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
Explain Citrate toxicity and how to monitor it.
Citrate toxicity occurs when liver can not metabolise citrate which manifest as decreased in Ionised Cal
**Monitor for Citrate Triad
• metabolic acidosis
• increased in anion gap
• high total to ionised calcium ratio (>2.5)
- hypercalcaemia
- increasing cal replacement requirement
Q4H - Q6H EUC + ABG to check ionised cal
Explain why Calcium replacement is necessary and how to administer and monitor it.
- Cal is metabolised when binded by Citrate therefore need to be replaced
- Commence at 100% replacement then perform ABG 1 hour post commencement Q4H afterwards.
Why is Ionised Cal being measured in Citrate CRRT?
• monitoring via ABG, decreasing iCal level can be an indication of Citrate toxicity and also to avoid Hypercalcaemia.
Describe how Heparin function as anticuagulation agent in CRRT
Heparin binds and activate circulating antithrombin III → inhibits thrombin, factor IX & X → results in ↑ clotting time.
- most commonly used
- inexpensive & widely available, easy to monitor & reversed (protamine)
- optimal regime available
- must be administered by cautious balance b/w therapeutic benefits of preventing clot of the CRRT circuit & risk of systemic bleeding
State the types of fluids used w/ non-citrate anticoagulation Tx.
CRRT circuit primed using 1L 0.9% NaCl w/ 5000u of Heparin.
- additional Heparin infusion through Anticoagulation port to maintain APTT (30-40secs-sample collected from pt Artline)
Haemosol B0 - PBP,Dialysate & Post Replacement Fluid
Describe method of monitoring and adjusting heparin Tx in pt requiring heparin CRRT
Dose commence at 5-10u/kg/hr approx 3.3mls/hr (15k U/50mls)
Maintain APTT 30-40secs-blood sample collected from pt Artline
Recheck in 4-6 hours post commencement
Describe how to safety connect CRRT machine to a patient.
- Use asceptic technique + sterile gloves when connecting lines to pt.
- Aspirate and discard 5mls ea line to remove heparin from line
- Further aspirate 10mls ea line, flush 10mls NaCl 0.9%- check ease of blood flow
- Connect RED port - ACCESS, BLUE port - RETURN, Cal syringe - CVC
- Follow PRISMAFLEX instruction - Ensure to unclamp circuit lines then press START.
- Check iCa 1 hour post commencement
Describe safely returning blood in case of cessation of CRRT or temporary stopping of Tx (OT, changing circuit, no longer needed)
- use asceptic technique w/ sterile gloves
- press STOP → Auto Return or Saline Recirc → d/c red access fr Vascath → connect to a 3 way tap which is spike to 1L NaCl 0.9%
- flush return line 10mls NaCl 0.9%
- Heparin lock the Vascath (5k U/ml - inject as per lumen indication), label the Vascath ‘Heparin locked’
Explain the possible causes for the following alarms
- Access Pressure (normally -ve)
- Return Pressure (normally +ve)
- Filter Pressure
• Access pressure extreme -ve pressure alarm
- Line clamped, kinked, obstructed
- VasCath obstructed
- pt movement, coughing or being suctioned
- BFR too high
• Access extremely +ve
- Red clamp is closed
- obstructed/kinked VasCath or Access Line
- Pt coughing, moving, positioning.
- BFR too low
• Return Pressure
- Blue clamp is closed
- Obstructed/kinked VasCath or Access Line ? Clot
- Pt coughing, moving, positioning.
- BFR too high
- High Airway Pressure
- Filter clotting/clotted
• Filter Pressure
- Filter clotting/clotted
Explain strategies to improve filter life.
- Ongoing TMP monitoring
- Regular Check of APTT
- Increase BFR, PBP rate
Explain Strategy to improve clearance
- Increase BFR - utilises UF
- Increase PBP - Utilises Convection
- Increase Effluent Dose.
Describe the possible complications of associated with CRRT
HHATCHI
• Hypothermia
• Hypomagnesaemia, HypoKalaemia, Hypophosphataemia
• Anemia
• Thrombocytopaenia
• Coagulopathy - Bleeding (overheparinisation) regular check of APTT
• HITS - Heparin induced thrombocytopaenia
• Infection
Discuss Nx Strategy in managing pt requiring CRRT
- Hourly Obs (Haemodynamics, RR, SpO2)
- CRRT hourly monitoring, OBS (BFR, Fluid removal, & Line Pressures)
- Monitoring APTT / iCa as per protocol + regular EUC CMP.
- Monitoring for any signs of Citrate Toxicity. (Triad Cit Tox)
- Appropriate documentation
- Monitor for complications (HHATCHI)
have metaraminol + NaCl 0.9% pump set ready when starting CRRT
What are the signs of the Triad of Citrate Toxicity?
• Metabolic Acidosis w/ high Anion Gap • Increasing totCal/iCal ration (>2.5:1) • Cal Gap phenomenon - ↓ iCal - ↑ Calcium replacement requirement - HyperCal -
Discuss the importance of regular monitoring of blood electrolytes and acid-base balance
- Regular check of EUC/CMP can minimise risk of arrhythmia
* Also help early identify Citrate toxicity
Why do we need to have pt temperature monitored?
CRRT can induced hypothermia due to blood being exposed to extracorporeal circuit outside the body.
- use active warming and/or warming blanket when required is suggested.
