In treating venous air embolism during posterior fossa surgery in the sitting position, which maneuver is NOT appropriate?

In treating venous air embolism during posterior fossa surgery in the sitting position, which maneuver is NOT appropriate?

• A. Discontinue N2O
• B. Apply jugular venous pressure
• C. Implement positive end-expiratory pressure (PEEP)
• D. Administer epinephrine to treat hypotension

Answer: (C)

In venous air embolism during a sitting neurosurgical case, the priority is to stop air entrainment and support circulation while the air bubbles are managed. Stopping nitrous oxide prevents further expansion of gas bubbles, and raising the central venous pressure (for example, with jugular vein compression) helps reduce ongoing air entry and aids in trapping the bubbles in the right heart. Providing 100% oxygen accelerates nitrogen washout from the bubbles and improves tissue oxygenation. If hypotension occurs, vasoactive support like epinephrine can help maintain perfusion. Positive end-expiratory pressure is not appropriate because increasing intrathoracic and central venous pressures can worsen venous return and hemodynamic instability during an air embolism. It may also raise right-sided pressures enough to promote air passage through any intracardiac shunt, risking paradoxical embolism. Therefore, PEEP is avoided in the acute management of venous air embolism.

In venous air embolism during a sitting neurosurgical case, the priority is to stop air entrainment and support circulation while the air bubbles are managed. Stopping nitrous oxide prevents further expansion of gas bubbles, and raising the central venous pressure (for example, with jugular vein compression) helps reduce ongoing air entry and aids in trapping the bubbles in the right heart. Providing 100% oxygen accelerates nitrogen washout from the bubbles and improves tissue oxygenation. If hypotension occurs, vasoactive support like epinephrine can help maintain perfusion.

Positive end-expiratory pressure is not appropriate because increasing intrathoracic and central venous pressures can worsen venous return and hemodynamic instability during an air embolism. It may also raise right-sided pressures enough to promote air passage through any intracardiac shunt, risking paradoxical embolism. Therefore, PEEP is avoided in the acute management of venous air embolism.