Chapter 45 Drugs Used to Treat the Muscular System 45-1 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Lesson Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives  Describe the nursing assessment data needed to evaluate a patient with a skeletal muscle disorder.  Identify the therapeutic response and the common and serious adverse effects from skeletal muscle relaxant therapy.  Describe the effect of centrally acting skeletal muscle relaxants on the central nervous system (CNS) and the safety precautions required during their use. Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 45-3

Objectives (cont.)  Describe the physiologic effects of neuromuscular blocking agents and assessments needed as well as the equipment needed in the immediate patient care area when neuromuscular blocking agents are administered.  Identify the effect of neuromuscular blocking agents on consciousness, memory, and the pain threshold. Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 45-4

Nursing Assessment  Assess for skeletal muscle disorders  Current history Reason for treatment, degree of impairment 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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 45-5

Nursing Assessment (cont.)  Activity and exercise Extent of daily exercise Determine which ADLs require help Ask about assistive devices (cane, walker)  Sleep and rest  Elimination  Nutrition: history and weight  Physical examination  Review laboratory diagnostic studies and laboratory reports Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 45-6

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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 45-7

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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 45-8

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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. 45-9

Nursing Implications: Neuromuscular Blockers  Used during anesthesia and surgery to relax muscle groups; used during mechanical ventilation to improve oxygenation  PATIENT MUST BE INTUBATED AND RECEIVING MECHANICAL VENTILATION!  May produce increased salivation, keep suction nearby  Monitor for respiratory distress  Assist with deep-breathing exercises, coughing activities Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

Audience Response Question 1  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.” Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

Patient Education  Pain relief  Activity and exercise  Psychosocial  Sedative effect of certain medications Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

Drug Class: Centrally Acting Skeletal Muscle Relaxants  Actions  Act by CNS depression, although exact mechanism of action not known  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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

Audience Response Question 2  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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

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  Common adverse effects  Nausea, fatigue, headache, drowsiness, dizziness Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

Audience Response Question 3  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.” Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Direct-Acting Skeletal Muscle Relaxant  Drug: dantrolene (Dantrium)  Actions  Produces generalized mild weakness of skeletal muscles; decreases force of reflex muscle contractions  Uses  Controls spasticity of chronic disorders like cerebral palsy, multiple sclerosis, spinal cord injury, stroke syndrome  Common adverse effects  Weakness, drowsiness, dizziness, lightheadedness; diarrhea Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

Audience Response Question 4  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) Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Neuromuscular Blocking Agents  Actions  Interrupt transmission of impulses from motor nerves to muscles at the skeletal neuromuscular junction  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  To be administered by anesthesia provider or by critical care nurse while on ventilator Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc

Audience Response Question 5  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 Mosby items and derived items © 2013, 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.