What form of anticoagulation is the “best”

Or why is Citrate better then Heparin or Prostacyclin

Anticoagulation and clotting

• Any blood surface interface– Hemofilter– Bubble trap– Catheter– Areas of turbulence resistance

• Luer lock connections / 3 way stopcocks

Sites of Action of CitrateContact Phase (intrinsic)

XII activationXI IX Ca++

Tissue Factor (extrinsic)TF:VIIa

THROMBIN Ca++

fibrinogen

prothrombin

X Xa Va VIIIa Ca++ platelets

CLOT

platelets / monocytes / macrophages

CITRATECitrate

• ACD-A (Baxter, Deerfield, IL)– 1000 cc bag, industry standard

• CaCl 8 gms/1 liter of NS– pharmacy made

• Normocarb Dialysis/Replacement Soln (Dialysis Soln Inc)– Can be prepared at bedside or pharmacy

• Normal Saline

Solutions needed for Citrate Protocol

(Pediatric Nephrology 2002 17:150-154 )

(Citrate = 1.5 x BFR150 mls/hr)

(Ca = 0.4 x citrate rate60 mls/hr)

Normocarb Dialysate

Normal Saline Replacement Fluid

Calcium can be infused in 3rd lumen of triple lumen access if available.

(BFR = 100 mls/min)

ACD-A/Normocarb Wt range 2.8 kg – 115 kgAverage life of circuit on citrate 72 hrs (range 24-143 hrs)

Pediatr Neph 2002, 17:150-154

Citrate: Technical Considerations• Measure patient and system iCa in 2 hours then at 6

hr increments• Standing protocol on nursing flow sheet adjusted by

bedside ICU nurse• Pre-filter infusion of Citrate

– Aim for system iCa of 0.25-0.4 mmol/l• Adjust for levels

• Systemic calcium infusion– Aim for patient iCa of 1.1-1.3 mmol/l

• Adjust for levels

Orders for citrate and Ca rates(adapted for N Gibney)

CITRATE INFUSION SLIDING SCALE CALCIUM INFUSION SLIDING SCALE

PRISMA iCa++ INFUSION ADJUSTMENT PATIENT iCa++ INFUSION ADJUSTMENT

>20 kg < 20 kg > 20 kg < 20 kg

< 0.25 by 10 ml/hr by 5 ml/hr > 1.3 by 10 ml/hr by 5 ml/hr

0.25 – 0.4(Optimum range)

Noadjustment

Noadjustment

1.1 – 1.3(Optimum range)

Noadjustment

Noadjustment

0.4– 0.5 by 10 ml/hr by 5 ml/hr 0.9 – 1.1 by 10 ml/hr by 5 ml/hr

> 0.5 by 20 ml/hr by 10 ml/hr < 0.9 by 20 ml/hr by 10 ml/hr

NOTIFY MD IF CITRATE INF. RATE > 200 ML/HR NOTIFY MD IF CALCIUM INF. RATE > 200 ML/HR

• 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

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

Complications of Citrate:

• Citrate Lock– Seen with rising total Ca with dropping patient

ionized Ca due to citrate delivery exceeds citrate clearance

– Rx of “citrate lock”• Increase clearance and decrease citrate rate

• Metabolic Alkalosis – Resolved with NaHCO3 bath of 25 meq/l

Incidence

• In a recent survey of PICU and CRRT databases in NA 70% of all programs use citrate as a primary mode of anticoagulation to avoid bleeding risks