Basic Sciences Applied to the Specialty
Basic sciences in this exam are applied, not isolated facts. Anatomy, physiology, pathology and pharmacology must explain operative risk and clinical findings.
Core rules
- Coronary anatomy and collateral supply determine ischemia patterns and bypass targets; the left main and proximal LAD are high-risk territories.
- Pulmonary physiology: shunt, dead space and compliance explain hypoxemia after lung resection and one-lung ventilation.
- Coagulation and platelet function explain bleeding after cardiopulmonary bypass; heparin reversal and transfusion thresholds matter.
- Pharmacology: beta-blockers, vasopressors, inotropes and antibiotics have clear indications and hazards in perioperative care.
Worked example
A patient after pneumonectomy becomes hypoxemic with a normal chest radiograph. The reasoning should include shunt and ventilation-perfusion mismatch, not simply pneumonia. Fluid overload can worsen right-heart strain after pneumonectomy; assess volume status first.
Traps
Do not memorize anatomy without applying it to operative risk; do not attribute all postoperative hypoxemia to atelectasis; do not ignore heparin rebound or platelet dysfunction; do not use inotropes without identifying the cause of low output.