ESPEN Congress Vienna 2009

Nutritional implications of renal replacement therapy in ICU

Why and how renal replacement therapy is used

M. Joannidis (Austria)

WHY and HOWrenal replacement therapy is

used?

M. JoannidisICU, Dept Internal Medicine IMedical University Innsbruck

„Critical illness“

Acute Stress Response

Trauma/Infection

Immunological

Response

Neuroendocrine Response

Metabolic Response

Iatrogenic Factors

ESPEN Congress Vienna 2009

Normoglycaemia in the acute patient not so crucial - and potentially

Hazardous

F. Brunkhorst (Germany)

WHY

should we use RRT?

Correct answer

„To replace the function of the most important organ of the body“

(Single) Organ Dysfunction and Hospital LOS

Liangos et al. CJASN 2006

Are we doing a good job..….by replacing renal function?

Do patients survive with this treatment?

End Stage Renal Disease

• 30% patients die within the first 12 months after starting dialysis

Mortality of AKI in ICU patients requiring RRT and not requiring RRT

Clermont G,Kidney Int. 2002

Loss of Renal Function

Consequences

• Uremia• Acid-base disorders

->Metabolic Acidosis• Electrolyte disorders (K+)• Endocrine disorders

(Vit D3, EPO, GH)• Metabolic disorder• Hypervolemia ( ↓ fluid excretion)• Inflammation

Chronic

++

++

++/--

Acute

+/-+/-

+/--

-++

Loss of Renal Function

Consequences

• Uremia• Acid-base disorders

->Metabolic Acidosis• Electrolyte disorders (K+)• Endocrine disorders

(Vit D3, EPO, GH)• Metabolic disorder

• Hypervolemia (↓ fluid excretion)

• Inflammation

Chronic

++

++

++/--

Acute

+/-+/-

+/--

-++

RRT

Why RRT….

Based on which criterion?

• GFR (eGFR)?• UO?• Acid-base?• Electrolytes?

CKD

AKI

Early vs late start of RRT

Liu et al, CJASN 2006

Initiation of CRRT A worldwide practice survey (B.E.S.T kidney)

• Oliguria/anuria 70.2%

• High urea/creatinine 53.0%

• Metabolic acidosis 43.6%

• Fluid overload 36.7%

Uchino et al, Intensive Care Med 2007

• Intubation

Start of CRRT in SEPSIS

• vasopressors

Death

• IRV

• AKI

Clinical trials -CRRT in Sepsis

• randomized trial with 24 pt. in early septic shock

• 48 h isovolemic CVVH 2L/h vs. stand. med. treatment

• 72 h observation period• primary parameters:

– C3a + C5a, interleukins 6, 8 + 10, TNF

– MODS

• No significant changes in cytokines or C3a + C5a by CVVH

• MODS – no difference between both groups.

• CVVH does not result in improvement of oxygenation or hemodynamics

Cole L et al., Crit Care Med 2002

Initiation of CRRT:Early isovolumetric CVVH in septic schock

Survival

Piccinni, Intensive Care Med 2005

40 postoperative pats.•septic shock•acute lung injury

Intitation-criterion:•oliguria >12h

•Modality:•CVVH

•45 ml/kg/h 8h•20 ml/kg/h 16h•daily filter change

HOW?Intermittent RRT (IRRT)

HOW?Continuous RRT (CRRT)

CVVHF

CVVHDFSLED

Which modality of RRT in (critically ill) patients?

IHDCVVHD

PD

CVVHDF vs IHD for acute kidney injury in patients with MODS

• RCT• N=360 (175 HDF/189 IHD)• Sepsis 56% /69% • SAPS II 64 /65• Katechol 89% /86%

Vinsonneau C, Lancet 2006

The VA/NIH Acute Renal Failure Trial Network.Patients

Enrollment, Randomization, and Follow-up of Study

N Engl J Med 2008;359:7-20

IHD daily or SLED orCVVHDF 35 ml/kg/h

IHD every other day or SLED or

CVVHDF 20 ml/kg/h

Recommendation:

-> use the cheapest modality-> use the lowest intensity possible

n=1124

General considerations

• Dose delivery – Physicochemical differences: convection

vs. diffusion• Hemodynamic stability• Fluid removal• Costs

QB= 150-250 ml/minQF = 20 - 50 ml/minConvection +++Diffusion -Adsorption +

-> Urea Clearance ~ 20 - 50 ml/min

Continuous

0

TMP

Ultrafiltrate

Substitutionfluid

TMP

Dialysate

QB= 100-150 ml/minQD = 20 - 50 ml/minConvection +Diffusion +++Adsorption +

Hemofiltration (HF) Hemodialyis (HD)

0

0,25

0,5

0,75

1

10 100 1000 10.000 100.000

HFHD

Sieving-coefficient and Treatment modality

Molekülgröße (D)

Sie

bkoe

ffizi

ent

urea

CVVHF

CVVHDFSLED

Why should we need ….

IHDCVVHD

QB= 100 - 250 ml/minQD= 10 - 35 ml/minQF = 10 - 50 ml/minQD+ QF = 20 - 85 ml/min

Convektion +++Diffusion +++Adsorption +Urea. Cl. ~ 20 - 85 ml/min

Hemodiafiltration (HDF)

0

TMP

dialysateultrafiltrat(+dialysate)

substitutionfluid

Additional small molecular clearance by CVVHDF

Kindgen-Milles et al 2000

Is increased middle molecule clearance clinically relevant??

Impact of added dialysis dose on survival in ARF

Saudan P., Kidney Int 2006

(UF~25 ml/kg/h)

(UF+D~42ml/kg/h)

p=0.03

28 day mortality: 61% vs 41%, p= 0.0390 day mortality: 66% vs 41%, p =0.0005

N=206 , Apache II ~ 26, 60% patients with sepsis

weekly Kt/V~ 11

~ 7

Requirement of CVVHDF mainly resulted from technical limitaions of some older CRRT machines ….

QB= 200 - 350 ml/minQD= 500 (- 800) ml/minConvection +Diffusion +++Adsorption +

-> Urea Cl. ~ 200 - 300 ml/min

Intermittent Hemodialysis (IHD)

0

TMP =400

Dialysate

/treatment time!!!

Hybrid Techniquese.g. Sustained Low Efficiency Dialysis (SLED)

• F60S, 1.3 m²• QB=200 ml/min• QD=100 ml/min• duration of a single

session 8-12 h

Kielstein JT, AJKD 2004

Effects of different modalities of RRT on BUN

Time (day)0 1 2 3 4 5 6 7

BU

N (m

g/dL

)

0

20

40

60

80

100

120

CVVHIHDSLED

Liao Z., Artif.Organs 2003

Effects of different modalities of RRT on middle molecules (ß2-MG)

Liao Z., Artif.Organs 2003

Time (day)0 1 2 3 4 5 6 7

b2M

(mg/

dL)

0

1

2

3

4

5

6

CVVHIHDSLED

Effects of different modalities of RRT on Phosphate Removal

CRRT > SLED > IHD

Extended Daily Dialysis versus CVVH: Effect on Acid-base Balance

Baldwin I, Intensive Care Med 2007

Bicarbonate Base Excess

SLED: Qd=280 ml/min, 8h/dCVVH: UF=2L/hN=16

General considerations

• Dose delivery – Physicochemical differences: convection

vs. diffusion• Hemodynamic stability• Fluid removal• Costs

CVVH vs. IHD in Septic Shock

John S. (2001), NDT 16: 320IHD (n=10) CVVHF (n= 20)

Hemodynamic EffectsSLED vs CVVH

Kielstein J, AJKD 2003

MAP HR

CO SVR

RCT, n=19/20, ICU pat. + ARF + mechanical ventilation

Choice of Modality Initiation

Continuation

UnstableStable

N Engl J Med 2008;359:7-20

Fluid removal-Example:patient with ARF, 70 kg BW,average daily fluid intake 4L

Daily IHD: 3 h23 ml/min

0.4 ml/min/kg

CVVH: 24 h2.5 ml/min

0.03 ml/min/kg

SLEDD: 12 h 5.5 ml/min

0.09 ml/min/kg

Required ultrafiltration

4000 ml/24 h

Frequency of Hypotensive Episodes

Ronco et al, Int. J. Artif. Organs 1988

SLED IHDCVVH

…..Costs

Comparison of costs of RRT

Manns B, Crit Care Med 2003

Berbece AN , Kidney Int 2006

Comparison of costs of RRT

Summary

CVVH(DF) IHD (daily) SLED

Middle molecules ++ - -

Hemodynamic tol. ++ +/- ++

Fluid removal ++ +/- +

Dose ++ +/- +

Costs - + ++

Renal Recovery ++ - ?

Anticoagulation - + +/-

The Principle of Peritoneal Dialysis

CAPD

High volume peritoneal dialysis vs daily hemodialysis:

A randomized, controlled trial in patients with acutekidney injury

N=60/60

Gabriel DP, Kidney Int 2008

High volume peritoneal dialysis vs daily hemodialysis:

A randomized, controlled trial in patients with acutekidney injury

• Peritonitis 18% (HVPD)• Catheter Infection 13% (DHD)

• weekly Kt/V 3.6 (HVPD)• weekly Kt/V 4.7 (DHD)

Gabriel DP, Kidney Int 2008

CRRT, SLED ….CVVHF

CVVH

DF

SLED

IHD

CVVHD

PD

Take Home Messages

• Dose:

• Inititation:

1) „Individualised“ dose!2) Minimal dose:

>20-22ml/kg/h CRRT>1.3 Kt/V (4h) IHD

early:• Oliguria/Acidosis (?)• BUN >50-70 mg% (?)