What laboratory result should a nurse highlight before administering metformin to a client with diabetes mellitus type 2?

• A. Lactic Acid 27 mg/dL
• B. Potassium (K) 4.5 mEq/L
• C. Blood Glucose 150 mg/dL
• D. Creatinine 1.2 mg/dL

Answer: (A)

Highlighting a lactic acid level of 27 mg/dL is crucial before administering metformin due to the risk of lactic acidosis, a serious and potentially life-threatening condition. Metformin is contraindicated in patients with conditions that increase the risk of lactic acidosis, including renal impairment or elevated blood lactic acid levels. The normal lactic acid levels typically range from 0.5 to 2.2 mmol/L (about 4.5 to 19.8 mg/dL), thus a lactic acid level of 27 mg/dL indicates a significantly elevated state that would warrant immediate medical attention and potentially contraindicate the use of metformin.

In contrast, a potassium level of 4.5 mEq/L is within the normal range and does not signal any immediate concern related to metformin administration. A blood glucose level of 150 mg/dL, while indicating the need for diabetes management, does not present a safety concern specific to metformin. Creatinine levels of 1.2 mg/dL, while they can indicate potential issues, generally fall within acceptable limits for metformin use in the absence of other contraindicating factors unless the patient's overall renal function is compromised. Thus, highlighting an elevated lactic acid