CRRT - Prismaflex Flashcards
List indications for CRRT
(FWWNDOH)
- Fluid overload
- Worsening Acedemia (metabolic acidosis)
- Worsening Azotemia (urea >30mmol/L)
- Nod obstructive oliguria, anuria
- Organ uraemic involvement (↑ body waste product due to multi organ condition E.g - encephalopathy,neuropathy,myopathy)
- Drug overdose
- Hyperkalemia or rapidly increasing K+
What is the 3 principles of CRRT
- Diffusion - movement of S & M size solutes from area of high concetration to lower concentration across a semi permeable membrane (SPM).
- Ultra filtration (UF)- movement of water and solutes across a SPM through solvent drag (from +ve to -ve pressure area) resulted from convection and hydrostatic pressure (HP)
- Convection - movement of solute across SMP by HP which facilitates water flow that drags solutes along with it.
List common sites for VasCath
- IJ - pref R) side due to direct line to Superior Vena Cava (SVC)
- Subclavian - nurses preferred, easy access & cleaning, allows mobility, CXR to confirm position, may cause pneumothorax.
- Femoral - Prone to kinking, doesn’t allow mobility, easier insertion.
May confirm with CXR, Transducer, or ABG
List the 4 modes of CRRT
- SCUF - Slow Continous UF
- CVVH - Cont Veno-Venous Haemofiltration
- CVVHD - Cont Veno-Venous HaemoDialysis
- CVVHDF - Cont Veno-Venous HaemoDiaFiltration
define SCUF
Slow Cont UF - uses principle of UF, used when only goal is fluid removal.
Acces ————( [Filter]-Effluent )———— Return
Define CVVH
Cont Veno-Venous Haemofiltration uses convection & UF to clear water and solutes. Use to remove S, M + L solutes
Acces ——[+PBP]——( [Filter]-Effluent)——[+Post]—— Return
Define CVVHD
Continous Veno-venous Haemodialysis uses principle of Diffusion and UF. Uses dialysate fluid to facilitate diffusion gradient and remove S M sized molecules
Acces ————(-Dialysate-[Filter]-Effluent)———— Return
define CVVHDF
Continous Veno-Venous HaemoDiaFiltration uses all 3 principles of CRRT. Use to remove S, M & L molecules
Acces —[+PBP]-(+Dialysate [Filter]-Effluent)-[+Post]— Return
Define dialysate fluid
Its a synthetic solution which facilitates diffusion gradient that run through counter flow of blood
Define replacement fluids
Pre dilution replacement fluids enhances convection and UF, post dilution enhances diffusion. Replaces fluid lost as ultrafiltrate/effluent.
Define blood flow rate (BFR)
flow rate of blood accessed from patient, starts at 50-100mls/hr to 180-200mls/hr to prevent clottingy
Define effluent fluid
Waste product (solutes) and fluids (solvent) discarded from pt
What is the standard effluent dose?
- 25mls/kg/hr
- (50% dialysate, 200mls Post Replacement Fluid, PBP rest)
- E.G 100kgs.
- 25x100 = 2500mls/hr Effluent dose
- 2500mls = 1250 dialysate, 200mls PRF, 1050 PBP
What are the available CRRT fluids in ICU?
In **mmol/L
1.) Haemosol B0 = Na+ 140/ Ca ²+ 1.75,/ Mg ²+ 0.5/ Cl 109
HCO ³ 32/ Lac 3
2.) Prism0Citrate 18/0 = Citrate 18/ Na+ 140/ Cl 86,/ Nil K+,Cal,Mg
3.) Prism0Cal B22 = HCO ³ 22/ Lac 3/ Na+ 140/ Cl 120/ K+ 4/ Mg 0.5
Glu 6.1
4.) NaCl 0.9% 1L = Replacement Fluid.
Why do we have to add KCL? How much do we add?
- DO NOT ADD IF K+ >5.0 as per ICU Protocol**
- to maintain homeostasis K+ target range = 3.5-5.0 mmol/L
- in Haemosol B0 = add (20mmol/L in 5L bag) total concetration of 4mmol/L in all the bags of fluid.
- in Citrate, Add 20mmols in PBP fluid bag (Prism0Citrate 18/0 - 5L) total concentration of 4mmol/L. Dialysate solution has preadded 20mmols/5L Hence theres no need to add more K+
Demonstrate how to calculate flow rates & setting using non-citrate CRRT.
- 25mls/kg/hr
- (50% dialysate, 200mls Post Replacement Fluid, PBP rest)
- E.G 100kgs.
- 25x100 = 2500mls/hr Effluent dose
- 2500mls = 1250 dialysate, 200mls PRF, 1050 PBP
- Heparin infusion concentration (15000u in 50mls NaCl) run through coagulation port. Commence at 5-10u/kg/hr
- E.G 70kg * 10u = 700u/hr = approx. 2.3mls/hr w/ above concentration
Demonstrate how to calculate flow rates and settings using Citrate anticoagulation CRRT
**Citrate dose = Q Cit (PBP flow rate in ml/min) x C cit (18mmol/L) ÷ BFR (default 150mls/hr)
E.G. = BFR 150
1500 ÷ 60 x 18 / 150 = 3 mmol/hr
**Citrate flow rate (Qc) (mls/min) = Dose of Citrate (3mmol/L) x BFR (150mls/hr) ÷ Citrate Concetration (18mmols/L)
3x 150 ÷ 18 = 25mls/min x 60 (1hr) = 1500
Describe the purpose of anticoagulation in CRRT
- anticoagulation in CRRT = improve CRRT efficiency
(CRRT stimulates coagulation cascade when blood is in contact with artificial filters and tubing) - most commonly used anticoagulation in ICU
- Heparin w/ Haemosol B0 - inhibits factor IX,X,Thrombin= inc clotting time
- Citrate w/ Prism0Citrate 18/0 - binds with Ionised Cal = inhibit clotting cascade.
Differentiate regional and systemic anticoagulation in CRRT.
- Regional = Circuit Anticoagulation = less interruption of therapy
- Systemic = Pt Systemic Coagulation
Indications for CRRT
Pt at risk of bleeding (SHHIC) • recent Surgery or trauma • Haemorrhagic disorder i.e Leukemia, dec PLT • HITS • Intracranial Lesions • uncontrolled Coagulopathy
Explain how Citrate functions as regional coagulant in CRRT
- Blood accessed from pt mixed w/ Citrate during Pre dilution (PBP) which then prevents clotting in the circuit (regional)(by binding to calcium-impedes clotting cascade)of CRRT machine.
Describe fluids that are required during citrate anticoagulation
(OBS)
- Prism0Citrate 18/0 - PBP (Orange)
- Prism0Cal B22 - Dialysate (Black)
- NaCl 0.9% - Post dilution replacement fluid (Saline)
Explain how CRRT machine controls citrate anticoagulation
Machine calculates the Citrate dose in accordance to BFR & PBP flow rate.
Explain the importance of frequent monitoring of blood electrolytes and acid base balance in pt requiring citrate anticoagulation CRRT
- CRRT may cause acid base and electrolyte imbalance due to clearance of small and mid molecules