CRRT

CRRT

By Courtney Chastain MSN, RN, ACCNS-AG, CCRN-CMC-CSC

Objectives

• Understand use of CRRT in the critical care

• Understand the components of the NxSWtage System One

• Understand hemodynamics associated witht eh CRRT patient

• Understand management of the patient on CRRT

• Learn troubleshooting techniques for the NxStage System One

Why CRRT?

• CRRT is an extracorpeal blood purification therapy designed to replace kidney function

• ​Mimics native kidney function

• Removes fluids, ​wastes, and uremic toxins over a continuous time frame in a slower, controlled manner

• Dialysis of choice for critically ill, hemodynamically unstable patients with or without AKI or CKD

​Indications for CRRT

• Electrolyte abnormalities

• Acid-base disturbances

• Uremia

• Toxin ingestion

• Intolerance to intermittent hemodialysis (HD)

• Hypervolemic or edematous pts. unresponsive to diuretics​

• Better for rapid solute or electrolyte correction

• Rapid shifts cause altered perfusion and instability

• Blood flow 300-400 mL/min

• Fluid removal 1-4 L/tx

​Intermittent HD

• ​Slower and better-tolerated

• Slower electrolyte and fluids shifts​

• ​Only done in ICU

• Blood flow 150-300 mL/min

• ​Fluid removal 0-100 mL/hr

​CRRT

CRRT vs Intermittent HD

​CRRT Therapy Modes

• CVVH (Continuous venovenous hemofiltration)

  • ​Uses ultrafiltration, convection and solute removal

• CVVHD (Continuous venovenous hemodialyis)

  • Uses ultrafiltration, diffusion, solute removal

• CVVHDF (Continuous venovenous hemodiafiltration)

  • Uses ultrafiltration, convection, diffusion, solute removal

• SCUF (Slow, continuous ultrafiltration)

  • Uses ultrafiltration only​

​Ultrafiltration

• Fluids move across membranes when the pressure gradient changes

  • Ex.-squeezing a sponge increases pressure in the sponge and water comes out

  • When blood is squeezed through a filter, the fluid crosses the membrane and is pushed out

​Convection

• ​Provided by therapy fluid

• The water drag that moves solutes from the blood compartment to the waste compartment

• Allows larger molecules to cross the semipermeable membrane​

• Can be useful in removing inflammatory mediators in sepsis​

​CVVH

​Diffusion

• Movement of solutes from area of higher concentration to lower concentration

• How solute removal occurs

  • Solutes-electrolytes, acids, creatinine, BUN

• Dialysate solution provides the gradient for diffusion

Subject | Subject

Some text here about the topic of discussion

​CVVHD

​Adsorption

• Binding of molecules and solutes to a surface

• Insluin, some antiobiotics, anticoagulants, and some inflammatory mediators adhere to the filter

• Anticoagulation is usually given to reduce the activation of the clotting cascade

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​Anticoagulation

• Anticoagulation is often given pre-filter to reduce adsorption

• Heparin at a set rate of 500-1000 units/hr is often given

  • PTT monitoring is same as titratable heparin

  • Pharmacy will help convert unit/hr to unit/kg/hr to program pump

• ​Argatroban alternative to heparin in case of HIT or heparin allergy

Catheter Maintenance

• When opening dialysis line, both patient and nurse should be masked

• Unless ordered otherwise, catheter is to be packed with Heparin 1,000 u/mL in each line

• Dialysis ports MUST be capped at all times when not connected to a machine

• Sterile dressing changes are performed every 7 days and prn​

NxStage System One

User Interface

User Interface

Therapy Summary Screen

History Screen

Starting CRRT

• ​Clear all pumps and empty all foleys/drains

  • Enter these into I&O

• Take total intake ​and add/subtract net gain/loss

  • That is your starting ​net UF

• Next top of the hour, start your hourly readings

Troubleshooting

Filter Clotting-Assessment​