A client with type 2 diabetes on metformin undergoes contrast-enhanced CT. Review the trend and answer each question.

Quick answer
The correct answers reflect recognition of contrast-induced AKI with early signs of lactic acidosis, the need to hold metformin, and escalation of care.

Why this is correct
Creatinine rises from 1.4 to 2.3 mg/dL over 48 hours with falling urine output, rising lactate, and compensatory tachycardia. This pattern indicates acute kidney injury, most likely contrast-induced in the setting of pre-existing CKD, not simply dehydration.

Clinical picture
Contrast-induced AKI typically presents within 48-72 hours. Metformin is contraindicated when eGFR is below 30 mL/min/1.73 m² or during acute kidney injury due to risk of lactic acidosis. Rising lactate with declining renal function is an early warning sign.

Memory hook
Metformin + contrast + falling eGFR = hold metformin, monitor for lactic acidosis, escalate care.

NCLEX decision rule
Metformin should be withheld during acute kidney injury and for at least 48 hours after contrast if renal function deteriorates. Lactic acidosis is a medical emergency requiring immediate provider notification.

Why the alternatives are wrong
Volume depletion alone would typically improve with IV fluids, not worsen. Pre-existing CKD alone would not explain the acute rise. Restarting metformin or continuing current management would be unsafe.