Increased chest tube drainage is independently associated with adverse outcome after cardiac surgery

Abstract

Objective: To investigate the clinical relevance of specific volume criteria for hemorrhage in a patient population undergoing cardiac surgery with cardiopulmonary bypass (CPB).

Design: A retrospective analysis; postoperative hemorrhage was defined by a fixed set of criteria ≥200 mL/h in any 1 hour or part thereof, or (2) ≥2 mL/kg/h for 2 consecutive hours in the first 6 hours after surgery. Classification and regression tree (CART) analysis were used to validate the results of the specific volume criteria. Multivariate regression analysis was applied to investigate the association of specific volume criteria for hemorrhage with clinical outcomes.

Setting: A university hospital.

Participants: All adult cardiac surgery patients undergoing surgery with CPB at the authors' center in 2006.

Interventions: None.

Measurements and main results: A total of 1,188 patients underwent cardiac surgery, and 76 patients (6.4%) experienced postoperative hemorrhage according to the fixed criteria for blood loss. Blood loss as measured by these criteria was associated with a higher 30-day mortality (odds ratio [OR] = 2.9, p < 0.001), incidence of stroke (OR = 3.3, p = 0.0033), re-exploration (OR = 103.655, p < 0.0001), intensive care unit stay >72 hours (OR = 1.3, p < 0.0001), and mechanical ventilation >24 hours (OR = 3.4, p = 0.0002). The clinical relevance of these criteria is supported by CART analysis.

Conclusions: Postoperative hemorrhage (drainage loss) exceeding 200 mL/h in 1 hour or 2 mL/kg for 2 consecutive hours occurring within 6 hours after cardiac surgery is associated with higher 30-day mortality and other postoperative complications. Further research is needed to validate these results.