Continuous Renal Replacement Therapy and Coagulation Disorders among Patients undergoing Cardiac Surgery: A Case-Control Study

Introduction: Acute kidney injury (AKI) is a common complication after cardiac surgery and 1-3% of patients suffering AKI require continuous renal replacement therapy (CRRT). Although blood coagulopathy is usual after cardiac surgery, this disorder is worsened in patients requiring CRRT because of the need for anticoagulation for effective therapy delivery. Aim: To investigate the postoperative coagulation disorders among patients undergoing cardiac surgery and the effects of CRRT on the coagulation status of patients sustaining AKI severe enough to require CRRT. Method: A case-control study was conducted among 131 (response rate 12.1%) patients who were admitted to the 8-bed cardiac surgery intensive care unit (ICU) of a general, tertiary hospital in Athens from January 2010 to November 2011. Data collection was performed in November 2013, using a short structured questionnaire covering basic demographic, perioperative and clinical data and reviewing the electronic medical records. Patients were allocated to: (a) A control group of 74 patients who did not undergo CRRT, and (b) a CRRT group (cases) of 57 patients who underwent CRRT within the first 24 hours of their ICU admission. Prothrombin time (PT), activated partial thromboplastin time (aPTT), international normalized ratio (INR) and platelets levels were measured: (a) One hour before (baseline) and 24 and 48 hours after the CRRT initiation for the CRRT group, and (b) 12 hours after the ICU admission (baseline) and 24 and 48 hours after the first measurement for the control group. Comparison was made of the two groups on their coagulation status at baseline and 24 and 48 hours after the first measurement. In addition, the changes over time of blood coagulation tests (PT, APTT, INR), and platelets levels for each patient group were compared separately. Statistical analysis was performed with the Statistical Package for Social Sciences (SPSS), version 19.0, using t-test, x2test and two-way ANOVA. Results: CRRT patients had significantly higher levels of PT, APTT and INR (p<0.001) than the control group. In addition, investigating each group separately, it was found that the patients of both groups developed significant coagulation disorders over time (p<0.001), regardless of CRRT. Conclusions: Although all patients undergoing cardiac surgery are at high risk for coagulation disorders postoperatively, CRRT appears to be significantly associated with the occurrence of postoperative coagulopathy. The early identification of these patients could contribute to more effective management, preventing life-threatening postoperative bleeding.

Category: Volume 53, N 4
Hits: 1060 Hits
Created Date: 15-12-2014
Authors: Stavros Theologou , Konstantinos Giakoumidakis