During positive-pressure mechanical ventilation, what is the effect on intrathoracic pressure and how should chest-tube management be adjusted?

• A. Positive pressure increases intrathoracic pressure; ensure the drainage system remains patent and adjust suction per protocol.
• B. Positive pressure decreases intrathoracic pressure and reduces air leaks.
• C. Positive pressure has no effect on intrathoracic pressure and drainage.
• D. Positive pressure increases air leaks but does not affect suction.

Answer: (A)

Positive-pressure ventilation raises the pressure inside the chest during inspiration, increasing intrathoracic (intrapleural) pressure. That higher pressure pushes air from the lung into the pleural space and out through the chest tube, which can worsen a pneumothorax or increase the amount of air being evacuated.

So chest-tube management should focus on keeping the drainage system open and functioning while following the unit’s suction protocol. Ensure the tubing and underwater seal are patent (no kinks or occlusions) and adjust suction as prescribed to optimize air removal and lung re-expansion. Always monitor for persistent air leaks or changes in drainage and respond per protocol.

The other options don’t fit because they describe decreases in intrathoracic pressure or no effect, or claim suction isn’t affected—none align with how positive-pressure ventilation actually changes pleural pressures and chest-tube dynamics.