The chest and lungs allow for respiration. The purpose of respiration is to keep the body adequately supplied with oxygen and protected from excess accumulation of carbon dioxide. It involves the movement of air back and forth from the alveoli to the outside environment, gas exchange across the alveolar-pulmonary capillary membranes, and circulatory system transport of oxygen to, and carbon dioxide from, the peripheral tissues. This chapter focuses on the examination of the chest and lungs.
- 1.
Inspect the chest; front and back, noting thoracic landmarks for:
- •
Size and shape (anteroposterior diameter compared with the lateral diameter)
- •
Symmetry
- •
Color
- •
Superficial venous patterns
- •
Prominence of ribs
- •
- 2.
Evaluate respirations for:
- •
Rate
- •
Rhythm or pattern
- •
- 3.
Inspect chest movement with breathing for symmetry and use of accessory muscles.
- 4.
Note any audible sounds with respiration (e.g., stridor or wheezes).
- 5.
Palpate the chest for:
- •
Thoracic expansion
- •
Sensations such as crepitus, grating vibrations
- •
Tactile fremitus
- •
- 6.
Perform direct or indirect percussion on the chest, comparing sides for:
- •
Diaphragmatic excursion
- •
Percussion tone intensity, pitch, duration, and quality
- •
- 7.
Auscultate the chest with the stethoscope diaphragm, from apex to base, comparing sides for:
- •
Intensity, pitch, duration, and quality of breath sounds
- •
Unexpected breath sounds (crackles, rhonchi, wheezes, friction rubs)
- •
Vocal resonance
- •
Anatomy and Physiology
The chest, or thorax, is a structure of bone, cartilage, and muscle capable of movement as the lungs expand. It consists anteriorly of the sternum, manubrium, xiphoid process, and costal cartilages; laterally, of the 12 pairs of ribs; and posteriorly, of the 12 thoracic vertebrae ( Figs. 14.1 and 14.2 ). All the ribs are connected to the thoracic vertebrae; the upper seven are attached anteriorly to the sternum by the costal cartilages, and ribs 8, 9, and 10 join with the costal cartilages just above them. Ribs 11 and 12, sometimes referred to as floating ribs, attach posteriorly but not anteriorly. The lateral diameter of the chest generally exceeds the anterior-posterior (AP) diameter in adults.
The primary muscles of respiration are the diaphragm and the intercostal muscles. The diaphragm is the dominant muscle. It contracts and moves downward during inspiration, lowering the abdominal contents to increase the intrathoracic space. The external intercostal muscles increase the AP chest diameter during inspiration, and the internal intercostals decrease the lateral diameter during forceful expiration. The sternocleidomastoid and trapezius muscles may also contribute to respiratory movements. These “accessory” muscles are used during exercise or when there is pulmonary compromise ( Fig. 14.3 ).
The interior of the chest is divided into three major spaces: the right and left pleural cavities and the mediastinum. The mediastinum, situated between the lungs, contains the heart and major blood vessels. The pleural cavities are lined with serous membranes (parietal and visceral pleurae) that surround the lungs. A tiny space between the parietal and visceral pleura is lined by a small amount of fluid to allow easy lung sliding. The spongy and highly elastic lungs are paired but not symmetric, the right having three lobes and the left having two ( Fig. 14.4 ). The left upper lobe has an inferior tonguelike projection, the lingula, which is a counterpart of the right middle lobe. Each lung has a major fissure—the oblique—that divides the upper and lower portions. In addition, a lesser horizontal fissure divides the upper portion of the right lung into the upper and middle lobes at the level of the fifth rib in the axilla and the fourth rib anteriorly. Each lobe consists of blood vessels, lymphatics, nerves, and an alveolar duct connecting with the alveoli (as many as 300 million in an adult). The entire lung is shaped by an elastic subpleural tissue that limits its expansion. Each lung apex is rounded and extends anteriorly about 4 cm above the first rib into the base of the neck in adults. Posteriorly, the apices of the lungs rise to about the level of T1. The lower borders descend on deep inspiration to about T12 and rise on forced expiration to about T9. The base of each lung is broad and concave, resting on the convex surface of the diaphragm. The medial surfaces of the lung are to some extent concave, providing a cradle for the heart.
The tracheobronchial tree is a tubular system that provides a pathway along which air is filtered, humidified, and warmed as it moves from the upper airway to the alveoli. The trachea is 10 to 11 cm long and about 2 cm in diameter. It lies anterior to the esophagus and posterior to the isthmus of the thyroid. The trachea divides into the right and left main bronchi at about the level of T4 or T5 and just below the manubriosternal joint ( Box 14.1 ) called the sternal angle or angle of Louis.
Anteriorly
The right lung may ride higher because of the fullness of the dome of the liver. Except for an inferior lateral triangle, the anterior view on the right is primarily the upper and middle lobes, separated by the horizontal fissure at about the fifth rib in the midaxilla to about the fourth at the sternum; on the left as on the right, the lower lobe is set off by a diagonal fissure stretching from the fifth rib at the axilla to the sixth at the midclavicular line.
Posteriorly
Except for the apices, the posterior view is primarily the lower lobe, which extends from about T3 to T10 or T12 during the respiratory cycle.
Right Lateral
The lung underlies the area extending from the peak of the axilla to the seventh or eighth rib. The upper lobe is demarcated at about the level of the fifth rib in the midaxillary line and the sixth rib more anteriorly.
Left Lateral
The lung underlies the area extending from the peak of the axilla to the seventh or eighth rib. The entire expanse is virtually bisected by the oblique fissure from about the level of the third rib medially to the sixth rib anteriorly.
The right bronchus is wider, shorter, and more vertically placed than the left bronchus (and therefore more susceptible to aspiration of foreign bodies). The main bronchi are divided into three branches on the right and two on the left, each branch supplying one lobe of the lungs. The branches then begin to subdivide into terminal bronchioles and ultimately into respiratory bronchioles.
The bronchial arteries branch from the anterior thoracic aorta and the intercostal arteries, supplying blood to the lung tissue. The bronchial vein is formed at the hilum of the lung, but most of the blood supplied by the bronchial arteries is returned by the pulmonary veins ( Fig. 14.5 ).
Anatomic Landmarks
The following topographic markers on the chest are used to describe findings ( Fig. 14.6 ):
- 1.
The nipples
- 2.
The manubriosternal junction (angle of Louis). A visible and palpable angulation of the sternum and the point at which the second rib articulates with the sternum. One can count the ribs and intercostal spaces from this point. The number of each intercostal space corresponds to that of the rib immediately above it.
- 3.
The suprasternal notch. A depression, easily palpable and most often visible at the base of the ventral aspect of the neck, just superior to the manubriosternal junction.
- 4.
Costal angle. The angle formed by the costal margins at the sternum. It is usually no more than 90 degrees, with the ribs inserted at approximately 45-degree angles.
- 5.
Vertebra prominens. The spinous process of C7. It can be more readily seen and felt with the patient’s head bent forward. If two prominences are felt, the upper is that of the spinous process of C7, and the lower is that of T1. It is difficult to use this as a guide to counting ribs posteriorly because the spinous processes from T4 down project obliquely, thus overlying the rib below the number of its vertebra.
- 6.
The clavicles
Infants and Children
Before birth the lungs contain no air, and the alveoli are collapsed. Fetal gas exchange is mediated by the placenta. Relatively passive respiratory movements occur throughout gestation; they do not open the alveoli or expand the lungs. The lung is not fully grown at birth. The number of alveoli increases at a rapid rate in the first 2 years of life. This slows down by age 8 years.
At birth the change in respiratory function is rapid and dramatic. After the infant’s initial gasp and cry, the lungs fill with air for the first time. When the umbilical cord is cut shortly thereafter, maternal blood no longer comes through the placenta. At this point blood flows through the infant lungs more vigorously. The pulmonary arteries expand and relax, offering much less resistance than the systemic circulation. This relative decrease in pulmonary pressure most often leads to closure of the heart’s foramen ovale within minutes after birth, and the increased oxygen tension in the arterial blood usually stimulates contraction and closure of the ductus arteriosus (see Clinical Pearl, “Patent Ductus Arteriosus [PDA]” ). The pulmonary and systemic circulations adopt their mature configurations, and the lungs are fully integrated for postnatal function.
The chest of the newborn is generally round, the AP diameter approximating the lateral diameter, and the circumference is roughly equal to that of the head until the child is about 2 years old ( Fig. 14.7 ). With growth, the chest assumes adult proportions, with the lateral diameter exceeding the AP diameter.
The heart’s foramen ovale and the ductus arteriosus do not always close so readily. This failure to close is more common in premature infants born before 30 weeks of gestation. A large PDA, sometimes appreciated as a “machine-like” continuous murmur on auscultation, can lead to left ventricular overload and heart failure.
The relatively thin chest wall of the infant and young child makes the bony structure more prominent than in the adult. It is more cartilaginous and yielding, and the xiphoid process is often more prominent and more movable.
Pregnant Patients
Mechanical and biochemical factors, including the enlarged uterus and an increased level of circulating progesterone, interact to create changes in the respiratory function of the pregnant patient. Anatomic changes that occur in the chest as the lower ribs flare include an increase in the lateral diameter of about 2 cm and an increase in the circumference of 5 to 7 cm. The costal angle progressively increases from about 68.5 degrees to approximately 103.5 degrees in later pregnancy. The diaphragm at rest rises as much as 4 cm above its usual resting position, yet diaphragmatic movement increases so that the major work of breathing is done by the diaphragm. Minute ventilation increases due to increased tidal volume, although the respiratory rate remains relatively unchanged.
Older Adults
The barrel chest that is seen in many older adults results from loss of muscle strength in the thorax and diaphragm (see Fig. 14.9 ), coupled with the loss of lung resiliency. In addition, skeletal changes of aging tend to emphasize the dorsal curve of the thoracic spine, resulting in an increased AP chest diameter. There may also be stiffening and decreased expansion of the chest wall.
The alveoli become less elastic and relatively more fibrous. The associated loss of some of the interalveolar folds decreases the alveolar surface available for gas exchange. This and the loss of strength in the muscles of respiration result in underventilation of the alveoli in the lower lung fields and a decreased tolerance for exertion. The net result of these changes is a decrease in vital capacity and an increase in residual volume.
Aging mucous membranes tend to become drier and older adults are less able to clear mucus. Retained mucus encourages bacterial growth and predisposes the older adult to respiratory infection.
Review of Related History
For each of the symptoms or conditions discussed in this section, targeted topics to include in the history of the present illness are listed. Responses to questions about these topics provide clues for focusing the physical examination and the development of an appropriate diagnostic evaluation. Questions regarding medication use (prescription and over-the-counter preparations) as well as complementary and alternative therapies are relevant for each.
History of Present Illness
Cough
- •
Onset: sudden, gradual; duration
- •
Nature of cough: dry, moist, wet, hacking, hoarse, barking, whooping, bubbling, productive, nonproductive
- •
Sputum production: duration, frequency, with activity, at certain times of day
- •
Sputum characteristics: amount, color (clear, purulent, blood-tinged, mostly blood), foul odor
- •
Pattern: occasional, regular, paroxysmal; related to time of day, weather, activities (e.g., exercise), talking, deep breaths; change over time
- •
Severity: tires patient, disrupts sleep or conversation, causes chest pain
- •
Associated symptoms: shortness of breath, chest pain or tightness with breathing, fever, nasal congestion, noisy respirations, hoarseness, gagging
- •
Efforts to treat: prescription or nonprescription drugs, vaporizers, lozenges, dry candy, frequent sips of water
Coughs
Coughs are a common symptom of a respiratory problem. They are usually preceded by a deep inspiration; this is followed by closure of the glottis and contraction of the chest, abdominal, and even the pelvic muscles, and then a sudden, spasmodic expiration, forcing a sudden opening of the glottis. Air and secretions are exhaled. The causes may be related to localized or more general insults at any point in the respiratory tract. Coughs may be voluntary, but they are usually reflexive responses to an irritant such as a foreign body (microscopic or larger), an inflammatory process like asthma, an infectious agent, an underlying problem in the lung parenchyma such as pulmonary fibrosis, or a mass of any sort compressing the respiratory tree. They may also be a clue to an anxiety state.
Describe a cough according to its moisture, frequency, regularity, pitch and loudness, quality, and circumstances. The type of cough may offer some clue to the cause. Although a cough may not have a serious cause, do not ignore it.
Dry or Moist.
A moist or productive cough may be caused by infection and can be accompanied by sputum production. A dry or nonproductive cough can have a variety of causes (e.g., cardiac problems, allergies, gastroesophageal reflux with pharyngeal irritation), which may be indicated by the quality of its sound.
Onset.
An acute onset, particularly with fever, suggests infection; in the absence of fever, a foreign body or inhaled irritants are additional possible causes.
Frequency of Occurrence.
Note whether the cough is seldom or often present. An infrequent cough may result from allergens or environmental insults.
Regularity.
A regular, paroxysmal cough is heard in pertussis. An irregularly occurring cough may have a variety of causes (e.g., smoking, early congestive heart failure, an inspired foreign body or irritant, or a tumor within or compressing the bronchial tree).
Pitch and Loudness.
A cough may be loud and high-pitched or quiet and relatively low-pitched.
Postural Influences.
A cough may occur soon after a person has reclined or assumed an erect position (e.g., with a nasal drip or pooling of secretions in the upper airway).
Quality.
A dry cough may sound loud and harsh if it is caused by compression of the respiratory tree (as by a tumor) or hoarse if it is caused by croup. Pertussis produces an inspiratory whoop at the end of a paroxysm of coughing in older children and adults.
Sputum
The production of sputum is generally associated with cough. Sputum in more than small amounts and with any degree of consistency always suggests the presence of disease. If the onset is acute, infection is most probable. A chronic cough implies a significant anatomic change (e.g., tumor, cavitation, or bronchiectasis). The Differential Diagnosis table delineates possible pathologic conditions and their accompanying sputum findings.
Shortness of Breath ( Box 14.2 )
- •
Onset: sudden or gradual; duration; gagging or choking event before onset
- •
Pattern
- •
Position most comfortable, number of pillows used to sleep comfortably
- •
Related to extent of exercise, certain activities, time of day, eating, environmental exposure
- •
Harder to inhale or exhale
- •
Severity: extent of activity limitation, fatigue with breathing, anxiety about getting air
- •
Associated symptoms: pain or discomfort (relationship to specific point in respiratory exertion, location), cough, diaphoresis, ankle edema
- •
Efforts to treat: oxygen use
Dyspnea, or difficult and labored breathing with shortness of breath, is commonly observed with pulmonary or cardiac compromise. A sedentary lifestyle and obesity can cause it in an otherwise well person. In general, dyspnea increases with the severity of the underlying condition. It is important to establish the amount and kind of effort that produces dyspnea:
- •
Is it present even when the patient is resting?
- •
How much walking? On a level surface? Upstairs?
- •
Is it necessary to stop and rest when climbing stairs?
- •
With what other activities of daily life does dyspnea begin? With what level of physical demand?
Other manifestations of respiratory difficulty include the following:
Orthopnea —shortness of breath that begins or increases when the patient lies down; ask whether the patient needs to sleep on more than one pillow and whether that helps.
Paroxysmal nocturnal dyspnea —a sudden onset of shortness of breath after a period of sleep; sitting upright is helpful.
Platypnea —dyspnea increases in the upright posture.
Chest Pain (see Clinical Pearl, “Chest Pain” )
- •
Onset and duration; associated with trauma, coughing, lower respiratory infection, recent anesthesia or surgery, history of thrombosis, prolonged immobilization increasing risk for pulmonary embolism
- •
Associated symptoms: shallow breathing, fever, coughing, anxiety about getting air, radiation of pain to neck or arms
- •
Efforts to treat: heat, splinting, pain medication
- •
Other medications: recreational drug use (e.g., cocaine)
Chest pain does not generally originate in the heart when:
- •
There is a constant achiness that lasts all day.
- •
It does not radiate.
- •
It is made worse by pressing on the chest wall.
- •
It is a fleeting, needle-like jab that lasts only a few seconds.
- •
It is situated in the shoulders or between the shoulder blades in the back.
Think of the heart but, importantly, in such circumstances, also think of other possibilities in the chest (e.g. pulmonary embolism, pleurisy, aortic dissection, tumor, etc.).
Past Medical History
- •
Thoracic, nasal, and/or pharyngotracheal trauma or surgery, hospitalizations for pulmonary disorders, dates
- •
Use of oxygen or ventilation-assisting devices including continuous or bilevel positive airway pressure machines (CPAP or BiPAP, respectively)
- •
Chronic pulmonary diseases: tuberculosis (date, treatment, compliance), bronchitis, emphysema, bronchiectasis, asthma, cystic fibrosis
- •
Other chronic disorders: cardiac, cancer, blood clotting disorders
- •
Testing: allergy, pulmonary function tests, Interferon Gamma Release Assay (IGRA), tuberculin skin tests, chest imaging
- •
Immunization against Streptococcus pneumoniae, influenza
Family History
- •
Tuberculosis
- •
Cystic fibrosis
- •
Emphysema
- •
Allergy, asthma, atopic dermatitis
- •
Malignancy
- •
Bronchiectasis
- •
Bronchitis
- •
Clotting disorders (risk of pulmonary embolism)
Personal and Social History
- •
Employment: nature of work, extent of physical and emotional effort and stress, environmental hazards, exposure to chemicals, animals, vapors, dust, pulmonary irritants (e.g., asbestos), allergens, use of protective masks
- •
Home environment: location, possible allergens, type of heating, use of air-conditioning, humidifier, ventilation, use of smoke and carbon monoxide detectors in the home
- •
Tobacco use: type of tobacco (cigarettes, e-cigarettes, cigars, pipe, smokeless), duration and amount (Pack years = Number of years of smoking × Number of packs smoked per day), age started, efforts to quit smoking with factors influencing success or failure, the extent of smoking by others at home or at work (secondhand smoking)
- •
Exposure to respiratory infections, influenza, tuberculosis
- •
Nutritional status: weight loss or obesity
- •
Use of complementary and alternative therapies
- •
Exercise tolerance: amount of exercise, diminished ability to perform up to expectations
- •
Regional or travel exposures (e.g., tuberculosis [TB] infection in India, China, Indonesia, South Africa, and Nigeria; histoplasmosis in southeastern and midwestern United States; coccidioidomycosis [valley fever] in southwestern United States, Mexico, Central and South America; schistosomiasis in east and southwest Asia, Africa, and the Caribbean)
- •
Hobbies: owning birds or other animals, woodworking or welding
- •
Use of alcohol or recreational drugs (e.g., cocaine, inhaled methamphetamine); see Clinical Pearl, “Pain from Cocaine”
If an adult—especially a young adult—or an adolescent describes severe, acute chest pain, ask about recreational drug use, particularly cocaine. Cocaine can cause tachycardia, hypertension, coronary arterial spasm (with infarction), and pneumothorax (lung collapse), with severe acute chest pain being the common result.
Infants and Children
- •
Low birth weight, prematurity and gestational age at birth, use of antenatal steroids for lung maturation, history of intubation, duration of ventilation assistance, respiratory distress syndrome, bronchopulmonary dysplasia (chronic lung disease), transient tachypnea of the newborn
- •
Coughing or sudden onset of difficulty breathing, possible aspiration of small object, toy, or food
- •
Possible ingestion of kerosene, antifreeze, or hydrocarbons in household cleaners
- •
Apneic episodes: associated perioral cyanosis, breath-holding, posttussive emesis, history of sudden infant death in sibling
- •
Swallowing dysfunction or other neuromuscular disorders, recurrent spitting up and gagging, recurrent pneumonia (possible gastroesophageal reflux)
- •
Immunization status—especially pneumococcal and influenza vaccines
Pregnant Patients
- •
Weeks of gestation or estimated date of delivery
- •
Presence of multiple fetuses, polyhydramnios, or other conditions in which a larger uterus displaces the diaphragm further upward
- •
Exercise type and energy expenditure
- •
Exposure to and frequency of respiratory infections, status of influenza immunization
Older Adults
- •
Exposure to and frequency of respiratory infections, status of pneumococcal, influenza, and pertussis vaccines
- •
Need for supplemental oxygen
- •
Effects of weather on respiratory efforts and occurrence of infections
- •
Immobilization or marked sedentary habits
- •
Difficulty swallowing or choking/coughing episodes when eating
- •
Alteration in daily living habits or activities as a result of respiratory symptoms
- •
Because older adults are at risk for chronic respiratory diseases (lung cancer, chronic bronchitis, emphysema, and tuberculosis), reemphasize the following:
- •
Smoking history
- •
Cough, dyspnea on exertion, or breathlessness
- •
Blood-tinged or yellowish/greenish sputum
- •
Fatigue
- •
Significant weight changes
- •
Fever, night sweats
- •
Equipment
- •
Marking pen
- •
Centimeter ruler and tape measure
- •
Stethoscope with bell and diaphragm (for infants, you need a smaller stethoscope)
- •
Drapes
Examination and Findings
Inspection
Have the patient sit upright, if possible without support, unclothed to the waist. Clothing of any kind is a barrier for inspection, palpation, percussion, and auscultation. A drape should cover the patient when full exposure is not necessary. The room and stethoscope should be comfortably warm, and a bright tangential light is needed to highlight chest movement. Position the patient so that the light source comes at different angles to accentuate findings that are more subtle and otherwise difficult to detect, such as retractions, or the presence of deformity (e.g., minimal pectus excavatum). If the patient is in bed and mobility is limited, you should have access to both sides of the bed. After informing the patient, do not hesitate to raise and lower the bed as needed.
Note the shape and symmetry of the chest from both the back and the front, the costal angle, the angle of the ribs, and the intercostal spaces. The bony framework is obvious, the clavicles prominent superiorly, the sternum usually rather flat and free of an abundance of overlying tissue. Box 14.3 lists thoracic landmarks to use as you record findings.) The chest will not be absolutely symmetric, but one side can be used as a comparison for the other. The AP diameter of the chest is ordinarily less than the lateral diameter ( Fig. 14.8 ). The relationship is expressed as the thoracic ratio and is expected to be about 0.70 to 0.75. It does increase with age; however, when the AP diameter approaches or equals the lateral diameter (a ratio of 1.0 or even greater), there is most often a chronic condition present. Barrel chest ( Fig. 14.9 ) results from compromised respiration as in, for example, chronic asthma, emphysema, or cystic fibrosis. The ribs are more horizontal, the spine is somewhat kyphotic, and the sternal angle is more prominent. The trachea may be posteriorly displaced.
In conjunction with the anatomic landmarks of the chest, the following imaginary lines on the surface will help localize the findings on physical examination ( Fig. 14.10 ):
Midsternal line: vertically down the midline of the sternum
Right and left midclavicular lines: parallel to the midsternal line, beginning at midclavicle; the inferior borders of the lungs generally cross the sixth rib at the midclavicular line
Right and left anterior axillary lines: parallel to the midsternal line, beginning at the anterior axillary folds
Right and left midaxillary lines: parallel to the midsternal line, beginning at the midaxilla
Right and left posterior axillary lines: parallel to the midsternal line, beginning at the posterior axillary folds
Vertebral line: vertically down the spinal processes
Right and left scapular lines: parallel to the vertebral line, through the inferior angle of the scapula when the patient is erect
The spinous process of the seventh cervical vertebra is readily palpated. The thoracic vertebrae can then be counted down from that point ( Fig. 14.11 ).
Other changes in chest wall contour may be the result of structural problems in the spine, rib cage, or sternum. The spine may be deviated either posteriorly (kyphosis) or laterally (scoliosis) (see Figs. 22.31, B , and 22.72 ). Two common structural findings are pigeon chest (pectus carinatum), which is a prominent sternal protrusion, and funnel chest (pectus excavatum), which is an indentation of the lower sternum above the xiphoid process ( Fig. 14.12 ). See Clinical Pearl, “The Sequence of Steps.”
The sequence of steps in examination of the chest and lungs is inspection, palpation, percussion, and auscultation. The integration of all four, together with the history, will often provide adequate information regarding the pathologic process. Listening to the lungs without also inspecting and palpating the chest will deny you the chance to interpret your findings in the most accurate way. Dullness on percussion, for example, is present in both pleural effusion and lobar pneumonia. Breath sounds are absent in the former and may be bronchial in the latter. On palpation you will often find that tactile fremitus is absent when an effusion exists and is increased with lobar pneumonia.
Observing Respiration
Determine the respiratory rate. The adult rate at rest should be 12 to 16 respirations per minute; the ratio of respirations to heartbeats is approximately 1 : 4. Do not tell the patient that you are going to count the respirations to prevent the patient from varying the rate. Count the respiratory rate after palpating the pulse, just as if you were counting the pulse rate for a longer time. Respiratory rates can vary in the different waking and sleep states. The expected rate of respirations (breaths per minute) depends on a number of factors, including the age of the individual and the degree of exertion. Noting the behavior of the patient relative to the rate is often helpful. Matching your respiratory rate to that of the patient can give you a sense of whether or not the patient is tachypneic or bradypneic.
Note the pattern (or rhythm) of respiration and the way in which the chest moves ( Fig. 14.13 ). Expect the patient to breathe easily, regularly, and without apparent distress. The pattern of breathing should be even, neither too shallow nor too deep. Note any variations in respiratory rate.
- •
Gender: greater in men, but the difference between the sexes diminishes with advancing age
- •
Age: increases with advancing age
- •
Family history of asthma, cystic fibrosis, tuberculosis, and other contagious disease; neurofibromatosis
- •
Smoking
- •
Sedentary lifestyle or forced immobilization
- •
Occupational exposure to asbestos, dust, or other pulmonary irritants and toxic inhalants
- •
Extreme obesity
- •
Difficulty swallowing for any reason
- •
Weakened diaphragm and chest muscles (e.g., amyotrophic lateral sclerosis, polymyositis)
- •
History of frequent respiratory infections
Tachypnea is a persistent respiratory rate above this in an adult. Confirm that the respiratory rate is persistent. Rapid breathing may occur during hyperventilation or simply as a self-conscious response to your observation. It is often a symptom of protective splinting from the pain of a broken rib or pleurisy. Massive liver enlargement or abdominal ascites may prevent descent of the diaphragm and produce a similar pattern. Bradypnea, a rate slower than 12 respirations per minute, may indicate neurologic or electrolyte disturbance, infection, or a conscious response to protect against the pain of pleurisy or other irritative phenomena. It may also indicate an excellent level of cardiorespiratory fitness.
Note any variations in respiratory rhythm. It may be difficult to discern abnormalities unless they are quite obvious ( Box 14.4 ). Hyperventilation can be due to breathing rapidly (tachypnea), breathing deeply (hyperpnea), or both. Exercise and anxiety can cause hyperpnea, but so can central nervous system and metabolic disease. Kussmaul breathing, always deep and most often rapid, is the eponym applied to the respiratory effort associated with metabolic acidosis. Hypopnea, on the other hand, refers to abnormally shallow respirations (e.g., when pleuritic pain limits excursion).
The rate and depth of breathing will:
| INCREASE WITH | DECREASE WITH |
|---|---|
| Acidosis (metabolic) | Alkalosis (metabolic) |
| Central nervous system lesions (pons and medulla) | Central nervous system lesions (cerebrum) |
| Anxiety | Myasthenia gravis |
| Aspirin poisoning | Narcotic overdoses |
| Oxygen need (hypoxemia) | Obesity (extreme) |
| Pain |
A regular periodic pattern of breathing with intervals of apnea followed by a crescendo/decrescendo sequence of respiration is called periodic breathing or Cheyne-Stokes respiration (see Fig. 14.13 ). Children and older adults may exhibit this pattern during sleep, but otherwise it occurs in patients who are seriously ill, particularly those with brain damage at the cerebral level, with drug-associated respiratory compromise or severe congestive heart failure ( Box 14.5 ).
Apnea, which is the absence of spontaneous respiration, may have its origin in the respiratory system and in a variety of central nervous system and cardiac abnormalities. Common contributors include seizures, central nervous system trauma or hypoperfusion, a variety of infections of the respiratory passageway, drug ingestions, and obstructive sleep disorders.
| Primary apnea | A self-limited condition, and not uncommon after a blow to the head. It is especially noted immediately after the birth of a newborn, who will breathe spontaneously when sufficient carbon dioxide accumulates in the circulation. |
| Secondary apnea | Breathing stops and will not begin spontaneously unless resuscitative measures are immediately instituted. Any event that severely limits the absorption of oxygen into the bloodstream will lead to secondary apnea. |
| Reflex apnea | When irritating and nausea-provoking vapors or gases are inhaled, there can be an involuntary, temporary halt to respiration. |
| Sleep apnea | Characterized by periods of an absence of breathing and oxygenation during sleep. Due to blockage of the airway when the soft tissue in the back of the throat collapses during sleep, airflow is not maintained through the nose and mouth. |
| Apneustic breathing | Characterized by a long inspiration and what amounts to expiration apnea. The neural center for control is in the pons and medulla. When it is affected, breathing can become gasping because inspirations are prolonged and expiration constrained. |
| Periodic apnea of the newborn | A normal condition characterized by an irregular pattern of rapid breathing interspersed with brief periods of apnea that one usually associates with rapid eye movement sleep. |
An occasional deep, audible sigh that punctuates an otherwise regular respiratory pattern is associated with emotional distress or an incipient episode of more severe hyperventilation. Sighs also occur in normal respiration.
If the pulmonary tree is seriously obstructed for any reason, inspired air has difficulty overcoming the resistance and getting out. Air trapping is the result of a prolonged but inefficient expiratory effort. Air trapping can also result from increased resistance (i.e. chronic bronchitis), decreased elastic recoil of the lung (i.e., emphysema) or a drop in the critical closing pressure of the airway (i.e., asthma). Any one of these, or a combination will lead to decreased expiratory flow rates which ultimately can lead to air-trapping. The rate of respiration increases to compensate; as this happens, the effort becomes more shallow, the amount of trapped air increases, and the lungs hyperinflate. On a chronic basis, this can lead to a barrel chest.
Biot or ataxic respiration consists of irregular respirations varying in depth and interrupted by intervals of apnea, but lacking the repetitive pattern of periodic respiration. On occasion, the respirations may be regular, but the apneic periods may occur in an irregular pattern. Biot respiration usually is associated with severe and persistent increased intracranial pressure, respiratory compromise resulting from drug poisoning, or brain damage at the level of the medulla and generally indicates a poor prognosis.
Inspect the chest wall movement during respiration. Again, different angles of illumination will aid inspection and help delineate chest wall movement and possible deformities. Expansion should be symmetric, without apparent use of accessory muscles. Chest asymmetry can be associated with unequal expansion and respiratory compromise caused by pneumonia, a collapsed lung, or limited lung expansion from extrapleural air, fluid, or a mass. Unilateral or bilateral bulging can be a reaction of the ribs and interspaces to respiratory obstruction. A prolonged expiration and bulging on expiration are probably caused by airway outflow obstruction or the valvelike action of compression by a tumor, aneurysm, or enlarged heart. When this happens, the costal angle widens beyond 90 degrees.
Retractions are seen when the chest wall seems to cave in at the sternum, between the ribs, at the suprasternal notch, above the clavicles, and at the lowest costal margins. This suggests an obstruction to inspiration at any point in the respiratory tract. As intrapleural pressure becomes increasingly negative, the musculature “pulls back” in an effort to overcome blockage. Any significant obstruction makes the retraction observable with each inspiratory effort. The degree and level of retraction depend on the extent and level of obstruction ( Box 14.6 ). When the obstruction is high in the respiratory tree (e.g., with tracheal or laryngeal involvement), breathing is characterized by stridor. With paradoxical breathing, on inspiration the lower thorax is drawn in, and on expiration, the opposite occurs. This develops when negative intrathoracic pressure is transmitted to the abdomen by a weakened, poorly functioning diaphragm; obstructive airway disease; or during sleep, in the event of upper airway obstruction.
Determining the patency of the upper airway is essential to a complete evaluation of pulmonary status. The upper airway obstructed when there is:
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Inspiratory stridor (with an I/E ratio of more than 2 : 1)
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A hoarse cough or cry
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Flaring of the alae nasi
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Retraction at the suprasternal notch
The upper airway is severely obstructed when:
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Stridor is inspiratory and expiratory
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Cough has a barking character
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Retractions also involve the subcostal and intercostal spaces
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Cyanosis is obvious even with supplemental oxygen
When the obstruction is above the glottis:
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Stridor tends to be quieter
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The voice is muffled
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Swallowing is more difficult
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Cough is not a factor.
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The head and neck may be awkwardly positioned to preserve the airway (e.g., extended with retropharyngeal abscess; head to the affected side with peritonsillar abscess)
When the obstruction is below the glottis:
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Stridor tends to be louder, more rasping
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The voice is hoarse
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Swallowing is not affected
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Cough is harsh, barking
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Positioning of the head is not a factor
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