David E. Trachtenbarg, M.D.

Diabetic ketoacidosis occurs when a patient's plasma glucose concentration is above 250 mg per dL, pH level is less than 7.30, and bicarbonate level is 15 mEq per L or less. Treatment involves fluids, insulin, and monitoring electrolyte levels.

Patient information: "Diabetic Ketoacidosis: What It Is and How to Prevent It,” p. 1721

Editorial: "Hyperglycemic Crises: Improving Prevention and Management,” p. 1659

GREGG D. STONER, M.D.

Hyperosmolar hyperglycemic state is a life-threatening emergency caused by infections, certain medications, noncompliance, undiagnosed diabetes, substance abuse, and coexisting diseases. Vigorous correction of dehydration followed by potassium and insulin replacement is crucial.

Editorial: "Hyperglycemic Crises: Improving Prevention and Management,” p. 1659

Susan Klein, M.D.

A thorough clinical breast examination, imaging, and tissue sampling are needed for definitive diagnosis of breast masses. Fine-needle aspiration can differentiate solid and cystic masses. Core-needle biopsy allows histologic diagnosis and differentiates in situ and invasive disease. Ultrasonography, mammography, and magnetic resonance imaging can be used to guide diagnosis.

ALAN M. ADELMAN, M.D., M.S., and MEL P. DALY, M.D.

Dementia is a common disorder in older patients. The initial evaluation of a patient with suspected dementia includes the Mini-Mental State Examination, blood chemistry profiles, and structural neuroimaging.