Which finding indicates there is no air leak present?

• A. No bubbling with minimal float ball oscillation at the bottom
• B. Continuous bubbling in the water seal
• C. Intermittent bubbling with float ball oscillation
• D. Bubbling from right to left

Answer: (B)

In a chest drainage system, air leaks show up as bubbling in the water-seal chamber. If there’s no air leak, you’d expect no bubbling in that chamber, with only minimal movement of the float ball indicating stable conditions. Continuous bubbling means a persistent air leak; intermittent bubbling means a leak that isn’t constant; any unusual directional bubbling isn’t a standard sign and still points to air movement. So the finding that indicates no air leak is the absence of bubbling in the water-seal chamber with only minimal float-ball movement.