Key components in the evaluation of patients with pulmonary symptoms are the history, physical examination, and, in many cases, a chest x-ray. These components establish the need for subsequent testing, which may include pulmonary function testing and arterial blood gas (ABG) analysis, computed tomography (CT) or other chest imaging tests, and bronchoscopy.
The history can often establish whether symptoms of cough, dyspnea, chest pain, wheezing, stridor, and hemoptysis are likely to be pulmonary in origin. When more than one symptom occurs concurrently, the history should focus on which symptom is primary. A history should also establish whether constitutional symptoms, such as fever, weight loss, and night sweats, are present. Other important information includes
- Occupational and environmental exposures
- Family history, travel history, and contact history
- Previous illnesses and comorbidities
- Use of prescription, over-the-counter, or illicit drugs
- Use of tobacco products or other inhaled substances
- Previous test results (eg, tuberculin skin test, chest x-rays)
Physical examination starts with assessment of general appearance. Discomfort and anxiety, body habitus, and the effect of talking or movement on symptoms (eg, inability to speak full sentences without pausing to breathe) all can be assessed while greeting the patient and taking a history and may provide useful information relevant to pulmonary status. Next, inspection, auscultation, and chest percussion and palpation are done.
Inspection should focus on
- Signs of respiratory difficulty and hypoxemia (eg, restlessness, tachypnea, cyanosis, accessory muscle use)
- Signs of possible chronic pulmonary disease (eg, clubbing, pedal edema)
- Chest wall deformities
- Abnormal breathing patterns (eg, prolonged expiratory time, Cheyne-Stokes respiration, Kussmaul respirations)
- Jugular venous distention
A sign of hypoxemia is cyanosis (bluish discoloration of the lips, face, or nail beds), which requires the presence of at least 5 g/dL of unsaturated hemoglobin and thus signifies low arterial oxygen saturation (< 85%); the absence of cyanosis does not exclude the presence of hypoxemia.
Signs of respiratory difficulty include tachypnea, use of accessory respiratory muscles (sternocleidomastoids, intercostals, scalenes) to breathe, intercostal retractions, and paradoxical breathing. Patients with chronic obstructive pulmonary disease (COPD) sometimes brace their arms against their legs or the examination table while seated (ie, tripod position) in a subconscious effort to provide more leverage to accessory muscles and thereby enhance respiration. Intercostal retractions (inward movement of the rib interspaces) are common among infants and older patients with severe airflow limitation. Paradoxical breathing (inward motion of the abdomen during inspiration) signifies respiratory muscle fatigue or weakness.
Signs of possible chronic pulmonary disease include clubbing, barrel chest (the increased anterior-posterior diameter of the chest present in some patients with emphysema), and pursed lip breathing.
Clubbing is enlargement of the fingertips (or toes) due to proliferation of connective tissue between the fingernail and the bone. Diagnosis is based on an increase in the profile angle of the nail as it exits the finger (to >180°) or on an increase in the phalangeal depth ratio (to > 1—see figure Measuring finger clubbing). “Sponginess” of the nail bed beneath the cuticle also suggests clubbing. Clubbing is most commonly observed in patients with lung cancer but is an important sign of chronic pulmonary disease, such as cystic fibrosis and idiopathic pulmonary fibrosis; it also occurs (but less commonly) in cyanotic heart disease, chronic infection (eg, infective endocarditis), stroke, inflammatory bowel disease, and cirrhosis. Clubbing occasionally occurs with osteoarthropathy and periostitis (primary or hereditary hypertrophic osteoarthropathy); in this instance, clubbing may be accompanied by skin changes, such as hypertrophied skin on the dorsa of the hands (pachydermoperiostosis), seborrhea, and coarse facial features. Digital clubbing can also occur as a benign hereditary abnormality that can be distinguished from pathologic clubbing by the absence of pulmonary symptoms or disease and by the presence of clubbing from an early age (by patient report).
Measuring finger clubbing
The ratio of the anteroposterior diameter of the finger at the nail bed (a–b) to that at the distal interphalangeal joint (c–d) is a simple measurement of finger clubbing. It can be obtained readily and reproducibly with calipers. If the ratio is > 1, clubbing is present. Finger clubbing is also characterized by loss of the normal angle at the nail bed.
Barrel chest is the increased anterior-posterior diameter of the chest present in some patients with emphysema.
In pursed lip breathing, the person exhales through tightly closed lips and inhales through the nose with the mouth closed. This maneuver increases pressure in the airways to keep them open and thereby decrease gas trapping.
Chest wall deformities, such as pectus excavatum (a sternal depression usually beginning over the midportion of the manubrium and progressing inward through the xiphoid process) and kyphoscoliosis, may restrict respirations and exacerbate symptoms of preexisting pulmonary disease. These abnormalities can usually be observed during careful examination after the patient's shirt is removed. Inspection should also include an assessment of the abdomen and the extent of obesity, ascites, or other conditions that could affect abdominal compliance.
Abnormal breathing patterns may suggest underlying disease processes. A prolonged expiratory to inspiratory ratio occurs in obstructive lung disease. Some abnormal breathing patterns cause fluctuations in respiratory rate so respiratory rate should be assessed and counted for 1 minute.
- Cheyne-Stokes respiration (periodic breathing) is a cyclic fluctuation of respiratory rate and depth. From periods of brief apnea, patients breathe progressively faster and deeper (hyperpnea), then slower and shallower until they become apneic and repeat the cycle. Cheyne-Stokes respiration is most often caused by heart failure, a neurologic disorder (eg, stroke, advanced dementia), or drugs. The pattern in heart failure has been attributed to delays in cerebral circulation; respiratory centers lag in recognition of systemic acidosis/hypoxia (causing hyperpnea) or alkalosis/hypocapnia (causing apnea).
- Biot respiration is an uncommon variant of Cheyne-Stokes respiration in which irregular periods of apnea alternate with periods in which 4 or 5 deep, equal breaths are taken. It differs from Cheyne-Stokes respiration in that it is characterized by abrupt starts and stops and lacks periodicity. It results from injury to the central nervous system and occurs in such disorders as meningitis.
- Kussmaul respirations are deep, regular respirations caused by metabolic acidosis.
Jugular venous distension is evaluated with the patient reclining at 45°. The top of the venous column is normally just above the clavicles (upper limit of normal: 4 cm above the sternal notch in a vertical plane). An increase in the height of the column may indicate left ventricular dysfunction, pulmonary hypertension, or both and should prompt a search for other signs of cardiac disorder (eg, 3rd heart sound [S3] gallop, dependent edema).
Lung auscultation is arguably the most important component of the physical examination. All fields of the chest should be listened to, including the flanks and the anterior chest, to detect abnormalities associated with each lobe of the lung. Features to listen for include
- Character and volume of breath sounds
- Presence or absence of vocal sounds
- Pleural friction rubs
Cardiac auscultation may reveal signs of pulmonary hypertension, such as a loud pulmonic 2nd heart sound (P2), and of right heart failure, such as a right ventricular 4th heart sound (S4) and tricuspid regurgitation.
The character and volume of breath sounds are useful in identifying pulmonary disorders. Vesicular breath sounds are the normal sounds heard over most lung fields. Bronchial breath sounds are slightly louder, harsher, and higher pitched; they normally can be heard over the trachea and over areas of lung consolidation, such as occur with pneumonia.
Adventitious sounds are abnormal sounds, such as crackles, rhonchi, wheezes, and stridor.
- Crackles (previously called rales) are discontinuous adventitious breath sounds. Fine crackles are short, high-pitched sounds; coarse crackles are longer-lasting, low-pitched sounds. Crackles have been compared to the sound of crinkling plastic wrap or the opening of Velcro® (in interstitial lung disease) and can be simulated by rubbing strands of hair together between 2 fingers near one’s ear. They occur most commonly with atelectasis, alveolar filling processes (eg, pulmonary edema), and interstitial lung disease (eg, pulmonary fibrosis); they signify opening of collapsed airways or alveoli.
- Rhonchi are low-pitched respiratory sounds that can be heard during inspiration or expiration. They occur in various conditions, including chronic bronchitis. The mechanism may relate to variations in obstruction as airways distend with inhalation and narrow with exhalation.
- Wheezes are whistling, musical breath sounds that are worse during expiration than inspiration and involve narrowing of small airways. Wheezing can be a physical finding or a symptom and is usually associated with dyspnea.
- Stridor is a high-pitched, predominantly inspiratory sound formed by extrathoracic upper airway obstruction. It usually can be heard without a stethoscope. Stridor is usually louder than wheezing, is predominantly inspiratory, and is heard loudly over the larynx. It should trigger a concern for life-threatening upper airway obstruction.
- Decreased breath sounds signify poor air movement in airways, as occurs with asthma and COPD where bronchospasm or other mechanisms limit airflow. Breath sounds may also be decreased in the presence of a pleural effusion, pneumothorax, or obstructing endobronchial lesion.
Vocal sounds are heard during auscultation while patients vocalize.
- Bronchophony and whispered pectoriloquy occur when the patient’s spoken or whispered voice is clearly transmitted through the chest wall. Voice transmission results from alveolar consolidation, as occurs with pneumonia.
- Egophony (E to A change) is said to occur when, during auscultation, a patient says the letter “E” and the examiner hears the letter “A,” again as occurs with pneumonia.
Friction rubs are grating or creaking sounds that fluctuate with the respiratory cycle and sound like skin rubbing against wet leather. They are a sign of pleural inflammation and are heard in patients with pleuritis or empyema and after thoracotomy.
Percussion and palpation
Percussion is the primary physical maneuver used to detect the presence and level of pleural effusion. Finding areas of dullness during percussion signifies underlying fluid or, less commonly, consolidation.
Palpation includes tactile fremitus (vibration of the chest wall felt while a patient is speaking); it is decreased in pleural effusion and pneumothorax and increased in pulmonary consolidation (eg, lobar pneumonias). Point tenderness on palpation may signal underlying rib fracture, costochondral dislocation or inflammation, or pleural inflammation.
A right ventricular impulse at the left lower sternal border may become evident and may be increased in amplitude and duration (right ventricular heave) in patients with cor pulmonale.