Exam 6: Chapter 45- Drugs used to treat the muscular system
Skeletal muscle disorders include:
cerebral palsy, multiple sclerosis, muscular dystrophy, spinal cord injury, osteoarthritis, rickets, poliomyelitis, scoliosis, and stroke.
Secretions are increased with the use of what?
neuromuscular blocking agents
Activities or occupations at higher risk include:
those requiring lifting of heavy objects, resulting in dislocations, sprains, fractures, joint replacements.
Drug Class: Centrally Acting Skeletal Muscle Relaxants-table 45-1
-Actions: Act by CNS depression, although exact mechanism of action not known; benefits come from sedative effects rather than actual muscle relaxation -Uses: In combination with physical therapy, rest, and analgesics to relieve muscle spasm associated with painful musculoskeletal conditions -Common adverse effects: Sedation, weakness, lethargy, GI complaints -Serious adverse effects: Hepatotoxicity, blood dyscrasias - should NOT be used for muscle spasticity associated w/spinal cord or CP disease; may cause further impairment -Benefits come from sedative effects rather than actual muscle relaxation.
Drug Class: Neuromuscular Blocking Agents; TABLE 45-2
-Actions: Interrupt transmission of impulses from motor nerves to muscles at the skeletal neuromuscular junction -Meds have no effect on LOC, memory or pain threshold -Uses: Produce adequate muscle relaxation during anesthesia; ease endotracheal intubation and prevent laryngospasm; decrease muscular activity in electroshock therapy; aid in muscle spasms associated with tetanus -Must have emergency equipment nearby; administered only by qualified anesthetist or anesthesiologist -To be administered by anesthesia provider or by critical care nurse while on ventilator -Must be observed closely for s/s of respiratory failure -These agents have no effect on consciousness, memory, or pain threshold; analgesics and sedatives must also be administered because the patient may be in extreme pain and unable to speak.
Nursing Implications: Musculoskeletal Disorders
-Adapt procedures for self-care -Administer prescribed medications -Instruct on application of heat/cold packs, elevate extremity immediately after injury -Maintain prescribed activity level and immobilization of affected part -Range-of-motion exercises -Promote relaxation
Nursing Assessment
-Assess for skeletal muscle disorders -Including CP, MS, muscular dystrophy, OA, scoliosis, CVA -Current history: -Reason for treatment, degree of impairment: ask about occumpations that require heavy lifting -Pain level and use of analgesics -Extent of muscle spasticity and muscle groups affected -History: Describe diagnoses that cause impairment, details of additional injuries -Medication history -Activity and exercise: -Extent of daily exercise -Determine which ADLs require help -Ask about assistive devices (cane, walker) -Ask about nonpharmacologic treatments: heating pad/massage, acupuncture, cupping -Sleep and rest -Elimination -Nutrition: history and weight -Physical examination -Review laboratory diagnostic studies and laboratory reports
Drug Class: Neuromuscular Blocking Agents (cont.)
-Common adverse effects: Salivation—histamine release may cause bronchospasm, bronchial and salivary secretions, flushing, edema, and urticaria -Mild to moderate discomfort in neck, upper back, and lower intercostal and abdominal muscles -Serious adverse effects: Signs of respiratory distress, diminished cough reflex, inability to swallow -Treatment of overdose: airway and oxygen management, neostigmine, pyridostigmine, atropine -Drug interactions: beta-blockers, diuretics, aminoglycoside antibiotics=all enhance good and bad SE ?Drug interactions: aminoglycoside antibiotics, beta-adrenergic blocking agents, and diuretics enhance therapeutic and toxic effects. ?Treatment of overdose: artificial respirations and antidotes to reverse the effects.
Drug Class: Centrally Acting Skeletal Muscle Relaxants (cont.)
-Drug: baclofen (Lioresal, Kemstro) -Actions: Act somewhat differently from the centrally acting agents -Uses: -Manage muscle spasticity resulting from multiple sclerosis, spinal cord injuries, cerebral palsy -Intrathecal pump infusion is used for management of CP (cerebral palsy) -Common adverse effects: Nausea, fatigue, headache, drowsiness, dizziness
Drug Class: Direct-Acting Skeletal Muscle Relaxant
-Drug: dantrolene (Dantrium) -Actions: Produces generalized mild weakness of skeletal muscles; decreases force of reflex muscle contractions Produces hyperreflexia, clonus, muscle stiffness, spasticity, involuntary muscle movements -Uses: Controls spasticity of chronic disorders like cerebral palsy, multiple sclerosis, spinal cord injury, stroke syndrome Also used to treat neuroleptic malignant syndrome associated with use of antipsychotic agents, certain ansthetics. -Common adverse effects: Weakness, drowsiness, dizziness, lightheadedness; diarrhea -Serious SE: photosensitivity, hepatotoxicity
Assessment of Respiratory function
-Nurse monitors adverse effects up to 48 hours or more after administration of neuromuscular blocking agents -Observe respiratory function, ability to swallow secretions, cough reflex -Monitor VS and arterial blood gases -Watch for hypoxia, hypercapnia (tachycardia, hypotension, cyanosis) -Suction, oxygen, mechanical ventilator, resuscitation equipment should be nearby -Neuromuscular blockers paralyze muscles but do NOT relieve pain -Remember secretions are increased w/these meds
Patient Education
-Pain relief -Activity and exercise -Psychosocial -Sedative effect of certain medications
Nursing Implications: Neuromuscular Blockers (cont.)
-Patients will still experience pain and are unable to speak to request medication; provide analgesics -Deal calmly with patient having respiratory distress -Aminoglycosides and tetracyclines potentiate the neuromuscular blocking activity
Detection of Respiratory depression
-Restlessness, anxiety, lethargy, decreased alertness, headache are early signs -Use of abdominal, intercostal, or neck muscles; flaring of nostrils -Shallow, rapid respirations; cyanosis
Nursing Implications: Neuromuscular Blockers
-Used during anesthesia and surgery to relax muscle groups; used during mechanical ventilation to improve oxygenation -Medication paralyzes the muscles, including the diaphragm -PATIENT MUST BE INTUBATED AND RECEIVING MECHANICAL VENTILATION! -May produce increased salivation, keep suction nearby -Monitor for respiratory distress; assist w/deep breathing, coughing
Drug Therapy for Muscle Disorders: Skeletal Muscle Relaxants
-Used to treat low back pain and spastic muscle conditions -Spasticity: muscle hypertonicity and involuntary jerks; stiff, awkward movements; complication of multiple sclerosis, cerebral palsy -Muscle spasms: sudden alternating contractions and relaxations or sustained contractions of muscles
Which is an important action of neuromuscular blocking agents? A) Producing muscle relaxation and reducing the use of anesthetic agents during general surgery B) Improving muscular strength and decreasing risk for blood clots C) Inducing amnesia in the event of a patient undergoing a medical procedure D) Providing effective pain relief to a patient undergoing a short-term procedure
Answer: A Rationale: Neuromuscular blocking agents are used to produce enough muscle relaxation during anesthesia to reduce the use (and adverse effects) of general anesthetics, ease endotracheal intubation and prevent laryngospasm, decrease muscular activity in electroshock therapy, and aid in the muscle spasms associated with tetanus. They do not provide analgesia, sedation, or affect blood clotting.
Which statement made by a patient with a long history of multiple sclerosis indicates a need for the nurse to further educate the patient? A) "I'm feeling fatigued, but I'll stay on the medication and give it time to work." B) "I stopped taking my baclofen (Lioresal) 2 days ago." C) "I'll continue my physical therapy along with the medications I'm taking." D) "My muscle spasms are so much less severe since I've been taking Lioresal."
Answer: B Rationale: Baclofen, a skeletal muscle relaxant that acts to reduce reflex activity at the spinal cord, must not be discontinued abruptly or a severe exacerbation of spasticity and hallucinations may result. When taken appropriately, it is very effective in the management of muscle spasticity in multiple sclerosis and spinal cord injuries.
A student nurse is caring for a patient with a traumatic spinal cord injury who just received a neuromuscular blocking agent. Which statement made by the student requires correction by the supervising nurse? A) "I'll be certain the respiratory emergency equipment is nearby in case of severe adverse effects." B) "The patient has received a neuromuscular blocking agent, and that's all that will be needed." C) "The patient will receive a lower dosage because of the spinal cord injury." D) "I'll be sure to administer an analgesic and sedative after the neuromuscular blocking agent is given."
Answer: B Rationale: Neuromuscular blocking agents interrupt transmission of impulses, but they have no effect on consciousness, memory, or the pain threshold. It is the responsibility of the nurse to provide analgesics and sedatives on schedule to supplement the neuromuscular blocking agent. The patient could be in severe pain but be unable to communicate his or her needs to the nurse.
Which medication does the nurse expect to be ordered for a patient with cerebral palsy who is experiencing significant muscle contractions and stiff, involuntary muscle movements and spasticity? A) Baclofen (Lioresal) B) Atracurium besylate (Tracrium) C) Dantrolene (Dantrium) D) Succinylcholine (Anectine)
Answer: C Rationale: Dantrolene is very effective in the treatment of muscle spasticity resulting from cerebral palsy. It is a direct-acting muscle relaxant that acts on the skeletal muscle to reduce the force of reflex muscle contractions.
What is the function of centrally acting skeletal muscle relaxants? A) Act directly on skeletal muscle fibers B) Produce muscle relaxation without sedation C) Directly affect nerve conduction D) Treat acute muscle injuries with associated muscle spasm
Answer: D Rationale: Centrally acting skeletal muscle relaxants are used to treat acute muscle injuries with associated muscle spasms. The exact mechanism of action of these agents is not fully known, except that they act by CNS depression. They do not directly affect the muscles, nerve conduction, or neuromuscular junctions. Because of the CNS depression, they do produce sedation, which may be partially responsible for the relief the patient obtains. These agents are used along with rest, analgesics, and physical therapy for acute painful musculoskeletal disorders.
Nonpharmacologic treatments may be used, including:
a heating pad, massage therapy, acupuncture, and cupping.