Overview
This lecture covers high-yield internal medicine topics and board-style questions, focusing on common diagnoses, key clinical findings, management steps, and relevant lab findings for the medicine shelf.
Cardiology Murmurs & Heart Disease
- Diastolic murmur at left 4th interspace is tricuspid stenosis; increased by preload, decreased by afterload.
- Carcinoid syndrome causes right-sided heart lesions (tricuspid regurg, pulmonic stenosis) due to serotonin; diagnosed via urine 5-HIAA, treated with octreotide.
- Most common arrhythmia with mitral stenosis or Graves’ is atrial fibrillation (AFib).
Key Endocrine & Metabolic Diseases
- Whipple’s triad (hypoglycemia, symptoms, relief with glucose) suggests insulinoma or sulfonylurea use; check secretagogue screen.
- HHNS is seen in type 2 diabetes with high glucose, no ketosis, treated with fluids and insulin; correct sodium using 1.6 mEq/L for every 100 mg/dL glucose above normal.
- Acromegaly is screened with elevated IGF-1, confirmed by failure of GH suppression with glucose; treated first with surgery.
Infectious Diseases
- Vibrio from shellfish, Yersinia from pork, C. diff after antibiotics (treated with metronidazole or vancomycin).
- Pertussis presents with severe cough, subconjunctival hemorrhage, lymphocytosis; macrolides for treatment and prophylaxis.
- PCP pneumonia in immunocompromised patients, prophylaxed with TMP-SMX at CD4 < 200; add steroids if PaO2 < 70 or A–a gradient > 35.
- Salmonella typhi causes typhoid fever (rose spots), treated with fluoroquinolones.
Hematology
- Porphyria cutanea tarda: UROD deficiency, photosensitivity, treated with phlebotomy.
- Lead poisoning: high ferritin, low TIBC, treated with DMSA, EDTA, or succimer; supplement with B6.
- Anemia of chronic disease: high ferritin, low TIBC, low transferrin saturation.
- Thalassemias: target cells, microcytic anemia, normal RDW in thalassemia but increased in iron deficiency.
Renal & Electrolyte
- Kidney stones: calcium oxalate (envelope), uric acid (radiolucent), cysteine (hexagon), struvite (coffin) from Proteus; diagnosed by CT, treated with fluids, pain control, tamsulosin.
- CKD: metabolic acidosis, hyperkalemia, hypocalcemia, hyperphosphatemia, low EPO; treat with phosphate binders (sevelamer), calcitriol, EPO.
- Indications for dialysis: AEIOU (acidosis, electrolytes, ingestion, overload, uremia).
Dermatology & Rheumatology
- Stevens-Johnson syndrome: <10% BSA, triggered by drugs (e.g., allopurinol); stop offending agent.
- Eczema (atopic dermatitis): topical steroids; eczema herpeticum is superinfection with HSV.
- Pemphigus vulgaris: mucosal lesions, positive Nikolsky, antibodies to desmosomes; treat with oral steroids.
- Bullous pemphigoid: no mucosal involvement, negative Nikolsky, antibodies to hemidesmosomes; treat with topical steroids.
GI & Liver
- C. diff infection treated with metronidazole, oral vancomycin, or fidaxomycin; prevent with handwashing.
- IBS: young female, relieved by defecation; IBS-D treated with loperamide, IBS-C with laxatives.
- Diverticulitis: left lower quadrant pain, CT diagnosis, treated with cipro and metronidazole; risk for colovesical fistula.
- H. pylori test by urease breath, stool antigen, or biopsy; triple therapy (CAP: clarithro, amoxicillin, PPI).
Key Terms & Definitions
- Jugular venous A wave — represents atrial contraction on venous tracing.
- Whipple’s triad — hypoglycemia, symptoms, relief with glucose.
- Carcinoid syndrome — serotonin-secreting tumor causing flushing, diarrhea, right heart lesions.
- Empyema — pleural fluid with pH < 7.2, glucose < 60, high LDH, bugs present.
- Target cells — RBCs seen in thalassemia.
- RDW (Red cell distribution width) — increased in iron deficiency anemia, normal in thalassemias.
- AEIOU — dialysis indications: Acidosis, Electrolytes, Ingestion, Overload, Uremia.
Action Items / Next Steps
- Review these notes repeatedly before the exam.
- Complete the four practice NBME medicine exams.
- Prepare for tomorrow's review, continuing from slide 49.