Table 3 Perioperative stressors and right heart physiologic responses
Stressor | Stress response | Examples |
|---|---|---|
Systemic hypotension | ↓Systolic and diastolic pressure leading to reducing coronary perfusion, especially with elevated RV pressure | Induction; rapid blood loss |
Hypoxemia | ↑Pulmonary vascular resistance | Single lung ventilation; reduced minute ventilation in MAC cases; postoperative opioid-related respiratory depression |
Hypercarbia | ↑Pulmonary vascular resistance | Pneumoperitoneum; release of tourniquet |
Acidosis | ↑Pulmonary vascular resistance, ↓systemic BP, and reduced response to vasopressors | Shock with increased lactate, hypercapnia, ketoacidosis |
Positive pressure ventilation | ↑Pulmonary vascular resistance | Intubation; high inspired pressures that create more dead space; high PEEP |
Hypervolemia | Elevated PCWP can increase PA, RV, and RA pressures and if acute can reduce RV output or cause acute TR | Excessive IVF administration; TACO; steep Trendelenburg |
Hypovolemia | Low filling pressures can greatly reduce RV output | Rapid acute blood loss; steep reverse Trendelenburg especially with pneumoperitoneum; prone position with increased chest pressure or abdominal pressure retarding IVC flow for RA/RV filling |