NBME Questions and Answers 100% Graded

1. Patient had anaphylaxis following the transfusion of fresh frozen plasma. What is the genetic deficiency? IgA deficiency. Patient with this disease may have preformed antibodies against IgA 2. How does sitagliptin work? It is a competitive inhibitor of dipeptidyl peptidase-4 (DPP4). It prevents breakdown of GI incretins (ex: glucagon-like peptide, GLP-1) and promote endogenous release of insulin. ** DPP4 inhibitor increases endogenous insulin 3. What are acoustic neuromas? Vestibular schwannoma Benign tumors of Schwann cells that arise from the vestibulocochlear nerve (CN VIII). 4. How does acoustic neuromas cause symptoms? Lesions of CN VIII leads to ipsilateral hearing loss and positional dizziness Compression of the cerebellar peduncles leads to ipsilateral dysmetria 5. What is the classic presentation of pyloric stenosis? Male infant 3-6 weeks of age with repeated vomiting after feeds, dehydration, and hypochloremic, hypokalemic metabolic alkalosis 6. Explain the electrolyte and metabolic derangement seen with pyloric stenosis Vomiting -> Hypochloremia Hypovolemia + excess bicarb -> RAAS activation -> increase renal tubule bicarb reabsorption - > Metabolic alkalosis Metabolic alkalosis + hypovolemia + increased aldosterone -> renal potassium excretion -> hypokalemia 7. How does hypokalemia worsens metabolic alkalosis? Hypokalemia further worsens metabolic alkalosis via trans-cellular exchange or extracellular sodium and protons in for potassium ions 8. IV drug user presents with tricuspid regurgitation and signs and symptoms of right-sided heart failure. Diagnosis? Tricuspid valve endocarditis 9. Tricuspid valve endocarditis is associated with what organisms?