Which statement is true regarding myocardial functioning in the normal heart, based upon the Frank Starling law?

A. Myocardial infarction one year ago:

A myocardial infarction (MI) that occurred one year ago is not directly related to the current acid-base imbalance described in the scenario. While a history of MI may have implications for the client's overall cardiovascular health and management, it is not the most likely cause of the acid-base imbalance indicated by the laboratory results.

B. Occasional use of antacids:

Occasional use of antacids is unlikely to cause the acid-base imbalance described in the scenario. Antacids primarily work by neutralizing gastric acid and are not typically associated with significant alterations in acid-base status, especially when used intermittently.

C. Chronic renal insufficiency:

Chronic renal insufficiency is the most likely cause of the acid-base imbalance indicated by the laboratory results. A low hemoglobin level suggests anemia, which can occur in chronic kidney disease due to decreased erythropoietin production. An elevated creatinine clearance indicates impaired kidney function, as the kidneys are clearing creatinine at a faster rate than normal. Decreased urine specific gravity suggests the kidneys' inability to concentrate urine properly, which is a common finding in renal insufficiency. Renal insufficiency can lead to metabolic acidosis due to the kidneys' decreased ability to excrete acid and regulate bicarbonate levels.

D. Shortness of breath with exertion:

Shortness of breath with exertion, a symptom commonly seen in COPD exacerbations, is unlikely to directly cause the acid-base imbalance described in the scenario. While respiratory distress can lead to respiratory acidosis, which is characterized by elevated carbon dioxide levels and decreased pH, the laboratory results indicate metabolic rather than respiratory acidosis.

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a progressive neurodegenerative disorder affecting motor neurons in the brain and spinal cord. Understanding the pathophysiological process of ALS is crucial for providing accurate information about the disease prognosis to the client. Here's why option B is the correct choice:

A) It occurs as a complication of a spinal cord injury:

This statement is incorrect. ALS is not a complication of a spinal cord injury. While both conditions involve motor neuron dysfunction, they have different etiologies and pathophysiological processes. ALS is characterized by the degeneration of motor neurons in the brain and spinal cord, leading to muscle weakness and atrophy, whereas spinal cord injury results from trauma to the spinal cord.

B) Muscle weakness is progressive, degenerative, and fatal:

Correct. ALS is characterized by progressive degeneration of motor neurons, leading to muscle weakness, atrophy, and eventual paralysis. The disease is relentless and fatal, typically within 2 to 5 years of diagnosis, although survival can vary widely among individuals. As motor neurons degenerate, voluntary muscle control is lost, eventually affecting the ability to speak, swallow, breathe, and move. Respiratory failure is the most common cause of death in ALS patients.

C) Mental status changes occur late in the disease:

While cognitive and behavioral changes can occur in some individuals with ALS, particularly in the later stages of the disease, they are not universal. ALS primarily affects motor neurons, leading to progressive muscle weakness and paralysis. However, some individuals may experience frontotemporal dementia (FTD), a type of cognitive impairment characterized by changes in behavior, personality, and language.

D) Autonomic nervous system and sensory changes occur:

ALS primarily affects motor neurons rather than sensory neurons or the autonomic nervous system. Sensory symptoms such as numbness, tingling, or loss of sensation are not typical features of ALS. Autonomic dysfunction, including changes in heart rate, blood pressure, or bowel and bladder function, is not a prominent feature of ALS.