Re: Letter by Spronk et al entitled 'Regional citrate anticoagulation does not prolong filter survival during CVVH'

摘要

In reply to the correspondence of Spronk et al , we generally agree with several considerations that have been highlighted and offer the following dialogue.We concur that a number of factors contribute to filter circuit life span, specifically patient-related or catheter-related factors, chosen modality of continuous renal replacement therapy (CRRT), and ultrafiltration and blood flow rates as outlined in the letter by Spronk et al .Furthermore, we acknowledge that our study had limitations that necessitate consideration and could potentially have influenced the observed difference in filter circuit life span between regional citrate (RCA) and systemic heparin anticoagulation (SHA) . First, we were unable to incorporate data on individual filter transmembrane pressure, specific patient-related factors (eg, hematocrit, activate partial thromboplastin time), and selected catheter-related factors (eg, position, age, and size of catheter). Second, although our study included 4 centers, the protocol for CRRT was instituted regionally through the Department of Critical Care Medicine, University of Calgary, Calgary, Canada, for the Calgary Health Region. Therefore, our data in essence represent the experience of a single large center that will undoubtedly vary if compared with other single center studies, such as the data described by Spronk et al . This is significant because those differences may reflect local practice, institutional experience, and other aspects of CRRT such as available technology (eg, CRRT machines and types/sizes of filters), modalities, methods for anticoagulation (eg, commercially available citrate vs pharmacy specific), and numerous other logistic factors. Third, our study was an observational study and not a blinded randomized comparison of the 2 methods of anticoagulation. Finally, we did not integrate other potentially important outcomes such as clinically relevant thrombocytopenia, bleeding episodes, need for blood product transfusion, or overall cost.