Timing of chest tube removal after coronary artery bypass surgery

Assessing the impact of chest tube removal timing following a coronary artery bypass grafting surgery on the clinical outcome.

Eighty-three consecutive patients were randomly assigned to either have the chest tube removed 24 hours (Group A) or 48 hours (Group B) postoperatively. Chest tubes were removed on the condition that drainage was less than 100 cc for the last 8 hours. Pre- and postoperative data were analyzed.

The following preoperative and intraoperative risk factors were more prevalent among Group A patients: previous MI (60.5% vs 40.7%, p = 0.11), previous CVA (9.1% vs 0%, p = 0.11), hypertension (72.7% vs 55.6%, p = 0.14), pump time (111.6 min vs 96.8 min, p = 0.07), and cross-clamp time (73.8 min vs 64.4 min, p = 0.07). Postoperatively, there was a lower demand for analgesics in Group A (2.1 times for 12 hours at 36 hours vs 3.6 p = 0.09), lower white blood cell count (10,947 at 48 hours vs 11,576, p = 0.39) a higher oxygen saturation (91.9% at 48 hours vs 88.9%, p = 0.07), higher expiratory volumes (594 mL at 36 hours vs 514 mL p = 0.08) and earlier mobilization (23% walking at 48 hours vs 4%, p = 0.01). Pleural effusion and atelectasis were less frequent in Group A in both chest X-rays (66% vs 73%, p = 0.6 and 64% vs 75%, p = 0.47, respectively) and CT scans (19% vs 41%, p = 0.1 and 84% vs 96%, p = 0.42, respectively). There was no difference between the two groups in the prevalence of serous wound discharge and the length of hospital stay and there were no reported cases of pneumonia throughout the study.

In cases where no excessive drainage accumulates, early removal of the chest tubes was found to be a policy that improves the postoperative outcome and decreases the need for supportive treatment such as analgetics, physiotherapy, nurse care, and oxygen. This policy did not involve significant residual effusions.