If the patient has a wet-suction CCD, verify that the water seal and suction chambers are filled with sterile water to the
recommended level
–The water seal chamber should bubble gently when the lungs are forcefully deflated (e.g., during coughing, vigorous
exhalation, Valsalva maneuver). Continuous bubbling without suction indicates a leak in the insertion site, a continuing
bronchopleural air leak, or a break in the system integrity (e.g., break in the tubing or a loose connection between the
CCD and the chest tube)
- Check for leaks in the system by placing a padded hemostat or clamp at the dressing site. If the bubbling stops, the leak
is at the insertion site. If the bubbling continues, the leak is in the tubing or in a connection
–If there is no air leak, the water level will fluctuate with the patient’s spontaneous respirations (known as tidaling [e.g.,
fluctuation in the water level, ~ 5–10 cm]). The water level rises with inhalation and falls during exhalation. This pattern
is reversed if the patient is receiving positive pressure mechanical ventilation
- Absence of tidaling indicates the lungs have reexpanded or the tubing is occluded
• If the CCD is connected to external suction (used to enhance pressure), verify the suction in the suction control chamber
is at the prescribed level (e.g., -20 cm H2O/-15 mm Hg for most adults or -7–14 cm H2O/-5–10 mm Hg for infants or for
patients with friable lung tissue). The height of the column of water in the suction control chamber determines the amount
of suction, not the control on the suction source. There will begentle bubbling in the suction control chamber while suction
is in effect. Refill the suction control chamber with sterile water (usually through a self-sealingdiaphragm) if the prescribed
water level has evaporated below the prescribed level