List and describe manifestations, pathophysiology, and clinical features of pulmonary fibrosis, neuromuscular disorders and flail chest
Describe the clinical manifestations of myasthenia gravis and Guillain-Barre syndrome
Neuromuscular disorders are classified as restrictive lung disorders. Patients affected by restrictive lung disorders experience difficulty breathing and have a particularly difficult time taking in deep breaths resulting in low lung volumes. Neuromuscular disorders affect the neuromuscular system which controls voluntary muscles resulting in muscle weakness and/or paralysis. Unfortunately, the muscles needed to breathe are voluntary muscles. The primary muscle used in breathing, the diaphragm, can become impaired when a dysfunction in the neuromuscular system occurs. The neuromuscular system consists of the brain, nerves, neurotransmitter chemicals, neuromuscular junction and spinal cord.
There are many neuromuscular disorders; however, our focus will be on Myasthenia gravis and Guillian-Barre. Myasthenia gravis is an autoimmune disorder that is characterized by progressive descending weakness of the voluntary muscles. Weakness begins in the head and descends to the feet (mind to ground). It is the most common neuromuscular disorder and affects women more than men. In order to function correctly, muscles must be able to contract and relax. Myasthenia gravis is a disorder of the neuromuscular junction that prevents proper contraction of the voluntary muscles and is caused when antibodies attack the receptors for acetycholine at the neuromuscular junction thus preventing muscle contraction. Acetycholine is a chemical that is carried by the nerves and released from the nerve endings. Acetylcholine travels across a muscle synapse (the space between a motor neuron and a skeletal muscle) and attaches to many receptor sites found on the muscles. The synapse between a motor neuron and a skeletal muscle cell is referred to as a neuromuscular junction. When enough of the receptor sites have been activated by acetylcholine then the muscle contracts. For a muscle to contract it must be stimulated by a motor neuron.
Guillian-Barre is also an autoimmune disorder and is characterized by progressive ascending weakness of the voluntary muscles. Weakness and tingling begins at the legs and moves or ascends up past the diaphragm (ground to brain). If this disorder becomes severe enough then paralysis can occur. There is no known cause of Guillian-Barre and there is no known cure. Guillian-Barre is usually followed by a bacterial or viral infection. It is believed that an infection changes the nature of cells in the nervous system causing the immune system to treat the cells as foreign invaders. The attack by the immune system destroys the myelin sheath that surrounds and protects the nerves. The myelin sheath insulates the nerves that conduct the electrical impulses so the impulses are able to travel uninterrupted back and forth between the brain and muscles.
Though both Myasthenia gravis and Guillian-Barre seem very similar, they are very different. Myasthenia gravis can be diagnosed by performing a Tensilon (edrophonium) test.
Guillian-Barre can be diagnosed by performing a lumbar puncture and assessing the cerebrospinal fluid. Both disorders will require the use of high dose steroids and though there is no known cure for Guillian-Barre there are treatments available for Myasthenia gravis. These treatments include the use of anticholinesterase drugs.
Provide detailed responses to the following questions.
Explain how neuromuscular disorders result in a restrictive lung disorder?
How is the Tensilon test performed?
How does the Tensilon test prove a diagnosis for or against Myasthenia gravis?
Explain the treatment for Myasthenia gravis.
Can the Tensilon test be used to diagnosis Guillian-Barre? Why or why not?
Once the symptoms of Guillian-Barre become severe enough then what role do respiratory therapists play?
Submit your answers in at least 500 words on a Word document. You must cite at least three references in APA format to defend and support your position.