When evaluating a patient’s hyperkalemia secondary to lisinopril usage, what crucial laboratory monitoring is necessary?

Monitoring potassium serum concentration is fundamental when evaluating a patient’s hyperkalemia secondary to lisinopril usage. Lisinopril, an angiotensin-converting enzyme (ACE) inhibitor, is known to reduce aldosterone levels, which can lead to decreased potassium excretion by the kidneys and an increased risk of hyperkalemia. Given this mechanism, it is vital to routinely measure serum potassium levels to ensure they remain within a safe range, especially after initiating or adjusting the dosage of an ACE inhibitor like lisinopril.

While monitoring serum creatinine levels is important for assessing renal function and potential acute kidney injury, which can also be affected by lisinopril and contribute to hyperkalemia, the direct correlation of hyperkalemia with elevated potassium levels makes potassium serum concentration the priority focus in this context. The other options, such as complete blood count and liver function tests, are not directly relevant to the assessment of hyperkalemia caused by lisinopril, making them less crucial in this particular situation.