Review Question - QID 108996

A 57-year-old immigrant from Nigeria presents to the emergency department for sudden, severe pain and swelling in her lower extremity. She was at a rehabilitation hospital when her symptoms started. The patient has a medical history of obesity, diabetes, bipolar disorder, and tonic-clonic seizures. Her current medications include metformin, insulin, lisinopril, and valproic acid. The patient has IV drug and alcohol use disorder and has presented to the ED many times for intoxication. Her temperature is 98.6°F (37°C), blood pressure is 115/71 mmHg, pulse is 72/min, and respirations are 12/min. Physical exam reveals anasarca and asymmetric lower extremity swelling. Based on the results of a doppler ultrasound of her swollen lower extremity, heparin is started. The patient is then transferred to the general medicine floor for continued management. Laboratory studies are shown below.

Serum:
Na+: 137 mEq/L
K+: 5.5 mEq/L
Cl-: 100 mEq/L
HCO3-: 24 mEq/L
Urea nitrogen: 22 mg/dL
Ca2+: 5.7 mg/dL
Creatinine: 1.7 mg/dL
Glucose: 70 mg/dL

Which of the following is the most likely diagnosis?