Fluid and Electrolyte Disorders: The Daily PANCE Blueprint
A 67-year-old man presents to the clinic with complaints of muscle weakness and cramps in his calves and lower back. He has a history of hypertension and is currently taking lisinopril and furosemide. Over the past two weeks, he has noticed increasing difficulty in walking up stairs and has experienced several episodes of stumbling. His blood pressure today is 165/95 mm Hg, and his pulse is 88/min. On neurological examination, he demonstrates decreased reflexes and reduced muscle strength in the lower extremities. Laboratory results reveal a normal erythrocyte sedimentation rate, and his ECG shows flat and inverted T waves with occasional premature ventricular contractions. What is the most likely cause of his symptoms?
A. Hypocalcemia
B. Hyperkalemia
C. Hyponatremia
D. Hypokalemia
E. Hypercalcemia
Answer and topic summary
The answer is D. Hypokalemia
Hypokalemia is characterized by muscle weakness, cramps, and fatigue. It is often associated with the use of diuretics such as furosemide, which can lead to potassium loss. The ECG findings of flat T waves and occasional premature ventricular contractions further support the diagnosis of hypokalemia, as these are classic signs of potassium deficiency.
Incorrect Answers:
- A. Hypocalcemia – While hypocalcemia can cause muscle cramps, it typically also presents with other signs such as paresthesias or tetany, which are not mentioned here. The ECG findings are also more consistent with hypokalemia.
- B. Hyperkalemia – Hyperkalemia usually presents with ECG changes such as peaked T waves and, in severe cases, widening of the QRS complex, which are not observed in this patient.
- C. Hyponatremia – Hyponatremia can cause confusion, seizures, and muscle cramps, but it is less likely to present with the described ECG changes or specific muscle weakness.
- E. Hypercalcemia – Hypercalcemia often presents with symptoms like polyuria, polydipsia, constipation, and confusion, along with shortened QT interval on ECG, which is not described in this case.
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Smarty PANCE Content Blueprint Review:
Covered under ⇒ PANCE Blueprint Renal System ⇒ ⇒
Also covered as part of the Emergency Medicine EOR and General Surgery PAEA EOR topic list
