Impact of retained blood requiring reintervention on outcomes after cardiac surgery

Objectives: Evacuation of shed blood from around the heart and lungs is a critical requirement for patients in early recovery after cardiac surgery. Incomplete evacuation of shed blood can result in retained blood, which may require subsequent reinterventions to facilitate recovery. The purpose of this study was to determine the incidence of retained blood requiring reintervention and examine the impact on outcomes. Methods: We performed a cross-sectional, observational study of all adult patients undergoing cardiac surgery between 2006 and 2013. Subjects who required an intervention to remove blood, blood clot, or bloodily fluid were attributed to the retained blood group. These patients were compared with those not presenting with any of the defined criteria for retained blood. Multivariate regression was performed to account for confounders. Results: Of 6909 adult patients who underwent cardiac surgery, 1316 (19%) presented with a retained blood-related condition. Retained blood was associated with increased in-hospital mortality (odds ratio [OR], 4.041; 95% confidence interval [CI], 2.589-6.351, P < .001) and a length of stay more than 13 days in the hospital (OR, 3.853; 95% CI, 2.882-5.206; P < .001) and 5 days in the intensive care unit (OR, 4.602; 95% CI, 3.449-6.183; P < .001). The OR for a time of ventilation greater than 23 hours was 3.596 (95% CI, 2.690-4.851; P < .001) and for incidence of renal replacement therapy was 4.449 (95% CI, 3.188-6.226; P < .001). Conclusions: Postoperative retained blood is a common outcome and associated with higher in-hospital mortality, longer intensive care unit and hospital stay, and higher incidence of renal replacement therapy. Further research is needed to validate these results and explore interventions to reduce these complications.