If the venous cannula is inserted too far into the inferior vena cava during CPB, which problem may occur?

If the venous cannula is inserted too far into the inferior vena cava during CPB, which problem may occur?

• A. Abdominal distention
• B. Air embolism
• C. Pulmonary edema
• D. Cerebral edema

Answer: (A)

The main idea is that venous drainage during CPB depends on proper cannula position. If the venous cannula is advanced too far into the inferior vena cava, the tip can enter the hepatic veins or press against the IVC wall, obstructing hepatic venous outflow. This creates back pressure in the liver and abdominal venous system, leading to hepatic congestion and abdominal distension as blood backs up in the abdomen. The other issues listed are not directly caused by this specific misplacement: air embolism would require air entry into the circuit, pulmonary edema and cerebral edema stem from different pathophysiology (cardiac failure or cerebral issues), not from hepatic venous outflow obstruction due to a too-deep cannula.

The main idea is that venous drainage during CPB depends on proper cannula position. If the venous cannula is advanced too far into the inferior vena cava, the tip can enter the hepatic veins or press against the IVC wall, obstructing hepatic venous outflow. This creates back pressure in the liver and abdominal venous system, leading to hepatic congestion and abdominal distension as blood backs up in the abdomen. The other issues listed are not directly caused by this specific misplacement: air embolism would require air entry into the circuit, pulmonary edema and cerebral edema stem from different pathophysiology (cardiac failure or cerebral issues), not from hepatic venous outflow obstruction due to a too-deep cannula.