The nurse is reviewing a client's serum laboratory findings. Which finding indicates to the nurse to hold a scheduled dose of captopril? Reference Range: Hemoglobin (Hgb) [14 to 18 g/dL (140 to 180 g/L)] Potassium (K+) [3.5 to 5 mEq/L (3.5 to 5 mmol/L)] Total Calcium 19 to 10.5 mg/dL (2.25 to 2.62 mmol/L)] Prothrombin (PT) [11 to 12.5 seconds; 85% to 100%] International normalized ratio (INR) [0.8 to 1.1]

Rationale: A. Prothrombin time 4 times greater than the control value: A markedly prolonged PT suggests a coagulation abnormality, but it is not directly related to captopril therapy. ACE inhibitors like captopril do not significantly alter clotting times. B. Hemoglobin of 8.2 g/dL (82 g/L): Severe anemia is a concerning finding, but it is not a contraindication to administering captopril. Anemia may warrant further investigation, yet it does not necessitate holding the medication. C. Calcium of 14.4 mg/dL (3.60 mmol/L): This value indicates hypercalcemia, which is a critical abnormality but not directly linked to ACE inhibitor administration. Captopril primarily affects potassium balance rather than calcium regulation. D. Potassium of 6.1 mEq/L (6.1 mmol/L): ACE inhibitors such as captopril reduce aldosterone secretion, which can lead to potassium retention and hyperkalemia. A potassium level of 6.1 is dangerously high, posing risks for life-threatening arrhythmias, this finding requires holding the medication and notifying the provider.