crrt sudan 2017 dr. osama el shahat

Dr. Osama El-Shahat

Consultant Nephrologist Head of Nephrology Department

New Mansoura General Hospital (international)

ISN Educational Ambassador

When

What

HOW

to start ?

Modality ?

can we do it ?

Stage-based management

General Principles

Stage 1 (Risk)

Risk for more severe AKI Monitor (prevent

progression)

Stage 2 (Injury)

Risk of AKI-related mortality/morbidity high Conservative therapy)

Stage 3 (Failure)

Highest risk of death Consider RRT

Avoid subclavian catheters if possible

Discontinue all nephrotoxic agents when possible

Consider invasive diagnostic workup

Consider Renal Replacement Therapy

1 2 3

Non-invasive diagnostic workup

Ensure volume status and perfusion pressure

Check for changes in drug dosing

AKI Stage

Consider functional hemodynamic monitoring

Monitoring Serum creatinine and urine output

Consider ICU admission

Avoid hyperglycemia

Consider alternatives to radiocontrast procedures

When to start ?

Renal Indications

Life-threatening indications

Hyperkalemia

Metabolic Acidosis

Pulmonary edema

Uremic complications

Non Renal Indications

Fluid removal in congestive

heart failure& Fluid

management in multiorgan

failure

Cytokine manipulation in

sepsis

Treatment of drug overdose

Nutrition support

Crit Care Med 2008, Vol. 36, No 4 (suppl.)

Early RRT seems better

What Modality ?

1. Peritoneal dialysis (PD)

2. Intermittent Hemodialysis (IHD)

3. Slow Low-Efficiency Dialysis (SLED)

4. Continuous Renal Replacement Therapy (CRRT)

• Slow Continuous Ultrafiltration (SCUF)

• Continuous Venovenous Hemofiltration (CVVH)

• Continuous Venovenous Hemodialysis (CVVHD)

• Continuous Venovenous Diafiltration (CVVHDF)

Advantages Hemodynamic stability

Slow correction

Easy access placement

No Anticoagulation

Tolerated in children

Disadvantages Risk of infections

Difficulty to use with abdominals surgery

Logestics

PD … the modality first used for the treatment of KI

Blood Purif 2013;36:226–230 DOI: 10.1159/000356627

©

Is an extracorporeal blood purification therapy

intended to substitute for impaired renal function over

an extended period of time and applied for or aimed

at being applied for Extended time 24 -72 h.

Bellomo R., Ronco C., Mehta R, Nomenclature for Continuous Renal Replacement Therapies, AJKD, Vol 28, No. 5, Suppl 3, November 1996

©

Mimic the functions and physiology of the native organ

Qualitative and quantitative blood purification

Restore and maintain of homeostasis

Avoid complications and good clinical tolerance

Provide conditions favoring recovery of renal function

Mode of therapy

Principle method of solute clearance

CVVH Convection

CVVHD Diffusion

CVVHDF Convection & Diffusion

SCUF Ultrafiltration (fluids)

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• CRRT clearance of solute is dependent on the following:

◦ The molecule size of the solute

◦ The pore size of the semi-permeable membrane

• The higher the ultrafiltration rate (UFR), the greater the

solute clearance.

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• Small molecules easily pass through a membrane driven by

diffusion and convection.

• Middle and large size molecules are cleared primarily by

convection.

• Semi-permeable membrane remove solutes with a molecular

weight of up to 50,000 Daltons.

• Plasma proteins or substances highly protein—bound will not

be cleared.

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• Sieving Coefficient

◦ The ability of a substance to pass through a membrane from

the blood compartment of the hemofilter to the fluid

compartment.

◦ A sieving coefficient of 1 will allow free passage of a

substance; but at a coefficient of 0, the substance is unable to

pass.

• .94 Na+

• 1.0 K+

• 1.0 Cr

• 0 albumin will not pass

Ronco C et al Kidney Int 56 ( suppl 72 ) s-8-s-14 , 1999

5.6.2: We suggest using CRRT, rather than standard

intermittent RRT, for hemodynamically unstable patients. (2B)

5.6.1: Use continuous and intermittent RRT as complementary

therapies in AKI patients. (Not Graded

Study Modality % recovering renal function

SUPPORT IHD* 67%**

Morgera et al. CRRT 90%

Ronco et al. CRRT 90%

Mehta et al. IHD

CRRT

59%

92%

BEST Kidney† IHD

CRRT

65%

89%

Davenport, A Sem Dialysis, 2009

5.6.3: We suggest using CRRT, rather than intermittent RRT, for AKI patients

with acute brain injury or other causes of increased intracranial pressure or

generalized brain edema. (2B)

KDIGO® AKI Guideline March 2012

The elimination of

inflamatory mediator

occurs only during the 1st

hour after application of

new filter.

Cytokines removal

capacity of curently

available membranes

hardly matches the

productin observed in

severly affected septic

patients.

De Vriese As-JAM Soc Nephrol 10-846-853 1999

Typically performed over 6-12 hours

Can be performed with a conventional dialysis

machine

– A little less labor intensive

– Requires less training/startup

Fliser D and Kielstei JT Nat Clin Pract Nephrol, 2006

Slow Low-Efficiency Daily Dialysis (SLED)

Major advantages: flexibility, reduced costs, low or absent

anticoagulation

Similar adequacy and hemodynamics

One small study (16 pts) showed slightly higher acidosis and lower

BP (Baldwin 2007)

VA trial (Palevsky NEJM 2008) suggests similar outcomes as

CRRT and IRRT.

Vanholder et al. Critical Care 2011, 15:204

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CRRT requires:

◦ A central double-lumen veno-venous hemodialysis catheter

◦ An extracorporeal circuit and a hemofilter

◦ A blood pump and a effluent pump.

◦ With specific CRRT therapies dialysate and/or replacement

pumps are required.

Solution

Anticoagulation

Dose

5.4.1: We suggest initiating RRT in patients with AKI via an uncuffed

nontunneled dialysis catheter, rather than a tunneled catheter. (2D)

5.4.2: When choosing a vein for insertion of a dialysis catheter in

patients with AKI, consider these preferences (Not Graded):

First choice: right jugular vein;

Second choice: femoral vein;

Third choice: left jugular vein;

Last choice: subclavian vein with preference for the dominant side.

Vascular access


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• The length of the catheter chosen will depend upon the site used

Size of the catheter is important in the pediatric population.

• The following are suggested guidelines for the different sites:

RIJ= 15 cm French

LIJ= 20 cm French

Femoral= 25 cm French

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• Physician Rx and adjusted based on pt. clinical need.

• Sterile replacement solutions may be:

Bicarbonate-based or Lactate-based solutions

Electrolyte solutions

Must be sterile and labeled for IV Use

Higher rates increase convective clearances

You are what you replace

Bicarbonate versus lactatebased fluid replacement in CVVH

Prospective, randomized study

Results Serum lactate concentration was

significantly higher and the

bicarbonate was lower in patients

treated with lactatebased solutions

Increased incidence of CVS events in

pts ttt with lactate solution

◦ Hypotension

◦ Increased dose of inotropic support

barenborck and colleague

Barenbrock M et al; Kidney Int (2000

Replacement Fluids

5.7.3: We suggest using bicarbonate, rather than lactate, as a

buffer in dialysate and replacement fluid for RRT in patients

with AKI and liver failure and/or lactic acidemia. (2B)


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• Through diffusion, dialysate corrects underlying metabolic

problems

• Dialysate is dependent on buffering agent, electrolytes, and

glucose

• Dialysate formulas should reflect normal plasma values to

achieve homeostasis

5.5.1: We suggest to use dialyzers with a biocompatible membrane

for IHD and CRRT in patients with AKI. (2C)

High Flux membrane , synthetic , biocompatable ,

acting by providing both methods of detoxications:

A. Diffusion : for low molecular weight toxins.

B. Convection : for large molecules.


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• Hemofilter membrane are composed of:

High flux material

Synthetic/biocompatible material

• Structural design is characterized by:

High fluid removal

Molecular cut-off weight of 30,000-50,000 Daltons.

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• The semi-permeable membrane provides: An interface between the blood and dialysate

compartment.

• Biocompatibility minimizes: Severe patient reactions

Decreases the complement activation

Modality Advantages Disadvantages

Heparin Good anticoagulation Thrombocytopenia bleeding

LMWH Less thrombocytopenia bleeding

Citrate Lowest risk of bleeding Metabolic alkalosis,

hypocalcemia special dialysate

Regional Heparin Reduced bleeding Complex management

Saline flushes No bleeding risk Poor efficacy

Prostacycline Reduced bleeding risk Hypotension poor efficacy

5.3.2.1: For anticoagulation in intermittent RRT, we

recommend using either unfractionated or low-

molecular weight heparin, rather than other

anticoagulants. (1C)

5.3.2.2: For anticoagulation in CRRT, we suggest using

regional citrate anticoagulation rather than heparin in

patients who do not have contraindications for citrate.

(2B)


Dose ?

©

100

90

80

70

60

50

40

30

20

10

0

Group 1(n=146)

( Uf = 20 ml/h/Kg)

Group 2 (n=139)

( Uf = 35 ml/h/Kg)

Group 3 (n=140)

( Uf = 45 ml/h/Kg)

41 % 57 % 58 %

p < 0.001 p n..s.

p < 0.001

Su

rviv

al (%

)

Effects of different doses in CVVH on outcome of ARF - Ronco & Bellomo study.

Lancet . july 00

©

An increased treatment dose from 20 ml/h/kg to 35 ml/h/kg

significantly improved survival.

A delivery of 45ml/kg/hr did not result in further benefit in

terms of survival, but in the septic patient an improvement was

observed.

Our data suggest an early initiation of treatment and a

minimum dose delivery of 35 ml/h/kg (ex. 70 kg patient =

2450 ml/h) improve patient survival rate.

Effects of different doses in CVVH on outcome of ARF - Ronco & Bellomo study. Lancet . july 00

RCT of 1124 critically ill pts with AKI and sepsis or at least one

organ failure to intensive or less intensive renal-replacement

therapy

Hemodynamically unstable pts received CRRT or SLEDD,

Stable pts IRRT

Intensive RRT= IRRT or SLEDD 6x/wk or CRRT at 35 ml/kg/hr

Less intensive RRT= IRRT or SLED 3x/wk or CRRT at 20

ml/kg/hr

VA/NIH Acute Renal Failure Trial Network. (NEJM 2008;359:7):

VA/NIH Acute Renal Failure Trial Network. (NEJM 2008;359:7):

No difference in mortality

1508 Critically ill patients with ARF on CVVHF were randomized to:-

low (25 mL/kg/hr – 747 patients)

high intensity (40 mL/kg/hr – 761 patients) effluent rates.

N Engl J Med. 2009 Oct 22;361(17):1627-38

The RENAL Replacement Therapy Study

There was no

difference in 90 day

mortality rate (44.7%)

or the need for RRT at

90 day between the

two treatment groups.

5.8.1: The dose of RRT to be delivered should be prescribed

before starting each session of RRT. (Not Graded)

We recommend frequent assessment of the actual

delivered dose in order to adjust the prescription. (1B)

5.8.2: Provide RRT to achieve the goals of electrolyte, acid-

base, solute, and fluid balance that will meet the

patient’s needs. (Not Graded)


CRRT is the modality of choice for hemodynamically

unstable patients who needs RRT .

The current trend is to provide RRT earlier in AKI

There may be a recovery advantage to using CRRT vs.

HD for initial management of AKI but no difference on

mortality

CRRT has many non renal indication which must be

considered

Dose: Optimal intensity of CRRT is controversial

Dialytic Support by CRRT = Individualization

When no plan ! Higher morbidity & mortality

©

An increased treatment dose from 20 ml/h/kg to 35 ml/h/kg

significantly improved survival.

A delivery of 45ml/kg/hr did not result in further benefit in

terms of survival, but in the septic patient an improvement was

observed.

Our data suggest an early initiation of treatment and a

minimum dose delivery of 35 ml/h/kg (ex. 70 kg patient =

2450 ml/h) improve patient survival rate.

Effects of different doses in CVVH on outcome of ARF - Ronco & Bellomo study. Lancet . july 00

crrt sudan 2017 dr. osama el shahat

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