Post on 31-May-2015
Dr. Osama El-ShahatConsultant Nephrologist
Head of Nephrology department-NMGH (Egypt)
ObjectivesObjectives
Treatment Non- dialytic support Dialytic support
DiagnosisIncidence Mortality Biomarkers
DefinatinonARF AKI
ARF AKI
1802: Ischuria Renalis (William Heberden)
1909: Acute Bright’s Disease (William Osler)
W.W.I: War Nephritis
W.W.II: Acute Kidney Insufficiency (Bywaters & Beall)
1951: Acute Renal Failure (Homer W. Smith)
2006 : Acute Kidney Injury (AKI Network)
By AKI we actually mean “loss of small solute clearance” (urea/creatinine increase in blood)
This implies loss of GFR
So…clinically we actually mean
“acute decrease in GFR”
What do we mean by AKI?What do we mean by AKI?
Lameire N, Van BW, Vanholder R. Nat Clin Pract Nephrol 2006; 2: 364–377.
Can we do staging for AKI?
AKIN Classification
RIFLE Versus AKINRIFLE Versus AKIN
Nephrology Self-Assessment Program - Vol 10, No 3, May 2011
The use of the RIFLE system resulted in a higher detection
rate of AKI during the first 48 hours of ICU stay.
What is the advantages of RIFLE Criteria ?
Applying the RIFLE criteria revealed new insights.
Firstly,the RIFLE classification is feasible and fairly straightforward.
Secondly, the patients categorized as RIFLE-F had a far higher mortality than RIFLE-I and -R patients.
Max Bell et al; Nephrol Dial Transplant 2005 20:354 –360
Number of ARF Hospitalizations: Number of ARF Hospitalizations: 19791979 to to 20022002Rates per 1,000 personsRates per 1,000 persons
0.0
0.5
1.0
1.5
2.0
2.5
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002
Source: National Center for Health Statistics, National Hospital Discharge Survey
Mortality in Sepsis and RIFLE
Critical Care 2007; 11:411
Causes of AKICauses of AKI
Pre renal Intrinsic renal Post renal
Decrease in effective
blood volume.Arterial
occlusionOr
stenosis.Homodynamic
Form.
VascularVasculitis.Malignant
hypertension
Acute Glomerulonephritis
AcuteInterstitialnephritis
Acute Tubularnecrosis
Ischemic. Nephrotoxic.
ObstructionOf
CollectingSystem
OrExtra renaldrainage
ExogenousAntibiotic
Radio contrastcisplatin
EndogenousIntra tubular pigmentIntra tubular protein.Intra tubular crystal.
CAUSES OF AKI
Post-OP, sepsis, shock,multi-organ
failure 70%
Post-OP, sepsis, shock,multi-organ
failure 70%
Obstructive uropathy 15%
Obstructive uropathy 15%
Glomerulonephritis 5%Glomerulonephritis 5%
Nephrotoxic agents 10%Nephrotoxic agents 10% reduced blood flowreduced blood flow
ischemiaischemia
acute tubular necrosisacute tubular necrosis
Findings that suggest prerenal causes:Volume depletionCongestive heart failureSevere liver disease or other edematous states
Findings that suggest postrenal causes:Palpable bladder or hydronephrotic kidneysEnlarged prostateAbnormal pelvic examinationLarge residual bladder urine volumeHistory of renal calculi,
Findings that suggest intrinsic renal disease:
Exposure to nephrotoxic drugs or hypotensiveRecent radiographic procedures with contrast
Examine the urine sediment:
•If no abnormalities: suspect prerenal or postrenal azotemia•If eosinophils: suspect acute interstitial nephritis•If red blood cell casts: suspect glomerulonephritis or vasculitis•If renal tubular epithelial cells and muddy brown casts: suspect acute tubular necrosis
Findings that suggest prerenal azotemia :
Urinary sodium concentration <20 mEq/LUrine : plasma creatinine ratio >30Renal failure index <1Renal failure index Renal failure index = (urinary sodium concentration × plasma creatinine concentration)/urinary creatinine concentrationUrine osmolality >500 mOsm/kg
Findings that suggest acute tubular necrosis or postrenal azotemia: Urinary sodium concentration >40 mEq/LUrine:plasma creatinine ratio <20Renal failure index >1Urine osmolality <400 mOsm/kg
Timing nephrology consultationTiming nephrology consultation (Mehta, Am J Med 2002)
In-hospital mortalityEarlyEarly
consult
Delayed Delayed
consultP
40%67%<0,001
Early nephrologist involvement in patients with AKI may reduce the risk of a further decrease in kidney function.
Am J Kidney Dis. 2011;57(2):228-234
New urinary biomarkers for the early detection of acute kidney disease
Han, Bonventre,Current Opin Crit Care 2004, 10:476–482
Neutrophil gelatinase associated lipocalin
Early detection of AKI by Cystatin C
Definition of AFArea under the ROC
Day - 2Day - 1Day 0
≥ 50 % increase0.820.970.99
≥ 100 % increase0.920.980.98
≥ 200 % increase0.970.990.99
•Changes in cystatin C were able to detect the onset of AKI one to two days earlier than comparable changes in serum creatinine
1. RIFLE- R ( ≥ 50 % increase ): 1.5 ± 0.6 days earlier2. RIFLE- I ( ≥ 100 % increase): 1.2 ± 0.9 days earlier3. RIFLE- F ( ≥ 200 % increase): 1.0 ± 0.6 days earlier
Herget-Rosenthal et al, Kidney Int 2004, 66: 1115- 1122
Loop diuretics in AKI
Diuretics, particularly high doses of loop diuretics, are frequently administered to patients with acute renal failure. This is done in part in an attempt to convert oliguric to nonoliguric acute renal failure.
However, a retrospective observational report found that the use of diuretics in this setting may increase the risk of death and no recovery of renal
function.
3.4.13.4.1: We recommend not using diuretics to prevent AKI. (1B1B)
3.4.23.4.2: We suggest not using diuretics to treat AKI, except in the
management of volume overload. (2C2C)
There is insufficient evidence that the low-There is insufficient evidence that the low-dose dopamine improves survival or obviates the dose dopamine improves survival or obviates the
need for dialysis in persons with acute renal failure. need for dialysis in persons with acute renal failure. The routine use of low-dose dopamine should be The routine use of low-dose dopamine should be
discouraged until a prospective, randomized, discouraged until a prospective, randomized, placebo-controlled trial establishes its safety and placebo-controlled trial establishes its safety and
efficacy.efficacy.
Is the administration of dopamine associated with adverse or favorable outcomes in acute renal failure? Auriculin Anaritide Acute Renal
Failure Study Group.
Low Dose Dopamine in Low Dose Dopamine in AKIAKI
3.5.13.5.1: We recommend not using low-dose dopamine to prevent or treat AKI. (1A)
IV Fluids in AKI
3.1.13.1.1: In the absence of hemorrhagic shock, we
suggest using isotonic crystalloids rather than
colloids (albumin or starches) as initial
management for expansion of intravascular
volume in patients at risk for AKI or with AKI.
(2B2B)
Contrast Induced AKI
4.4.14.4.1 :We recommend i.v. volume expansion with either isotonic sodium chloride or sodium bicarbonate solutions, rather than no i.v.
volume expansion, in patients at increased risk for CI-AKI. (1A1A)
4.5.14.5.1 :We suggest not using prophylactic intermittent hemodialysis (IHD) or hemofiltration (HF) for contrast-media removal in patients at
increased risk for CI-AKI. (2C2C)
4.4.34.4.3 :We suggest using oral NAC, together with i.v. isotonic
crystalloids, in patients at increased risk of CI-AKI. (2D2D)
4.3.24.3.2: We recommend using either iso-osmolar or low-osmolar iodinated contrast media, rather than high-osmolar iodinated contrast
media in patients at increased risk of CI-AKI. (1B1B)
Bicarbonate or Saline
Among the large
randomized trials there was
no evidence of benefit for
hydration with sodium
bicarbonate compared with
sodium chloride for the
prevention of CI-AKI.
Contrast Induced AKI
Stage-based management
General Principles
Stage 1 (RiskRisk)
Risk for more severe AKI
Monitor (prevent progression)
Stage 2 (InjuryInjury)
Risk of AKI-related mortality/morbidi
ty highConservative therapy)
Stage 3 (FailureFailure)
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
Risk InjuryFailure
High Risk
Indications for RRT in critically ill AKI patients
Renal Indications
Life-threatening indications
Hyperkalemia Metabolic Acidosis Pulmonary edema Uremic omplications
Gibney et al, Clin J Am Soc Nephrol 2008
5.1.15.1.1: InitiateInitiate RRTRRT emergentlyemergently when life-threatening changes in fluid, electrolyte, and acid-base balance exist.(Not Graded)
5.1.25.1.2: Consider the broaderbroader clinicalclinical contextcontext, the presence of conditions that can be modified with RRT, and trendstrends ofof laboratorylaboratory tests—rather than single BUN and creatinine thresholds alone—when making the decision to start RRT. (Not Graded)
Dialysis Interventions for Treatment of Dialysis Interventions for Treatment of AKI
KDIGO® AKI Guideline March 2012
When to start RRTWhen to start RRT? ?
Crit Care Med 2008, Vol. 36, No 4 )suppl.)
Early RRT seems betterEarly RRT seems better
What What ModalityModality ??
1. Peritoneal dialysis (PD)
2. Intermittent Hemodialysis (IHD)
3. Slow Low-Efficiency Daily Dialysis (SLED)
4. Continuous Renal Replacement Therapy (CRRT)
• Slow Continuous Ultrafiltration (SCUFSCUF)
• Continuous Venovenous Hemofiltration (CVVHCVVH)
• Continuous Venovenous Hemodialysis (CVVHDCVVHD)
• Continuous Venovenous Diafiltration (CVVHDFCVVHDF)
AdvantagesHemodynamic stability
Slow correction
Easy access placement
No Anticoagulation
Tolerated in children
Peritoneal Dialysis )PD) In AkI
DisadvantagesRisk of infectionsDifficulty to use with abdominals surgeryLogestics
Potential Advantages of CRRTCRRT
Homodynamic stability
Recovery of renal function
Brain edema
Biocompatibility
Removal of cytokines
Nutritional support
Correction of metabolic acidosis
CVVHCVVH Avoids Hypertensive Episodes
Ronco C et al Kidney Int 56 ) suppl 72 ) s-8-s-14 , 1999Ronco C et al Kidney Int 56 ) suppl 72 ) s-8-s-14 , 1999
5.6.2:5.6.2: We suggest using CRRT, rather
than standard intermittent RRT, for hemodynamically unstable patients. (2B)
5.6.15.6.1: Use continuous and
intermittent RRT as complementary therapies in AKI patients. (Not Graded
Dialysis Interventions for Treatment of AKI
KDIGO® AKI Guideline March 2012
StudyModality %recovering renal function
SUPPORTIHD*67%**
Morgera et al.CRRT90%
Ronco et al.CRRT90%
Mehta et al.IHD
CRRT59%
92%
BEST Kidney†IHD
CRRT65%
89%
Is their an alternative to CRRT ?Is their an alternative to CRRT ?
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 )SLEDSLED)
Slow Low-Efficiency Daily Dialysis (SLEDSLED)
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
Mode of therapy
Principle method of solute clearance
CVVHConvection
CVVHDDiffusion
CVVHDFConvection & Diffusion
SCUFUltrafiltration (fluids)
HowHow we can do itwe can do it ?
Processes of care, more pertinent to Nephrologists:-
Vascular Access
Membrane characteristics
Solution
Anticoagulation
Dose
5.4.15.4.1: We suggest initiating RRT in patients with AKI via an uncuffed nontunneled dialysis catheter, rather than a tunneled catheter. (2D)
5.4.25.4.2: 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
KDIGO® AKI Guideline March 2012
Bicarbonate versus lactate based fluid replacement in CVVH
Prospective, randomized study
Results : Serum lactate concentration was
significantly higher and the
bicarbonate was lower in patients
treated with lactate based 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
Solutions for CRRTSolutions for CRRT
5.7.35.7.3: 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)
Dialysis Interventions for Treatment of AKI
KDIGO® AKI Guideline March 2012
TheThe MembraneMembrane
High Flux membrane , synthetic , biocompatable ,
acting by providing both methods of detoxications:
a)Diffusion : for low molecular weight toxins.
b)Convection : for large molecules.
5.5.15.5.1: We suggest to use dialyzers with a biocompatible
membrane for IHD and CRRT in patients with
AKI. (2C)
KDIGO® AKI Guideline March 2012
Modality AdvantagesDisadvantages
HeparinGood anticoagulation Thrombocytopenia bleeding
LMWHLess thrombocytopeniableeding
Citrate Lowest risk of bleedingMetabolic alkalosis,
hypocalcemia special dialysate
Regional Heparin
Reduced bleedingComplex management
Saline flushes No bleeding risk Poor efficacy
Prostacycline Reduced bleeding riskHypotension poor efficacy
Dose Dose
5.8.15.8.1: 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)
5.8.25.8.2: Provide RRT to achieve the goals of
electrolyte, acid-base, solute, and fluid balance
that will meet the patient’s needs. (Not Graded)
ConclusionsConclusionsConclusionsConclusions
Early detection and treatment of AKI may improve outcomes.
Even a minor acute reduction in kidney function has an adverse prognosis.
Hunting AKI in ICU….use a RIFLE .
Continuous renal replacement therapy is a standard of care and has improved outcomes from AKI in critically ill patients.
Early start of CRRT is associated with better recovery of AKI than IHD but no difference on mortality.
There is a dialysis dose effect on out come.
Thank you Thank you
Indications for RRT in critically ill AKI patients
RenalRenal ReplacementReplacementRenal SupportRenal Support
Life-threatening indications
Hyperkalemia
Acidemia
Pulmonary edema Uremic complications Solute control Fluid removal Regulation of acid-base and electrolyte status
Nutrition Fluid removal in congestive heart failure Cytokine manipulation in sepsis Cancer chemotherapy Treatment of respiratory acidosis of ARDS Fluid management in multiorgan failure
Contrast-induced AKI4.3.1 :Use the lowest possible dose of
contrast medium in patients at risk for CI-AKI. (Not Graded)
4.3.2 :We recommend using either iso-osmolar or low-osmolar iodinated
contrast media, rather than high-osmolar iodinated contrast media in patients at
increased risk of CI-AKI. (1B)
Contrast-induced AKI4.4.1 :We recommend i.v. volume expansion
with either isotonic sodium chloride or sodium bicarbonate solutions, rather than
no i.v. volume expansion, in patients at increased risk for CI-AKI. (1A)
4.4.2 :We recommend not using oral fluids alone in patients at increased risk of CI-
AKI. (1C)4.4.3 :We suggest using oral NAC, together
with i.v. isotonic crystalloids, in patients at increased risk of CI-AKI. (2D)
Contrast-induced AKI4.4.4 :We suggest not using theophylline to
prevent CI-AKI. (2C)4.4.5 :We recommend not using fenoldopam
to prevent CI-AKI. (1B)4.5.1 :We suggest not using prophylactic
intermittent hemodialysis (IHD) or hemofiltration (HF) for contrast-media
removal in patients at increased risk for CI-AKI. (2C)
Medications3.4.1 :We recommend not using diuretics to
prevent AKI. (1B)3.4.2 :We suggest not using diuretics to treat
AKI, except in the management of volume overload. (2C)
3.5.1 :We recommend not using low-dose dopamine to prevent or treat AKI. (1A)
3.5.2 :We suggest not using fenoldopam to prevent or treat AKI. (2C)
By AKI we actually mean “loss of small solute clearance” (urea/creatinine increase in blood)
This implies loss of GFR
So…clinically we actually mean
“acute decrease in GFR”
What do we mean by AKI?What do we mean by AKI?
How to define AKI?
Serum creatinine or other solute
If serum creatinine, do we choose
• Absolute increase ?• Percent increase ?• Over what time ?• Minimum peak ?
Change of case mix in Change of case mix in AKIAKI
1974-19791974-1979 1995-20001995-2000
Mortality: Mortality: 5454%% Mortality : Mortality : 5353%%
92%92%85%85%
Ricci, Ronco Crit Care Clin 21:357-366,2005Ricci, Ronco Crit Care Clin 21:357-366,2005
Incidence of ARF, need of RRT, and mortality in 187 patients with proven sepsis (surgical ICU Ghent –16 months)
23
50
28
53
69
0
10
20
30
40
50
60
70
Mortality ICU Mortality hosp Need of RRT
- ARF+ ARF
Hoste et al JASN 14:1022-1030,2003
%
Hospital mortality rates in RRT patients and matched control critically ill patients in Austria
0
10
20
30
40
50
60
70
Controls RRT
0
10
20
30
40
50
60
70
80
< 40 40-60 > 60
Control RRT
Ho
spita
l mo
rtal
ity
%
<40 40-60 >60Age groupsMetnitz et al Crit Care Med 30:2051-2058, 2002
ACUTE KIDNEY INJURY
The most frequent scenario is of AKI
occurring in the setting of circulatory
disturbance caused by severe illness
particularly if sepsis is involved.
Data from high quality RCTs are lackingThe current trend is to provide RRT earlierThere may be a recovery advantage to using
CRRT vs. HD for initial management of AKI but no difference on mrtalitaty
Dose: No benefit to “intensive” therapy
Dialytic Support of Dialytic Support of AKI =AKI =
ConclusionsConclusionsConclusionsConclusions
IndividualizatiIndividualizationon
Urine NGAL excretion post cardiac surgery in children
Neutrophil gelatinase associated lipocalin
Mishra J, et al, Lancent 2005; 365:1231-1238
Management priorities in AKI (I)
Detect as early as possible even minimal AKIExclude other renal causes of AKISearch for and correct prerenal and postrenal
factorsReview medications and stop nephrotoxinsOptimize cardiac output and renal blood flowRestore and/or increase urine flowMonitor fluid intake and output, daily weight
Management priorities in AKI (II)
Search for and treat acute complications (hyperkalemia, hyponatremia, acidosis hyperphosphatemia , pulmonary edema)
Provide early nutritional supportSearch for and aggressively treat infectionsInitiate dialysis before uremic complications
emergeDose drugs appropriate for their clearanceStop and repair ongoing intracellular injury
Dose Dose
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):
Optimal intensity of RRT is controversial
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:- lowlow (25 mL/kg/hr – 747 patients) highhigh 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.
5.3.2.15.3.2.1: For anticoagulation in intermittent RRT, we
recommend using either unfractionated or
low-molecular weight heparin, rather
than other anticoagulants. (1C)
5.3.2.25.3.2.2: For anticoagulation in CRRT, we suggest
using regional citrate anticoagulation
rather than heparin in patients who do not
have contraindications for citrate. (2B)
KDIGO® AKI Guideline March 2012
5.8.15.8.1: 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)
5.8.25.8.2: Provide RRT to achieve the goals of electrolyte,
acid-base, solute, and fluid balance that will
meet the patient’s needs. (Not Graded)
KDIGO® AKI Guideline March 2012
Dose Dose
More than 200 different definitions of ARF +++
58 creatinine levels (1.5 to 10 mg/dl)
33 UO thresholds (0 à 950 ml/24h)
Community acquired Hospital-acquired ICU-acquiredIncidence Low Moderate (5%) High (10-20%)Cause Single Multiple MOF
pre<post<renal pre<ATN<post MOF + ATNOutcome good less good poor
70-90% survival 30-50% survival 10-30%survival
Schrier & Gottschalk, Diseases of the Kidney, 1996.