USMLE® Step 1 style questions USMLE
USMLE® Step 2 style questions USMLE
A 31-year-old woman, G1P0 at 12 weeks gestation, comes to the emergency department because of persistent vomiting for the past 5 days. She has been unable to keep down solids or liquids for the last 36 hours. Vital signs show her temperature is 37°C (98.6°F), pulse is 95/min, respirations are 12/min, and blood pressure is 112/78mmHg. Her pre-pregnancy weight was 61kg (135lb) and her current weight is 58kg (128lb). Physical examination shows dry mucous membranes, crackled lips, and poor sign turgor. In a case of suspected hyperemesis gravidarum which of the following investigations is required to establish the underlying cause?