Patient Factors Associated with Frequent Clotting of Dialysers during Haemodiafiltration in Critically Ill Patients: A Post Hoc Analysis of a Randomised Controlled Study

Abstract

Continuous haemodiafiltration (CVVHDF) is the main form of renal replacement therapy in critically ill patients with severe acute kidney injury. Clotting of the dialysers during CVVHDF is frequent, because most patients with acute kidney injury have an increased risk of bleeding and cannot be systemically anticoagulated. Using data from a randomised controlled trial comparing the efficiency of CVVHDF by placing the dialysis catheter tip at the right atrium or superior vena cava, this study assessed the patient factors associated with an increased risk of frequent clotting of the dialysers—defined by > 1 dialysers clotted per day of CVVHDF. Of the 94 patients included in this study, a higher body mass index, a higher platelet count and a lower International Normalized Ratio were associated with an increased risk of frequent clotting of dialysers in the univariate analyses. Use of aspirin or clopidogrel, causes of acute kidney injury and daily dose of unfractionated heparin used were not significantly associated with the risk of frequent clotting of dialysers. In the multivariate parsimony model, only a high body mass index (odds ratio 1.06 per point increment, 95% confidence interval 1.01 to 1.13; P=0.036) and a high platelet count (odds ratio 1.84 per 100×1079/1 increment, 95% confidence interval 1.17 to 2.91; P=0.009), both in a relatively linear fashion, were independently associated with an increased risk of frequent clotting of dialysers. Optimising the position of the tip of the dialysis catheter may be particularly important for patients with a high body mass index and platelet count in order to reduce frequent clotting of dialysers during CVVHDF.

Platelet Function in Acute Kidney Injury: A Systematic Review and a Cohort Study

“…In total, 58 studies were eligible for inclusion. Of these, nine investigated platelet function in AKI patients, 28 29 30 52 53 54 55 56 57 46 studies examined platelet count only 23 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 and 3 investigated mean platelet volume. 103 104 105 Thirty-two studies were set in an ICU and twenty-six were set in a medical ward.…”

“…Twenty-nine studies (28 including adults and 1 including children) investigated platelet count or thrombocytopenia prevalence in ICU patients, 28 52 53 54 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 and 24 studies included medical ward patients with either lupus nephritis ( n = 1), 93 rifampicin treatment ( n = 1), 94 snake bite ( n = 2), 91 92 decompensated liver cirrhosis ( n = 3), 30 57 95 infectious diseases ( n = 8), 83 84 85 86 87 88 89 90 or AKI of mixed origin ( n = 9). 23 29 96 97 98 99 100 101 102 Further, three studies investigated mean platelet volume in AKI patients, of which two were set in an ICU 103 104 and one was set in a medical ward.…”

Vascular Access Site for Renal Replacement Therapy in Acute Kidney Injury: A Post hoc Analysis of the ATN Study

“…We acknowledge that there is no single parameter that determines catheter functionality, and certain parameters may be influenced by physician decisions, hence we looked at a combination of factors including catheter blood flow rates, duration of catheter usage, dialyzer clotting resulting in filter change as well as dialysis dose delivered (17, 18). In comparison to the Cathedia study, we noted a higher incidence of catheter malfunction in the femoral group compared to the other groups as shown by the shorter catheter duration and lower delivered Kt/V (19).…”

Applying the Cell-Based Coagulation Model in the Management of Critical Bleeding

“…protein C, protein S and antithrombin) 18 and procoagulants (e.g. hepatocyte tissue factor) 19 , other important factors that can also affect bleeding or thrombotic risk in vivo may include platelet count 20,21 and status of the platelet activation (as evidenced by release of platelet microparticles and microRNAs) 22,23 . Indeed, omission of pharmacological thromboprophylaxis due to a perceived increased risk of bleeding from an abnormal INR or aPTT has been reported to be associated with an increased risk of mortality 24,25 , and FFP transfusion is not very effective in correcting an abnormal INR or aPTT in the critically ill or reducing risk of bleeding in patients with chronic liver disease 26,27 .…”