What is the systematic bedside physical examination of the respiratory system?

Systematic Bedside Physical Examination of the Respiratory System

Begin with inspection of the patient's breathing position, thoracic shape, and respiratory dynamics, followed by palpation of chest wall mechanics and tactile fremitus, then proceed to auscultation for breath sounds and adventitious sounds, while systematically assessing for extrathoracic respiratory signs including cyanosis, accessory muscle use, and work of breathing. 1

Initial Inspection

Patient Positioning and General Appearance

• Observe the breathing position adopted by the patient (e.g., tripod position, inability to lie flat), which indicates respiratory distress severity. 1
• Assess for cyanosis (central versus peripheral), which reflects inadequate oxygenation. 2
• Look for use of accessory muscles including sternocleidomastoid activation, suprasternal retractions, and intercostal retractions, which indicate increased work of breathing. 3

Thoracic Configuration

• Evaluate chest wall shape for barrel chest (hyperinflation), pectus excavatum, kyphoscoliosis, or asymmetry. 1
• Inspect for thoracic deformities that may restrict lung expansion or suggest chronic respiratory disease. 1

Respiratory Dynamics

• Count respiratory rate over a full 60 seconds to accurately assess tachypnea (normal adult: 12-20 breaths/min; severe tachypnea in infants: ≥70 breaths/min). 3
• Observe breathing pattern for regularity, depth (hyperpnea), and rhythm. 2, 1
• Assess symmetry of chest expansion bilaterally during inspiration to detect unilateral pathology (pneumothorax, consolidation, pleural effusion). 1
• Evaluate synchrony of rib cage and abdominal movements; paradoxical breathing (inward abdominal movement during inspiration) suggests diaphragmatic dysfunction or severe respiratory distress. 1

Neck Examination

• Inspect for tracheal deviation, which indicates mediastinal shift from tension pneumothorax, large pleural effusion, or atelectasis. 1
• Look for jugular venous distension, suggesting right heart strain from pulmonary hypertension or cor pulmonale. 1
• Assess for suprasternal retractions and tracheal tugging, which indicate significant respiratory compromise requiring accessory muscle recruitment. 3

Specific Respiratory Signs

• Observe for nasal flaring, an attempt to reduce inspiratory resistance that signals respiratory distress. 3
• Listen for audible sounds without a stethoscope: stridor (upper airway obstruction), wheezing (lower airway obstruction), or grunting (effort to maintain positive end-expiratory pressure in lower respiratory disease). 2, 3
• Check for pursed-lip breathing, which indicates air trapping and is common in COPD. 1

Palpation

Chest Wall Mechanics

• Palpate chest expansion by placing hands on the posterior lower chest wall with thumbs at the midline; asymmetric movement confirms unilateral pathology. 1
• Assess for subcutaneous emphysema (crepitus), which may indicate pneumothorax, pneumomediastinum, or recent chest trauma. 2, 4

Tactile Fremitus

• Palpate tactile fremitus by placing the ulnar aspect of the hand on symmetric chest wall locations while the patient says "ninety-nine." 1
• Increased fremitus indicates consolidation (pneumonia) where solid tissue transmits vibrations better than air-filled lung. 1
• Decreased or absent fremitus suggests pleural effusion, pneumothorax, or emphysema, where fluid or air blocks vibration transmission. 1

Tracheal Position

• Palpate the trachea in the suprasternal notch to confirm midline position; deviation indicates mediastinal shift. 1

Auscultation

Systematic Approach

• Auscultate all lung fields systematically in a superior-to-inferior pattern, comparing side-to-side at each level (anterior, lateral, posterior). 1
• Listen during both inspiration and expiration to detect timing and character of abnormal sounds. 1

Normal Breath Sounds

• Vesicular breath sounds (soft, low-pitched) are normal over most lung fields. 1
• Bronchial breath sounds (loud, high-pitched) are normal over the trachea but abnormal over peripheral lung fields, indicating consolidation. 1

Adventitious Sounds

• Wheezing (high-pitched whistling on expiration or inspiration) indicates lower airway obstruction from bronchospasm, asthma, or COPD. 2
• Crackles/rales (discontinuous popping sounds) suggest fluid in small airways (pulmonary edema, pneumonia, interstitial lung disease); timing matters—early inspiratory crackles suggest small airway disease, late inspiratory crackles suggest restrictive disease. 1
• Rhonchi (low-pitched continuous sounds) indicate secretions in larger airways. 1
• Pleural friction rub (creaking or grating sound) suggests inflamed pleural surfaces rubbing together (pleuritis, pulmonary embolism). 1
• Absent or diminished breath sounds indicate pneumothorax, large pleural effusion, or severe emphysema. 2

Extrathoracic Respiratory Signs

Digital Examination

• Inspect fingers for clubbing (loss of nail bed angle, increased nail curvature), which suggests chronic hypoxemia from interstitial lung disease, bronchiectasis, lung cancer, or cyanotic heart disease. 1

Cardiovascular Assessment

• Measure pulsus paradoxus (>10 mmHg drop in systolic BP during inspiration), which indicates severe asthma, COPD exacerbation, or cardiac tamponade. 1

Oxygen Saturation

• Measure pulse oximetry on all patients with respiratory symptoms; SpO₂ <93% at sea level mandates supplemental oxygen and further evaluation. 3
• SpO₂ <90% is a strong predictor of mortality and requires immediate hospitalization. 3

Point-of-Care Ultrasound Integration

When available, bedside lung ultrasound should be incorporated as a primary diagnostic modality for respiratory failure, achieving >90% diagnostic accuracy for common etiologies. 2

Pneumothorax Detection

• Use a linear high-frequency probe (5-12 MHz) with depth set to 5-7 cm, starting at the 3rd-4th intercostal space in the mid-clavicular line. 2, 4
• Absence of lung sliding plus absence of B-lines suggests pneumothorax (sensitivity 89-100%, specificity 99%). 2, 4
• Presence of a lung point (transition between pneumothorax and normal sliding) is 100% specific for pneumothorax. 4

Interstitial and Parenchymal Disease

• Multiple vertical B-lines (comet tails) with 7 mm spacing indicate interstitial syndrome. 2
• Coalescent B-lines (<3 mm apart) suggest pulmonary edema or confluent pneumonia. 2
• Consolidation appears as tissue-like echogenicity with air bronchograms (sensitivity and specificity >90%). 2

Pleural Effusion

• Anechoic (black) fluid collection above the diaphragm confirms pleural effusion. 2

Common Pitfalls to Avoid

• Do not assume absent lung sliding alone confirms pneumothorax; it also occurs with atelectasis, consolidation, lung contusion, or main-stem intubation—look for absent B-lines and a lung point to confirm. 2, 4
• Do not rely on a single examination; serial observations improve detection of evolving respiratory compromise. 3
• Do not assume all subcostal retractions in children <2 years indicate pneumonia; isolated mild retractions without danger signs (grunting, nasal flaring, severe tachypnea) may reflect simple nasal obstruction due to highly compliant chest walls. 3
• Do not overlook the importance of systematic technique; interobserver agreement for respiratory signs is historically low, emphasizing the need for standardized examination methods. 1