Practical Considerations for CRRT
Helen Currier RN, BSN, CNNNancy McAfee RN, BSN, CNN
Advantages of CRRT
• SLOW: Hemodynamically unstable patients may not tolerate the rapid ultrafiltration of intermittent hemodialysis
• CONTINUOUS: Can help preserve metabolic stability in critically ill patients; can maintain fluid balance for oliguric patients who require high daily input (IV medications, parenteral nutrition)
CVVH SYSTEM
Venous chamber
Replacement fluid
Heparin Drainage bag/UF
From the patient
To the patient
Roller pump
Hemofilter
IV pump
Air detector
bm14 roller pump
Roller pump
Venous chamber
Replacement fluid
Heparin
Drainage bag/UF
From the patient
To the patient
Roller Pump
Hemofilter
IV pump
Dialysate
IV pump
Air detector
bm14 roller pump
Roller Pump
CVVHD SYSTEM
Success with CRRT
• Access• Equipment• Tubing/filter• Prime• Anticoagulation• Staffing
Access-What Works?
• Hemodialysis /Pheresis Line• Shortest, fattest catheter possible
(highest flows with least resistance)
• May need two single lumen lines
• Leg position-be creative
• Tape on the skin-may need to get creative
Blood Pump Systems for
CRRT
CRRT Machines: Current Generation
Tubing and Equipment
• Tubing volume ranges from 44-110 ml
• Filter volume ranges from 28 – 83 ml
• Hotline volume 18.5 ml
• Blood volume of patient (~70 ml/kg)
• PRISMA – 108 ml
• BM-25 -Smallest filter + tubing + hotline = 90.5 ml
Extracorporeal Volume
• Blood volume in extracorporeal circuit is very large compared to a small infant or child
• Patients require a blood prime if the circuit >10% of their blood volume
Blood Prime
• Whole blood• PRBC + Albumin 5%• PRBC + NS• PRBC + FFP• Larger patients Albumin 5%• AN-69 filter requires special
considerations
• What is the link– Blood bank blood has
• ICa of 0.04 mmol/l• K+ of 40-60 mEq/l• pH of 6.4
• Reaction can be mitigated by buffering the blood and giving IV calcium at initiation
Bradykinin Release Syndrome
(Brophy et al Am J Kidney Dis. 2001 Jul;38(1):173-8 )
Buffered System
• ECMO circuits are commonly primed with a cocktail to correct the pH, Hct, and K of banked blood – Addition of THAM
– calcium chloride – Heparin– Sterile Water– Sodium bicarb
Bypass System
• Transfuse the PRBC post-filter directly into the patient
• The patient is then connected to the circuit
• Using the same rate for priming on and infusing the PRBC (mixed with NS or Alb)
• Thus the patient’s blood can be used as a “bradykinin filter” (Brophy,et al 2001AJKD)
Thermal Regulation
• Hotline® Blood warming tubing• Place at venous return to patient• Leave on at constant
temperature of 39o C• Treat temp elevations if they
occur
Anticoagulation
Heparin• Heparin bolus then
continuous infusion• Maintain activated
clotting time (ACT) ~200
• Risk of bleeding, thrombocytopenia
Citrate
• Citrate infusion to CRRT circuit
• Calcium infusion to patient at separate site
• Monitor for metabolic alkalosis
CRRT Staffing in PICU/IICU
• Nephrology/Dialysis RN sets-up & initiates therapy
• PICU/IICU RN manages patient• Nephrology/Dialysis RN on call 24/7• Acuity assigned to pump as if a
separate patient• Staffing determined by acuity
3rd International Conference on Pediatric Continuous Renal
Replacement Therapy (PCRRT)
June, 2004Coronado Springs Disney Orlando,
Flwww.pcrrt.com
CRRT Modalities
• CAVH: Continuous Arteriovenous Hemofiltration
• SCUF: Slow Continuous Ultrafiltration
• CVVH: Continuous Venovenous Hemofiltration
• CVVHD: Continuous Venovenous Hemodialysis
bm25™: Blood Pump Module
• Blood monitor– Blood flow rate:
30-350 mL / min
-- Safety features: pressure monitors
air detector
clot trap
venous clamp
blood leak detector
bm25™: Fluid Control Module
• Balancing monitor– Substitution pump / filtrate
pump– Integrated scales– Fluid heater– TMP monitor
– Operational ranges• Replacement fluid 300-
9000 mL/hr • Filtrate pump 100 - 11,000
mL/hr• Net UFR 0.1 – 2000 mL/hr
• 2 integrated modules
– Blood module (bm 11a™)
– Balancing module / scales (bm14™)
Baxter bm25™
CRRT Modalities
• CAVH: Continuous Arteriovenous Hemofiltration
• SCUF: Slow Continuous Ultrafiltration
• CVVH: Continuous Venovenous Hemofiltration
• CVVHD: Continuous Venovenous Hemodialysis
bm25™: Blood Pump Module
• Blood monitor– Blood flow rate:
30-350 mL / min
-- Safety features: pressure monitors
air detector
clot trap
venous clamp
blood leak detector
bm25™: Fluid Control Module
• Balancing monitor– Substitution pump / filtrate
pump– Integrated scales– Fluid heater– TMP monitor
– Operational ranges• Replacement fluid 300-
9000 mL/hr • Filtrate pump 100 - 11,000
mL/hr• Net UFR 0.1 – 2000 mL/hr
• 2 integrated modules
– Blood module (bm 11a™)
– Balancing module / scales (bm14™)
Baxter bm25™
CVVH SYSTEM
Venous chamber
Replacement fluid
Heparin Drainage bag/UF
From the patient
To the patient
Roller pump
Hemofilter
IV pump
Air detector
bm14 roller pump
Roller pump
Venous chamber
Replacement fluid
Heparin
Drainage bag/UF
From the patient
To the patient
Roller Pump
Hemofilter
IV pump
Dialysate
IV pump
Air detector
bm14 roller pump
Roller Pump
CVVHD SYSTEM