Clinical meaning
The chest assessment is a cornerstone of the registered nurse's physical examination competency, requiring systematic evaluation of the respiratory, cardiovascular, and musculoskeletal structures contained within and surrounding the thoracic cage. A thorough understanding of thoracic anatomy, respiratory physiology, and the pathophysiological basis of abnormal findings is essential in nursing practice to detect, interpret, and communicate clinically significant changes that guide medical decision-making. The thoracic cage is formed by 12 pairs of ribs (7 true ribs articulating directly with the sternum via costal cartilages, 3 false ribs with cartilages joining the costal margin, and 2 floating ribs without anterior attachment), the sternum (manubrium, body, and xiphoid process), and the 12 thoracic vertebrae. The thorax contains the lungs (each divided into lobes: right upper, middle, and lower; left upper and lower), the heart within the mediastinum, the great vessels, the trachea, the mainstem bronchi, the esophagus, the thoracic duct, and the thoracic segments of the sympathetic trunk. Surface landmark identification is critical for accurate documentation and communication. The sternal angle (angle of Louis), the palpable ridge at the junction of the manubrium and body of the sternum, marks the articulation of the second rib and serves as the primary reference point for rib counting. The lung apices extend approximately 2-4 cm above the clavicles. The oblique (major) fissure separating the upper and lower lobes runs from the T3 spinous process posteriorly to the sixth rib at the midclavicular line anteriorly. The horizontal (minor) fissure of the right lung extends from the fourth rib at the sternum to the fifth rib at the midaxillary line. The four components of the systematic chest assessment follow the traditional sequence of inspection, palpation, percussion, and auscultation (IPPA). Inspection evaluates the anteroposterior (AP) to lateral diameter ratio (normal 1:2; increased AP diameter or barrel chest suggests air trapping from COPD or chronic asthma), respiratory rate and pattern (eupnea 12-20 breaths/minute in adults; tachypnea, bradypnea, Cheyne-Stokes, Kussmaul, Biot respiration patterns have specific pathological significance), use of accessory muscles (sternocleidomastoid, scalene, and intercostal muscles indicate increased work of breathing), symmetry of chest expansion, skin color and integrity, chest wall deformities (pectus excavatum, pectus carinatum, kyphosis, scoliosis), and the presence of surgical scars, drains, or devices. Palpation assesses several critical parameters. Chest expansion (or excursion) is evaluated by placing the hands firmly on the posterior chest wall at the level of T9-T10 with thumbs meeting at the midline, then asking the patient to take a deep breath -- symmetrical outward movement of 3-5 cm is normal; asymmetric expansion suggests unilateral pathology (pneumothorax, pleural effusion, lobar pneumonia, atelectasis, or mainstem bronchus obstruction on the diminished side). Tactile (vocal) fremitus is assessed by placing the ulnar surface of the hand on the chest wall while the patient repeats 'ninety-nine' or 'blue moon' in a low-pitched voice. Vibrations are transmitted through the lung parenchyma to the chest wall; fremitus is INCREASED when the underlying lung is consolidated (pneumonia fills alveoli with inflammatory exudate that transmits vibrations more efficiently than air-filled alveoli), and DECREASED or ABSENT when air (pneumothorax) or fluid (pleural effusion) separates the lung parenchyma from the chest wall, dampening vibration transmission. Crepitus (subcutaneous emphysema) is palpated as a crackling, rice-crispy sensation beneath the skin indicating air tracking through subcutaneous tissues (seen in pneumothorax, pneumomediastinum, or after thoracic procedures). Percussion of the chest wall produces characteristic tones that reflect the density of underlying structures. Resonance is the normal percussion note heard over aerated lung tissue -- a loud, low-pitched, long-duration sound. Hyperresonance is louder, lower-pitched, and longer than resonance, indicating excessive air content (pneumothorax, emphysema, or large bullae). Dullness replaces resonance when air-filled lung is replaced by fluid or solid tissue (pleural effusion, consolidation from pneumonia, atelectasis, or tumor) -- it is a soft, high-pitched, short-duration sound similar to percussion over the liver or thigh. Flatness is an extreme form of dullness heard over completely solid structures (massive pleural effusion, large tumor). Tympany is a drum-like sound normally heard over the stomach (gastric air bubble in the left lower chest) and indicates a large air-filled cavity. Diaphragmatic excursion is assessed by percussing the posterior chest from resonant to dull areas during full inspiration and full expiration, measuring the distance between the two dullness boundaries; normal excursion is 3-5 cm bilaterally and symmetric. Auscultation with the diaphragm of the stethoscope evaluates breath sounds, adventitious sounds, and voice sounds. Normal breath sounds include vesicular sounds (soft, low-pitched, rustling quality heard over most of the peripheral lung fields during inspiration with a shorter, softer expiratory phase), bronchovesicular sounds (moderate pitch and intensity heard over the mainstem bronchi at the first and second intercostal spaces anteriorly and between the scapulae posteriorly, with equal inspiratory and expiratory phases), and bronchial (tubular) sounds (loud, high-pitched, hollow quality normally heard only over the trachea, with a longer expiratory than inspiratory phase). The critical pathological finding is hearing bronchial breath sounds in areas where vesicular sounds should be heard -- this indicates consolidation (pneumonia), where the solid inflammatory exudate transmits the high-frequency bronchial sounds directly to the chest wall without the normal filtering effect of air-filled alveoli. Adventitious breath sounds include crackles (formerly called rales), wheezes, rhonchi, stridor, and pleural friction rub. Fine crackles are brief, discontinuous, high-pitched popping sounds typically heard during late inspiration, caused by the sudden opening of small airways and alveoli that have collapsed during expiration due to fluid, exudate, or decreased surfactant. They are characteristic of heart failure (pulmonary edema), pneumonia, pulmonary fibrosis, and atelectasis. Coarse crackles are louder, lower-pitched, longer, and heard during both inspiration and expiration, caused by air bubbling through secretions in larger airways (bronchitis, bronchiectasis, pulmonary edema). Wheezes are continuous, high-pitched, musical sounds caused by air flowing through narrowed airways (bronchospasm in asthma, airway inflammation, mucus plugging, tumors). Rhonchi are continuous, low-pitched, rumbling sounds from secretions or obstruction in large airways that often clear with coughing. Stridor is a high-pitched, monophonic sound heard primarily during inspiration (or biphasic in severe cases), indicating upper airway obstruction at or above the level of the larynx -- this is always an emergency finding requiring immediate evaluation. Pleural friction rub is a grating, leathery sound heard during both inspiration and expiration, caused by inflamed parietal and visceral pleural surfaces rubbing against each other (pleuritis, pulmonary embolism with pulmonary infarction). Voice sounds (transmitted voice assessment) provide additional diagnostic information in the setting of suspected consolidation or effusion. Bronchophony is tested by auscultating while the patient says 'ninety-nine' -- normally heard as muffled, indistinct sounds; in consolidation, the words become louder and clearer. Egophony is tested by auscultating while the patient says 'E' -- normally heard as 'E'; in consolidation or at the upper border of a pleural effusion, the sound changes to a nasal 'A' (E-to-A change). Whispered pectoriloquy is tested by auscultating while the patient whispers '1-2-3' -- normally whispered words are inaudible at the chest wall; in consolidation, whispered words are clearly transmitted and audible, indicating dense lung tissue transmitting high-frequency sounds.