Internal Medicine
Internal Medicine tests common adult presentations, chronic disease control, ECG and fluid/electrolyte decisions, and safe referral. The exam favors bedside reasoning over rare syndromes.
Core rules
- Chest pain: obtain ECG within 10 minutes; ST elevation in contiguous leads means STEMI. Inferior STEMI (II, III, aVF) often involves the right ventricle; avoid nitrates if there is hypotension or suspected RV infarct.
- Heart failure: assess congestion and perfusion; use loop diuretics for congestion, not routinely in a dry patient.
- COPD/asthma: confirm reversible obstruction; systemic steroids for exacerbation; antibiotics only with bacterial signs.
- Diabetes: metformin first unless contraindicated; assess renal function; avoid sliding-scale-only regimens.
- CKD: adjust doses; avoid NSAIDs and contrast when possible.
Worked example
A 58-year-old smoker has crushing substernal pain for 40 minutes, diaphoresis, BP 90/60, JVD, and ST elevation in II, III, aVF. This is inferior STEMI with probable RV involvement. Give aspirin, activate PCI, and avoid nitroglycerin because of hypotension and RV infarct risk; use cautious fluids if RV infarct is present without pulmonary edema. Reasoning: ST elevation localizes the infarct, and hypotension changes immediate therapy.
Traps
- Missing aortic dissection before anticoagulation.
- Treating anemia as the cause of dyspnea without an ECG.
- Using ACE inhibitors in acute severe renal failure or pregnancy.
- Ignoring drug interactions in older adults.