Brophy University of Iowa Citrate Anticoagulation Patrick Brophy MD, MHCDS Professor & Director...
-
Upload
arnold-cook -
Category
Documents
-
view
217 -
download
0
Transcript of Brophy University of Iowa Citrate Anticoagulation Patrick Brophy MD, MHCDS Professor & Director...
Brophy University of Iowa
Citrate Anticoagulation
Patrick Brophy MD, MHCDSProfessor & Director Pediatric
NephrologyUniversity of Iowa- Children’s Hospital
London 2015
Brophy University of Iowa
Objectives
Review rationale for anticoagulation Options Available data
Brophy University of Iowa
Relevance to CRRT
Functional circuit life is imperative to: Dose delivery Staff statisfaction Patient morbidity (changing lines) Cost of therapy—multi circuit use
Brophy University of Iowa
Optimal Anticoagulation
Should be: Readily available Consistently delivered (protocols) Safe!!!! Easily monitored Commercially available Be associated with minimal side effects
Brophy University of Iowa
Anticoagulants
Saline Flushes Heparin Peds Citrate regional
anticoagulation Peds Low molecular weight
heparin Prostacyclin Nafamostat mesilate Danaparoid* Hirudin/Lepirudin Argatroban (thrombin
inhibitor)*
* No antidote known
Brophy University of Iowa
Brophy University of Iowa
Sites of Thrombus Formation
Any blood surface interface Hemofilter Bubble trap Catheter (Especially Pediatrics)
Areas of turbulence resistance Luer lock connections / 3 way stopcocks
Brophy University of Iowa
Citrate
Brophy University of Iowa
How does citrate work
Clotting is a calcium dependent mechanism, removal of calcium from the blood will inhibit clotting
Adding citrate to blood will bind the free calcium (ionized) calcium in the blood thus inhibiting clotting
Common example of this is blood banked blood
Brophy University of Iowa
CITRATE
CalciumDependentPathways
Brophy University of Iowa
How is citrate used?
In most protocols citrate is infused post patient but prefilter often at the “arterial” access of the dual (or triple) lumen access that is used for hemofiltration (HF)
Calcium is returned to the patient independent of the dual lumen HF access or can be infused via the 3rd lumen of the triple lumen access
Brophy University of Iowa
(Citrate = 1.5 x BFR150 mls/hr)
(Ca = 0.4 x citrate rate60 mls/hr) (8mg/ml)
Dialysate
Replacement Fluid
Calcium can be infused in 3rd lumen of triple lumen access if available.
(BFR = 100 mls/min)
Pediatr Neph 2002, 17:150-154
Brophy University of Iowa
Citrate: Technical Considerations
Measure patient and system iCa in 2 hours then at 6 hr increments
Pre-filter infusion of Citrate Aim for system iCa of 0.3-0.4 mmol/l
Adjust for levels Systemic calcium infusion
Aim for patient iCa of 1.1-1.3 mmol/lAdjust for levels
Brophy University of Iowa
Citrate: Advantages
No need for heparin Commercially available solutions exist (ACD-
citrate-Baxter) Less bleeding risk Simple to monitor
Many protocols exist
Brophy University of Iowa
Advantages of Citrate
Has zero effect upon patient bleeding as opposed to heparin which effects system and patient bleeding
Easy to monitor with ionized calcium assay Activated Clotting Time (ACT) nor PTT needed Programs report less clotted circuits = less disposable cost
and less overtime nursing hours Bedside surveys demonstrate less work of machinery
allowing more attention to patient
Brophy University of Iowa
Citrate: Problems
Metabolic alkalosis Metabolized in liver / other tissues May be associated with post CRRT raclcitrant hypercalcemia
Electrolyte disorders Hypernatremia Hypocalcemia Hypomagnesemia
Cardiac toxicity Neonatal hearts
Brophy University of Iowa
Complications of Citrate:Metabolic alkalosis
Metabolic alkalosis due to citrate conversion to HCO3 Solutions with 35 meq/l
HCO3 NG losses TPN with acetate
component
Treatment Solutions with 35 meq/l
HCO3 Decrease bicarbonate
dialysis rate and replace at the same rate with NS (pH 5)
NG losses Replace with ½-2/3 NS
TPN with acetate component Use high Cl ratio
Brophy University of Iowa
Complications of Citrate: “Citrate Lock”
Seen with rising total calcium with dropping/Stable patient ionized calcium Essentially delivery of citrate exceeds hepatic metabolism and
CRRT clearance Treatment of “citrate lock”
Decrease or stop citrate for 1 hr then restart at 70% of prior rate or Increase D or FRF rate to enhance clearance
Brophy University of Iowa
Citrate or Heparin: literature
Brophy University of Iowa
Hoffbauer R et al. Kidney Int. 1999;56:1578-1583.
Citrate Unfractionated Heparin
Brophy University of Iowa
Anticoagulation
In adults: Monchi M et al. Int Care Med 2004;30:260-65
Median filter life was 70 hr Citrate, 40 hr Heparin Fewer PRBC transfused in Citrate group (surrogate of
bleeding per study) 0.2 units/day of CVVH Citrate vs 1 units/day of CVVH Heparin
Brophy University of Iowa
Heparin or Citrate?.
single center - 209 adults regional anticoagulation : trisodium citrate vs standard
heparin protocol ( customized calcium-free dialysate)
CitACG was the sole anticoagulant in 37 patients, 87 patients received low-dose heparin plus citrate, and 85 patients received only hepACG.
Both groups receiving citACG had prolonged filter life when compared to the hepACG group.
significant cost saving due to prolonged filter life when using citACG.
Morgera S, et.al. Nephron Clin Pract. 2004; 97(4):c131-6.
Brophy University of Iowa
Seven ppCRRT centers 138 patients/442 circuits 3 centers: hepACG only 2 centers: citACG only 2 centers: switched from hepACG to citACG
HepACG = 230 circuits CitACG= 158 circuits NoACG = 54 circuits Circuit survival censored for
Scheduled change Unrelated patient issue Death/witdrawal of support Regain renal function/switch to intermittent HD
Brophy University of Iowa
Brophy University of Iowa
ppCRRT ACG Side Effects
Heparin 11 cases of systemic bleeding on heparin 5 cases no ACG used secondary to bleeding 1 case of HIT
Citrate 19 cases of metabolic alkalosis
1 change to heparin for hyperglycemia 1 change to heparin for alkalosis
3 cases of citrate lock
Brophy University of Iowa
Anticoagulation and CRRT
Heparin and citrate anticoagulation most commonly used methods
Heparin: bleeding risk Citrate: alkalosis, citrate lock
Brophy University of Iowa
Reference Tools
Adqi.net-web site for information on CRRT AKIN.org Crrtonline.com-web site for info on Dr Mehta’s meeting www.PCRRT.com Pediatric CRRT with links to other
meetings, protocols, industry PCRRT list serve (contact Tim Bunchman)
Brophy University of Iowa
Thanks
ppCRRT members Bedside ICU and Dialysis Nurses patients