Clinical Skills
Mastering respiratory examination begins with comprehensive symptom analysis. This guide covers the six cardinal respiratory symptoms, their diagnostic significance, and the clinical reasoning needed to differentiate between common and life-threatening conditions.
🎯 The Six Cardinal Respiratory Symptoms
Essential Respiratory History
Core Symptom Focus:
- Cough - character and timing
- Sputum production - volume and appearance
- Breathlessness (dyspnea) - patterns and triggers
- Wheeze - timing and variability
- Chest pain - quality and location
- Haemoptysis - volume and associated features
🤧 1. Cough: More Than Just a Reflex
Cough Physiology & Assessment
Cough Mechanism (3-Phase Reflex):
🎯 Phase 1
- Deep inspiration
🎯 Phase 2
- Forced expiration against closed glottis
🎯 Phase 3
- Sudden glottis opening → explosive air blast
Key Cough Characteristics:
🎯 Duration Analysis
- Weeks: Common cold, acute bronchitis
- Months to years: TB, chronic bronchitis, cancer
- Smoker's persistent cough: Lung cancer until proven otherwise
🎯 Timing Patterns
- Nocturnal: Asthma, heart failure
- Daytime variable: Asthma
- Meal-related: Aspiration
🎯 Character & Quality
- Bovine cough: Vocal cord paralysis (cancer invasion)
- Harsh/croupy: Laryngitis
- Weak cough: Vocal cord palsy, muscle weakness
🧫 2. Sputum: Diagnostic Clues in Secretions
Sputum Analysis
Normal vs. Abnormal Production:
- Normal: ~100ml mucus daily (swallowed unconsciously)
- Small cupful: Chronic bronchitis
- Small bucket: Bronchiectasis, lung abscess
- Very copious watery: Alveolar cell carcinoma (rare)
Sputum Appearance & Significance:
🎯 Clear/White (Mucoid)
- Mucus hypersecretion
- Chronic bronchitis
🎯 Yellow/Green (Purulent)
- Bacterial infection
- Asthma with eosinophils
🎯 Thick, Viscid, Stringy
- Asthma characteristic
🎯 Brown Bronchial Casts
- Bronchopulmonary aspergillosis
🎯 Pink, Frothy
- Pulmonary edema
- Acute heart failure
🎯 Rusty (Brownish-Red)
- Pneumonia (iron from blood)
🎯 Blood-Streaked
- Cancer, TB, bronchiectasis
🎯 Offensive Smell
- Anaerobic infection
- Lung abscess/empyema with fistula
😮💨 3. Breathlessness (Dyspnea): Patterns & Mechanisms
Dyspnea Assessment
Three Basic Mechanisms:
🎯 Increased Work of Breathing
- Airway obstruction (asthma)
- Stiff lungs (pulmonary fibrosis)
- Stiff chest wall (scoliosis)
🎯 Decreased Neuromuscular Power
- Muscular dystrophies
- Myasthenia gravis
🎯 Increased Drive to Breathe
- Hypoxia, acidosis (chemical)
- Lung receptor stimulation (neurological)
Timeline Diagnostic Clues:
🎯 Seconds to Minutes
- Left ventricular failure
- Pulmonary embolism
- Pneumothorax
🎯 Days to Weeks
- Asthma exacerbation
- Pneumonia
- Allergic alveolitis
- Pleural effusion
🎯 Months to Years
- COPD
- Chronic asthma
- Anemia
- Pulmonary fibrosis
Pattern-Specific Dyspnea:
🎯 Nocturnal Patterns
- PND: Heart failure, mitral stenosis
- 2-3 AM wheeze: Poorly controlled asthma
🎯 Orthopnea
- Cardiac failure
- Bilateral diaphragmatic paralysis
🎯 Trigger-Based
- Allergens, exercise → Asthma
- Farm/bird exposure → Allergic alveolitis
- Workplace exposure → Occupational asthma
Diagnostic Gold Standard: Treatment response provides crucial diagnostic information—diuretics (pulmonary edema), steroids (asthma/alveolitis), bronchodilators (asthma).
🎵 4. Wheeze vs. Stridor: Airway Sound Differentiation
Respiratory Sound Assessment
Wheeze Characteristics:
🎯 Definition
- Musical sound from oscillating airways
- Naked ear = wheeze, stethoscope = rhonchi
🎯 Timing & Severity
- Usually expiratory (both phases in severe obstruction)
- Disappears in very severe obstruction ("silent chest")
Wheeze Patterns:
🎯 Variable Wheeze
- Trigger-dependent (exercise, allergens)
- Nocturnal worsening
- Diagnosis: Asthma
🎯 Persistent Wheeze
- Asthma, chronic bronchitis
- Emphysema, major airway obstruction
🎯 Localized Wheeze
- Unaffected by coughing
- Cause: Local obstruction (tumor, TB stenosis)
Stridor vs. Wheeze:
🎯 Stridor Features
- Loud, harsh, mainly inspiratory
- Heard at mouth without stethoscope
- Laryngeal/tracheal/major airway obstruction
- Emergency situation!
🎯 Key Differentiator
- Inspiratory noise > expiratory noise → Suspect stridor
💔 5. Chest Pain: Respiratory vs. Other Causes
Thoracic Pain Assessment
Critical Anatomical Fact:
- Lung parenchyma has NO pain fibers
- Pain originates from pleura or chest wall
- Lung cancer/fibrosis typically painless until advanced
Pleuritic Pain Features:
🎯 Quality & Triggers
- Sharp, stabbing quality
- Worsens with breathing, coughing, movement
- Parietal pleura sensitivity
🎯 Common Causes
- Pleurisy + fever + purulent sputum = Infection
- Dyspnea + haemoptysis = Pulmonary embolism
- Trauma + palpation reproducibility = Musculoskeletal
Other Respiratory Pains:
🎯 Referred Pain Patterns
- Central diaphragmatic → Shoulder (phrenic nerve C3-5)
- Peripheral diaphragmatic → Lower chest/upper abdomen
🎯 Specific Syndromes
- Large pleural effusion: Dull heaviness
- Pleural malignancy: Constant, severe pain
- Pneumothorax: Pleuritic or dragging sensation
- Tietze's syndrome: Sternocostal junction pain/swelling
- Tracheitis: Central "raw feeling"
- Persistent cough: Central soreness, rib fractures
🩸 6. Haemoptysis: Differential Diagnosis
Blood Expectoration Assessment
First: Confirm Pulmonary Origin
🎯 Haemoptysis vs. Haematemesis
- Haemoptysis: Bright red, frothy, mixed with sputum, coughed
- Haematemesis: Dark coffee-ground, mixed with food, vomited
- Nasal origin: Appears in mouth without cough
Volume Significance:
- >200ml/24 hours = High mortality risk
- TB patients can die suddenly from massive haemoptysis
Causes by Category:
🎯 Traumatic
- Wounds, post-intubation, foreign body
🎯 Infective
- Bronchiectasis (recurrent over years)
- Acute bronchitis, pneumonia, TB
- Lung abscess, fungal/parasitic infections
🎯 Neoplastic
- Bronchial carcinoma (smoker ≥40 years)
- Bronchial adenoma
🎯 Vascular
- Pulmonary infarction (with pleuritic pain)
- Osler-Weber-Rendu syndrome, AV malformation
🎯 Parenchymal
- Cystic fibrosis, Wegener's granulomatosis
- Sarcoidosis, Goodpasture's syndrome
- Idiopathic pulmonary fibrosis, connective tissue diseases