23.3: Breath Sounds and Lung Assessment
By the end of this section, you will be able to:
- Recognize how to assess the different types of breath sounds
- Identify different respiration patterns
- Examine how to perform a nursing assessment of the lungs
Auscultation of the lungs is one of the most important aspects of a focused respiratory assessment. With practice, you will become proficient at determining whether the sounds you are hearing are normal or if they are indicative of an underlying medical condition. There are several distinct adventitious , or abnormal, lung sounds with which you will become familiar.
Auscultation of the Lungs
Correct placement of the stethoscope during auscultation of lung sounds is important to obtain a quality assessment (Figure 23.14). The stethoscope should not be placed over clothes or hair because these may create inaccurate sounds from friction. The best position to listen to lung sounds is with the patient sitting upright; however, if the patient is acutely ill or unable to sit upright, you can turn them side to side in a lying position. Avoid listening over bones, such as the scapulae or clavicles or over the female breasts to ensure you are hearing adequate sound transmission. Listen to sounds from side to side rather than down one side and then down the other side. This side-to-side pattern allows you to compare sounds in symmetrical lung fields.
Using the diaphragm of the stethoscope, listen to the movement of air through the airways during inspiration and expiration . Instruct the patient to take deep breaths through their mouth. Listen through the entire respiratory cycle because different sounds may be heard on inspiration and expiration. As you move across the different lung fields, the sounds produced by airflow vary depending on the area you are auscultating because the size of the airway changes.
There are various respiratory assessment considerations that should be noted with assessment of children including the following:
- The respiratory rate in children less than 12 months of age can range from thirty to sixty breaths per minute, depending on whether the infant is asleep or active.
- Infants have irregular or periodic newborn breathing in the first few weeks of life; therefore, it is important to count the respirations for a full minute. During this time, you may notice periods of apnea lasting up to ten seconds. This is not abnormal unless the infant is showing other signs of distress. Signs of respiratory distress in infants and children include nasal flaring and sternal or intercostal retractions.
- Up to three months of age, infants are considered “obligate” nose-breathers, meaning their breathing is primarily through the nose.
- The anteroposterior-transverse ratio is typically 1:1 until the thoracic muscles are fully developed around six years of age.
Normal Breath Sounds
Before auscultating the lungs, it is important to be familiar with normal breath sounds so you can compare them to any abnormal sounds heard during the assessment. Table 23.6 describes the different types of normal breath sounds and where they can be heard.
| Type | Anatomical Location | Description |
|---|---|---|
| Bronchial breath sounds | Over trachea and larynx |
|
| Bronchovesicular breath sounds | Over the major bronchi (near first and second intercostal spaces) |
|
| Vesicular breath sounds | Throughout lung fields |
|
Adventitious Breath Sounds
Adventitious lung sounds are sounds heard in addition to normal breath sounds. They most often indicate an airway problem or disease, such as accumulation of mucus or fluids in the airways, obstruction, inflammation, or infection. These sounds include rales/crackles, rhonchi , wheezes, stridor , and pleural rub (Table 23.7).
| Type | Description | Causes |
|---|---|---|
| Fine crackles (rales) | Intermittent high-pitched popping or crackling sounds heard on inspiration | Conditions that cause fluid accumulation in the alveoli and interstitial spaces (e.g., pneumonia or congestive heart failure) |
| Coarse crackles | Intermittent, low-pitched gurgling sounds heard on inspiration; lungs sound “wet” | Conditions that cause fluid accumulation in the alveoli and interstitial spaces (e.g., pneumonia or congestive heart failure) |
| Rhonchi | Continuous, low-pitched, whistling-type noises produced during expiration (sometimes during inspiration) | Conditions that cause narrowing of large airways (bronchoconstriction) or mucosal edema (e.g., bronchitis) |
| Wheeze | Continuous, high-pitched, whistling-type noises produced during expiration (sometimes during inspiration) | Conditions that cause narrowing of small airways (bronchoconstriction) or mucosal edema (e.g., asthma) |
| Stridor | High-pitched “crowing” sound heard only on inspiration | Mechanical obstruction at the level of the trachea or upper airway that is life-threatening if left untreated |
| Friction rub | Grating sound heard on either inspiration or expiration | Inflammation of the lung pleura that causes friction when the surfaces rub together (e.g., pleuritis) |
Assessment of Respiration Patterns
In addition to listening to breathing sounds, it is important to assess the patient’s breathing pattern. A normal breathing pattern for adults consists of twelve to twenty breaths per minute that result in full lung expansion, as evidenced by adequate chest rise and fall. The chest rise should be symmetrical on both sides and the patient should look comfortable, without the use of accessory muscles during breathing. There are several abnormal breathing patterns you should assess for, with the most common types described in Table 23.8.
| Breathing Pattern | Description |
|---|---|
| Agonal breathing |
|
| Apnea |
|
| Bradypnea |
|
| Cheyne-Stokes respiration |
|
| Dyspnea |
|
| Kussmaul respiration |
|
| Orthopnea |
|
| Tachypnea |
|
Nursing Assessment of the Lungs
While nursing assessment of the lungs should focus on thorax configuration, breath sounds, and breathing pattern, other parameters should be assessed simultaneously, including
- skin color (cyanosis or pallor may be an indicator of inadequate gas exchange);
- pain with breathing,
- use of accessory muscles, and
- finger clubbing.
These parameters are discussed in more detail in Chapter 18 Oxygenation and Perfusion.
Identification of Complications in Lung Function
During the nursing assessment, identification of complications in lung function should be noted. There are many common disorders that can negatively affect the respiratory system (Table 23.9).
| Disorder | Description | Associated Assessment Findings |
|---|---|---|
| Atelectasis | Alveoli collapse, resulting in limited air movement and gas exchange |
|
| Bronchitis | Inflammation of the bronchial tubes, often occurring because of a respiratory infection |
|
| Chronic obstructive pulmonary disease (COPD) | Chronic inflammatory condition of the airways and lungs |
|
| Pleural effusion | Abnormal accumulation of fluid in the pleural cavity |
|
| Pneumothorax | Abnormal accumulation of air in the pleural space |
|
| Pulmonary edema | Abnormal accumulation of fluid in the lungs |
|
After performing a thorough lung assessment, the nurse will document findings in the medical record. Examples of documented assessments are as follows:
Sample documentation of expected findings:
Patient denies cough, chest pain, or shortness of breath. Denies past or current respiratory illnesses or diseases. Symmetrical anterior and posterior thorax . Anteroposterior-transverse ratio is 1:2. Respiratory rate is 16 breaths/minute, unlabored, regular, and inaudible through the nose. No retractions, accessory muscle use, or nasal flaring. Chest rise and fall are equal bilaterally. Skin is pink, warm, and dry. No crepitus , masses, or tenderness upon palpation of anterior and posterior chest. Lung sounds clear bilaterally in all lobes anteriorly and posteriorly. No adventitious sounds. SpO2 saturation 99 percent on room air .
Sample documentation of unexpected findings:
Patient reports shortness of breath for five to six hours. Patient has labored breathing at rest. Nail beds are cyanotic. Respiratory rate is tachypneic at 32/minute with neck and abdominal accessory muscle use. Lung expansion is symmetrical. Pursed-lip breathing noted with intermittent productive cough. Reports coughing up blood-tinged green sputum for two days. Anterior and posterior chest walls have no tenderness, masses, or crepitus upon palpation. On auscultation, bilateral coarse crackles over lung bases. Expiratory wheezes are audible and heard with stethoscope scattered throughout lung fields. Pulse oximetry 93 percent on room air .
Cultural and Genetic Variations
Historically, studies have indicated that there are differences in lung capacity and function between different races and ethnicities. However, recent studies suggest that while race and ethnicity may have a small influence on lung function, they are not the only determining factors (Braun, 2015). It is more likely a combination of complex environmental, biological, and social factors that determine lung capacity and function. Genetics, however, play a large role in determining lung capacity and function. Several different genes and mutations have been linked to various respiratory disorders and lung cancers. Additionally, studies have shown significant differences in lung function between sexes. For example, respiratory disorders including asthma, COPD, and pulmonary hypertension, are more common and severe in females (Silveyra et al., 2021).
Behavioral and Lifestyle Variations
The biggest risk factor for developing respiratory disorders is tobacco use and smoking. In fact, patients who smoke are twelve times more likely to die from COPD than patients who do not smoke (Centers for Disease Control and Prevention, 2021). Other behavioral and lifestyle factors that increase the risk for developing respiratory disorders include
- sedentary lifestyle,
- substance abuse (e.g., drugs, alcohol), and
- occupational exposure to air pollution.