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Terminology and Common Issues in Pediatric CRRT. John Gardner RN, BSN Nurse Manager Pediatric Nephrology & Transplant DeVos Children’s Hospital Grand Rapids Michigan. Over View. Terminology Common issues Access Anticoagulation Extracorporeal circuit size Blood priming Hypothermia
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Terminology and Common Issues in Pediatric CRRT John Gardner RN, BSN Nurse Manager Pediatric Nephrology & Transplant DeVos Children’s Hospital Grand Rapids Michigan
Over View • Terminology • Common issues • Access • Anticoagulation • Extracorporeal circuit size • Blood priming • Hypothermia • Staffing
Terminology • SCUF slow continuous ultrafiltration • CAVH continuous arteriovenous hemofiltration • CAVHD continuous arteriovenous hemodialysis
Terminology • CVVH continuous venovenous hemofiltration • CVVHD continuous venovenous hemodialysis • CVVHDF continuous venovenous hemodiafiltration
CAVH/CVVH: Convective Clearance • CVVH/CAVH • Convective clearance • Replacement solutions • Physiologic sterile solution that is either infused pre filter (NA) or post filter (outside of NA) that infused at a set rate (Qr)
CAVHD/CVVHDDiffusive Clearance • CVVHD/CAVHD • Diffusive clearance • Dialysate • Physiologic sterile solution that is infused countercurrent to the blood flow rate (Qd)
CAVHDF/CVVHDFConvective and Diffusive Clearance • CVVHDF/CAVHDF • Convective clearance • Replacement solutions • Diffusive clearance • Dialysis solution
Urea Clearance CVVH Vs CVVHD(Maxvold Et Al, Crit Care Med, April 2000) • Study design • Fixed blood flow rate-4 mls/kg/min • HF-400 (0.3 m2 polysulfone) • Cross over for 24 hrs each to FRF or Dx flow at 2000 mls/hr/1.73 m2 • TPN protein delivery at 1.5 gms/kg/day
Comparison of Urea Clearance: CVVH Vs CVVHD(Maxvold Et Al, Crit Care Med April 2000) p = NS Urea Clearance (mls/min/1.73 m2) BFR = 4 mls/kg/min FRF/Dx FR = 2 l/1.73 m2/hr SAM = 0.3 m2
Vascular Access • Properly functioning access is key to successful CRRT therapy Adequacy Filter life Decreased blood loss Staff satisfaction
Ideal Catheter Characteristics • Easy insertion • Permits adequate blood flow without vessel damage, large diameter with shortest length • Low resistance, decreased arterial and venous pressures • Minimal technical flaws High recirculation rate Kinking
Vascular Access Placement • Femoral • Internal jugular • Sub-clavian (avoid if possible) • Match catheter size to pt. Size and anotomical site • One dual- or triple-lumen or two single lumen uncuffed catheters
Common Causes of Poor Catheter Flow Rates • Catheter tip position – is the tip in proper placement? • Kink • Tight suture • Clamp • Decreased intrvascular volume • Increased intrathoracic pressure • Thrombosis or fibrin sheath formation
Comparison of Upper Vs. Lower Body Location Line Placement(Kendall 8 Fr 9 and 12 CmN = 20; 120 Treatments) P value NS NS NS NS Gardner et al, CRRT San Diego 1998
(Ca = 0.4 x citrate rate 60 mls/hr) (Citrate = 1.5 x BFR 150 mls/hr) Pediatr Neph 2002, 17:150-154 (BFR = 100 mls/min) Normal Saline Replacement Fluid Calcium can be infused in 3rd lumen of triple lumen access if available. Normocarb Dialysate • ACD-A/Normocarb Wt range 2.8 kg – 115 kg • Average life of circuit on citrate 72 hrs (range 24-143 hrs)
Citrate ~ running it Arterial access Venous access Citrate infusion via “y” adaptor
CaCl infusion line/or TPN/or Med line Venous line “arterial” line
Anticoagulation • Heparin • Initial bolus 10 to 30 mg./ Kg • Continuous infusion of 10 to 30 mg./Kg • Maintain an activated clotting time (ACT) of 180-210 • Risks of heparin anticoagulation: Bleeding Thrombocytopenia
Anticoagulation • Citrate • Citrate infusion to CRRT circuit • Calcium infusion to to patient via separate central line • Monitor post filter ionized calcium, adjust citrate infusion per protocol • Monitor systemic ionized calcium, adjust calcium infusion per protocol • Monitor for metabolic alkalosis and citrate loc
Extracorporeal Circuit Volume • Circuit volumes should be < 10% of the patients intravascular blood volume • Human blood volume formula • < 10kg 80ml/kg • >10kg 70ml/kg • Removal of > 10% blood volume extracorporeal can result in hemodynamic instability (shock)
Blood Priming • Indications Circuit volume >10% of the patients blood volume Hemodynamic instability
Complications of Blood Priming • PRBC from the blood bank tend to have an increased potassium • The HCT of PRBC is around 80% • A 50% dilution with normal saline or 5% albumin should be performed prior to circuit prime • Bradykinin release syndrome may be seen with AN- 69 membranes (brophy,et al 2001ajkd) • System clotting
Blood Priming Methods • More concerning with AN-69 or membranes, less concerns with polysulphone membranes • Zero balance ultrafiltration (Z-BUF) • Normalizes electrolytes and improves acid-base status of the prime prior to pt connection by performing CVVH, CVVHD or CVVHDF for 30 minutes • Hackbarth et al, Peds Neph, 2005 20:1328-33 • Bypass maneuver • The patient is transfused with the PRBC at the same time and rate as the circuit is primed with the patients blood. The NS prime is wasted • Brophy et al, am J kid Dis, 2001 Jul;38(1):173-8
Hypothermia • Significant in pediatrics • The smaller the more difficult • Heat loss related to rate of blood flow and volume of blood in circuit • Blood flow rate • Higher blood flow rate decrease heat loss due to less time outside of the body
Hypothermia Nursing Intervention • External warming devices • Radiant warmers • Baer hugger • Heating mattress • Blood warmers • Solutions heaters • Monitoring • Skin breakdown and patient temperature
Staffing • Staffing ratios • Education • System setup • Pump management • Program management
A National Survey(April Tanner RN, Atlanta Ga, PCRRT 3, Orlando 2004) • An national review of current trends in CRRT • An 18 question survey sent to pediatric centers that offer CRRT • Free-standing or based in adult facility • 42 centers responded
Education • Wide variety of teaching methods • Didactic/hands on skills lab training occurs in 69% of initial training sessions • 12% require mentoring shifts • 17% offer informal training • 7% utilize bedside training methods
Education • Annual recertification - 43% • More frequent recertification occurs 26% • Smaller volume programs • 19% of programs have no formal annual competency or recertification programs • Many centers education programs are under review
Logistics and Coordination of System Set-up • 11 of 42 centers have no formal 24/7 coverage • In 93% of center’s RNs manage the pump • Dialysis, ECMO, and physicians make up the other % • Charge structure • The dept.That sets up equipment receives revenue in majority of centers • 21 of 42 centers also have daily charges • Varied response as to where revenue goes
Conclusion • The education and competency of the bedside staff is essential for successful care of a child on CRRT • No better teacher than the child • Communication to colleagues throughout your program and throughout the world are critical in improvement in over all care