SlideShare a Scribd company logo
1 of 46
RENAL REPLACEMENT
THERAPIES IN CRITICAL CARE
DR YOGESH RATHOD
CHRISTIAN MEDICAL COLLEGE, VELLORE.
TOO MANY QUESTIONS?
• What therapy should we use?
• When should we start it?
• What are we trying to achieve?
• How much therapy is enough?
• When do we stop/switch?
• Can we improve outcomes?
Does the literature help us?
RENAL FAILURE OF ANY CAUSE
Many physiologic derangements:
• Homeostasis of water and electrolytes as the excretion of the daily
metabolic load of fixed hydrogen ions is no longer possible.
• Toxic end-products of nitrogen metabolism (urea, creatinine, uric acid,
among others) accumulate in blood and tissue.
• Endocrine organ dysfunction and failing production of erythropoietin and
1,25 dihydroxycholecalciferol (calcitriol).
EVALUATING ARF
• Severity of ARF/AKI should not be estimated from measurements of blood urea
or creatinine alone .
• Cockcroft & Gault equation or MDRD eGFR or reciprocal creatinine plots should
not be used when the GFR is <30 mL/min or to determine the need for acute
RRT.
AKI CLASSIFICATION SYSTEMS 1: RIFLE
Bellomo R, Ronco C, Kellum JA, et al. Acute renal failure - definition, outcome measures, animal models, fluid therapy and information
technology needs: the second International Consensus Conference of the Acute Dialysis Initiative (ADQI) group. Crit Care 2004; 8: R204–R212.
AKI CLASSIFICATION SYSTEMS 2: AKIN
Stage Creatinine criteria Urine output criteria
1
1.5 - 2 x baseline (or rise > 26.4
mmol/L)
< 0.5 ml/kg/hour for > 6 hours
2 >2 - 3 x baseline < 0.5 ml/kg/hour for > 12 hours
3
> 3 x baseline (or > 354 mmol/L
with acute rise > 44 mmol/L)
< 0.3 ml/kg/hour for 24 hours or
anuria for 12 hours
Patients receiving RRT are Stage 3 regardless of creatinine or urine output
Mehta RL, Kellum JA, Shah SV, et al. Acute Kidney Injury Network: report of an
initiative to improve outcomes in acute kidney injury. Crit Care 2007;11:R31.
PROPOSED INDICATIONS FOR RRT
• Oliguria < 200ml/12 hours
• Anuria < 50 ml/12 hours
• Hyperkalaemia > 6.5 mmol/L
• Severe acidaemia pH < 7.0
• Uraemia > 30 mmol/L
• Uraemic complications (pericarditis, nausea, vomiting, poor appetite,
hemorrhage, lethargy, malaise, somnolence, stupor, coma, delirium, asterixis,
tremor, seizures)
• Dysnatraemias > 155 or < 120 mmol/L
• Hyper/(hypo)thermia
• Drug overdose with dialysable drug
• Refractory hypertension
Lameire, N et al. Lancet 2005; 365: 417-430
“NON-RENAL” INDICATIONS
• TO GET RID OF Substances with higher degrees of protein binding
and sometimes for substances with very long plasma half-lives.
• In general, the size of the molecule and the degree of protein
binding determines the degree to which the substance can be
removed (i.e. smaller, nonprotein bound substances are easiest to
remove).
• RRT can be used as sorbent hemoperfusion for substances that
include drugs, poisons, contrast agents, and cytokines.
ACUTE KIDNEY INJURY IN THE ICU
• AKI is common: 3-35%* of admissions
• AKI is associated with increased mortality
• “Minor” rises in Cr associated with worse outcome
• AKI developing after ICU admission (late) is associated
with worse outcome than AKI at admission
• AKI requiring RRT occurs in about 4-5% of ICU
admissions and is associated with worst mortality risk
**
* Brivet, FG et al. Crit Care Med 1996; 24: 192-198
** Metnitz, PG et al. Crit Care Med 2002; 30: 2051-2058
MORTALITY BY AKI SEVERITY
Clermont, G et al. Kidney International 2002; 62: 986-996
THE IDEAL RENAL REPLACEMENT
THERAPY
• Allows control of intra/extravascular volume
• Corrects acid-base disturbances
• Corrects uraemia & effectively clears “toxins”
• Promotes renal recovery
• Improves survival
• Is free of complications
• Clears drugs effectively (?)
INTERMITTENT THERAPIES - PROS
(Relatively) Inexpensive
Flexible timing allows for mobility/transport
Rapid correction of fluid overload
Rapid removal of dialyzable drugs
Rapid correction of acidosis & electrolyte
abnormality
Minimises anticoagulant exposure
Intermittent Therapies - CONS
Hypotension 30-
60%
Cerebral oedema
Limited therapy duration
Renal injury & ischaemia
Gut/coronary ischaemia
INTRADIALYTIC HYPOTENSION:
RISK FACTORS
• LVH with diastolic dysfunction or LV systolic dysfunction / CHF
• Valvular heart disease
• Pericardial disease
• Poor nutritional status / hypoalbuminaemia
• Uraemic neuropathy or autonomic dysfunction
• Severe anaemia
• High volume ultrafiltration requirements
• Predialysis SBP of <100 mm Hg
• Age 65 years +
• Pressor requirement
MANAGING INTRA-DIALYTIC
HYPOTENSION
• Dialysate temperature modelling
• Low temperature dialysate
• Dialysate sodium profiling
• Hypertonic Na at start decreasing to 135 by end
• Prevents plasma volume decrease
• Midodrine if not on pressors
• Colloid/crystalloid boluses
• Sertraline (longer term HD)
2005 National Kidney Foundation K/DOQI GUIDELINES
CONTINUOUS THERAPIES - PROS
Haemodynamic stability => ?? better renal
recovery
Stable and predictable volume control
Stable and predictable control of chemistry
Stable intracranial pressure
Disease modification by cytokine removal
(CVVH)?
Continuous Therapies - CONS
Anticoagulation requirements
Higher potential for filter clotting
Expense – fluids etc.
Immobility & Transport issues
Increased bleeding risk
High heparin exposure
RRT MOLECULAR
TRANSPORT MECHANISMS
• Ultrafiltration
• Diffusion
• Convection
• Adsorption
Fluid Transport
Solute Transport
}
SEMI-PERMEABLE MEMBRANES
• Semi-permeable membranes are the basis of all
blood purification therapies.
• They allow water and some solutes to pass
through the membrane, while cellular
components and other solutes remain behind.
• The water and solutes that pass through the
membrane are called ultrafiltrate.
• The membrane and its housing are referred to as
ULTRAFILTRATION
• Ultrafiltration is the passage of fluid through a membrane under
a pressure gradient.
• Pressures that drive ultrafiltration can be positive, that is the
pressure pushes fluid through the filter.
• They can also be negative, there may be suction applied that
pulls the fluid to the other side of the filter.
• Also osmotic pressure from non-permeable solutes.
• The rate of UF will depend upon the pressures applied to the
filter and on the rate at which the blood passes through the filter.
• Higher pressures and faster flows increase the rate of
ultrafiltration.
• Lower pressures and slower flows decrease the rate of
ultrafiltration.
Blood Out
Blood Into waste
(to patient)
(From patient)
HIGH PRESSLOW PRESS
Fluid Volume
Reduction
ULTRAFILTRATION
DIFFUSION
• Diffusion is the movement of a solute across a
membrane via a concentration gradient.
• For diffusion to occur, another fluid must flow on the
opposite side of the semi-permeable membrane. In
blood purification this fluid is called dialysate.
• Solutes always diffuse across a membrane from an
area of higher concentration to an area of lower
concentration until equilibration.
HAEMODIALYSIS: DIFFUSION
Dialysate In
Dialysate Out
(to waste)
Blood Out
Blood In
(to patient)
(from patient)
HIGH CONCLOW CONC
CONVECTION
• Convection is the movement of solutes through a
membrane by the force of water (“solvent drag”).
• Convection is able to move very large molecules if the
flow of fluid through the membrane is fast enough.
• In CRRT this property is maximized by using
replacement fluids.
• Replacement fluids are crystalloid fluids administered
at a fast rate just before or just after the blood enters
the filter.
to waste
HIGH PRESSLOW PRESS
Repl.
Solution
HAEMOFILTRATION:
CONVECTION
Blood Out
Blood In
(to patient)
(from patient)
ADSORPTION
• Adsorption is the removal of solutes from the blood
because they cling to the membrane.
• In blood purification. High levels of solute/molecule
adsorption can cause filters to clog and become ineffective.
ADSORPTION
• Molecular adherence to the surface or interior of the
membrane.
MOLECULAR WEIGHTS
Daltons
 Inflammatory Mediators (1,200-40,000)
“small”
“middle”
“large”
MAJOR RENAL REPLACEMENT TECHNIQUES
Intermittent ContinuousHybrid
IHD
Intermittent
haemodialysis
IUF
Isolated
Ultrafiltration
SLEDD
Sustained (or slow)
low efficiency daily
dialysis
SLEDD-F
Sustained (or slow)
low efficiency daily
dialysis with filtration
CVVH
Continuous veno-
venous haemofiltration
CVVHD
Continuous veno-
venous haemodialysis
CVVHDF
Continuous veno-
venous
haemodiafiltration
SCUF
Slow continuous
ultrafiltration
CRRT TREATMENT GOALS
• The concept behind CRRT is to dialyse patients in a
more physiologic way, slowly, over 24 hours, just like
the kidney
• Tolerated well by hemodynamically unstable patients
• Maintain fluid, electrolyte, acid/base balance
• Prevent further damage to kidney tissue
• Promote healing and total renal recovery
• Allow other supportive measures; nutritional support
RRT FOR ACUTE RENAL FAILURE
• Newer evidence from RENAL and ATN trials
suggest no difference between higher
therapy CRRT dose and better outcome
• There is no definitive evidence for
superiority of one therapy over another,
and wide practice variation exists
• Accepted indications for RTT vary
• No definitive evidence on timing of RRT
CRRT MODES OF THERAPY
• SCUF - Slow Continuous Ultrafiltration
• CVVH - Continuous Veno-Venous Hemofiltration
• CVVHD - Continuous Veno-Venous HemoDialysis
• CVVHDF - Continuous Veno-Venous HemoDiaFiltration
VASCULAR ACCESS AND THE
EXTRACORPOREAL CIRCUIT
• There are two options for vascular access for CRRT, venovenous and
arteriovenous.
• Venovenous access is by far the most commonly used in the modern ICU.
ELECTROLYTES & PH BALANCE
• Another primary goal for CRRT, specifically:
• Sodium
• Potassium
• Calcium
• Glucose
• Phosphate
• Bicarbonate or lactate buffer
• Dialysate and replacement solutions are used
in CRRT to attain this goal.
ANTICOAGULATION & CRRT
• Anticoagulation is needed as the clotting cascades are activated
when the blood touches the non-endothelial surfaces of the
tubing and filter.
• CRRT can be run without anticoagulation
SCUF
Primary therapeutic goal:
– Safe and effective management of fluid removal from the
patient
• No dialysate or replacement fluid is used
• Primary indication is fluid overload without uremia or
significant electrolyte imbalance.
• Removes water from the bloodstream through ultrafiltration.
• The amount of fluid in the effluent bag is the same as the
amount removed from the patient.
• Fluid removal rates are typically closer to 100-300 mL/hour.
SCUF
• High flux membranes
• Up to 24 hrs per day
• Objective VOLUME control
• Not suitable for solute
clearance
• Blood flow 50-200 ml/min
• UF rate 2-8 ml/min
SLED(D) & SLED(D)-F : HYBRID THERAPY
• Conventional dialysis equipment
• Online dialysis fluid preparation
• Excellent small molecule detoxification
• Cardiovascular stability as good as CRRT
• Reduced anticoagulation requirement
• 11 hrs SLED comparable to 23 hrs CVVH
• Decreased costs compared to CRRT
• Phosphate supplementation required
Fliser, T & Kielstein JT. Nature Clin Practice Neph 2006; 2: 32-39
Berbece, AN & Richardson, RMA. Kidney International 2006; 70: 963-968
COMPLICATIONS OF CRRT
• Bleeding
• Hypothermia
• Electrolyte Imbalances
• Acid-Base Imbalances
• Infection
• Appropriate Dosing of Medications
BEYOND RENAL
REPLACEMENT…
RRT AS BLOOD PURIFICATION
THERAPY
EXTRACORPOREAL BLOOD
PURIFICATION THERAPY (EBT)
Intermittent Continuous
TPE
Therapeutic
plasma exchange
HVHF
High volume
haemofiltration
UHVHF
Ultra-high volume
haemofiltration
PHVHF
Pulsed high volume
haemofiltration
CPFA
Coupled plasma
filtration and
adsorption
PEAK CONCENTRATION HYPOTHESIS
• Removes cytokines from blood compartment
during pro-inflammatory phase of sepsis
• Assumes blood cytokine level needs to fall
• Assumes reduced “free” cytokine levels leads
to decreased tissue effects and organ failure
• Favours therapy such as HVHF, UHVHF, CPFA
• But tissue/interstitial cytokine levels
unknown
Ronco, C & Bellomo, R. Artificial Organs 2003; 27: 792-801
THRESHOLD IMMUNOMODULATION
HYPOTHESIS
• More dynamic view of cytokine system
• Mediators and pro-mediators removed from blood to alter tissue
cytokine levels but blood level does not need to fall
• ? pro-inflammatory processes halted when cytokines fall to
“threshold” level
• We don’t know when such a point is reached
Honore, PM & Matson, JR. Critical Care Medicine 2004; 32: 896-897
MEDIATOR DELIVERY HYPOTHESIS
• HVHF with high incoming fluid volumes (3-6 L/hour)
increases lymph flow 20-40 times
• “Drag” of mediators and cytokines with lymph
• Pulls cytokines from tissues to blood for removal and
tissue levels fall
• High fluid exchange is key
Di Carlo, JV & Alexander, SR. Int J Artif Organs 2005; 28: 777-786
HIGH VOLUME HAEMOFILTRATION
• May reduce unbound fraction of cytokines
• Removes
– endothelin-I (causes early pulm hypertension in sepsis)
– endogenous cannabinoids (vasoplegic in sepsis)
– myodepressant factor
– PAI-I so may eventually reduce DIC
• Reduces post-sepsis immunoparalysis (CARS)
• Reduces inflammatory cell apoptosis
• Human trials probably using too low a dose (40 ml/kg/hour vs
100+ ml/kg/hour in animals)
SUMMARY
ARF is not an innocent bystander in ICU
We must ensure adequate dosing of RRT
Choice of RRT mode may not be critical
Septic ARF may be a different beast
We must strive to avert acute renal failure

More Related Content

What's hot

What's hot (20)

Pediatric hd dr. mohammed zedan
Pediatric hd   dr. mohammed zedanPediatric hd   dr. mohammed zedan
Pediatric hd dr. mohammed zedan
 
SUSTAINED LOW EFFICIENCY DAILY DIALYSIS (SLEDD)
SUSTAINED LOW EFFICIENCY DAILY DIALYSIS (SLEDD)SUSTAINED LOW EFFICIENCY DAILY DIALYSIS (SLEDD)
SUSTAINED LOW EFFICIENCY DAILY DIALYSIS (SLEDD)
 
Acute kidney injury defnition, causes,
Acute kidney injury   defnition, causes,Acute kidney injury   defnition, causes,
Acute kidney injury defnition, causes,
 
Dialyisis disequilibrium syndrome
Dialyisis disequilibrium syndromeDialyisis disequilibrium syndrome
Dialyisis disequilibrium syndrome
 
Crrt in aki
Crrt in akiCrrt in aki
Crrt in aki
 
Intra dialytic hypotension ,,, prof Alaa Sabry
Intra dialytic hypotension ,,,  prof Alaa SabryIntra dialytic hypotension ,,,  prof Alaa Sabry
Intra dialytic hypotension ,,, prof Alaa Sabry
 
Dialysis emergencies
Dialysis emergencies Dialysis emergencies
Dialysis emergencies
 
Renal replacement therapy
Renal replacement therapyRenal replacement therapy
Renal replacement therapy
 
Basics of Continuous Renal Replacement Therapy
Basics of Continuous Renal Replacement Therapy Basics of Continuous Renal Replacement Therapy
Basics of Continuous Renal Replacement Therapy
 
CRRT in ICU - AKI - Dr. Gawad
CRRT in ICU - AKI - Dr. GawadCRRT in ICU - AKI - Dr. Gawad
CRRT in ICU - AKI - Dr. Gawad
 
Peritoneal dialysis part1
Peritoneal dialysis part1Peritoneal dialysis part1
Peritoneal dialysis part1
 
Hemodialysis Anticoagulation - Different Protocols / Protocol Selection - Dr....
Hemodialysis Anticoagulation - Different Protocols / Protocol Selection - Dr....Hemodialysis Anticoagulation - Different Protocols / Protocol Selection - Dr....
Hemodialysis Anticoagulation - Different Protocols / Protocol Selection - Dr....
 
Hemodialysis in children
Hemodialysis in childrenHemodialysis in children
Hemodialysis in children
 
Hd Prescription
Hd PrescriptionHd Prescription
Hd Prescription
 
Continuous renal replacement therapy crrt
Continuous renal replacement therapy crrtContinuous renal replacement therapy crrt
Continuous renal replacement therapy crrt
 
Continuous Renal Replacement Therapy
Continuous Renal Replacement TherapyContinuous Renal Replacement Therapy
Continuous Renal Replacement Therapy
 
Renal Replacement therapy in the ICU
Renal Replacement therapy in the ICU Renal Replacement therapy in the ICU
Renal Replacement therapy in the ICU
 
Renal replacement therapy
Renal replacement therapyRenal replacement therapy
Renal replacement therapy
 
Continuous rrt and its role in critically ill patients [autosaved]
Continuous rrt and its role in critically ill patients [autosaved]Continuous rrt and its role in critically ill patients [autosaved]
Continuous rrt and its role in critically ill patients [autosaved]
 
CONTINUOUS RENAL REPLACEMENT THERAPY Crrt 2
CONTINUOUS RENAL REPLACEMENT THERAPY Crrt  2CONTINUOUS RENAL REPLACEMENT THERAPY Crrt  2
CONTINUOUS RENAL REPLACEMENT THERAPY Crrt 2
 

Viewers also liked

Viewers also liked (14)

From metabolic syndrome to cachexia: what’s new about metabolic biomarkers?
From metabolic syndrome to cachexia: what’s new about metabolic biomarkers?From metabolic syndrome to cachexia: what’s new about metabolic biomarkers?
From metabolic syndrome to cachexia: what’s new about metabolic biomarkers?
 
Label Printing Australia
Label Printing AustraliaLabel Printing Australia
Label Printing Australia
 
Class *sony-world-photography snap photos acquired @ www.google.com.
Class *sony-world-photography snap photos acquired @ www.google.com.Class *sony-world-photography snap photos acquired @ www.google.com.
Class *sony-world-photography snap photos acquired @ www.google.com.
 
Assignment 28
Assignment 28Assignment 28
Assignment 28
 
2017 Pets Reducing for Rescues Kickoff
2017 Pets Reducing for Rescues Kickoff2017 Pets Reducing for Rescues Kickoff
2017 Pets Reducing for Rescues Kickoff
 
Pan gu, the creator of the universe chinese myth of creation .
Pan gu, the creator of the universe   chinese myth of creation .Pan gu, the creator of the universe   chinese myth of creation .
Pan gu, the creator of the universe chinese myth of creation .
 
Picón, mi pueblo
Picón, mi puebloPicón, mi pueblo
Picón, mi pueblo
 
Design the implementation of CDEx Robust DC Motor.
Design the implementation of CDEx Robust DC Motor.Design the implementation of CDEx Robust DC Motor.
Design the implementation of CDEx Robust DC Motor.
 
Benefits developing country
Benefits developing countryBenefits developing country
Benefits developing country
 
Sueño fisiología y conducta
Sueño fisiología y conductaSueño fisiología y conducta
Sueño fisiología y conducta
 
Guía vegetariana para principiantes
Guía vegetariana para principiantesGuía vegetariana para principiantes
Guía vegetariana para principiantes
 
GWU- Mem2017 brochure
GWU- Mem2017 brochureGWU- Mem2017 brochure
GWU- Mem2017 brochure
 
Ecommerce trends 2017
Ecommerce trends 2017Ecommerce trends 2017
Ecommerce trends 2017
 
Es ea inicial estrategico
Es ea   inicial estrategicoEs ea   inicial estrategico
Es ea inicial estrategico
 

Similar to Renal replacement therapy

Blood pressure changes during
Blood pressure changes duringBlood pressure changes during
Blood pressure changes during
magdy elmasry
 

Similar to Renal replacement therapy (20)

Blood pressure changes during
Blood pressure changes duringBlood pressure changes during
Blood pressure changes during
 
Bloodpressurechangesduring
BloodpressurechangesduringBloodpressurechangesduring
Bloodpressurechangesduring
 
Classical ‘renal’ indications for starting renal replacement therapy (RRT)
Classical ‘renal’ indications for starting renal replacement therapy (RRT) Classical ‘renal’ indications for starting renal replacement therapy (RRT)
Classical ‘renal’ indications for starting renal replacement therapy (RRT)
 
Hyponatraemia 2014
Hyponatraemia 2014Hyponatraemia 2014
Hyponatraemia 2014
 
Dialysis
DialysisDialysis
Dialysis
 
Rrt dr.sarmistha
Rrt dr.sarmisthaRrt dr.sarmistha
Rrt dr.sarmistha
 
Renal Replacement therapy in the ICU
Renal Replacement therapy in the ICURenal Replacement therapy in the ICU
Renal Replacement therapy in the ICU
 
Renal Replacement Therapy IN ICCU
Renal Replacement Therapy IN ICCURenal Replacement Therapy IN ICCU
Renal Replacement Therapy IN ICCU
 
Medication and fluid therapy.pptx
Medication and fluid therapy.pptxMedication and fluid therapy.pptx
Medication and fluid therapy.pptx
 
Intravenous fluids
Intravenous fluidsIntravenous fluids
Intravenous fluids
 
Iv fluids TYPES OF IV FLIUDS
Iv fluids  TYPES OF IV FLIUDSIv fluids  TYPES OF IV FLIUDS
Iv fluids TYPES OF IV FLIUDS
 
Acute kidney injury and renal replacement therapies [autosaved]
Acute kidney injury and renal replacement therapies [autosaved]Acute kidney injury and renal replacement therapies [autosaved]
Acute kidney injury and renal replacement therapies [autosaved]
 
FLUIDS AND ELECTROLYTES
FLUIDS AND ELECTROLYTESFLUIDS AND ELECTROLYTES
FLUIDS AND ELECTROLYTES
 
Dialysis
DialysisDialysis
Dialysis
 
Acute Kidney Injury - Pediatric Perspective
Acute Kidney Injury - Pediatric PerspectiveAcute Kidney Injury - Pediatric Perspective
Acute Kidney Injury - Pediatric Perspective
 
Laboratory role in renal replacement therapy.pptx
Laboratory role in renal replacement therapy.pptxLaboratory role in renal replacement therapy.pptx
Laboratory role in renal replacement therapy.pptx
 
RRT
RRTRRT
RRT
 
Iv fluids
Iv fluidsIv fluids
Iv fluids
 
Postoperative fluid and electrolyte management.pptx
Postoperative fluid and electrolyte management.pptxPostoperative fluid and electrolyte management.pptx
Postoperative fluid and electrolyte management.pptx
 
Fluid and electrolyte imbalance [autosaved]
Fluid and electrolyte imbalance [autosaved]Fluid and electrolyte imbalance [autosaved]
Fluid and electrolyte imbalance [autosaved]
 

More from logon2kingofkings (11)

Journal club
Journal clubJournal club
Journal club
 
Hm
HmHm
Hm
 
Atc &amp; hm
Atc &amp; hmAtc &amp; hm
Atc &amp; hm
 
Traumatic brain injury
Traumatic brain injuryTraumatic brain injury
Traumatic brain injury
 
Current role of hyperbaric therapy (hbot)
Current role of hyperbaric therapy (hbot)Current role of hyperbaric therapy (hbot)
Current role of hyperbaric therapy (hbot)
 
TRAUMATIC BRAIN INJURY
TRAUMATIC BRAIN INJURYTRAUMATIC BRAIN INJURY
TRAUMATIC BRAIN INJURY
 
Prone cpcr
Prone cpcrProne cpcr
Prone cpcr
 
Acute fatty liver of pregnency
Acute fatty liver of pregnencyAcute fatty liver of pregnency
Acute fatty liver of pregnency
 
Pulmonary function tests
Pulmonary function testsPulmonary function tests
Pulmonary function tests
 
Perioperative fluid therapy
Perioperative fluid therapyPerioperative fluid therapy
Perioperative fluid therapy
 
Anticoagulant and regional anaesthesia
Anticoagulant and regional anaesthesiaAnticoagulant and regional anaesthesia
Anticoagulant and regional anaesthesia
 

Recently uploaded

Sonia Journal club presentation (2).pptx
Sonia Journal club presentation (2).pptxSonia Journal club presentation (2).pptx
Sonia Journal club presentation (2).pptx
palsonia139
 
THORACOTOMY . SURGICAL PERSPECTIVES VOL 1
THORACOTOMY . SURGICAL PERSPECTIVES VOL 1THORACOTOMY . SURGICAL PERSPECTIVES VOL 1
THORACOTOMY . SURGICAL PERSPECTIVES VOL 1
DR SETH JOTHAM
 

Recently uploaded (20)

Sonia Journal club presentation (2).pptx
Sonia Journal club presentation (2).pptxSonia Journal club presentation (2).pptx
Sonia Journal club presentation (2).pptx
 
World Hypertension Day 17th may 2024 ppt
World Hypertension Day 17th may 2024 pptWorld Hypertension Day 17th may 2024 ppt
World Hypertension Day 17th may 2024 ppt
 
Video capsule endoscopy (VCE ) in children
Video capsule endoscopy (VCE ) in childrenVideo capsule endoscopy (VCE ) in children
Video capsule endoscopy (VCE ) in children
 
Muscle Energy Technique (MET) with variant and techniques.
Muscle Energy Technique (MET) with variant and techniques.Muscle Energy Technique (MET) with variant and techniques.
Muscle Energy Technique (MET) with variant and techniques.
 
DIGITAL RADIOGRAPHY-SABBU KHATOON .pptx
DIGITAL RADIOGRAPHY-SABBU KHATOON  .pptxDIGITAL RADIOGRAPHY-SABBU KHATOON  .pptx
DIGITAL RADIOGRAPHY-SABBU KHATOON .pptx
 
Multiple sclerosis diet.230524.ppt3.pptx
Multiple sclerosis diet.230524.ppt3.pptxMultiple sclerosis diet.230524.ppt3.pptx
Multiple sclerosis diet.230524.ppt3.pptx
 
THORACOTOMY . SURGICAL PERSPECTIVES VOL 1
THORACOTOMY . SURGICAL PERSPECTIVES VOL 1THORACOTOMY . SURGICAL PERSPECTIVES VOL 1
THORACOTOMY . SURGICAL PERSPECTIVES VOL 1
 
hypo and hyper thyroidism final lecture.pptx
hypo and hyper thyroidism  final lecture.pptxhypo and hyper thyroidism  final lecture.pptx
hypo and hyper thyroidism final lecture.pptx
 
TEST BANK for The Nursing Assistant Acute, Subacute, and Long-Term Care, 6th ...
TEST BANK for The Nursing Assistant Acute, Subacute, and Long-Term Care, 6th ...TEST BANK for The Nursing Assistant Acute, Subacute, and Long-Term Care, 6th ...
TEST BANK for The Nursing Assistant Acute, Subacute, and Long-Term Care, 6th ...
 
The Orbit & its contents by Dr. Rabia I. Gandapore.pptx
The Orbit & its contents by Dr. Rabia I. Gandapore.pptxThe Orbit & its contents by Dr. Rabia I. Gandapore.pptx
The Orbit & its contents by Dr. Rabia I. Gandapore.pptx
 
Gallbladder Double-Diverticular: A Case Report المرارة مزدوجة التج: تقرير حالة
Gallbladder Double-Diverticular: A Case Report  المرارة مزدوجة التج: تقرير حالةGallbladder Double-Diverticular: A Case Report  المرارة مزدوجة التج: تقرير حالة
Gallbladder Double-Diverticular: A Case Report المرارة مزدوجة التج: تقرير حالة
 
TEST BANK For Huether and McCance's Understanding Pathophysiology, Canadian 2...
TEST BANK For Huether and McCance's Understanding Pathophysiology, Canadian 2...TEST BANK For Huether and McCance's Understanding Pathophysiology, Canadian 2...
TEST BANK For Huether and McCance's Understanding Pathophysiology, Canadian 2...
 
5cladba raw material 5CL-ADB-A precursor raw
5cladba raw material 5CL-ADB-A precursor raw5cladba raw material 5CL-ADB-A precursor raw
5cladba raw material 5CL-ADB-A precursor raw
 
TEST BANK for Wilkins’ Clinical Assessment in Respiratory Care, 9th Edition b...
TEST BANK for Wilkins’ Clinical Assessment in Respiratory Care, 9th Edition b...TEST BANK for Wilkins’ Clinical Assessment in Respiratory Care, 9th Edition b...
TEST BANK for Wilkins’ Clinical Assessment in Respiratory Care, 9th Edition b...
 
Hemodialysis: Chapter 2, Extracorporeal Blood Circuit - Dr.Gawad
Hemodialysis: Chapter 2, Extracorporeal Blood Circuit - Dr.GawadHemodialysis: Chapter 2, Extracorporeal Blood Circuit - Dr.Gawad
Hemodialysis: Chapter 2, Extracorporeal Blood Circuit - Dr.Gawad
 
SURGICAL ANATOMY OF ORAL IMPLANTOLOGY.pptx
SURGICAL ANATOMY OF ORAL IMPLANTOLOGY.pptxSURGICAL ANATOMY OF ORAL IMPLANTOLOGY.pptx
SURGICAL ANATOMY OF ORAL IMPLANTOLOGY.pptx
 
Mgr university bsc nursing adult health previous question paper with answers
Mgr university  bsc nursing adult health previous question paper with answersMgr university  bsc nursing adult health previous question paper with answers
Mgr university bsc nursing adult health previous question paper with answers
 
Factors Affecting child behavior in Pediatric Dentistry
Factors Affecting child behavior in Pediatric DentistryFactors Affecting child behavior in Pediatric Dentistry
Factors Affecting child behavior in Pediatric Dentistry
 
5Cladba ADBB 5cladba buy 6cl adbb powder 5cl ADBB precursor materials
5Cladba ADBB 5cladba buy 6cl adbb powder 5cl ADBB precursor materials5Cladba ADBB 5cladba buy 6cl adbb powder 5cl ADBB precursor materials
5Cladba ADBB 5cladba buy 6cl adbb powder 5cl ADBB precursor materials
 
CT scan of penetrating abdominopelvic trauma
CT scan of penetrating abdominopelvic traumaCT scan of penetrating abdominopelvic trauma
CT scan of penetrating abdominopelvic trauma
 

Renal replacement therapy

  • 1. RENAL REPLACEMENT THERAPIES IN CRITICAL CARE DR YOGESH RATHOD CHRISTIAN MEDICAL COLLEGE, VELLORE.
  • 2. TOO MANY QUESTIONS? • What therapy should we use? • When should we start it? • What are we trying to achieve? • How much therapy is enough? • When do we stop/switch? • Can we improve outcomes? Does the literature help us?
  • 3. RENAL FAILURE OF ANY CAUSE Many physiologic derangements: • Homeostasis of water and electrolytes as the excretion of the daily metabolic load of fixed hydrogen ions is no longer possible. • Toxic end-products of nitrogen metabolism (urea, creatinine, uric acid, among others) accumulate in blood and tissue. • Endocrine organ dysfunction and failing production of erythropoietin and 1,25 dihydroxycholecalciferol (calcitriol).
  • 4. EVALUATING ARF • Severity of ARF/AKI should not be estimated from measurements of blood urea or creatinine alone . • Cockcroft & Gault equation or MDRD eGFR or reciprocal creatinine plots should not be used when the GFR is <30 mL/min or to determine the need for acute RRT.
  • 5. AKI CLASSIFICATION SYSTEMS 1: RIFLE Bellomo R, Ronco C, Kellum JA, et al. Acute renal failure - definition, outcome measures, animal models, fluid therapy and information technology needs: the second International Consensus Conference of the Acute Dialysis Initiative (ADQI) group. Crit Care 2004; 8: R204–R212.
  • 6. AKI CLASSIFICATION SYSTEMS 2: AKIN Stage Creatinine criteria Urine output criteria 1 1.5 - 2 x baseline (or rise > 26.4 mmol/L) < 0.5 ml/kg/hour for > 6 hours 2 >2 - 3 x baseline < 0.5 ml/kg/hour for > 12 hours 3 > 3 x baseline (or > 354 mmol/L with acute rise > 44 mmol/L) < 0.3 ml/kg/hour for 24 hours or anuria for 12 hours Patients receiving RRT are Stage 3 regardless of creatinine or urine output Mehta RL, Kellum JA, Shah SV, et al. Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury. Crit Care 2007;11:R31.
  • 7. PROPOSED INDICATIONS FOR RRT • Oliguria < 200ml/12 hours • Anuria < 50 ml/12 hours • Hyperkalaemia > 6.5 mmol/L • Severe acidaemia pH < 7.0 • Uraemia > 30 mmol/L • Uraemic complications (pericarditis, nausea, vomiting, poor appetite, hemorrhage, lethargy, malaise, somnolence, stupor, coma, delirium, asterixis, tremor, seizures) • Dysnatraemias > 155 or < 120 mmol/L • Hyper/(hypo)thermia • Drug overdose with dialysable drug • Refractory hypertension Lameire, N et al. Lancet 2005; 365: 417-430
  • 8. “NON-RENAL” INDICATIONS • TO GET RID OF Substances with higher degrees of protein binding and sometimes for substances with very long plasma half-lives. • In general, the size of the molecule and the degree of protein binding determines the degree to which the substance can be removed (i.e. smaller, nonprotein bound substances are easiest to remove). • RRT can be used as sorbent hemoperfusion for substances that include drugs, poisons, contrast agents, and cytokines.
  • 9. ACUTE KIDNEY INJURY IN THE ICU • AKI is common: 3-35%* of admissions • AKI is associated with increased mortality • “Minor” rises in Cr associated with worse outcome • AKI developing after ICU admission (late) is associated with worse outcome than AKI at admission • AKI requiring RRT occurs in about 4-5% of ICU admissions and is associated with worst mortality risk ** * Brivet, FG et al. Crit Care Med 1996; 24: 192-198 ** Metnitz, PG et al. Crit Care Med 2002; 30: 2051-2058
  • 10. MORTALITY BY AKI SEVERITY Clermont, G et al. Kidney International 2002; 62: 986-996
  • 11. THE IDEAL RENAL REPLACEMENT THERAPY • Allows control of intra/extravascular volume • Corrects acid-base disturbances • Corrects uraemia & effectively clears “toxins” • Promotes renal recovery • Improves survival • Is free of complications • Clears drugs effectively (?)
  • 12. INTERMITTENT THERAPIES - PROS (Relatively) Inexpensive Flexible timing allows for mobility/transport Rapid correction of fluid overload Rapid removal of dialyzable drugs Rapid correction of acidosis & electrolyte abnormality Minimises anticoagulant exposure
  • 13. Intermittent Therapies - CONS Hypotension 30- 60% Cerebral oedema Limited therapy duration Renal injury & ischaemia Gut/coronary ischaemia
  • 14. INTRADIALYTIC HYPOTENSION: RISK FACTORS • LVH with diastolic dysfunction or LV systolic dysfunction / CHF • Valvular heart disease • Pericardial disease • Poor nutritional status / hypoalbuminaemia • Uraemic neuropathy or autonomic dysfunction • Severe anaemia • High volume ultrafiltration requirements • Predialysis SBP of <100 mm Hg • Age 65 years + • Pressor requirement
  • 15. MANAGING INTRA-DIALYTIC HYPOTENSION • Dialysate temperature modelling • Low temperature dialysate • Dialysate sodium profiling • Hypertonic Na at start decreasing to 135 by end • Prevents plasma volume decrease • Midodrine if not on pressors • Colloid/crystalloid boluses • Sertraline (longer term HD) 2005 National Kidney Foundation K/DOQI GUIDELINES
  • 16. CONTINUOUS THERAPIES - PROS Haemodynamic stability => ?? better renal recovery Stable and predictable volume control Stable and predictable control of chemistry Stable intracranial pressure Disease modification by cytokine removal (CVVH)?
  • 17. Continuous Therapies - CONS Anticoagulation requirements Higher potential for filter clotting Expense – fluids etc. Immobility & Transport issues Increased bleeding risk High heparin exposure
  • 18. RRT MOLECULAR TRANSPORT MECHANISMS • Ultrafiltration • Diffusion • Convection • Adsorption Fluid Transport Solute Transport }
  • 19. SEMI-PERMEABLE MEMBRANES • Semi-permeable membranes are the basis of all blood purification therapies. • They allow water and some solutes to pass through the membrane, while cellular components and other solutes remain behind. • The water and solutes that pass through the membrane are called ultrafiltrate. • The membrane and its housing are referred to as
  • 20. ULTRAFILTRATION • Ultrafiltration is the passage of fluid through a membrane under a pressure gradient. • Pressures that drive ultrafiltration can be positive, that is the pressure pushes fluid through the filter. • They can also be negative, there may be suction applied that pulls the fluid to the other side of the filter. • Also osmotic pressure from non-permeable solutes. • The rate of UF will depend upon the pressures applied to the filter and on the rate at which the blood passes through the filter. • Higher pressures and faster flows increase the rate of ultrafiltration. • Lower pressures and slower flows decrease the rate of ultrafiltration.
  • 21. Blood Out Blood Into waste (to patient) (From patient) HIGH PRESSLOW PRESS Fluid Volume Reduction ULTRAFILTRATION
  • 22. DIFFUSION • Diffusion is the movement of a solute across a membrane via a concentration gradient. • For diffusion to occur, another fluid must flow on the opposite side of the semi-permeable membrane. In blood purification this fluid is called dialysate. • Solutes always diffuse across a membrane from an area of higher concentration to an area of lower concentration until equilibration.
  • 23. HAEMODIALYSIS: DIFFUSION Dialysate In Dialysate Out (to waste) Blood Out Blood In (to patient) (from patient) HIGH CONCLOW CONC
  • 24. CONVECTION • Convection is the movement of solutes through a membrane by the force of water (“solvent drag”). • Convection is able to move very large molecules if the flow of fluid through the membrane is fast enough. • In CRRT this property is maximized by using replacement fluids. • Replacement fluids are crystalloid fluids administered at a fast rate just before or just after the blood enters the filter.
  • 25. to waste HIGH PRESSLOW PRESS Repl. Solution HAEMOFILTRATION: CONVECTION Blood Out Blood In (to patient) (from patient)
  • 26. ADSORPTION • Adsorption is the removal of solutes from the blood because they cling to the membrane. • In blood purification. High levels of solute/molecule adsorption can cause filters to clog and become ineffective.
  • 27. ADSORPTION • Molecular adherence to the surface or interior of the membrane.
  • 28. MOLECULAR WEIGHTS Daltons  Inflammatory Mediators (1,200-40,000) “small” “middle” “large”
  • 29. MAJOR RENAL REPLACEMENT TECHNIQUES Intermittent ContinuousHybrid IHD Intermittent haemodialysis IUF Isolated Ultrafiltration SLEDD Sustained (or slow) low efficiency daily dialysis SLEDD-F Sustained (or slow) low efficiency daily dialysis with filtration CVVH Continuous veno- venous haemofiltration CVVHD Continuous veno- venous haemodialysis CVVHDF Continuous veno- venous haemodiafiltration SCUF Slow continuous ultrafiltration
  • 30. CRRT TREATMENT GOALS • The concept behind CRRT is to dialyse patients in a more physiologic way, slowly, over 24 hours, just like the kidney • Tolerated well by hemodynamically unstable patients • Maintain fluid, electrolyte, acid/base balance • Prevent further damage to kidney tissue • Promote healing and total renal recovery • Allow other supportive measures; nutritional support
  • 31. RRT FOR ACUTE RENAL FAILURE • Newer evidence from RENAL and ATN trials suggest no difference between higher therapy CRRT dose and better outcome • There is no definitive evidence for superiority of one therapy over another, and wide practice variation exists • Accepted indications for RTT vary • No definitive evidence on timing of RRT
  • 32. CRRT MODES OF THERAPY • SCUF - Slow Continuous Ultrafiltration • CVVH - Continuous Veno-Venous Hemofiltration • CVVHD - Continuous Veno-Venous HemoDialysis • CVVHDF - Continuous Veno-Venous HemoDiaFiltration
  • 33. VASCULAR ACCESS AND THE EXTRACORPOREAL CIRCUIT • There are two options for vascular access for CRRT, venovenous and arteriovenous. • Venovenous access is by far the most commonly used in the modern ICU.
  • 34. ELECTROLYTES & PH BALANCE • Another primary goal for CRRT, specifically: • Sodium • Potassium • Calcium • Glucose • Phosphate • Bicarbonate or lactate buffer • Dialysate and replacement solutions are used in CRRT to attain this goal.
  • 35. ANTICOAGULATION & CRRT • Anticoagulation is needed as the clotting cascades are activated when the blood touches the non-endothelial surfaces of the tubing and filter. • CRRT can be run without anticoagulation
  • 36. SCUF Primary therapeutic goal: – Safe and effective management of fluid removal from the patient • No dialysate or replacement fluid is used • Primary indication is fluid overload without uremia or significant electrolyte imbalance. • Removes water from the bloodstream through ultrafiltration. • The amount of fluid in the effluent bag is the same as the amount removed from the patient. • Fluid removal rates are typically closer to 100-300 mL/hour.
  • 37. SCUF • High flux membranes • Up to 24 hrs per day • Objective VOLUME control • Not suitable for solute clearance • Blood flow 50-200 ml/min • UF rate 2-8 ml/min
  • 38. SLED(D) & SLED(D)-F : HYBRID THERAPY • Conventional dialysis equipment • Online dialysis fluid preparation • Excellent small molecule detoxification • Cardiovascular stability as good as CRRT • Reduced anticoagulation requirement • 11 hrs SLED comparable to 23 hrs CVVH • Decreased costs compared to CRRT • Phosphate supplementation required Fliser, T & Kielstein JT. Nature Clin Practice Neph 2006; 2: 32-39 Berbece, AN & Richardson, RMA. Kidney International 2006; 70: 963-968
  • 39. COMPLICATIONS OF CRRT • Bleeding • Hypothermia • Electrolyte Imbalances • Acid-Base Imbalances • Infection • Appropriate Dosing of Medications
  • 40. BEYOND RENAL REPLACEMENT… RRT AS BLOOD PURIFICATION THERAPY
  • 41. EXTRACORPOREAL BLOOD PURIFICATION THERAPY (EBT) Intermittent Continuous TPE Therapeutic plasma exchange HVHF High volume haemofiltration UHVHF Ultra-high volume haemofiltration PHVHF Pulsed high volume haemofiltration CPFA Coupled plasma filtration and adsorption
  • 42. PEAK CONCENTRATION HYPOTHESIS • Removes cytokines from blood compartment during pro-inflammatory phase of sepsis • Assumes blood cytokine level needs to fall • Assumes reduced “free” cytokine levels leads to decreased tissue effects and organ failure • Favours therapy such as HVHF, UHVHF, CPFA • But tissue/interstitial cytokine levels unknown Ronco, C & Bellomo, R. Artificial Organs 2003; 27: 792-801
  • 43. THRESHOLD IMMUNOMODULATION HYPOTHESIS • More dynamic view of cytokine system • Mediators and pro-mediators removed from blood to alter tissue cytokine levels but blood level does not need to fall • ? pro-inflammatory processes halted when cytokines fall to “threshold” level • We don’t know when such a point is reached Honore, PM & Matson, JR. Critical Care Medicine 2004; 32: 896-897
  • 44. MEDIATOR DELIVERY HYPOTHESIS • HVHF with high incoming fluid volumes (3-6 L/hour) increases lymph flow 20-40 times • “Drag” of mediators and cytokines with lymph • Pulls cytokines from tissues to blood for removal and tissue levels fall • High fluid exchange is key Di Carlo, JV & Alexander, SR. Int J Artif Organs 2005; 28: 777-786
  • 45. HIGH VOLUME HAEMOFILTRATION • May reduce unbound fraction of cytokines • Removes – endothelin-I (causes early pulm hypertension in sepsis) – endogenous cannabinoids (vasoplegic in sepsis) – myodepressant factor – PAI-I so may eventually reduce DIC • Reduces post-sepsis immunoparalysis (CARS) • Reduces inflammatory cell apoptosis • Human trials probably using too low a dose (40 ml/kg/hour vs 100+ ml/kg/hour in animals)
  • 46. SUMMARY ARF is not an innocent bystander in ICU We must ensure adequate dosing of RRT Choice of RRT mode may not be critical Septic ARF may be a different beast We must strive to avert acute renal failure