents with progressive dyspnea over 2 weeks. He describes "air hunger" and "I cannot get enough air." He has orthopnea requiring 3 pillows and bilateral lower extremity edema. Chest X-ray shows cardiomegaly and pulmonary vascular congestion.
Question: What is the primary pathophysiologic mechanism of his dyspnea?
A) Airflow obstruction from bronchoconstriction
B) Stimulation of pulmonary receptors from elevated left atrial pressures and restrictive mechanics from pulmonary edema
C) Muscle weakness from deconditioning
D) Chemoreceptor stimulation from metabolic acidosis
Answer: B - Heart failure produces dyspnea through elevated left atrial pressures causing pulmonary congestion (stimulating pulmonary receptors) and pulmonary edema creating restrictive mechanics that limit tidal volume. 1, 3 The descriptors "air hunger" and "inability to get enough air" are characteristic of restrictive mechanics. 1, 3
Slide 8: Differential Diagnosis - Pulmonary Causes (Obstructive)
COPD Exacerbation
- Airflow obstruction → increased resistive load
- Dynamic hyperinflation → increased elastic load
- Increased dead space → hypercapnia → chemoreceptor stimulation
- Patients describe "My breathing requires work" (46.3%) and "My breath doesn't go out all the way" (29.6%) 5
Key clinical features: 3
- Increased dyspnea, cough, sputum production in patients with smoking history
- Decreased breath sounds, wheezing on examination 6
Asthma Exacerbation
- Bronchoconstriction → airflow obstruction
- Airway inflammation → stimulation of irritant receptors
- Patients describe "chest tightness" specifically related to bronchoconstriction 1, 3, 4
- Episodic symptoms triggered by environmental exposures
- Expiratory wheezing on examination 5
Slide 9: Differential Diagnosis - Pulmonary Causes (Restrictive/Parenchymal)
Pneumonia
- Alveolar consolidation → impaired gas exchange → hypoxemia → chemoreceptor stimulation
- Pleural inflammation → stimulation of pulmonary receptors
Key clinical features: 3
- Fever, productive cough, pleuritic chest pain, focal crackles
Interstitial Lung Disease
- Stimulation of pulmonary receptors (mechanical)
- Restrictive mechanics → limited tidal volume
- Impaired gas exchange → hypoxemia
- Patients describe "air hunger" due to restrictive mechanics 3, 4
Key clinical features: 3
- Progressive dyspnea, dry cough, bibasilar crackles
- Clubbing on examination 6
Pleural Effusion
- Compressive atelectasis → stimulation of pulmonary receptors
- Restrictive mechanics from reduced lung volume
Key clinical features: 3
- Decreased breath sounds, dullness to percussion 6
Pneumothorax
Pathophysiology: 3
- Sudden lung collapse → restrictive mechanics
- Pleural irritation → stimulation of receptors
Key clinical features: 3
- Sudden-onset dyspnea, pleuritic chest pain, decreased breath sounds
Slide 10: MCQ #4 - Pneumonia vs. Pulmonary Embolism
Case: A 55-year-old woman presents with 2 weeks of progressive dyspnea, fever to 38.9°C, productive cough with yellow sputum, and right-sided pleuritic chest pain. Examination reveals focal crackles in the right lower lung field. Oxygen saturation is 89% on room air.
Question: What is the most likely diagnosis?
A) Pulmonary embolism
B) Pneumonia
C) COPD exacerbation
D) Interstitial lung disease
Answer: B - The combination of fever, productive cough, pleuritic chest pain, and focal crackles is characteristic of pneumonia. 3 Pulmonary embolism typically presents with acute dyspnea, pleuritic chest pain, tachycardia, and hypoxemia but without fever or productive cough. 3
Slide 11: Differential Diagnosis - Pulmonary Vascular
Pulmonary Embolism
- Vascular obstruction → stimulation of pulmonary vascular receptors
- Increased dead space → hypercapnia → chemoreceptor stimulation
- Impaired gas exchange → hypoxemia → chemoreceptor stimulation
Key clinical features: 3
- Acute dyspnea, pleuritic chest pain, tachycardia, hypoxemia
- May have pleural rub on examination 6
Idiopathic Pulmonary Hypertension
- Stimulation of pulmonary vascular receptors
- Right ventricular strain → decreased cardiac output
- Requires pulmonary vasodilators if appropriate 7
Slide 12: Differential Diagnosis - Non-Cardiopulmonary
Anemia
- Decreased oxygen carrying capacity → tissue hypoxia → chemoreceptor stimulation
- Compensatory increased cardiac output
Metabolic Acidosis
- Diabetic ketoacidosis, uremia, renal tubular acidosis
- Direct chemoreceptor stimulation → increased respiratory drive
Neuromuscular Disease
Pathophysiology: 1
- Muscle weakness (myasthenia gravis, Guillain-Barré, spinal cord injury)
- Impaired ventilatory mechanics → reduced afferent feedback for given motor command
Obesity/Chest Wall Disease
Pathophysiology: 1
- Decreased chest wall compliance (severe kyphoscoliosis, obesity)
- Impaired ventilatory mechanics → increased work of breathing
Panic Disorder/Hyperventilation Syndrome
- Behavioral factors → increased respiratory drive
- Patients describe "effort," "suffocation," and "rapid breathing" 1, 3, 4
Slide 13: MCQ #5 - Multifactorial Dyspnea
Case: A 78-year-old obese man (BMI 38) with COPD and diastolic heart failure presents with worsening dyspnea. He describes both "chest tightness" and "air hunger." Hemoglobin is 9.2 g/dL. Chest X-ray shows hyperinflation and mild pulmonary vascular congestion.
Question: How many distinct pathophysiologic mechanisms are contributing to his dyspnea?
A) One (airflow obstruction only)
B) Two (airflow obstruction and heart failure)
C) Four (airflow obstruction, restrictive mechanics from obesity, heart failure, and anemia)
D) Five (all of the above plus panic disorder)
Answer: C - This patient has multiple contributing mechanisms: (1) COPD causing airflow obstruction and dynamic hyperinflation, (2) obesity causing decreased chest wall compliance, (3) diastolic heart failure causing restrictive mechanics from pulmonary congestion, and (4) anemia causing decreased oxygen carrying capacity. 1 More than 30% of dyspnea cases are multifactorial. 1
Slide 14: Initial Diagnostic Approach - History
History and physical examination remain the mainstays of diagnostic evaluation and are adequate to make a diagnosis in 66% of patients. 1, 6
Critical History Elements:
- Acute (<2 weeks), subacute (2 weeks), or chronic (>4-8 weeks)
- Constant vs. intermittent (triggers: exertion, specific activities, time of day, environmental exposures, emotional stress)
- "Chest tightness" → bronchoconstriction
- "Air hunger"/"inability to get deep breath" → restrictive mechanics or heart failure
- "Effort"/"suffocation" → possibly panic disorder
- Cardiac: orthopnea, paroxysmal nocturnal dyspnea, peripheral edema
- Pulmonary: cough (productive vs. dry), wheezing, pleuritic chest pain
- Systemic: fever, weight loss
- Smoking history, chemical exposures, medication use
- Known cardiac or pulmonary disease
Slide 15: Initial Diagnostic Approach - Physical Examination
Key Examination Findings by Etiology: 6, 2
Cardiac:
- Jugular venous distention → heart failure 6
- S3 gallop, displaced PMI → systolic dysfunction
- Peripheral edema → heart failure 3
Pulmonary:
- Decreased breath sounds → COPD, pleural effusion, pneumothorax 3, 6
- Wheezing → asthma, COPD 6, 5
- Focal crackles → pneumonia 3
- Bibasilar crackles → heart failure or interstitial lung disease 3
- Dullness to percussion → pleural effusion 6
- Pleural rub → pulmonary embolism or pneumonia 6
Other:
Critical caveat: History and physical examination alone have high specificity (96%) but low sensitivity (59%) for cardiac causes—do not rely on clinical assessment alone. 3
Slide 16: MCQ #6 - Physical Examination
Case: A 62-year-old man presents with progressive dyspnea over 3 weeks. Examination reveals elevated JVD to 12 cm, bibasilar crackles, S3 gallop, and 2+ bilateral lower extremity pitting edema. Oxygen saturation is 91% on room air.
Question: Based on the physical examination, what is the most likely diagnosis?
A) COPD exacerbation
B) Pneumonia
C) Congestive heart failure
D) Pulmonary embolism
Answer: C - The combination of elevated JVD, S3 gallop, bibasilar crackles, and peripheral edema is highly specific for congestive heart failure. 3, 6 However, physical examination alone has low sensitivity (59%) for cardiac causes, so confirmatory testing is needed. 3
Slide 17: First-Line Diagnostic Testing
Initial testing should be performed systematically in all patients with chronic dyspnea: 7, 3, 6, 2
Laboratory Tests:
- Complete blood count: Assess for anemia or infection 7, 3, 6, 2
- Basic metabolic panel: Evaluate for renal dysfunction, electrolyte abnormalities, acid-base disturbances 7, 3, 6, 2
- Thyroid function: Rule out thyroid disease 8
Imaging:
- Chest radiography: Identify pneumonia, heart failure, pleural effusion, pneumothorax, masses 7, 3, 6, 2
- Critical caveat: Normal chest radiography does not exclude cardiac disease, particularly early heart failure or diastolic dysfunction 3
Cardiac Testing:
Pulmonary Testing:
- Spirometry: Identify obstructive or restrictive patterns 7, 3, 6, 2, 8
- Pulse oximetry: Assess for hypoxemia requiring supplemental oxygen 7, 3, 6, 2
Biomarkers:
- BNP or NT-proBNP: BNP <100 pg/mL or NT-proBNP <125 pg/mL effectively excludes heart failure 3
- Age-stratified cutoffs improve specificity: NT-proBNP <125 pg/mL (age <75) or <450 pg/mL (age ≥75) 3
- D-dimer: May help rule out pulmonary emboli 6
Slide 18: Point-of-Care Ultrasound (POCUS)
POCUS is an extension of the physical examination and improves diagnostic accuracy: 1, 3
Evidence:
- POCUS added to standard diagnostic pathway leads to statistically significantly more correct diagnoses than standard pathway alone 3
- Improves sensitivity to detect heart failure, pneumonia, pulmonary embolism, pleural effusion, and pneumothorax 3
Key Findings:
- B-lines → pulmonary edema (heart failure)
- Consolidation → pneumonia
- Pleural effusion → fluid accumulation
- Absent lung sliding → pneumothorax
- Right ventricular strain → pulmonary embolism
POCUS should be performed by trained professionals for specific pulmonary and cardiovascular indications. 1
Slide 19: MCQ #7 - First-Line Testing
Case: A 58-year-old woman with 3 months of progressive dyspnea on exertion. Initial testing shows: Hemoglobin 10.2 g/dL, creatinine 2.8 mg/dL, BNP 450 pg/mL, chest X-ray with cardiomegaly, ECG with left ventricular hypertrophy, spirometry with FEV1/FVC 0.78 (normal).
Question: Which diagnosis is most likely based on first-line testing?
A) COPD
B) Anemia
C) Heart failure
D) Interstitial lung disease
Answer: C - The elevated BNP (450 pg/mL), cardiomegaly on chest X-ray, and LVH on ECG all point to heart failure. 3 While anemia (Hgb 10.2) and renal dysfunction (Cr 2.8) may contribute, the BNP elevation is most specific for heart failure. Normal spirometry rules out obstructive disease. 6, 2
Slide 20: Second-Line Diagnostic Testing
When first-line testing is nondiagnostic, proceed to specialized evaluation: 7, 3, 4, 6, 2, 8
Cardiac Testing:
- Echocardiography: Assess left ventricular systolic and diastolic function, valvular disease, right ventricular strain, pericardial effusion 7, 3, 4, 6, 2
- Stress testing (exercise ECG or imaging): Provoke ischemia or arrhythmias that occur only with exertion 3, 4
- Cardiac MRI: For cardiomyopathies or infiltrative diseases when echocardiography inconclusive 3
- Coronary CT angiography: If ischemia suspected 3
Pulmonary Testing:
- Formal pulmonary function testing with DLCO: Characterize obstructive or restrictive patterns and assess gas exchange 7, 3, 4, 6, 2, 8
- Chest CT: Most appropriate imaging study for diagnosing suspected pulmonary causes 1, 6
- Inspiratory and expiratory CT to evaluate for air trapping in small airways disease 1
- Hyperpolarized Xenon-MRI: FDA-approved for functional imaging; shows impaired ventilation in COVID-19, COPD, small airways disease 1
Invasive Testing (with specialty consultation):
- Right heart catheterization: Diagnose pulmonary arterial hypertension 6
- Bronchoscopy: Diagnose certain interstitial lung diseases 6
- Cardiopulmonary exercise testing: Critical for unexplained dyspnea when initial tests are nondiagnostic 8
Slide 21: Specialty Referral Indications
Specialty referral is indicated when diagnosis remains elusive after initial workup: 1, 3, 4
Referral Options:
- Pulmonology: For suspected pulmonary causes (interstitial lung disease, pulmonary hypertension, unexplained restrictive pattern) 1, 3, 4
- Cardiology: For suspected cardiac causes (diastolic dysfunction, valvular disease, ischemia) 1, 3, 4
- Multidisciplinary dyspnea clinic: May help identify potentially treatable underlying causes 1, 3, 4
- Palliative care: For refractory dyspnea with limited life expectancy 7, 3
Slide 22: MCQ #8 - Second-Line Testing
Case: A 50-year-old woman with 6 months of progressive dyspnea on exertion. First-line testing (CBC, BMP, chest X-ray, ECG, spirometry, pulse oximetry) is entirely normal. She describes "air hunger" with exercise. She has no cardiac risk factors.
Question: What is the most appropriate next step?
A) Reassure and observe
B) Prescribe anxiolytics for presumed panic disorder
C) Order echocardiography and formal pulmonary function testing with DLCO
D) Refer to psychiatry
Answer: C - When first-line testing is nondiagnostic, second-line noninvasive testing is indicated. 2, 8 Echocardiography can identify diastolic dysfunction (which may not be evident on chest X-ray or ECG), and formal PFTs with DLCO can identify early interstitial lung disease or pulmonary vascular disease. 3, 6, 2 "Air hunger" suggests restrictive mechanics, which could be from diastolic heart failure or early interstitial disease. 1, 3
Slide 23: Diagnostic Algorithm for Chronic Dyspnea
Step 1: History and Physical Examination 1, 6
- Quality of dyspnea, timing, triggers, associated symptoms, risk factors
- Examination for JVD, breath sounds, wheezing, crackles, edema, clubbing
Step 2: First-Line Testing (All Patients) 7, 3, 6, 2
- CBC, BMP, chest X-ray, ECG, spirometry, pulse oximetry
- Consider BNP/NT-proBNP if heart failure suspected
- Consider POCUS if available and trained personnel 1, 3
Step 3: Diagnosis Made?
- Yes: Treat underlying cause 7
- No: Proceed to Step 4
Step 4: Second-Line Testing 3, 4, 6, 2
- Echocardiography (if cardiac cause suspected)
- Formal PFTs with DLCO (if pulmonary cause suspected)
- Chest CT (if parenchymal lung disease suspected) 1, 6
- Stress testing (if exercise-induced symptoms) 4
Step 5: Diagnosis Still Elusive?
- Specialty referral: Pulmonology, cardiology, or multidisciplinary dyspnea clinic 1, 3, 4
- Consider cardiopulmonary exercise testing 8
- Consider invasive testing: Right heart catheterization, bronchoscopy 6
Slide 24: MCQ #9 - Diagnostic Algorithm
Case: A 65-year-old man with 2 months of progressive dyspnea. He describes "chest tightness" with exertion. He has a 40 pack-year smoking history. First-line testing shows: Normal CBC and BMP, chest X-ray with hyperinflation, normal ECG, spirometry with FEV1/FVC 0.62 and positive bronchodilator response, oxygen saturation 94% on room air.
Question: What is the most appropriate next step?
A) Proceed directly to chest CT
B) Order echocardiography
C) Diagnose COPD and initiate bronchodilator therapy
D) Refer to pulmonology immediately
Answer: C - First-line testing has established the diagnosis: spirometry showing FEV1/FVC <0.70 with bronchodilator response confirms COPD. 6, 2 The smoking history, "chest tightness" (suggesting bronchoconstriction), and hyperinflation on chest X-ray all support this diagnosis. 1, 3 No further testing is needed before initiating treatment. Specialty referral is indicated only when diagnosis remains elusive. 1, 3
Slide 25: Treatment Principles
Three main treatment goals: 2
1. Correctly Identify and Treat Underlying Disease
- Cardiac causes: Optimize heart failure medications (ACE inhibitors, beta-blockers, diuretics) 7
- Pulmonary causes: Bronchodilators for COPD/asthma, anti-inflammatory or antifibrotic therapy for interstitial disease 7
- Pulmonary vascular disease: Address underlying cause, consider pulmonary vasodilators 7
- Anemia: Treat underlying cause, consider transfusion or erythropoietin
- Metabolic acidosis: Correct underlying disorder (insulin for DKA, dialysis for uremia)
2. Optimize Recovery
- Pulmonary rehabilitation and exercise training: For chronic dyspnea with reduced functional capacity 7
- Improved nutrition: Address malnutrition contributing to muscle weakness 9
- Oxygen therapy: For documented hypoxemia 9
3. Improve Dyspnea Symptoms
- Non-pharmacological: Optimal positioning, cooling methods for face 7
- Pharmacological: Opioids are first-line with strong evidence for dyspnea relief 7
- Morphine 2.5-10 mg PO every 2 hours PRN or 1-3 mg IV every 2 hours PRN for opioid-naïve patients 7
Six-minute walk test can measure effect of ongoing intervention. 2
Slide 26: MCQ #10 - Treatment
Case: A 70-year-old man with idiopathic pulmonary fibrosis and refractory dyspnea despite optimal antifibrotic therapy and supplemental oxygen. He has limited life expectancy (<6 months). He describes severe "air hunger" at rest that limits all activities.
Question: What is the most appropriate next step in management?
A) Increase oxygen flow rate
B) Initiate morphine 2.5 mg PO every 2 hours as needed
C) Prescribe anxiolytics
D) Recommend pulmonary rehabilitation
Answer: B - Opioids are the first-line pharmacological treatment with strong evidence for dyspnea relief. 7 For opioid-naïve patients with refractory dyspnea, morphine 2.5-10 mg PO every 2 hours PRN is recommended. 7 Given his limited life expectancy and refractory symptoms, palliative care consultation should also be considered. 7, 3 Increasing oxygen beyond what corrects hypoxemia is unlikely to help, and pulmonary rehabilitation is not appropriate for someone with such limited functional status and life expectancy.
Slide 27: Common Pitfalls and How to Avoid Them
Pitfall 1: Attributing Dyspnea to "Normal Aging"
- Avoid: Dyspnea should not be considered part of normal aging 9
- Action: Always pursue diagnostic evaluation 9
Pitfall 2: Relying Solely on History and Physical
- Avoid: Clinical assessment alone has low sensitivity (59%) for cardiac causes 3
- Action: Always perform first-line testing even when clinical diagnosis seems clear 3
Pitfall 3: Assuming Normal Chest X-ray Excludes Cardiac Disease
- Avoid: Normal chest radiography does not exclude early heart failure or diastolic dysfunction 3
- Action: Consider BNP/NT-proBNP and echocardiography if clinical suspicion remains 3
Pitfall 4: Missing Multifactorial Causes
- Avoid: More than 30% of cases are multifactorial 1
- Action: Continue evaluation even after identifying one cause if symptoms seem disproportionate 1
Pitfall 5: Ignoring Quality of Dyspnea
- Avoid: Patient descriptors provide valuable pathophysiologic clues 1, 5
- Action: Specifically ask patients to describe the quality of their breathing discomfort 1
Pitfall 6: Delaying Specialty Referral
- Avoid: Prolonged evaluation without diagnosis delays treatment 1
- Action: Refer to pulmonology, cardiology, or multidisciplinary dyspnea clinic when diagnosis remains elusive after second-line testing 1, 3, 4
Slide 28: MCQ #11 - Comprehensive Case
Case: A 68-year-old woman presents with 3 months of progressive dyspnea. She describes "My breathing is heavy" and "I cannot get enough air." She has hypertension and diabetes. Examination shows JVD to 10 cm, bibasilar crackles, and 1+ peripheral edema. Initial testing: Hemoglobin 11.8 g/dL, creatinine 1.2 mg/dL, BNP 380 pg/mL, chest X-ray with cardiomegaly and mild pulmonary vascular congestion, ECG with LVH, spirometry with FEV1/FVC 0.76 (normal pattern).
Question: What is the most likely diagnosis and appropriate next step?
A) COPD; start bronchodilators
B) Heart failure; order echocardiography and optimize heart failure medications
C) Interstitial lung disease; order chest CT
D) Anemia; start iron supplementation
Answer: B - The clinical presentation (JVD, bibasilar crackles, peripheral edema), descriptors ("My breathing is heavy" is most frequent in CHF patients at 74.4%), elevated BNP (380 pg/mL), cardiomegaly, and LVH all point to heart failure. 3, 5 Echocardiography is the appropriate next step to assess systolic and diastolic function. 3, 4 Normal spirometry rules out obstructive disease. 6 While mild anemia may contribute, heart failure is the primary diagnosis requiring treatment. 7
Slide 29: Special Populations and Considerations
Elderly Patients
- Respiratory sensation is diminished with aging 9
- Breathlessness may not develop until more advanced stage of disease 9
- Focus on cardiac disease, respiratory disease, and deconditioning as most likely causes 9
Post-COVID-19 Patients
- Air trapping on expiratory CT associated with lung function impairment 1
- Hyperpolarized Xenon-MRI may show impaired ventilation 1
- Consider small airways disease in differential 1
Patients with Linguistic/Cultural Differences
- Linguistic and cultural differences exist in how patients characterize symptoms 1
- Some patients have difficulty grasping the concept of "quality" of breathing sensations 1
- Use interpreter services and multiple descriptors to clarify 1
Patients with Psychiatric Comorbidities
- "Effort," "suffocation," and "rapid breathing" characterize panic attacks 1
- However, these descriptors are nonspecific 1
- Always rule out organic causes before attributing dyspnea to psychiatric disorder 1
Slide 30: MCQ #12 - Final Integration Case
Case: A 52-year-old woman with no past medical history presents with 6 weeks of intermittent dyspnea triggered by cold air and exercise. She describes "chest tightness" and "I feel that my airway is obstructed." She has no fever, cough, or edema. Examination shows diffuse expiratory wheezing. Oxygen saturation is 96% on room air. Chest X-ray is normal. Spirometry shows FEV1/FVC 0.68 with 15% improvement after bronchodilator.
Question: What are the pathophysiologic mechanisms and appropriate treatment?
A) Increased respiratory drive from chemoreceptor stimulation; treat with supplemental oxygen
B) Impaired ventilatory mechanics from airflow obstruction and bronchoconstriction; treat with inhaled bronchodilators
C) Restrictive mechanics from pulmonary edema; treat with diuretics
D) Muscle weakness from neuromuscular disease; refer to neurology
Answer: B - This patient has asthma based on: (1) episodic symptoms triggered by cold air and exercise, (2) "chest tightness" which is relatively specific for bronchoconstriction, (3) expiratory wheezing, and (4) spirometry showing obstruction with bronchodilator response. 1, 3, 4, 5 The pathophysiology involves impaired ventilatory mechanics from airflow obstruction due to bronchoconstriction. 1 Treatment is inhaled bronchodilators (short-acting beta-agonists for acute symptoms, inhaled corticosteroids for long-term control). 7