The nurse is reviewing the laboratory test results of a client with long standing hypertension. Which result would be of most concern to the nurse?

A) Blood urea nitrogen (BUN) 20 mg/dL: While this BUN level is slightly elevated, it is not as concerning as the creatinine level. Elevated BUN can indicate dehydration or other issues but does not necessarily signal acute kidney injury. B) Creatinine 2.6 mg/dL: This result is the most concerning because it indicates impaired kidney function. Normal creatinine levels are typically between 0.6 and 1.2 mg/dL. An elevated creatinine level suggests that the kidneys are not filtering waste effectively, which is a significant concern for a client with long-standing hypertension. C) Hemoglobin 12.8 g/dL: This hemoglobin level is within the normal range for adults and does not present an immediate concern. D) Potassium 3.8 mEq/L: This potassium level is also within the normal range (3.5 to 5.0 mEq/L) and does not raise any alarms in terms of electrolyte imbalances.