Anemia, Blood Transfusion, and Filter Life Span in Critically Ill Patients Requiring Continuous Renal Replacement Therapy for Acute Kidney Injury: A Case-Control Study

Abstract

Background. Filter clotting is frequent during continuous renal replacement therapy (CRRT), which increases anemia risk. We studied anemia and blood transfusion in critically ill patients requiring CRRT for acute kidney injury and assessed the relationship between CRRT filter life span and PRBC transfusion. Methods. A case-control study was conducted at a tertiary-care intensive care unit (ICU) where CRRT cases were matched with controls for age, gender, admission category, and severity of illness. Daily hemoglobin levels, blood transfusions, and life span of CRRT filter were noted. CCRT patients were categorized according to the median of the filter life span (20 hours). Results. Ninety-five cases and 102 controls were enrolled. The hemoglobin level on admission was similar in the two groups, yet cases had significantly lower hemoglobin levels than controls (72.8 ± 15.3 versus 82.5 ± 20.7 g/L, p<0.001) during ICU stay. Anemia <70 g/L occurred in 50% of cases and 19% of controls (p<0.001). Most (56.3%) cases were transfused compared with 29.9% for controls (p<0.001) with higher number of transfused packed red blood cell (PRBC) units in cases (2.6 ± 4.0 versus 1.5 ± 3.2 units per patient, p=0.03). Patients with shorter versus longer filter life had similar hemoglobin level in the first 7 days of CRRT with no difference in PRBC transfusion requirement. Prefilter heparin use and hemodialysis access location were not associated with longer filter life span. The mortality was similar in patients with shorter versus longer filter life. Conclusions. CRRT in ICU was associated with larger drop in hemoglobin and more PRBC transfusion. Shorter (<20 hours) versus longer CCRT filter life was not associated with increased PRBC transfusion.

Overview of Renal Replacement Therapy Use in a General Intensive Care Unit

“…A study published by Al-Dorzi et al showed that CRRT use among ICU patients is inevitably linked with a larger decline in hemoglobin levels, requiring red blood cell transfusion [26]. This association has also been identified in our critically ill patients.…”

Artificial Liver Support with CytoSorb and MARS in Liver Failure: A Retrospective Propensity Matched Analysis

“…Patients in the CytoSorb group experienced a significant decrease in hemoglobin levels, while patients in the MARS group did not. As this decrease was observed over a median period of more than 72 h, we cannot assess if it is due to erythrocyte entrapment or destruction within the CytoSorb/CRRT filter as demonstrated by Al-Dorzi et al [ 44 ] or to critical illness and the frequent blood withdrawal in the ICU [ 45 ]. A decrease in platelet count was observed for both MARS and CytoSorb groups.…”

Impact of anemia requiring transfusion or erythropoiesis-stimulating agents on new-onset cardiovascular events and mortality after continuous renal replacement therapy

“…Therefore, critically ill patients with acute kidney injury (AKI) are at a higher risk of developing anemia due to both kidney dysfunction and the severity of their illness. Renal replacement therapy, including continuous renal replacement therapy (CRRT), can further exacerbate anemia because of blood loss from hemofilter clotting that cannot be returned 13 as well as bleeding associated with catheters or anticoagulation 14 .…”