NCLEX: Respiratory disorders

Respiratory disorders: A look at respiratory disorders

Focus topic: Respiratory disorders

The respiratory system functions primarily to maintain the exchange of oxygen and carbon dioxide in the lungs and tissues and to regulate acid-base balance. Any change in this system affects every other body system. Conversely, changes in other body systems may reduce the lungs’ ability to provide oxygen and eliminate carbon dioxide.

Respiratory disorders: Anatomy and physiology

Focus topic: Respiratory disorders

The respiratory system consists of the airways, lungs, bony thorax, and respiratory muscles and functions in conjunction with the central nervous system (CNS). These structures work together to deliver oxygen to the bloodstream and remove excess carbon dioxide from the body.

Respiratory disorders

Respiratory disorders: Airways

Focus topic: Respiratory disorders

The airways are divided into the upper and lower airways. The upper airways include the nasopharynx (nose), oropharynx (mouth), laryngopharynx, and larynx. Their purpose is to warm, filter, and humidify inhaled air. They also help make sound and send air to the lower airways.

The top tier

Focus topic: Respiratory disorders

The epiglottis is a flap of tissue that closes over the top of the larynx when the patient swallows. It protects the patient from aspirating food or fluid into the lower airways.
The larynx is located at the top of the trachea and houses the vocal cords. It’s the transition point between the upper and lower airways.

Lowdown on the lower airways

Focus topic: Respiratory disorders

The lower airways begin with the trachea, which then divides into the right and left mainstem bronchial tubes. The mainstem bronchi divide into the lobar bronchi, which are lined with mucusproducing ciliated epithelium, one of the lungs’ major defense systems.
The lobar bronchi then divide into secondary bronchi, tertiary bronchi, terminal bronchioles, respiratory bronchioles, alveolar ducts and, finally, into the alveoli, the gas-exchange units of the lungs. The lungs in a typical adult contain about 300 million alveoli.

Respiratory disorders: Lungs

Focus topic: Respiratory disorders

Each lung is wrapped in a lining called the visceral pleura. The larger of the two lungs, the right lung has three lobes: upper, middle, and lower. The smaller left lung has only an upper and a lower lobe.

Smooth sliding

Focus topic: Respiratory disorders

The lungs share space in the thoracic cavity with the heart, great vessels, trachea, esophagus, and bronchi. All areas of the thoracic cavity that come in contact with the lungs are lined with parietal pleura.
A small amount of fluid fills the area between the two layers of the pleura. This pleural fluid allows the layers of the pleura to slide smoothly over one another as the chest expands and contracts. The parietal pleurae also contain nerve endings that transmit pain signals when inflammation occurs.

Respiratory disorders: Thorax

Focus topic: Respiratory disorders

The bony thorax includes the clavicles, sternum, scapula, 12 sets of ribs, and 12 thoracic vertebrae. You can use specific parts of the thorax, along with some imaginary vertical lines drawn on the chest, to help describe the locations of your findings.

Respiratory disorders

Respiratory disorders

Ribs are made of bone and cartilage and allow the chest to expand and contract during each breath. All ribs attach to the vertebrae. The first seven ribs also attach directly to the sternum. The 8th, 9th, and 10th ribs attach to the costal cartilage of the ribs above. The 11th and 12th ribs are called floating ribs because they don’t attach to anything in the front.

Respiratory disorders: Respiratory muscles

Focus topic: Respiratory disorders

The diaphragm and the external intercostal muscles are the primary muscles used in breathing. They contract when the patient inhales and relax when the patient exhales. The respiratory center in the medulla initiates each breath by sending messages to the primary respiratory muscles over the phrenic nerve. Impulses from the phrenic nerve adjust the rate and depth of breathing, depending on the carbon dioxide and pH levels in the cerebrospinal fluid (CSF).

Accessory to breathing

Focus topic: Respiratory disorders

Accessory inspiratory muscles also assist in breathing. They include the trapezius, sternocleidomastoid, and scalenes, which work together to elevate the scapula, clavicle, sternum, and upper ribs. That elevation expands the front-to-back diameter of the chest when use of the diaphragm and intercostal muscles isn’t effective. If the patient has an airway obstruction, he may also use the abdominal and internal intercostal muscles to exhale.

Respiratory disorders: Pulmonary circulation

Focus topic: Respiratory disorders

Oxygen-depleted blood enters the lungs from the pulmonary artery off the right ventricle, then flows through the main pulmonary vessels into the pleural cavities and the main bronchi, where it continues to flow through progressively smaller vessels until it reaches the single-celled endothelial capillaries serving the alveoli. Here, oxygen and carbon dioxide diffusion takes place.

Movin’ and diffusin’

Focus topic: Respiratory disorders

In diffusion, molecules of oxygen and carbon dioxide move in opposite directions between the alveoli and the capillaries. Partial pressure — the pressure exerted by one gas in a mixture of gas – es — dictates the direction of movement, which is always from an area of greater concentration to one of lesser concentration. During diffusion, oxygen moves across the alveolar and capillary membranes into the bloodstream, where it’s taken up by the hemoglobin (Hb) in the red blood cells (RBCs). This oxygen movement displaces the carbon dioxide in those RBCs, which then moves back through the alveoli.

Where do we go from here?

Focus topic: Respiratory disorders

After passing through the pulmonary capillaries, the oxygenated blood flows through progressively larger vessels, enters the main pulmonary vein, and flows into the left atrium for distribution throughout the body.

Respiratory disorders: Acid-base balance

Focus topic: Respiratory disorders

The lungs help maintain acid-base balance in the body by maintaining external respiration (gas exchange in the lungs) and internal respiration (gas exchange in the tissues). Oxygen collected in the lungs is transported to the tissues by the circulatory system, which exchanges it for the carbon dioxide produced by cellular metabolism. Because carbon dioxide is 20 times more soluble than oxygen, it dissolves in the blood, where most of it forms bicarbonate (base) and smaller amounts form carbonic acid (acid).

Respiratory disorders

Balancing act

Focus topic: Respiratory disorders

The lungs control hydrogen ion concentration and bicarbonate levels by controlling the amount of carbon dioxide eliminated. In response to signals from the medulla, the lungs can change the rate and depth of ventilation. Such changes maintain acid-base balance by adjusting the amount of carbon dioxide that’s lost. For example, in metabolic alkalosis, which results from excess bicarbonate retention, the rate and depth of ventilation decrease so that carbon dioxide is retained. This increases carbonic acid levels. In metabolic acidosis (a condition resulting from excess acid retention or excess bicarbonate loss), the lungs increase the rate and depth of ventilation to exhale excess carbon dioxide, thereby reducing carbonic acid levels.

When the balance tips

Focus topic: Respiratory disorders

Inadequately functioning lungs, however, can produce acid-base imbalances. For example, hypoventilation (reduced rate and depth of ventilation) of the lungs, which results in carbon dioxide retention, causes respiratory acidosis. Conversely, hyperventilation (increased rate and depth of ventilation) of the lungs leads to increased exhalation of carbon dioxide and results in respiratory alkalosis.

Respiratory disorders: Assessment

Focus topic: Respiratory disorders

Because the body depends on the respiratory system for survival, respiratory assessment is a critical nursing responsibility. By performing it thoroughly, you can detect obvious and subtle respiratory changes.

Respiratory disorders: History

Focus topic: Respiratory disorders

Begin your assessment with a thorough health history. Keep your questions open-ended. You may have to conduct the interview in several short sessions, depending on the severity of your patient’s condition.

Current health status
Ask your patient to tell you about his reason for seeking care. Because many respiratory disorders are chronic, ask him how the latest episode compared with the previous episode and what relief measures helped or didn’t help. A patient with a respiratory disorder may complain of shortness of breath, cough, sputum production, wheezing, chest pain, and ankle and leg edema. Gain a history of the patient’s shortness of breath by determining its severity. Ask the patient these questions:
• What do you do to relieve the shortness of breath?
• How well does it work?

Three-pillow pileup

Focus topic: Respiratory disorders

A patient with orthopnea (shortness of breath when lying down) tends to sleep with his upper body elevated. Ask this patient how many pillows he uses. The answer describes the severity of orthopnea. For instance, a patient who uses three pillows can be said to have “three-pillow orthopnea.”

Cough it up

Focus topic: Respiratory disorders

Ask the patient with a cough these questions:
• When did the cough start?
• Is the cough productive?
• If the cough is chronic, has it changed recently? If so, how?
• What makes the cough better?
• What makes it worse?
• What medications are you taking? (Angiotensin-converting enzyme inhibitors can cause a cough in some patients.)

Spit it out

Focus topic: Respiratory disorders

When a patient produces sputum, ask him to estimate the amount produced in teaspoons or some other common measurement. Also ask him these questions:
• At what time of day do you cough most often?
• What’s the color and consistency of the sputum?
• If sputum is a chronic problem, has it changed recently? If so, how?

Tell me about the wheeze, please

Focus topic: Respiratory disorders

If a patient wheezes, ask these questions:
• At what time of day does wheezing occur?
• What makes you wheeze?
• Do you wheeze loudly enough for others to hear it?
• What helps stop your wheezing?

A pain in the chest

Focus topic: Respiratory disorders

Chest pain that occurs from a respiratory problem usually results from pleural inflammation, inflammation of the costochondral junctions, soreness of chest muscles because of coughing, or indigestion. Less common causes of pain include rib or vertebral fractures caused by coughing or by osteoporosis. If the patient has chest pain, ask him these questions:
• Where is the pain exactly?
• What does it feel like? Is it sharp, stabbing, burning, or aching?
• Does it move to another area?
• How long does it last?
• What causes it to occur or makes it better?
• Do you have associated symptoms, such as shortness of breath or nausea and vomiting?

Previous health status
Focus your questions on identifying previous respiratory problems, such as asthma or emphysema. A history of these conditions provides instant clues to the patient’s current condition. Ask about his smoking history. Then ask about childhood illnesses. Infantile eczema, atopic dermatitis, or allergic rhinitis, for example, may precipitate current respiratory problems such as asthma.

Respiratory disorders

Respiratory disorders

Family history
Ask the patient if anyone in his family has had cancer, diabetes, sickle cell anemia, heart disease, or a chronic illness, such as asthma or emphysema. Be sure to determine whether the patient lives with anyone who has an infectious disease, such as influenza or tuberculosis (TB).

Respiratory disorders

Lifestyle patterns
The patient’s history should also include information about lifestyle, community, and other environmental factors that might affect his respiratory status or how he deals with respiratory problems. Most importantly, ask the patient if he smokes; if he does, ask when he started and how many cigarettes he smokes per day.
Also ask about interpersonal relationships, mental status, stress management, and coping style. Keep in mind that a patient’s sex habits or drug use may be connected with acquired immunodeficiency syndrome-related respiratory disorders.

Respiratory disorders: Physical examination

Focus topic: Respiratory disorders

In most cases, you’ll proceed with the physical examination after you’ve taken the patient’s history. However, you won’t have the chance to obtain a history if the patient develops an ominous sign such as acute respiratory distress.
A physical examination of the respiratory system follows four steps: inspection, palpation, percussion, and auscultation. Before you begin, introduce yourself, if necessary, and explain what you’ll be doing. Then make sure the room is well lit and warm.

Back to front

Focus topic: Respiratory disorders

Examine the back of the chest first, using inspection, palpation, percussion, and auscultation. Always compare one side with the other. Then examine the front of the chest using the same sequence. The patient can lie back when you examine the front of the chest if that’s more comfortable for him.

Inspection
First, inspect the chest. Help the patient into an upright position. The patient should be undressed from the waist up or clothed in an examination gown that allows easy access to his chest.

Beauty in symmetry

Focus topic: Respiratory disorders

Note masses or scars that indicate trauma or surgery. Look for chest wall symmetry. Both sides of the chest should be equal at rest and expand equally as the patient inhales. The diameter of the chest from front to back should be about half the width of the chest.

A new angle

Focus topic: Respiratory disorders

Also, look at the angle between the ribs and the sternum at the point immediately above the xiphoid process. This angle — the costal angle — should be less than 90 degrees in an adult. The angle will be larger if the chest wall is chronically expanded because of an enlargement of the intercostal muscles, as can happen with chronic obstructive pulmonary disease (COPD).

Breathing rate and pattern
To find the patient’s respiratory rate, count his respirations for a full minute — longer if you note abnormalities. Don’t tell him what you’re doing, or he might alter his natural breathing pattern.

Respiratory disorders

Adults normally breathe at a rate of 12 to 20 breaths/minute. The respiratory pattern should be even, coordinated, and regular, with occasional sighs. The inspiratory-expiratory ratio (length of inspiration to length of expiration) is about 1:2.

Muscles in motion

Focus topic: Respiratory disorders

When the patient inhales, his diaphragm should descend and the intercostal muscles should contract. This dual motion causes the abdomen to push out and the lower ribs to expand laterally.
When the patient exhales, his abdomen and ribs return to their resting position. The upper chest shouldn’t move much. Accessory muscles may hypertrophy with frequent use. Frequent use of accessory muscles may be normal in some athletes, but for other patients it indicates a respiratory problem, particularly when the patient purses his lips and flares his nostrils when breathing.

Inspecting related structures
Inspection of the skin, tongue, mouth, fingers, and nail beds may also provide information about respiratory status.

Gettin’ the blues

Focus topic: Respiratory disorders

Skin color varies considerably among patients, but in all cases, a patient with a bluish tint to his skin and mucous membranes is considered cyanotic. Cyanosis, which occurs when oxygenation to the tissues is poor, is a late sign of hypoxemia.
The most reliable place to check for cyanosis is the tongue and mucous membranes of the mouth. Cyanotic nail beds, nose, or ears can sometimes occur when the patient is cold, indicating low blood flow to those areas but not necessarily to major organs.

Clubbing clues

Focus topic: Respiratory disorders

When you check the fingers, look for clubbing, a possible sign of long-term hypoxia. A fingernail normally enters the skin at an angle of less than 180 degrees. When clubbing occurs, the angle is greater than or equal to 180 degrees.

Palpation
Palpation of the chest provides important information about the respiratory system and the processes involved in breathing. Here’s what to look for when palpating the chest.

No extra air

Focus topic: Respiratory disorders

The chest wall should feel smooth, warm, and dry. Crepitus indicates subcutaneous air in the chest, an abnormal condition. Crepitus feels like puffed-rice cereal crackling under the skin and indicates that air is leaking from the airways or lungs.
If a patient has a chest tube, you may find a small amount of subcutaneous air around the insertion site. If the patient has no chest tube or the area of crepitus is getting larger, alert the practitioner immediately.

Ouch! That hurts…

Focus topic: Respiratory disorders

Gentle palpation shouldn’t cause the patient pain. If the patient complains of chest pain, check for painful areas on the chest wall. Painful costochondral joints are typically located at the midclavicular line or next to the sternum. Rib or vertebral fractures will be quite painful over the fracture, although pain may radiate around the chest as well. Pain may also stem from sore muscles from protracted coughing or a collapsed lung.

Good — and bad — vibrations

Focus topic: Respiratory disorders

Palpate for tactile fremitus, palpable vibrations caused by the transmission of air through the bronchopulmonary system. Fremitus is decreased over areas where pleural fluid collects, at times when the patient speaks softly, and within pneumothorax, pleural effusion, and emphysema. Fremitus is increased normally over the large bronchial tubes and abnormally over areas in which alveoli are filled with fluid or exudate, as happens in pneumonia.

Respiratory disorders

Measure up

Focus topic: Respiratory disorders

To evaluate the patient’s chest wall symmetry and expansion, place your hands on the front of the chest wall, with your thumbs touching each other at the second intercostal space. As the patient inhales deeply, watch your thumbs. They should separate simultaneously and equally, to a distance several centimeters away from the sternum. Repeat the measurement at the fifth intercostal space. You can make the same measurement on the back of the chest near the tenth rib.

Percussion
Percuss the chest to find the boundaries of the lungs; determine whether the lungs are filled with air, fluid, or solid material; and evaluate the distance the diaphragm travels between the patient’s inhalation and exhalation.

Respiratory disorders

Different sites, different sounds

Percussion allows you to assess structures as deep as 3 (7.6 cm). You’ll hear different percussion sounds in different areas of the chest.
You also may hear different sounds after certain treatments.
For instance, if your patient has atelectasis and you percuss his chest before chest physiotherapy, you’ll hear a high-pitched, dull, soft sound. After physiotherapy, you should hear a low-pitched, hollow sound.

Ringing with resonance

You’ll hear resonant sounds over normal lung tissue, which you should find over most of the chest. In the left front chest, from the third or fourth intercostal space at the sternum to the third or fourth intercostal space at the midclavicular line, you should hear a dull sound. Percussion is dull here because that’s the space occupied by the heart. Resonance resumes at the sixth intercostal space.

Descending diaphragm

Percussion also allows you to assess how much the diaphragm moves during inspiration and expiration. The normal diaphragm descends 11/8 to 2 (3 to 5 cm) when the patient inhales. The diaphragm doesn’t move as far in patients with emphysema, respiratory depression, diaphragm paralysis, atelectasis, obesity, or ascites.

Auscultation
Auscultation helps you determine the condition of the alveoli and surrounding pleura. As air moves through the bronchial tubes, it creates sound waves that travel to the chest wall. The sounds produced by breathing change as air moves from larger airways to smaller airways. Sounds also change if they pass through fluid, mucus, or narrowed airways.

Preparing to auscultate
Auscultation sites are the same as percussion sites. Listen to a full inspiration and a full expiration at each site, using the diaphragm of the stethoscope. Ask the patient to breathe through his mouth; nose breathing alters the pitch of breath sounds.

Respiratory disorders

Be firm

To auscultate for breath sounds, press the stethoscope firmly against the skin. If the patient has abundant chest hair, press the diaphragm of the stethoscope down even more firmly so the hair doesn’t make a sound that might be mistaken for crackles. Remember that if you listen through clothing or chest hair, you
may hear unusual, deceptive sounds.

Normal breath sounds
You’ll hear four types of breath sounds over normal lungs. The type of sound you hear depends on where you listen:
• Tracheal breath sounds, heard over the trachea, are harsh, high pitched, discontinuous sounds. They occur when a patient inhales or exhales.
• Bronchial breath sounds, usually heard next to the trachea, are loud, high-pitched, and discontinuous. They’re loudest when the patient exhales.

• Bronchovesicular sounds, heard when the patient inhales or exhales, are medium-pitched and continuous. They’re heard next to the sternum, between the scapulae.
• Vesicular sounds, heard over the rest of the lungs, are soft and low-pitched. They’re prolonged during inhalation and shortened during exhalation.

What’s that sound?

Classify each sound according to its intensity, location, pitch, duration, and characteristic. Note whether the sound occurs when the patient inhales, exhales, or both. If you hear a sound in an area other than where you would expect to hear it, consider the sound abnormal.
For instance, bronchial or bronchovesicular breath sounds found in an area where you would normally hear vesicular breath sounds indicates that the alveoli and small bronchioles in that area might be filled with fluid or exudate, as occurs in pneumonia and atelectasis. In such a situation, you won’t hear vesicular sounds in those areas because no air is moving through the small airways.

Testing, testing

A patient with abnormal findings during a respiratory assessment may need further evaluation with such diagnostic tests as arterial blood gas (ABG) analysis or pulmonary function tests.

Vocal fremitus
Vocal fremitus is the sound produced by chest vibrations as the patient speaks. Abnormal transmission of voice sounds may occur over consolidated areas. The most common abnormal voice sounds are called bronchophony, egophony, and whispered pectoriloquy. Here’s what they sound like:
• Ask the patient to say “ninety-nine” or “blue moon.” Over normal lung tissue, the words sound muffled. In bronchophony, the words sound unusually loud over consolidated areas.
• Ask the patient to say “E.” Over normal lung tissue, the sound is muffled. In egophony, it will sound like the letter a over consolidated lung tissue.
• Ask the patient to whisper “1, 2, 3.” Over normal lung tissue, the numbers will be almost indistinguishable. In whispered pectoriloquy, the numbers will be loud and clear over consolidated lung tissue.

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