Presentation on theme: "Regional Citrate Anticoagulation during CVVH in the"— Presentation transcript:
1 Regional Citrate Anticoagulation during CVVH in the Pediatric Intensive Care UnitT Gaillot, V Phan, P Jouvet, F Gauvin, C Litalien
2 IntroductionCVVH is being increasingly utilized for the care of PICU patientsImperative need :Effective anticoagulation to prevent recurrent clotting of the extracorporeal circuit and to achieve efficient and uninterrupted therapyHistorically, systemic anticoagulation with heparin mainstay of anticoagulation for CVVHLimits/contraindications :High risk for bleedingActive bleedingHeparin-induced thrombocytopeniaUse of activated Protein CHeparin-induced major bleeding complications can be as high as 50 %.
3 Introduction Regional citrate anticoagulation (RCA): Attractive alternative to systemic heparinization with less risk of bleedingCitrate chelates ionized Ca2+, an essential cofactor in the clotting cascadeAnticoagulation is limited to the extracorporeal circuit by infusing citrate solution into the arterial limb of the circuitSystemic anticoagulation is avoided by restoring ionized Ca2+ in the systemic circulation by infusing Ca2+ solution through a separate central line
4 Introduction RCA and mean circuit lifetime: Adult studies Monchi et al, 2004: RCA vs heparin: 70 h vs 40 hDorval et al, 2003: 44 24 hPediatric studiesChadha et al, 2002: 51 8 hElhanan et al, 2004: 56 22 hBunchman et al, 2002: 71 7 h
5 Introduction RCA and complications: Citrate is metabolized in the liver and produces HCO3- and citric acid can result in metabolic alkalosisAccumulation of citrate may occur if liver metabolism is impaired can result in citrate toxicity or "citrate gap"
6 Objective To evaluate the mean circuit lifetime and metabolic complications of RCA in critically illchildren after the introduction of thisanticoagulation technique in our PICU
7 Material and methods Retrospective chart review Children who underwent hemofiltration with RCA from March 2003 to December 2003 were includedMean circuit lifetime (MCL) and reasons for circuit discontinuation were determinedMetabolic alkalosis : pH 7.45 and HCO3- 30 mmol/LCitrate gap : total to ionized Ca2+ ratio > 2.5
8 Calcium chloride (8g/1L NS) Material and methodsNormocarbRate: 2 L/1.73 m2/hSystemic infusionCalcium chloride (8g/1L NS)Rate: 0.4 X ACD-A rateACD-ARate: 1.5 X BFRDIALIZERPrismaM-10, M-60 or M-100(AN-69)From patientTo patientBFR: 2-8 ml/kg/minTarget post-filter ionized calciumTarget patient ionized calciumUltrafiltrateNormocarbRate: 2 L/1.73 m2/hBunchman et al , 2002
9 27 involuntary discontinuations (73%) MCL= 28 35 h Circuit failure (n=23, 85%) 10 Catheter dysfunction13 High transmembrane pressure and/or clottingTechnical failure (n=3, 11%)1 impossible auto-test1 screen failure1 unknown failure5 patientsmean age 5.5 6.8 y and weight 28.1 33 kg37 circuitsMean circuit lifetime (MCL) = 29 36 h10 elective discontinuations (27%) MCL= 29 32 hMedical cause (n=1, 4%)1 bleedingAge range:Weight range: 3.5 to 85.6 kgDiagnosis : 1 sepsis after cardiac surgery, 1 hemolytic uremicsyndrome after bone marrow transplantation and 3 probableischemic acute tubular necrosis (2 bone marrow transplantations and 1 liver transplantation)
10 Results Kaplan-Meier curve of time to circuit discontinuation RangeLe plus courtLe plus long50 % des circuits
11 Results Post filter ionized Ca2+ : 0.40 0.10 mmol/L Patient ionized Ca2+ : 1.14 0.13 mmol/L13 episodes (35 %) of metabolic alkalosis in 4 patients9 episodes (24 %) of citrate gap in 2 patients5 children with a mean age of ( ) and a mean weight of 28.133 kg (3.5 to 85.6 kg)Dual-lumen catheters (6.5 to 12 Fr)
12 ConclusionIn our PICU, the mean circuit lifetime using RCA was much shorter than those reported despite post-filter ionized Ca2+ within the optimum rangeMetabolic alkalosis was frequently encounteredCitrate toxicity occurred in 2 patients out of 5The use of RCA may be somewhat problematic in some critically ill childrenOptimum range for post-filter ionized Ca2+:In PICU, many factors including immaturity of the newborn liver and SIRS/MODS-related impaired hepatic metabolism, impaired hepatic function, may decrease citrate clearance and multiple transfusions may increase citrate load.
13 PerspectivesRCA remains an attractive option to provide anticoagulation in those patients with heparin contraindicationsProspective, randomized controlled trials comparing RCA and systemic heparinization are needed before RCA replaces heparin in all critically ill childrenThe recent introduction of a technique can lead to errors in interpreting a new protocol