Fundamentals of Nursing Q 52
After 1 week of hospitalization, Mr. Gray develops hypokalemia. Which of the following is the most significant symptom of his disorder?
A. Lethargy
B. Increased pulse rate and blood pressure
C. Muscle weakness
D. Muscle irritability
Correct Answer: C. Muscle weakness
Presenting symptoms of hypokalemia ( a serum potassium level below 3.5 mEq/liter) include muscle weakness, chronic fatigue, and cardiac dysrhythmias. The combined effects of inadequate food intake and prolonged diarrhea can deplete the potassium stores of a patient with GI problems. Significant muscle weakness occurs at serum potassium levels below 2.5 mmol/L but can occur at higher levels if the onset is acute. Similar to the weakness associated with hyperkalemia, the pattern is ascending in nature affecting the lower extremities, progressing to involve the trunk and upper extremities, and potentially advancing to paralysis.
Option A: Periodic paralysis is a rare neuromuscular disorder, which is inherited or acquired, that is caused by an acute transcellular shift of potassium into the cells. It is characterized by potentially fatal episodes of muscle weakness or paralysis that can affect the respiratory muscles. Clinical manifestations mainly involve the musculoskeletal and cardiovascular systems. Hence, the physical exam should focus on identifying neurologic manifestations and cardiac dysrhythmias.
Option B: Clinical symptoms of hypokalemia do not become evident until the serum potassium level is less than 3 mmol/L unless there is a precipitous fall or the patient has a process that is potentiated by hypokalemia. The severity of symptoms also tends to be proportional to the degree and duration of hypokalemia. Symptoms resolve with correction of the hypokalemia.
Option D: Affected muscles can include the muscles of respiration which can lead to respiratory failure and death. Involvement of GI muscles can cause an ileus with associated symptoms of nausea, vomiting, and abdominal distension. Severe hypokalemia can also lead to muscle cramps, rhabdomyolysis, and resultant myoglobinuria.