Incidence of chest tube clogging after cardiac surgery: a single-centre prospective observational study.

OBJECTIVES: Chest drainage following cardiac surgery is used to avoid complications related to the accumulation of blood and serous fluid in the chest. We aimed to determine the incidence of chest tube clogging and the role of bedside assessment in identifying the potential for failure to drain.
METHODS: Data from 150 patients undergoing cardiac surgery using cardiopulmonary bypass from March to October 2011 were prospectively entered into a database. Chest tubes were visually inspected and functionally assessed at four time intervals (Hours 0, 2-4, 6-8 and at removal), defining need for clearance and presence of partial or complete obstruction.
RESULTS: Complete data were available for 100 patients. We assessed 234 chest tubes: pericardial (n = 158); pleural (n = 76). The incidence of chest tube clogging for the entire group was 36% (any tube completely clogged at any time), with increased prevalence of clogging observed in urgent and reoperative cases and in those with increased intraoperative blood use. Among 51 tubes resulted to have a thrombus formation observed inside the chest tube at removal, 44 were clogged primarily in the internal portion of the tube, meaning that clogging could not be confirmed by simple bedside inspection of the indwelling tube.
CONCLUSIONS: The chest tubes can become clogged at any time after their placement. The status of urgency, reoperations and use of blood products can be contributing factors increasing the incidence of chest tube clogging. Clinicians likely underestimate the prevalence of this failure to drain, as most clogging occurs in the internal portion of the tube.