Pulmonary Examination

A thorough pulmonary examination is best when broken down into 4 basic parts: Inspection, palpation, percussion, and auscultation.

Before beginning any examination of the chest or any other body part, it is important to, as much as possible, have a setting that is private, well lit, and quiet.

Introduction

During the pulmonary examination, inspection is a useful tool for the physician from which much information can be garnered. Visual inspection can be used to appreciate the level of distress, use of accessory muscles, respiratory position, chest structure, respiratory pattern, and other clues outside of the chest.[1, 2, 3] Although inspection begins when the physician first visualizes the patient, it should ideally be performed with the patient properly draped so the chest wall can be visualized.

Initial Observations

The patient’s level of distress should be immediately assessed, as those in severe distress may be experiencing impending respiratory failure that requires intubation. The use of accessory muscles can also indicate increased work of breathing and should be noted on initial assessment. These muscles include the sternocleidomastoid, upper trapezius, pectoralis major, and others.[1, 2]

The position a patient assumes during respiration may also lend clues to a diagnosis. A patient with asthma or chronic obstructive pulmonary disease (COPD) exacerbation may be seen sitting and leaning forward with shoulders arched forward to assist the accessory muscles of respiration.

It is also important to note whether the trachea is midline or deviated. Tracheal deviation may occur ipsilateral to an abnormality (such as in collapse or mucous plugging) or contralateral to an abnormality (such as in pleural effusion or pneumothorax). Table 1 shows possible tracheal findings in several common disorders.[2]

Table 1. Pulmonary Examination Findings of Common Disorders (Open Table in a new window)

Chest Shape

Examination of the shape of the chest is used to assess the structure of the ribs and spine.

There are both congenital and acquired variations of chest wall structure. Congenital variations include pectus excavatum, in which the sternum is depressed relative to the ribs, or, conversely, pectus carinatum, which is characterized by anterior protrusion of the sternum. Kyphoscoliosis, which may be congenital or acquired, is a spinal deformity characterized by lateral curvature and forward flexion of the spine, which can result in restrictive lung disease.[2, 3]

Longstanding obstructive disease can lead to what is commonly known as “barrel” chest, in which the ribs lose their typical 45° downward angle, leading to an increase of the anteroposterior diameter of the chest.[2, 3]

Breathing Patterns

Differential breathing patterns can give clues to diseases of multiple different organ systems as much as the respiratory system itself. The breathing pattern encompasses the rate, rhythm, and volume of a patient’s breathing. The normal breathing rate is 10-14 breaths per minute, with an approximate 1:3 ratio of inspiration to expiration.

Three principal abnormal patterns of breathing have been described. Cheyne-Stokes respiration is characterized by periods of apnea that are interspersed between cycles of progressively increasing then decreasing respiratory rates, which often indicates uremia or congestive heart failure (CHF). Kussmaul breathing is a rapid, large-volume breathing caused by acidotic stimulation of the respiratory center; it can indicate metabolic acidosis. Biot breathing is an irregular breathing pattern alternating between tachypnea, bradypnea, and apnea, a possible indicator of impending respiratory failure.[3]

Extrathoracic Observations

Observations outside of the chest add information to the initial assessment. Peripheral cyanosis or clubbing indicates impaired oxygen delivery. Patients with a severe obstructive defect may breathe with pursed lips, as this can partially ameliorate the obstruction.[4]

Palpation is the tactile examination of the chest from which can be elicited tenderness, asymmetry, diaphragmatic excursion, crepitus, and vocal fremitus. Local tenderness can indicate trauma or costochondritis. Asymmetry and diaphragmatic excursion can be assessed by placing one hand posteriorly on each hemithorax near the level of the diaphragm, palms facing anteriorly with thumbs touching at the midline. When the patient inspires, each hand should rotate away from the midline equally. Unequal movement, or a minute amount of movement, indicates asymmetry and poor diaphragmatic excursion, respectively. Crepitus is the sensation of crackles under the fingertips during superficial palpation of the chest wall. This indicates the presence of subcutaneous air, which is often associated with a pneumothorax on the side of the abnormality.[4]

After superficial palpation, deeper examination of the lungs and air spaces can be accomplished via testing for vocal fremitus. The examiner places the ulnar edge of the hand on the chest wall while the patient repeats a specific phrase, typically “ninety-nine” or “one, two, three.” The strength of the vibrations felt indicates the attenuation of sounds transmitted through the lung tissues. Areas of increased vibration or fremitus correspond to areas of increased tissue density such as those caused by consolidation by pneumonia or malignancy. Overlying fatty tissue, increased airspace (such as in COPD), or fluid outside the lung space may decrease perceived fremitus.[2, 3, 4]

Table 1 illustrates changes in fremitus in several common disorders.[2, 3, 4]

Percussion is performed by placing the pad of the nondominant long finger on the chest wall and striking the distal interphalangeal joint of that finger with the top of the dominant long finger. This technique should be applied to the regions shown in the images below, comparing the two hemithoraces.[2]

Percussion produces sounds on a spectrum from flat to dull depending on the density of the underlying tissue. Areas of well-aerated lung will be resonant, or tympanic, to percussion. Dullness to percussion indicates denser tissue, such as zones of effusion or consolidation. Once an abnormality is detected, percussion can be used around the area of interest to define the extent of the abnormality.

Normal areas of dullness are those overlying the liver and spleen at the anterior bases of the lungs. Normal areas of tympany overlie the gastric bubble, often obscuring the dullness induced by the spleen. As with fremitus, sounds vary depending on the thickness of subcutaneous tissues. See Table 1 for percussion findings in several common disorders.[1, 2]

Introduction

The ideal position for auscultation is to place the patient in a sitting position. If a patient is to remain recumbent, roll the patient from one side to the other to examine the back. If the patient cannot be rolled from side to side, such as in certain ICU settings, auscultation over the anterior chest can be done to yield a more limited examination.

When auscultating, the patient should inhale and exhale through the mouth, deeper than their usual breaths. Auscultation should be performed with the diaphragm of the stethoscope applied directly to the skin, as clothing and other materials can dampen or distort perceived sounds. Auscultate in a pattern as shown in the images below. This should occur symmetrically between the two hemithoraces so that sounds may be compared between sides. Start near the apices and move down in a ladderlike pattern until below the level of the diaphragm is reached or breath sounds are no longer appreciated. This should be performed over the anterior and posterior chest.

The sounds heard during auscultation can be classified as breath sounds, created by air movement through the airways, and adventitious, or added sounds, which have multiple mechanisms of generation.[5, 6] Breath sounds can be classified as vesicular, bronchial, or absent/attenuated.[5, 6]

Vesicular Sounds

Vesicular sounds are generated by the turbulent flow of air through the airways of healthy lungs. These are typically soft and are characterized by inspiratory sounds that last longer than expiratory sounds. Normal lung tissues have a substantial amount of airspace to attenuate and soften the sound. These vesicular sounds vary considerably from patient to patient; thus, it is important to compare one hemidiaphragm to another by listening in a symmetrical pattern, as shown in the image below.[7]

Bronchial Breath Sounds

Bronchial breath sounds often result from consolidation within lung parenchyma with a patent airway leading to the involved area. The resulting breath sounds are amplified through the consolidation, leading to a louder breath sound.[6, 8] Typically, there is a pause between inspiratory and expiratory sounds, as the involved parenchyma does not fill with air during this time in inspiration. The pitch is usually high, as the sounds arise from the bronchi, and the expiratory phase generally lasts longer and is as intense as, or more intense than, the inspiratory phase.[6, 8]

Absent/Attenuated Sounds

Absent/attenuated sounds occur when there is no airflow to the region being auscultated. This can occur in a pneumothorax, hemothorax, pleural effusion, or parenchymal consolidation, which includes the feeding airway.[1, 2]

Adventitious sounds can be classified as crackles, wheezes, rhonchi, or stridor. These sounds occur in addition to the breath sounds described above.

Crackles

Crackles are sounds that are intermittent, nonmusical, very brief, and more pronounced during inspiration. The sound of hair being rubbed between one’s fingers is often used as an example to describe these types of sounds. Crackles can be classified as fine or coarse, depending on their sound quality.[9]

Fine crackles are typically produced by the forced reopening of alveoli that had closed during the previous expiration. These crackles are softer, and higher in pitch, while coarse crackles are louder and lower in pitch. Coarse crackles are typically a combination of alveolar reopening and bubbling of air through retained secretions in smaller airways.[7, 10, 11, 12]

Crackles can also be categorized as early or late, depending on when they are appreciated during the respiratory cycle. Early inspiratory crackles occur immediately after initiation of inspiration and are more often associated with interstitial lung disease.[7] Late inspiratory crackles begin in the first half of inspiration and continue until the end of inspiration. This type of crackle is more often associated with pulmonary edema and asthma.[13]

Table 2 summarizes typical differential diagnoses for varying types of crackles, based on their location within the respiratory cycle and their character.[7, 10, 11, 12] Note that each disease can present with multiple type of crackles simultaneously.

Table 2. Differential Diagnoses of Crackles (Open Table in a new window)

 

Wheezes

Wheezes are continuous, high-pitched, musical, predominantly expiratory sounds that are produced by air flowing through narrowed bronchi, causing fluttering and resonance of the bronchial walls. Thus, they are caused by pathology leading to the narrowing of bronchi, most commonly COPD, asthma, and bronchitis.[5, 6, 9]

Rhonchi

Rhonchi are low-pitched snorelike sounds that may occur throughout the respiratory cycle. They are often characterized by secretions within the large airways and can be heard in a wide variety of pathologies, any of which cause increased secretions, such as in cystic fibrosis, pneumonia, bronchitis, pulmonary edema, or emphysema.[5, 6, 12]

Stridor

Stridor is a loud, rough, continuous, high-pitched sound that is pronounced during inspiration; it indicates proximal airway obstruction. The sound is created by turbulent air flowing through a narrowed trachea or larynx and is loudest over the trachea. This is commonly a medical emergency and should be recognized early. Diagnoses that may present with stridor include epiglottitis, vocal cord dysfunction, croup, and airway edema (which could be secondary to trauma or an allergic reaction).[1, 2]

Pectoriloquy/Egophony

When abnormal breath sounds or adventitious sounds are appreciated on auscultation, it is important to examine the area with the abnormality more thoroughly. This includes auscultating around the area of the abnormality to define its extent, as well as using voice-generated sounds.

When spoken words travel through aerated lung, they are attenuated by airspaces as they move toward the periphery. However, when a consolidation is present, this aeration and attenuation is reduced. This causes increased transmission of whispered words, called pectoriloquy. This reduced aeration also results in a change of the pitch of the transmitted sounds, called egophony.

Whispered pectoriloquy can be elicited by having the patient whisper a repeated phrase (typically “ninety nine”). The transmitted sounds will be louder over the area of consolidation. Egophony can be elicited by having the patient say “ee,” and the transmitted sound will be heard as “aay” over an area of consolidation. Changes in pectoriloquy for several common disorders are shown in Table 1.[1, 2]

Nonpulmonary Sounds

Nonpulmonary sounds must also be appreciated during auscultation of the chest. One important nonpulmonary sound is a mediastinal crunch, caused by pneumomediastinum. This sound is characterized by crackles synchronous with cardiac contraction, and not with respiration. The patient can be asked to temporarily cease respiration to appreciate this difference.

Another important sound is a pleural rub, which can be appreciated as having a sandpaperlike quality and is typically present throughout the respiratory cycle. Inflammation or neoplasia can cause thickening of the pleural surfaces, which then creates more friction when sliding along one another, creating this sound.