Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal...

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Continuous Renal Continuous Renal Replacement Therapy - Replacement Therapy - CRRT CRRT

Transcript of Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal...

Page 1: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Continuous Renal Continuous Renal Replacement Therapy -Replacement Therapy -

CRRTCRRT

Page 2: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Classical ‘renal’ indications for starting Classical ‘renal’ indications for starting renal replacement therapy (RRT) are:renal replacement therapy (RRT) are:

Rapidly rising serum urea and creatinine Rapidly rising serum urea and creatinine or the development of uraemic or the development of uraemic complicationscomplications

Hyperkalaemia unresponsive to medical Hyperkalaemia unresponsive to medical managementmanagement

Severe metabolic acidosisSevere metabolic acidosis

Diuretic resistant pulmonary oedemaDiuretic resistant pulmonary oedema

Oliguria or anuriaOliguria or anuria

Page 3: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

‘‘Non renal’ indications for Non renal’ indications for starting RRT are:starting RRT are:

Management of fluid balance e.g. in Management of fluid balance e.g. in cardiac failurecardiac failure

Clearing of ingested toxinsClearing of ingested toxins Correction of electrolyte abnormalitiesCorrection of electrolyte abnormalities Removal of inflammatory mediators in Removal of inflammatory mediators in

sepsis?sepsis? RhabdomyolysisRhabdomyolysis

Page 4: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Diffusion- Diffusion- movement of solutes across a semi movement of solutes across a semi permeable membrane through a concentration permeable membrane through a concentration

gradientgradientGood for smaller sized moleculesGood for smaller sized molecules

Page 5: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Convection-Convection- movement of fluid across a movement of fluid across a semi permeable membrane creating a solute semi permeable membrane creating a solute

drag.drag.Good for smaller and middle sized moleculesGood for smaller and middle sized molecules

Page 6: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.
Page 7: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

When to start RRTWhen to start RRT Conventional starting criteria for RRT should be

used

Treatment should be started before complications develop- Earlier the better!

The rate of change of urea and creatinine is more significant than their absolute levels, however in most cases RRT should be started before urea is 20 – 30 mmol/L.

Initiation of RRT on the basis of fluid balance, urine output, potassium level or degree of acidosis will be dependent on the patient’s clinical condition.

Page 8: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

What type of RRTWhat type of RRT

SCUFSCUF CVVHCVVH CVVHDFCVVHDF CVVHDCVVHD SLED(D)SLED(D)

Page 9: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Ultrafiltration-UFUltrafiltration-UF

Page 10: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

CVVHCVVH

Page 11: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

CVVHDFCVVHDF

a blood pump a blood pump provides solute provides solute removal by removal by diffusion diffusion and convectionand convection simultaneously.simultaneously.

It offers high volume It offers high volume ultrafiltration using ultrafiltration using replacement fluid replacement fluid which can be which can be administered pre-administered pre-filter/ post-filter. filter/ post-filter.

Simultaneously, Simultaneously, dialysate is pumped in dialysate is pumped in counter flow to blood. counter flow to blood.

Page 12: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

CVVH v CVVHDFCVVH v CVVHDF There is no evidence to suggest that CVVH is There is no evidence to suggest that CVVH is

superior to CVVHDF in terms of patient superior to CVVHDF in terms of patient outcome or renal outcome (or vice versa).outcome or renal outcome (or vice versa).

With CVVHDF -UF flow rates may be reduced With CVVHDF -UF flow rates may be reduced therefore larger molecule removal by therefore larger molecule removal by convection is decreasedconvection is decreased

If adequate UF rates cannot be achieved If adequate UF rates cannot be achieved using CVVH due to machine limitations, then using CVVH due to machine limitations, then CVVHDF should be considered.CVVHDF should be considered.

A predominantly convective mode of A predominantly convective mode of clearance may be considered in severe clearance may be considered in severe sepsissepsis

Page 13: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Solute clearance- depends onSolute clearance- depends on Blood flowBlood flow RecirculationRecirculation Membrane characteristics- type of filterMembrane characteristics- type of filter Filter clotting- aim for 85% of prescribed Filter clotting- aim for 85% of prescribed

dosedose Pre/post dilution Pre/post dilution

The removal of potassium, correction of The removal of potassium, correction of acidosis or the removal of fluid may have acidosis or the removal of fluid may have just as much of an impact on patient just as much of an impact on patient outcome as solute clearance.outcome as solute clearance.

Page 14: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Pre filter dilutionPre filter dilution

Page 15: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Post filter dilutionPost filter dilution

Page 16: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Ultrafiltration flow ratesUltrafiltration flow rates Moves towards higher UF ratesMoves towards higher UF rates

Too low reduces clearance of solutesToo low reduces clearance of solutes

Too high- affect membrane Too high- affect membrane performanceperformance

Filtration fraction <25%Filtration fraction <25%

Page 17: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Ultrafiltration RatesUltrafiltration Rates Ronco et al (2000) large prospective studyRonco et al (2000) large prospective study

Suggestion that a higher level of solute clearance was Suggestion that a higher level of solute clearance was beneficial at higher UF rates. (35 mls/kg/hr)beneficial at higher UF rates. (35 mls/kg/hr)

American Acute Renal Failure Trials Network (ATN American Acute Renal Failure Trials Network (ATN study, 2008), did not find any difference in survival, study, 2008), did not find any difference in survival, rate of renal recovery or nonrenal organ failure in rate of renal recovery or nonrenal organ failure in ‘intensive’ versus ‘less-intensive’ renal support.‘intensive’ versus ‘less-intensive’ renal support.

The Australian/NZ RENAL study (Randomised The Australian/NZ RENAL study (Randomised Evaluation of Normal vs. Augmented Level of renal Evaluation of Normal vs. Augmented Level of renal replacement therapy in ICU, 2009) compared 40 replacement therapy in ICU, 2009) compared 40 ml/kg/h to 25 ml/kg/h of ultrafiltrate production in ml/kg/h to 25 ml/kg/h of ultrafiltrate production in CVVHDF. No difference in terms of outcome.CVVHDF. No difference in terms of outcome.

Page 18: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.
Page 19: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.
Page 20: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Points for considerationPoints for consideration

Replacement fluid Replacement fluid Membrane Membrane Anticoagulation Anticoagulation Flow rates- vascular accessFlow rates- vascular access Temperature managementTemperature management Drug dose adjustmentDrug dose adjustment

Page 21: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

ReplacementReplacement fluid fluid Composition similar to normal serum Composition similar to normal serum

electrolyteselectrolytes

Bicarbonate/lactate buffer.Bicarbonate/lactate buffer.

The individual components of filtration fluid The individual components of filtration fluid

vary but phosphate and potassium vary but phosphate and potassium supplementation is often needed.supplementation is often needed.

Bicarbonate may trigger inflammatory Bicarbonate may trigger inflammatory mediators, an undesirable side effect in the mediators, an undesirable side effect in the critically ill and could theoretically be harmful.critically ill and could theoretically be harmful.

Page 22: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

MembranesMembranes High surface areaHigh surface area Used to be cellulose, now synthetic Used to be cellulose, now synthetic

biocompatablebiocompatable Pore size affects solute transferPore size affects solute transfer Phosphates are lost at the same rate as Phosphates are lost at the same rate as

ureaurea Doesn’t clear protein bound molecules eg Doesn’t clear protein bound molecules eg

midazolammidazolam Doesn’t secrete toxins like a tubular cellDoesn’t secrete toxins like a tubular cell Removes glucoseRemoves glucose Future ? Bioartificial kidney with human Future ? Bioartificial kidney with human

tubular cells lining hollow fiberstubular cells lining hollow fibers

Page 23: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.
Page 24: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

AnticoagulationAnticoagulation

Page 25: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

AnticoagulationAnticoagulation

No anticoagulationNo anticoagulation UFH unfractioned heparinUFH unfractioned heparin LMWH low molecular weight heparin-LMWH low molecular weight heparin-

FragminFragmin ProstacyclinProstacyclin CitrateCitrate OthersOthers

Page 26: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

No AnticoagulationNo Anticoagulation

Increased risk of clottingIncreased risk of clotting Increased consumption of clotting factors Increased consumption of clotting factors

and plateletsand platelets Short circuit lifeShort circuit life

Preventative MeasuresPreventative Measures Pre-dilutionPre-dilution High FlowHigh Flow Aim for Filtration fraction of 25% or lessAim for Filtration fraction of 25% or less

Page 27: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

HeparinHeparin

Occurs naturally in human mast cells within the Occurs naturally in human mast cells within the connective tissue of the blood vessels, liver and connective tissue of the blood vessels, liver and lungs.lungs.

Results seen instantly with a half-life of 30 Results seen instantly with a half-life of 30 minutes – 2hoursminutes – 2hours

reversal with protamine sulphate but Fresh reversal with protamine sulphate but Fresh Frozen Plasma remains the definitive treatment.Frozen Plasma remains the definitive treatment.

Heparin induced Thrombocytopaenia (HIT)Heparin induced Thrombocytopaenia (HIT)

Keeling, D (2006) The management of heparin-induced thrombocytopenia Keeling, D (2006) The management of heparin-induced thrombocytopenia British Society for British Society for HaematologyHaematology 133: p259-269 133: p259-269

Page 28: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

HeparinHeparin Used in patients with normal coagulation profile, Used in patients with normal coagulation profile,

normal platelet count and not at risk of bleedingnormal platelet count and not at risk of bleeding

The most commonly used anticoagulation for CVVH.The most commonly used anticoagulation for CVVH.

Its cheap, effective and well tolerated.Its cheap, effective and well tolerated.

APTT and platelet counts routinely measuredAPTT and platelet counts routinely measured ((no consensus on the frequency of testing -no consensus on the frequency of testing -APTT does APTT does

not always reflect the anticoag effect of heparinnot always reflect the anticoag effect of heparin))

(There is no correlation between increasing APTT (There is no correlation between increasing APTT and filter life)and filter life)

Page 29: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

FragminFragmin

No evidence that it is superior to No evidence that it is superior to Unfractioned heparin in terms of efficacy or Unfractioned heparin in terms of efficacy or risk of side effectsrisk of side effects

Extended half lifeExtended half life

Less risk of HITLess risk of HIT

lack of reliable predictors of bleeding and lack of reliable predictors of bleeding and antithrombotic activityantithrombotic activity

Page 30: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

EpoprostenolEpoprostenol (prostacyclin, (prostacyclin, Flolan®)Flolan®)

Considerable use in IHD and CVVHConsiderable use in IHD and CVVH

Inhibits platelet aggregation Inhibits platelet aggregation

Can use in thrombocytopeniaCan use in thrombocytopenia

50% reduction in bleeding therefore 50% reduction in bleeding therefore beneficial with high risk of patientsbeneficial with high risk of patients

Short half life of 3 minutes Short half life of 3 minutes

IHD= intermittant haemodialysisIHD= intermittant haemodialysis

Page 31: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

EpoprostenolEpoprostenol (prostacyclin, (prostacyclin, Flolan®)Flolan®)

Common concernsCommon concerns Expensive and has powerful vasodilator Expensive and has powerful vasodilator

propertiesproperties Side effects of hypotension, flushing and Side effects of hypotension, flushing and

headache.headache. There is no reliable laboratory test to There is no reliable laboratory test to

quantify the anticoagulation effectquantify the anticoagulation effect Its not effective for filter membrane fouling Its not effective for filter membrane fouling

due to fibre clottingdue to fibre clotting

Page 32: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

CitrateCitrate

Citrate binds with calcium and makes it Citrate binds with calcium and makes it unavailable for clotting cascade so need tounavailable for clotting cascade so need to

-monitor serum calcium and give calcium -monitor serum calcium and give calcium infusioninfusion

-monitor sodium and acid-base status as -monitor sodium and acid-base status as citrate to bicarbonate.citrate to bicarbonate.

Suggestion that citrate prolongs CRRT Suggestion that citrate prolongs CRRT time and reduces need for blood time and reduces need for blood transfusions and/or haemorrhagetransfusions and/or haemorrhage

Page 33: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

OthersOthers

Danaparoids; Fondaparinux- little Danaparoids; Fondaparinux- little experience of use in CVVH; monitor anti experience of use in CVVH; monitor anti Xa levelsXa levels

Recombinant hirudin and argatroban are Recombinant hirudin and argatroban are direct thrombin inhibitors. Experience with direct thrombin inhibitors. Experience with these drugs is limited, but increasing and these drugs is limited, but increasing and they may have pharmacological they may have pharmacological advantages.advantages.

Page 34: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Vascular accessVascular access

Usually double D or D/O x sectionUsually double D or D/O x section >11FG for blood flows >200-250ml/min>11FG for blood flows >200-250ml/min Polyurethane- 3 weeksPolyurethane- 3 weeks Jugular -Right side less recirculationJugular -Right side less recirculation ? subclavian? subclavian Femoral catheters shorter than 20cm Femoral catheters shorter than 20cm

associated with increase recirculationassociated with increase recirculation

Page 35: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

HypothermiaHypothermia

Do the following have any place in Do the following have any place in preventing hypothermia ?preventing hypothermia ?

Wrap circuit Wrap circuit

Fluid warmerFluid warmer

Systemic warmingSystemic warming

Page 36: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

HypothermiaHypothermia

Do the following have any place in Do the following have any place in preventing hypothermia ?preventing hypothermia ? Wrap circuit Wrap circuit NONO Fluid warmerFluid warmerNONO Systemic warmingSystemic warmingthe only available optionthe only available option

Page 37: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Blood RequestsBlood Requests

Due to the high volumes of filtration Due to the high volumes of filtration fluid with the increased pump speed fluid with the increased pump speed and UF rates we need to monitor and UF rates we need to monitor phosphate and calcium daily phosphate and calcium daily

Bloods for U & E, FBC, Clotting- Bloods for U & E, FBC, Clotting- minimumminimum

dailydaily

Page 38: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

TROUBLE SHOOTINGTROUBLE SHOOTING

Connections top/bottom filter!Connections top/bottom filter!

Air detectorAir detector

Heparin infusion pumpHeparin infusion pump

Vascular accessVascular access

AlarmsAlarms

Page 39: Continuous Renal Replacement Therapy -CRRT. Classical ‘renal’ indications for starting renal replacement therapy (RRT) are: Rapidly rising serum urea.

Thank YouThank You