Forty-eight hours after the chest tube insertion Ms. Paul remains on mechanical ventilation. While assessing the chest tube system, you note small bubbles in the water seal chamber generated dur-ing peak inspiration

This is an indication of which of the following:
a. normal functioning of the water seal chamber.
b. bronchopleural fistula.
c. low water level in the chamber.
d. high suction pressure from the suction chamber.

ANS: B
Bubbling in the water seal chamber is an indication of a leak in the chest tube collection system. The leak can be generated by (1) cracked or broken collection system, (2) improperly positioned chest tubes, and (3) a persistent bronchopulmonary fistula. To rule out (1) versus (2), and (3), the chest tube should be clamped by the chest level. If the leak continues, the collection system is cracked or defective. If the leak stops, the chest tube is malposition or there is a bronchopulmo-nary fistula generating the leak.