PHYSICAL ASSESSMENT OF THE LOWER RESPIRATORY STRUCTURES AND BREATHING
Inspection of the thorax provides information about the muscu-loskeletal structure, the patient’s nutritional status, and the res-piratory system. The nurse observes the skin over the thorax for color and turgor and for evidence of loss of subcutaneous tissue. It is important to note asymmetry, if present. When findings are recorded or reported, anatomic landmarks are used as points of reference (Chart 21-7).
Normally, the ratio of the anteroposterior diameter to the lateral diameter is 1 2. However, there are four main deformities of the chest associated with respiratory disease that alter this relation-ship: barrel chest, funnel chest (pectus excavatum), pigeon chest (pectus carinatum), and kyphoscoliosis.
Barrel chest occurs as a result of overinflation ofthe lungs. There is an increase in the anteroposterior diameter of the thorax. In a patient with emphysema, the ribs are more widely spaced and the intercostal spaces tend to bulge on expiration. The appearance of the patient with advanced emphysema is thus quite characteristic and often allows the observer to detect its presence easily, even from a distance.
Funnel chest occurs whenthere is a depression in the lower portion of the sternum. This may compress the heart and great vessels, resulting in murmurs. Funnel chest may occur with rickets or Marfan’s syndrome.
A pigeon chest occurs as a re-sult of displacement of the sternum. There is an increase in the anteroposterior diameter. This may occur with rickets, Marfan’s syndrome, or severe kyphoscoliosis.
A kyphoscoliosis is characterized by elevation ofthe scapula and a corresponding S-shaped spine. This deformity limits lung expansion within the thorax. It may occur with os-teoporosis and other skeletal disorders that affect the thorax.
Observing the rate and depth of respiration is a simple but im-portant aspect of assessment. The normal adult who is resting comfortably takes 12 to 18 breaths per minute. Except for occa-sional sighs, respirations are regular in depth and rhythm. This normal pattern is described as eupnea.
Bradypnea, also called slow breathing, is associated with in-creased intracranial pressure, brain injury, and drug overdose. Tachypnea, or rapid breathing, is commonly seen in patients with pneumonia, pulmonary edema, metabolic acidosis, septicemia, severe pain, and rib fracture. Shallow, irregular breathing is re-ferred to as hypoventilation.
An increase in depth of respirations is called hyperpnea. An in-crease in both rate and depth that results in a lowered arterial PCO2 level is referred to as hyperventilation. With rapid breath-ing, inspiration and expiration are nearly equal in duration. Hy-perventilation that is marked by an increase in rate and depth, associated with severe acidosis of diabetic or renal origin, is called Kussmaul’s respiration.Apnea describes varying periods of cessation of breathing. If sustained, apnea is life-threatening. Cheyne-Stokes respiration is characterized by alternating epi-sodes of apnea (cessation of breathing) and periods of deep breath-ing. Deep respirations become increasingly shallow, followed by apnea that may last approximately 20 seconds. The cycle repeats after each apneic period. The duration of the period of apnea may vary and may progressively lengthen; therefore, it is timed and re-ported. Cheyne-Stokes respiration is usually associated with heart failure and damage to the respiratory center (drug-induced, tumor, trauma).
Biot’s respirations, or cluster breathing, are cycles of breaths that vary in depth and have varying periods of apnea. Biot’s res-pirations are seen with some central nervous system disorders.
Certain patterns of respiration are characteristic of specific dis-ease states. Respiratory rhythms and their deviation from normal are important observations that the nurse reports and documents. The rate and depth of different patterns of respiration are pre-sented in Figure 21-10.
In thin people, it is quite normal to note a slight retraction of the intercostal spaces during quiet breathing. Bulging during expiration implies obstruction of expiratory airflow, as in em-physema. Marked retraction on inspiration, particularly if asym-metric, implies blockage of a branch of the respiratory tree. Asymmetric bulging of the intercostal spaces, on one side or the other, is created by an increase in pressure within the hemitho-rax. This may be a result of air trapped under pressure within the pleural cavity where it does not normally appear (pneu-mothorax) or the pressure of fluid within the pleural space (pleural effusion).
The nurse palpates the thorax for tenderness, masses, lesions, res-piratory excursion, and vocal fremitus. If the patient has reported an area of pain or if lesions are apparent, the nurse performs di-rect palpation with the fingertips (for skin lesions and subcuta-neous masses) or with the ball of the hand (for deeper masses or generalized flank or rib discomfort).
Respiratory excursion is an estimation of thoracic expansion and may disclose significant information about thoracic movement during breathing. The nurse assesses the patient for range and symmetry of excursion. The patient is instructed to inhale deeply while the movement of the nurse’s thumbs (placed along the costal margin on the anterior chest wall) during inspiration and expiration is observed. This movement is normally symmetric.
Posterior assessment is performed by placing the thumbs adja-cent to the spinal column at the level of the tenth rib (Fig. 21-11). The hands lightly grasp the lateral rib cage. Sliding the thumbs medially about 2.5 cm (1 inch) raises a small skinfold between the thumbs. The patient is instructed to take a full inspiration and to exhale fully. The nurse observes for normal flattening of the skin-fold and feels the symmetric movement of the thorax.
Decreased chest excursion may be due to chronic fibrotic disease. Asymmetric excursion may be due to splinting second-ary to pleurisy, fractured ribs, trauma, or unilateral bronchial obstruction.
Sound generated by the larynx travels distally along the bronchial tree to set the chest wall in resonant motion. This is especially true of consonant sounds. The detection of the resulting vibra-tion on the chest wall by touch is called tactile fremitus.
Normal fremitus is widely varied. It is influenced by the thick-ness of the chest wall, especially if that thickness is muscular. However, the increase in subcutaneous tissue associated with obe-sity may also affect fremitus. Lower-pitched sounds travel better through the normal lung and produce greater vibration of the chest wall. Thus, fremitus is more pronounced in men than in women because of the deeper male voice. Normally, fremitus is most pronounced where the large bronchi are closest to the chest wall and least palpable over the distant lung fields. Therefore, it is most palpable in the upper thorax, anteriorly and posteriorly.
The patient is asked to repeat “ninety-nine” or “one, two, three,” or “eee, eee, eee” as the nurse’s hands move down the pa-tient’s thorax. The vibrations are detected with the palmar sur-faces of the fingers and hands, or the ulnar aspect of the extended hands, on the thorax. The hand or hands are moved in sequence down the thorax. Corresponding areas of the thorax are com-pared (Fig. 21-12). Bony areas are not tested.
Air does not conduct sound well but a solid substance such as tissue does, provided that it has elasticity and is not compressed. Thus, an increase in solid tissue per unit volume of lung will en-hance fremitus; an increase in air per unit volume of lung will im-pede sound. Patients with emphysema, which results in the rupture of alveoli and trapping of air, exhibit almost no tactile fremitus. A patient with consolidation of a lobe of the lung from pneumonia will have increased tactile fremitus over that lobe. Air in the pleural space will not conduct sound.
Percussion sets the chest wall and underlying structures in mo-tion, producing audible and tactile vibrations. The nurse uses percussion to determine whether underlying tissues are filled with air, fluid, or solid material. Percussion also is used to estimate the size and location of certain structures within the thorax (eg, di-aphragm, heart, liver).
Percussion usually begins with the posterior thorax. Ideally, the patient is in a sitting position with the head flexed forward and the arms crossed on the lap. This position separates the scapulae widely and exposes more lung area for assessment. The nurse percusses across each shoulder top, locating the 5-cm width of resonance overlying the lung apices (Fig. 21-13). Then the nurse proceeds down the posterior thorax, percussing symmetric areas at 5- to 6-cm (2- to 2.5-inch) intervals. The middle finger is positioned parallel to the ribs in the intercostal space; the fin-ger is placed firmly against the chest wall before striking it with the middle finger of the opposite hand. Bony structures (scapu-lae or ribs) are not percussed.
Percussion over the anterior chest is performed with the pa-tient in an upright position with shoulders arched backward and arms at the side. The nurse begins in the supraclavicular area and proceeds downward, from one intercostal space to the next. In the female patient, it may be necessary to displace the breasts for an adequate examination. Dullness noted to the left of the ster-num between the third and fifth intercostal spaces is a normal finding because it is the location of the heart. Similarly, there is a normal span of liver dullness in the right thorax from the fifth in-tercostal space to the right costal margin at the midclavicular line.
The anterior and lateral thorax is examined with the patient in a supine position. If the patient cannot sit up, percussion of the pos-terior thorax is performed with the patient positioned on the side.
Dullness over the lung occurs when air-filled lung tissue is re-placed by fluid or solid tissue. Table 21-3 reviews percussion sounds and their characteristics.
The normal resonance of the lung stops at the diaphragm. The position of the diaphragm is different during inspiration than during expiration.
To assess the position and motion of the diaphragm, the nurse instructs the patient to take a deep breath and hold it while the maximal descent of the diaphragm is percussed. The point at which the percussion note at the midscapular line changes from resonance to dullness is marked with a pen. The patient is then instructed to exhale fully and hold it while the nurse again per-cusses downward to the dullness of the diaphragm. This point is also marked. The distance between the two markings indicates the range of motion of the diaphragm.
Maximal excursion of the diaphragm may be as much as 8 to 10 cm (3 to 4 inches) in healthy, tall young men, but for most peo-ple it is usually 5 to 7 cm (2 to 2.75 inches). Normally, the di-aphragm is about 2 cm (0.75 inches) higher on the right because of the position of the heart and the liver above and below the left and right segments of the diaphragm, respectively. Decreased diaphrag-matic excursion may occur with pleural effusion and emphysema. An increase in intra-abdominal pressure, as in pregnancy or ascites, may account for a diaphragm that is positioned high in the thorax.
Auscultation is useful in assessing the flow of air through the bronchial tree and in evaluating the presence of fluid or solid ob-struction in the lung structures. The nurse auscultates for normal breath sounds, adventitious sounds, and voice sounds.
Examination includes auscultation of the anterior, posterior, and lateral thorax and is performed as follows. The nurse places the diaphragm of the stethoscope firmly against the chest wall as the patient breathes slowly and deeply through the mouth. Cor-responding areas of the chest are auscultated in a systematic fash-ion from the apices to the bases and along midaxillary lines. The sequence of auscultation and the positioning of the patient are similar to those used for percussion. It often is necessary to listen to two full inspirations and expirations at each anatomic location for valid interpretation of the sound heard. Repeated deep breaths may result in symptoms of hyperventilation (eg, light-headed-ness); this is avoided by having the patient rest and breathe nor-mally periodically during the examination.
Normal breath sounds are distinguished by their location over a specific area of the lung and are identified as vesicular, bron-chovesicular, and bronchial (tubular) breath sounds (Table 21-4).
The location, quality, and intensity of breath sounds are de-termined during auscultation. When airflow is decreased by bron-chial obstruction (atelectasis) or when fluid (pleural effusion) or tissue (obesity) separates the air passages from the stethoscope, breath sounds are diminished or absent. For example, the breath sounds of the patient with emphysema are faint or often com-pletely inaudible. When heard, the expiratory phase is prolonged. Bronchial and bronchovesicular sounds that are audible any-where except over the main bronchus in the lungs signify pathol-ogy, usually indicating consolidation in the lung (eg, pneumonia, heart failure). This finding requires further evaluation.
An abnormal condition that affects the bronchial tree and alve-oli may produce adventitious (additional) sounds. Adventitious sounds are divided into two categories: discrete, noncontinuous sounds (crackles) and continuous musical sounds (wheezes). The duration of the sound is the important distinction to make in identifying the sound as noncontinuous or continuous. Pleural friction rubs are specific examples of crackles (Table 21-5).
Crackles (formerly referred to as rales) are discrete, noncon-tinuous sounds that result from delayed reopening of deflated air-ways. Crackles may or may not be cleared by coughing. Crackles reflect underlying inflammation or congestion and are often pre-sent in such conditions as pneumonia, bronchitis, heart failure, bronchiectasis, and pulmonary fibrosis.
Friction rubs result from inflammation of the pleural surfaces that induces a crackling, grating sound usually heard in inspira-tion and expiration. The sound can be enhanced by applying pressure to the chest wall with the diaphragm of the stethoscope. The sound is imitated by rubbing the thumb and index finger to-gether near the ear. A friction rub is best heard over the lower lat-eral anterior surface of the thorax.
Wheezes are associated with bronchial wall oscillation andchanges in airway diameter. Wheezes are commonly heard in pa-tients with asthma, chronic bronchitis, and bronchiectasis.
The sound heard through the stethoscope as the patient speaks is known as vocal resonance. The vibrations produced in the larynx are transmitted to the chest wall as they pass through the bronchi and alveolar tissue. During the process, the sounds are diminished in intensity and altered so that syllables are not distin-guishable. Voice sounds are usually assessed by having the patient repeat “ninety-nine” or “eee” while the nurse listens with the stethoscope in corresponding areas of the chest from the apices to the bases.
Bronchophony describes vocal resonance that is more intense and clearer than normal. Egophony describes voice sounds that are distorted. It is best appreciated by having the patient repeat the letter E. The distortion produced by consolidation transforms the sound into a clearly heard A rather than E. Bronchophony and egophony have precisely the same significance as bronchial breathing with an increase in tactile fremitus. When an abnor-mality is detected, it should be evident using more than one as-sessment method. A change in tactile fremitus is more subtle and can be missed, but bronchial breathing and bronchophony can be noted loudly and clearly.
Whispered pectoriloquy is a very subtle finding, heard only in the presence of rather dense consolidation of the lungs. Trans-mission of high-frequency components of sound is so enhanced by the consolidated tissue that even whispered words are heard, a circumstance not noted in normal physiology. The significance is the same as that of bronchophony.
The physical findings for the most common respiratory dis-eases are summarized in Table 21-6.