Chest tubes and water seal

[Pludovici]

If a chest tube separates from the drainage device and you submerge the tube in sterile water to creste a water seal how does the patient not suck the water into the pleural space

[offlabel]

If a chest tube separates from the drainage device and you submerge the tube in sterile water to creste a water seal how does the patient not suck the water into the pleural space

He does...to an extent. The negative pressure generated in the tube isn't enough to drag the water all the way up the tube into the chest. But if you could see the end of the tube submerged in the water, you'd see the fluid level rise a little toward the patient on inspiration.