1.
Microcirculatory effects of the transfusion of leukodepleted or non-leukodepleted red blood cells in patients with sepsis: a pilot study
Donati A, Damiani E, Luchetti M, Domizi R, Scorcella C, Carsetti A, Gabbanelli V, Carletti P, Bencivenga R, Vink H, et al
Critical Care. 2014;18((2):):R33.
Abstract
INTRODUCTION Microvascular alterations impair tissue oxygenation during sepsis. A red blood cell (RBC) transfusion increases oxygen (O2) delivery but rarely improves tissue O2 uptake in patients with sepsis. Possible causes include RBC alterations due to prolonged storage or residual leukocyte-derived inflammatory mediators. The aim of this study was to compare the effects of two types of transfused RBCs on microcirculation in patients with sepsis. METHODS In a prospective randomized trial, 20 patients with sepsis were divided into two separate groups and received either non-leukodepleted (n=10) or leukodepleted (n=10) RBC transfusions. Microvascular density and perfusion were assessed with sidestream dark field (SDF) imaging sublingually, before and 1 hour after transfusions. Thenar tissue O2 saturation (StO2) and tissue hemoglobin index (THI) were determined with near-infrared spectroscopy, and a vascular occlusion test was performed. The microcirculatory perfused boundary region was assessed in SDF images as an index of glycocalyx damage, and glycocalyx compounds (syndecan-1, hyaluronan, and heparan sulfate) were measured in the serum. RESULTS No differences were observed in microvascular parameters at baseline and after transfusion between the groups, except for the proportion of perfused vessels (PPV) and blood flow velocity, which were higher after transfusion in the leukodepleted group. Microvascular flow index in small vessels (MFI) and blood flow velocity exhibited different responses to transfusion between the two groups (P=0.03 and P=0.04, respectively), with a positive effect of leukodepleted RBCs. When within-group changes were examined, microcirculatory improvement was observed only in patients who received leukodepleted RBC transfusion as suggested by the increase in De Backer score (P=0.02), perfused vessel density (P=0.04), PPV (P=0.01), and MFI (P=0.04). Blood flow velocity decreased in the non-leukodepleted group (P=0.03). THI and StO2 upslope increased in both groups. StO2 and StO2 downslope increased in patients who received non-leukodepleted RBC transfusions. Syndecan-1 increased after the transfusion of non-leukodepleted RBCs (P=0.03). CONCLUSIONS This study does not show a clear superiority of leukodepleted over non-leukodepleted RBC transfusions on microvascular perfusion in patients with sepsis, although it suggests a more favorable effect of leukodepleted RBCs on microcirculatory convective flow. Further studies are needed to confirm these findings. TRIAL REGISTRATION ClinicalTrials.gov, NCT01584999.
2.
Pharmacokinetics and pharmacodynamics of once-weekly subcutaneous epoetin alfa in critically ill patients: results of a randomized, double-blind, placebo-controlled trial
Vincent JL, Spapen HD, Creteur J, Piagnerelli M, Hubloue I, Diltoer M, Roman A, Stevens E, Vercammen E, Beaver JS
Critical Care Medicine. 2006;34((6):):1661-7.
Abstract
OBJECTIVE To describe the erythropoietin pharmacokinetic profile after once-weekly epoetin alfa treatment in critically ill patients. Secondary objectives were to compare pharmacodynamic and safety profiles between active treatment and placebo in these patients. DESIGN Randomized, double-blind, placebo-controlled study. SETTING Medical, surgical, or mixed medical/surgical intensive care units. PATIENTS A total of 73 anemic critically ill adults with an expected stay of >3 days and a hematocrit value of <38%. INTERVENTIONS Patients were randomized 2:1 to epoetin alfa, 40,000 IU, administered subcutaneously once weekly (n=48) or matching placebo (n=25) for up to 4 wks. MEASUREMENTS AND MAIN RESULTS Serum erythropoietin concentration and hematologic variables (percentage reticulocytes [RETI], hemoglobin [Hb], and total red blood cell [RBC] counts) were measured, and area under the serum concentration-time curve from time 0 to the last blood sampling time at time t (t: 120, 144, or 168 hrs) postdose (AUC0-Tlast) for these three variables was determined. Mean serum erythropoietin concentrations in placebo patients were slightly higher than typical physiologic levels of erythropoietin in healthy subjects, although not appropriate for the degree of anemia in these patients. Overall, exposure of endogenous erythropoietin in the placebo group (in terms of AUC0-Tlast) was only about 20% of exposure to exogenous erythropoietin in the epoetin alfa group. Baseline hemoglobin levels were the same in both groups (9. 9 g/dL). Mean change in hemoglobin level from baseline through day 29 was 1. 9 g/dL and 1. 6 g/dL in the epoetin alfa and placebo groups, respectively. Mean AUC(RETI)0-Tlast was higher with epoetin alfa than with placebo and was related to the AUC of erythropoietin. There were no apparent differences in AUC(Hb)0-Tlast and AUC(RBC)0-Tlast between epoetin alfa and placebo groups, which was most likely due to bleeding and transfusion events. Epoetin alfa was safe and well tolerated, with a rate of treatment-emergent complications similar to that seen with placebo. CONCLUSION Epoetin alfa, once weekly, augmented the erythropoietic response in critically ill patients as indicated by the increased erythropoietin levels and larger AUC(RETI)0-Tlast in treated patients.