Muscle flaccidity [Muscle hypotonicity]
Flaccid muscles are profoundly weak and soft, with decreased resistance to movement, increased mobility, and a greater than normal range of motion (ROM). The result of disrupted muscle innervation, flaccidity can be localized to a limb or muscle group or generalized over the entire body. Its onset may be acute, as in trauma, or chronic, as in neurologic disease.
Action stat!
If the patient's muscle flaccidity results from trauma, make sure his cervical spine has been stabilized. Quickly assess his respiratory status. If you note signs and symptoms of respiratory insufficiency—dyspnea, shallow respirations, nasal flaring, cyanosis, and decreased oxygen saturation—administer oxygen by nasal cannula or mask. Intubation and mechanical ventilation may be necessary.
History and physical examination
If the patient isn't in distress, ask about the onset and duration of muscle flaccidity and precipitating factors. Ask about associated symptoms, notably weakness, other muscle changes, and sensory loss or paresthesia.
Examine the affected muscles for atrophy, which indicates a chronic problem. Test muscle strength, and check deep tendon reflexes (DTRs) in all limbs. Then perform a complete neurologic examination.
Medical causes
Amyotrophic lateral sclerosis.Progressive muscle weakness and paralysis are accompanied by generalized flaccidity. Typically, these effects begin in one hand, spread to the arm, and then develop in the other hand and arm. Eventually, they spread to the trunk, neck, tongue, larynx, pharynx, and legs; progressive respiratory muscle weakness leads to respiratory insufficiency. Other findings include muscle cramps and coarse fasciculations, hyperactive DTRs, slight leg muscle spasticity, dysphagia, dysarthria, excessive drooling, and depression.
Brain lesions.Frontal and parietal lobe lesions may cause contralateral flaccidity, weakness or paralysis and, eventually, spasticity and possibly contractures. Other findings include hyperactive DTRs, a positive Babinski's sign, loss of proprioception, stereognosis, graphesthesia, anesthesia, and thermanesthesia.
Guillain-Barré syndrome.Guillain-Barré syndrome causes muscle flaccidity. Progression is typically symmetrical and ascending, moving from the feet to the arms and facial nerves within 24 to 72 hours of its onset. Associated findings include sensory loss or paresthesia, absent DTRs, tachycardia (or, less commonly, bradycardia), fluctuating hypertension and orthostatic hypotension, diaphoresis, incontinence, dysphagia, dysarthria, hypernasality, and facial diplegia. Weakness may progress to total motor paralysis and respiratory failure.
Huntington's disease.Besides flaccidity, progressive mental status changes up to and including dementia and choreiform movements are major symptoms of Huntington's disease. Others include poor balance, hesitant or explosive speech, dysphagia, impaired respirations, and incontinence.
Muscle disease.Muscle weakness and flaccidity are features of myopathies and muscular dystrophies.
Peripheral nerve trauma.Flaccidity, paralysis, and loss of sensation and reflexes in the traumatized innervated area can occur.
Peripheral neuropathy.With peripheral neuropathy, flaccidity usually occurs in the legs as a result of chronic progressive muscle weakness and paralysis. It may also cause mild to sharp burning pain, glossy red skin, anhidrosis, and a loss of vibration sensation. Paresthesia, hyperesthesia, or anesthesia may affect the hands and feet. DTRs may be hypoactive or absent.
Seizure disorder.Brief periods of syncope and generalized flaccidity commonly follow a generalized tonic-clonic seizure.
Spinal cord injury.Spinal shock can result in acute muscle flaccidity or spasticity below the level of injury. Associated signs and symptoms also occur below the level of injury and may include paralysis; absent DTRs; analgesia; thermanesthesia; loss of proprioception and vibration, touch, and pressure sensation; and anhidrosis (usually unilateral). Hypotension, bowel and bladder dysfunction, and impotence or priapism may also occur. Injury in the C1 to C5 region can produce respiratory paralysis and bradycardia.
Nursing considerations
▪ Provide regular, systematic, passive ROM exercises to preserve joint mobility and increase circulation.
▪ Reposition the patient every 2 hours to protect him from skin breakdown.
▪ Pad bony prominences and other pressure points.
▪ Treat isolated flaccidity by supporting the affected limb with a sling or splint.
▪ Consult a physical therapist and an occupational therapist to formulate a personalized therapy regimen and foster independence.
▪ Prepare the patient for diagnostic tests, such as cranial and spinal X-rays, computed tomography scans, and electromyography.
Patient teaching
▪ Teach the patient how to use assistive devices.
▪ Review the prescribed exercise regimen.
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 Muscle atrophy
Read excerpts from these other book chapters related to Muscle atrophy:
Copyright Details: Nursing: Interpreting Signs and Symptoms, Copyright © 2008 Williams & Wilkins.
More About Causes of Muscle atrophy
» Next page: Muscle weakness (Nursing: Interpreting Signs and Symptoms)
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