Accessory muscle use
When breathing requires extra effort, the accessory muscles—the sternocleidomastoid, scalene, pectoralis major, trapezius, internal intercostals, and abdominal muscles—stabilize the thorax during respiration. Some accessory muscle use normally takes place during such activities as singing, talking, coughing, defecating, and exercising. (See Accessory muscles: Locations and functions, page 20.)
More pronounced use of these muscles may signal acute respiratory distress, diaphragmatic weakness, or fatigue. It may also result from chronic respiratory disease. Typically, the extent of accessory muscle use reflects the severity of the underlying cause.
Action stat!
If the patient displays increased accessory muscle use, immediately look for signs of acute respiratory distress. These include a decreased level of consciousness, shortness of breath when speaking, tachypnea, intercostal and sternal retractions, cyanosis, adventitious breath sounds (such as wheezing or stridor), diaphoresis, nasal flaring, and extreme apprehension or agitation. Quickly auscultate for abnormal, diminished, or absent breath sounds. Check for airway obstruction and, if detected, attempt to restore airway patency. Insert an airway or intubate the patient. Then begin suctioning and manual or mechanical ventilation. Assess oxygen saturation using pulse oximetry if available. Administer oxygen; if the patient has chronic obstructive pulmonary disease (COPD), use only a low flow rate for mild COPD exacerbations. You may need to use a high flow rate initially, but be attentive to the patient's respiratory drive. Giving a patient with COPD too much oxygen may decrease his respiratory drive. An I.V. catheter may be required.
History and physical examination
If the patient's condition allows, examine him more closely. Ask him about the onset, duration, and severity of associated signs and symptoms, such as dyspnea, chest pain, cough, sputum production, or fever.
Explore his medical history, focusing on respiratory disorders, such as infection or COPD. Ask about cardiac disorders, such as heart failure, which may lead to pulmonary edema; inquire about neuromuscular disorders, such as amyotrophic lateral sclerosis, which may affect respiratory muscle function. Note a history of allergies or asthma. Because collagen vascular diseases can cause diffuse infiltrative lung disease, ask about such conditions as rheumatoid arthritis and lupus erythematosus.
Ask about recent trauma, especially to the spine or chest. Find out if the patient has recently undergone pulmonary function tests or received respiratory therapy. Ask about smoking and occupational exposure to chemical fumes or mineral dusts such as asbestos. Explore the family history for such disorders as cystic fibrosis and neurofibromatosis, which can cause diffuse infiltrative lung disease.
Perform a detailed chest examination, noting an abnormal respiratory rate, pattern, or depth. Assess the patient's chest for equal expansion during inspiration. Check the trachea for midline position. Assess the color, temperature, and turgor of the patient's skin, and check for clubbing. Auscultate the lungs for adventitious breath sounds.
Medical causes
Acute respiratory distress syndrome (ARDS).In ARDS, a life-threatening disorder, accessory muscle use increases in response to hypoxia. It's accompanied by intercostal, supracostal, and sternal retractions on inspiration and by grunting on expiration. Other characteristics include tachypnea, dyspnea, diaphoresis, diffuse crackles, and a cough with pink, frothy sputum. Worsening hypoxia produces anxiety, tachycardia, and mental sluggishness.
Airway obstruction.Acute upper airway obstruction can be life-threatening—fortunately, most obstructions are subacute or chronic. Typically, obstruction increases accessory muscle use. However, its most telling sign is inspiratory stridor. Associated signs and symptoms include dyspnea, tachypnea, gasping, wheezing, coughing, drooling, intercostal retractions, cyanosis, and tachycardia.
Amyotrophic lateral sclerosis.Typically, this progressive motor neuron disorder affects the diaphragm more than the accessory muscles. As a result, increased accessory muscle use is characteristic. Other signs and symptoms include fasciculations, muscle atrophy and weakness, spasticity, bilateral Babinski's reflex, and hyperactive deep tendon reflexes. Incoordination makes carrying out routine activities difficult for the patient. Associated signs and symptoms include impaired speech, difficulty chewing or swallowing and breathing, urinary frequency and urgency and, occasionally, choking and excessive drooling. ( Note: Other neuromuscular disorders may produce similar signs and symptoms.) Although the patient's mental status remains intact, his poor prognosis may cause periodic depression.
Asthma.During an acute asthma attack, the patient usually displays increased accessory muscle use. Accompanying it are severe dyspnea, tachypnea, wheezing, a productive cough, nasal flaring, and cyanosis. Auscultation reveals faint or possibly absent breath sounds, musical crackles, and rhonchi. Other signs and symptoms include tachycardia, diaphoresis, and apprehension caused by air hunger. Chronic asthma may also cause barrel chest.
Chronic bronchitis.With chronic bronchitis, a form of COPD, increased accessory muscle use may be chronic and is preceded by a productive cough and exertional dyspnea. Chronic bronchitis is accompanied by wheezing, basal crackles, tachypnea, jugular vein distention, prolonged expiration, barrel chest, and clubbing. Cyanosis and weight gain from edema account for the characteristic label of “blue bloater.” A low-grade fever may occur with secondary infection.
Emphysema.Increased accessory muscle use occurs with progressive exertional dyspnea and a minimally productive cough in this form of COPD. Sometimes called a “pink puffer,” the patient will display pursed-lip breathing and tachypnea. Associated signs and symptoms include peripheral cyanosis, anorexia, weight loss, malaise, barrel chest, and clubbing. Auscultation reveals distant heart sounds; percussion detects hyperresonance.
Pneumonia.Bacterial pneumonia usually produces increased accessory muscle use. Initially, this infection produces a sudden high fever with chills. Its associated signs and symptoms include chest pain, a productive cough, dyspnea, tachypnea, tachycardia, expiratory grunting, cyanosis, diaphoresis, and fine crackles.
Pulmonary edema.With acute pulmonary edema, increased accessory muscle use is accompanied by dyspnea, tachypnea, orthopnea, crepitant crackles, wheezing, and a cough with pink, frothy sputum. Other findings include restlessness, tachycardia, ventricular gallop, and cool, clammy, cyanotic skin.
Pulmonary embolism.Although signs and symptoms vary with the size, number, and location of the emboli, pulmonary embolism is a life-threatening disorder that may cause increased accessory muscle use. Typically, it produces dyspnea and tachypnea that may be accompanied by pleuritic or substernal chest pain. Other signs and symptoms include restlessness, anxiety, tachycardia, a productive cough, a low-grade fever and, with a large embolus, hemoptysis, cyanosis, syncope, jugular vein distention, scattered crackles, and focal wheezing.
Spinal cord injury.Increased accessory muscle use may occur, depending on the location and severity of the injury. An injury below Ll typically doesn't affect the diaphragm or accessory muscles, whereas an injury between C3 and C5 affects the upper respiratory muscles and diaphragm, causing increased accessory muscle use.
Associated signs and symptoms of spinal cord injury include unilateral or bilateral Babinski's reflex, hyperactive deep tendon reflexes, spasticity, and variable or total loss of pain and temperature sensation, proprioception, and motor function. Horner's syndrome (unilateral ptosis, pupillary constriction, facial anhidrosis) may occur with lower cervical cord injury.
Thoracic injury.Increased accessory muscle use may occur, depending on the type and extent of injury. Associated signs and symptoms of this potentially life-threatening injury include an obvious chest wound or bruising, chest pain, dyspnea, cyanosis, and agitation. Signs of shock, such as tachycardia and hypotension, occur with significant blood loss.
Other causes
Diagnostic tests and treatments.Pulmonary function tests (PFTs), incentive spirometry, and intermittent positive-pressure breathing can increase accessory muscle use.
Nursing considerations
▪ If the patient is alert, elevate the head of the bed to make his breathing as easy as possible.
▪ Encourage him to get plenty of rest.
▪ Reinforce the importance of drinking plenty of fluids to liquefy secretions.
▪ Administer oxygen, as ordered.
▪ Prepare the patient for such tests as PFTs, chest X-rays, lung scans, arterial blood gas analysis, complete blood count, and sputum culture.
Patient teaching
▪ Explain the underlying disorder and treatment plan.
▪ Explain how smoking endangers the patient's health, and refer him to an organized program to stop smoking.
▪ Teach him the signs and symptoms of infection, when to report them, and about prevention.
▪ Explain the purpose of prescribed drugs, such as bronchodilators and mucolytics, and make sure he knows their dosage, schedule, and how to administer them.
▪ Teach the patient relaxation techniques to reduce his apprehension and improve breathing.
▪ Provide instruction on pursed-lip breathing for patients with chronic lung disorders.
▪ Teach the patient coughing and deep- breathing exercises to help keep airways clear.
Pictures
Book Source Details
- Book Title: Nursing: Interpreting Signs and Symptoms
- Author(s): Springhouse
- Year of Publication: 2007
- Copyright Details: Nursing: Interpreting Signs and Symptoms, Copyright © 2007 Lippincott Williams & Wilkins.
Other Book Chapters Related to Myopathy
Read excerpts from these other book chapters related to Myopathy:
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- Muscle spasms
- "Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series" (2007)
- [ read ]
Copyright Details: Nursing: Interpreting Signs and Symptoms, Copyright © 2008 Williams & Wilkins.
More About Causes of Myopathy
» Next page: Muscle atrophy [Muscle wasting] (Nursing: Interpreting Signs and Symptoms)
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