Perioperative Critical Care
Perioperative critical care tests recognition and correction of failing oxygen delivery after thoracic or cardiac surgery. The exam expects physiology-based escalation, not reflexive fluid loading.
Core rules
- Hypotension requires differentiation by preload, contractility, afterload and rhythm; use bedside echo and mixed venous saturation when available.
- Low cardiac output after cardiac surgery may be due to tamponade, bleeding, ischemia, arrhythmia or vasoplegia; treat the cause.
- Ventilator strategy in acute lung injury uses lung-protective tidal volumes and adequate PEEP; one-lung ventilation needs careful hypoxia management.
- Sepsis requires cultures, antibiotics and source control; vasopressors support pressure but do not replace source control.
Worked example
A post-CABG patient has rising lactate, low urine output, distended neck veins and equalized filling pressures. The reasoning points to tamponade, not hypovolemia. Give oxygen and inotropes while arranging urgent echo and re-exploration; a fluid bolus alone could worsen congestion.
Traps
Do not treat every low blood pressure with fluids; do not miss bleeding because drains are not filling; do not ignore arrhythmia as a cause of low output; do not delay source control in mediastinitis or empyema.