Respiratory Assessment: Inspection, Palpation, Percussion, Auscultation, and SpO2

Respiratory assessment is a core nursing skill used to evaluate ventilation, oxygenation, and airway patency. This note reviews the five assessment techniques — inspection, palpation, percussion, auscultation, and SpO2 monitoring — with emphasis on recognizing early respiratory compromise before clinical deterioration.

Core Definition and Purpose

• Respiratory assessment evaluates ventilation, oxygenation, and airway patency.
• Techniques: inspection, palpation, percussion, auscultation, and SpO2 monitoring.
• Main purpose: identify early respiratory compromise, hypoxia, or airway obstruction before clinical deterioration.

Assessment Components at a Glance

• Inspection — detects early distress (work of breathing, respiratory rate).
• Palpation — detects structural changes (tracheal position, chest expansion, fremitus).
• Percussion — identifies lung density changes (air, fluid, consolidation).
• Auscultation — evaluates airway patency through breath sound quality.
• SpO2 monitoring — assesses oxygenation only (not ventilation).

Inspection

• Normal adult respiratory rate is 12–20 breaths/min; an increased rate often signals hypoxia or metabolic imbalance.
• Increased work of breathing is more significant than rate alone — it reflects distress earlier.
• Accessory muscle use and chest retractions indicate increased effort and possible respiratory failure.
• Pursed-lip breathing is associated with COPD and indicates air trapping during expiration.
• Cyanosis is a late sign of hypoxia, indicating severe oxygen deprivation.
• Clubbing of the fingers reflects long-term hypoxia (chronic lung disease, congenital heart disease).
• Early hypoxia signs: restlessness, anxiety, tachycardia.
• Late hypoxia signs: cyanosis, bradycardia.

Palpation

• The trachea should be midline; deviation suggests serious pathology.
• Deviation away from the affected side → tension pneumothorax (late sign). Simple pneumothorax may show no deviation.
• Deviation toward the affected side → atelectasis.
• Chest expansion should be equal bilaterally; asymmetry suggests lung collapse, effusion, or pneumonia.
• Increased tactile fremitus → lung consolidation (e.g., pneumonia).
• Decreased or absent tactile fremitus → pleural effusion or pneumothorax.
• Subcutaneous emphysema feels like crackling under the skin — indicates air leakage into soft tissue.

Percussion

• Resonant — normal air-filled lungs.
• Hyperresonant — excess air (COPD, pneumothorax).
• Dull — increased density (pneumonia, pleural effusion).
• Flat — very dense structures (muscle, liver).

Auscultation: Normal Breath Sounds

• Vesicular — soft, low-pitched; heard over most lung fields.
• Bronchial — loud, high-pitched; normal over the trachea only.
• Bronchovesicular — moderate; normal over major bronchi.

Auscultation: Abnormal Breath Sounds

• Crackles — discontinuous, heard on inspiration; fluid in alveoli (heart failure, pneumonia).
• Wheezes — continuous musical sounds on expiration; narrowed airways (asthma, COPD).
• Silent chest — life-threatening asthma; no wheezes because air movement is severely reduced.
• Absent breath sounds — pneumothorax or severe obstruction; requires immediate intervention.
• Stridor — high-pitched inspiratory sound; upper airway obstruction — emergency.
• Rhonchi — low-pitched, snoring-like; secretions in large airways; may clear with coughing.
• Pleural friction rub — grating sound on inspiration and expiration; inflamed pleura.

Oxygen Saturation (SpO2)

• Normal SpO2 in healthy adults: 95–100%. Values <90% indicate significant hypoxemia requiring urgent intervention.
• In COPD, acceptable SpO2 target is often 88–92% — excessive oxygen may suppress respiratory drive.
• SpO2 measures oxygenation only; it does not reflect ventilation or CO2 retention.
• False readings can occur with poor perfusion, movement, or nail polish — remove nail polish before monitoring.
• Clinical signs of distress always take priority over a single SpO2 reading.

Assessment Technique

• Position the patient upright when possible to maximize lung expansion.
• Assess lung fields systematically from apex to base, comparing both sides at the same level.
• Have the patient breathe slowly through the mouth to enhance detection of abnormal sounds.
• Listen to at least one full respiratory cycle at each location.

Critical Exam Priorities

• Stridor = airway obstruction = emergency.
• Silent chest in asthma = life-threatening; do not mistake absence of wheezing for improvement.
• Absent breath sounds = pneumothorax or severe obstruction.
• A normal SpO2 does not rule out respiratory failure, especially with CO2 retention.
• Crackles on inspiration, wheezes on expiration — a common exam trap.
• Increased fremitus → consolidation; decreased fremitus → effusion/pneumothorax.
• Unequal chest expansion is more significant than isolated abnormal breath sounds.

Rapid High-Yield Summary

• Normal RR: 12–20/min; work of breathing matters more than rate alone.
• Stridor → upper airway obstruction. Silent chest → life-threatening asthma. Absent breath sounds → pneumothorax or severe obstruction.
• Crackles → alveolar fluid. Wheezes → bronchospasm. Rhonchi → airway secretions.
• Hyperresonance → excess air (pneumothorax). Dullness → fluid or consolidation.
• SpO2 <90% needs urgent intervention; COPD target is often 88–92%.
• Early hypoxia: restlessness, anxiety, tachycardia. Late hypoxia: cyanosis, bradycardia.

Exam Strategy Focus

• Identify airway emergencies first: stridor, silent chest, absent breath sounds.
• Interpret breath sounds in terms of air, fluid, or obstruction patterns.
• Always interpret SpO2 alongside clinical signs — never rely on the number alone.

Key takeaways

• Stridor, silent chest, and absent breath sounds are airway emergencies requiring immediate action.
• Crackles = inspiration (fluid); wheezes = expiration (bronchospasm); rhonchi = secretions.
• Increased tactile fremitus = consolidation; decreased = effusion or pneumothorax.
• Hyperresonance = excess air; dullness = fluid or consolidation.
• Early hypoxia: restlessness, anxiety, tachycardia. Late hypoxia: cyanosis, bradycardia.
• Target SpO2 88–92% in COPD; <90% otherwise needs urgent intervention, but always correlate with clinical signs.