Upload
portsaid-neonatology
View
468
Download
0
Embed Size (px)
DESCRIPTION
Lecture given byProf Sonia Elsharkawy Head of pediatric department Suez canal university at our Port Said fifth neonatology conference
Citation preview
Management Of Acute Renal Injury In Pediatrics
ProfSonia Elsharkawy
Head of pediatric departmentSuez canal university
Objectives
Acute renal failure.•
•Definition of ARF.Definition of ARF.
• Classification of ARF.
• Causes of ARF.
• Symptoms & sings Of ARF.• Diagnosis Of ARF.& prevention
Indications and goals for acute renal replacement therapy
• Modalities for renal replacement therapy– Peritoneal dialysis– Intermittent hemodialysis– Continuous renal replacement therapy
(CRRT)
Special issues related to the infant
The Problematic Definition of The Problematic Definition of ARFARF
• The Conceptual Definition of Acute Renal Failure:
– “Sudden loss of renal function resulting in the loss of the kidneys’ ability to regulate electrolyte and fluid homeostasis”
The Problematic Definition of The Problematic Definition of ARFARF
• Pediatric AKI definition: a moving target
• Infants– Cr in the first few weeks of life may reflect
maternal values
• Children– Low baseline Cr makes 0.2-0.3 changes in Cr
significant– Varying muscle mass
• Adolescents– Similar to adults
ARF• Pre renal (functional)
• Renal-intrinsic (structural)
• Post renal (obstruction)
ARF Pirouz Daeihagh, M.D.Internal medicine/Nephrology Wake Forest University School of Medicine. Downloaded 4.6.09
Causes of ARF
Pre-renal Renal Post-renal Absolute hypovolaemia
Glomerular (RPGN)
Pelvi-calyceal
Relative hypovolaemia
Tubular (ATN)
Ureteric
Reduced cardiac output
Interstitial (AIN)
VUJ-bladder
Reno-vascular occlusion
Vascular (atheroemboli)
Bladder neck-urethra
ARF Pre renal
•Decreased renal perfusion without cellular injury
– 70% of community acquired cases– 30% hospital acquired cases
ARF Intrinsic• Acute tubular necrosis (ATN)
– Ischaemia
– Toxin
– Tubular factors
• Acute interstitial Necrosis (AIN)– Inflammation
– oedema
• Glomerulonephritis (GN)
ARF Post renal
• Post renal obstruction
• Obstruction to the urinary outflow tract
Blocked catheter– Malignancy
Contrast-Induced ARF
• Prevalence• Less than 1% in patients with normal
renal function
• Increases significantly with renal insufficiency
Contrast-Induced ARF• Risk Factors
• Renal insufficiency
• Diabetes mellitus
• Multiple myeloma
• High osmolar (ionic) contrast media
• Contrast medium volume
Contrast-induced ARF
Clinical Characteristics
• Onset - 24 to 48 hrs. after exposure
• Duration - 5 to 7 days
• Non-oliguric (majority)
• Dialysis - rarely needed
• Urinary sediment - variable
• Low fractional excretion of Na
Contrast-induced ARFProphylactic Strategies
• Use I.V. contrast only when necessary
• Hydration
• Minimize contrast volume
• Low-osmolar (nonionic) contrast media
• N-acetylcysteine.
Pediatric Modified RIFLE--Pediatric Modified RIFLE--definitiondefinition
Ackan-Arikan et al: Kid Int 2010
Pediatric Modified RIFLE Criteria
CrCl Urine output
Risk GFR decrease by 25% <0.5ml/kg/hour for 8 hours
Injury GFR decrease by 50% <0.5ml/kg/hour for 16 hours
Failure GFR decrease by 75% or GFR<35ml/min/1.73m 2
<0.3 ml/kg/hour for 24 hours or anuric for 12 hours
Loss Persistent ARF > 4 weeks
End stage
End Stage Renal Disease (>3 months)
GFR per Schwartz equation: GFR= Ht (cm) X constant / serum creat (mg/dl)
Acute Kidney Injury
AKI can be prevented by early recognition and treatment of the underlying cause, for example:
-Early treatment of infections/sepsis– Early treatment/prevention of dehydration– Correcting hypovolaemia
Monitoring use of drugs such as NSAIDs and ACE inhibitors, especially if a patient is acutely unwell
• Taking care with at-risk patients who need iodinated contrast agents with scans
BIOMARKERS
Biomarkers for Acute Kidney InjuryBiomarkers for Acute Kidney Injury
• Ideally AKI would have a biomarkers like myocardial infarction (i.e. troponin-1)
• Currently no Troponin-I like marker to identify the site or severity of injury, although various markers are being evaluated
– Kidney Injury Molecule (KIM-1)
– Neutrophil gelatinase-associated lipocalcin (NGAL)
– IL-18
– Cystatin C
(Changes in SCr may be a very late indicator of renal injury)
AKI in the ICU
• Treatment of acute kidney injury (AKI) is principally supportive -- renal replacement therapy (RRT) indicated in patients with severe kidney injury.
• Goal: optimization of fluid & electrolyte balance
Use an early warning score
that recognises and responds to
deterioration and acute illness
Staff should have competencies in:
• Monitoring • Measurement• Interpretation
Observations and assessment
Neonatal Renal Failure
In term neonates, renal failure is suspected when the plasma creatinine concentration is greater than 15 mg/L, for at least twenty four to forty eight hours, while maternal renal function is normal
Incidence
Precise incidence and prevalence of ARF in the newborn is
unknown , 6%- 24% (Andreoli, 2013).
In developing countries, the incidence and epidemiology of
acute renal failure in newborns was 3.9% of 1.000 live births
and 34.5% of 1.000 newborns admitted to the neonatal unit
(Andreoli, 2013).
The mortality of acute renal failure is still very high (30%-
60%) (Drukker & Guingard, 2012).
Etiology
Variety of congenital, developmental, and acquired conditions
(Mercado-Deane et al, 2012).
Prenatal injury/vascular damage: - Maternal
- Congenital renal diseases
Postnatal:
1- Prerenal: - Decreased true intravascular volume
- Decreased effective intravascular volume
2- Intrinsic: -ATN
-Interstitial nephritis
3- Postrenal (obstructive)
Management
Immediate Measures:Immediate Measures:
1- 1- volume trials.
2- Diuretics
3- Dopaminergic (Vasoactive) Agents
Conservative treatment.Conservative treatment.
Renal replacement therapyRenal replacement therapy
Renal TransplantationRenal Transplantation
Indications for Renal Replacement
• Volume overload
• Metabolic imbalance
• Toxins (endogenous or exogenous)
• Inability to provide needed daily fluids due to insufficient urinary excretion
Goals of Renal Replacement
• Restore fluid, electrolyte and metabolic balance
• Remove endogenous or exogenous toxins as rapidly as possible
• Permit needed therapy and nutrition
• Limit complications
R R T Includes: •Traditional intermittent hemodialysis,
• Peritoneal dialysis
• Variety of other intermittent and continuous therapy,
•Renal transplant
Indications to start RRT
• Anuria – oliguria(diuresis <200 ml in 12 hr)
• Severe metabolic acidosis(pH<7.10)
• Hyperazotemia(BUN> 80mg/dl) or creatinine >4mg/dl
• Hyperkalemia K >6.5mEq/l
• Clinical signs of uremic toxicity
• Severe dysnatremia Na<115 or Na>160mEq/l
• Hyperthermia (>40 deg.C without response to medical therapy)
• Anasarca or severe fluid overload
• Multiple organ failure with renal dysfunction and /SIRS, sepsis, or septic shock with renal dysfunction
BUT• The optimal timing of RRT for AKI is not
defined
• Timing of renal replacement therapy initiation in acute renal failure: a meta-analysis
Meta-analysis of randomized trials, early RRT was associated with a nonsignificant 36% mortality risk reduction (RR, 0.64; 95% confidence interval, 0.40 to 1.05; P = 0.08)
In cohort studies, early RRT was associated with a statistically significant 28% mortality risk reduction (RR, 0.72; 95% confidence interval, 0.64 to 0.82; P < 0.001).
• Seabra VF, Balk EM, Liangos O, Sosa MA, Cendoroglo M, Jaber BL.
Am J Kidney Dis. 2012;52:272–284
whenInitiate RRT Initiate RRT EEmergentlymergently
Life-threatening changes in fluid
Electrolyte
Acid-base balance
Uremic complications: pericarditis, pleuritis, encephalopathy, coagulopathy
Kidney Disease: Improving Global Outcomes (KDIGO), 2012
Technique and modalities
Technique and modalities
• All RRT consist of blood purification by having the blood flow through SPM.
• Blood flow into hollow fibers composed by biocompatible synthetic materials.
• Wide range of substances( water , urea,and low, middle and high mol.wt. solutes)allow the blood across such membranes by diffusion (solutes) and by convection(solute and water)
Modalities for Renal Replacement
• Hemodialysis.
• Peritoneal dialysis.
• Continuous renal replacement therapy (CRRT)
• Heamofiltiration.
• Renal replacement.
Principles of dialysis
• Dialysis = diffusion = passive movement of solutes across a semi-permeable membrane down concentration gradient– Good for small molecules
• (Ultra)filtration = convection = solute + fluid removal across semi-permeable membrane down a pressure gradient (solvent drag)– Better for removal of fluid and
medium-size molecules
Faber. Nursing in Critical Care 2009; 14: 4Foot. Current Anaesthesia and Critical Care 2005; 16:321-329
Principles of dialysis
Hemodialysis = solute passively diffuses down concentration gradient Dialysate flows countercurrent to blood flow. Urea, creatinine, K move from blood to dialysate Ca and bicarb move from dialysate to blood.
Hemofiltration: uses hydrostatic pressure gradient to induce filtration / convection plasma water + solutes across membrane.
Hemodiafiltration: combination of dialysis and filtration.
Intermittent hemodialysis (IHD)
• Oldest and most common technique• Primarily diffusive treatment: blood and dialysate are
circulated in countercurrent manner
• Best for removal of small molecules• typically performed 4 hours 3x/wk or daily
Continuous RRT Introduced in 1980s• involve either dialysis (diffusion-based solute
removal) or filtration (convection-based solute and water removal) treatments in a continuous mode with slower rate of solute or fluid removal
• CRRT includes continuous hemofiltration, hemodialysis and hemodiafiltration, all of which can be performed using arteriovenous or venovenous extracorporeal circuits.
Peritoneal dialysis
Considerations for Infants
ADVANTAGES
• No vascular access• No extracorporeal
perfusion• Simplicity• ? Preferred modality
for cardiac patients?
DISADVANTAGES• Infectious risk• Leak• ? Respiratory
compromise?
Intermittent hemodialysis Considerations for Infants
ADVANTAGES
• Rapid particle and fluid removal; most efficient modality
• Does not require anticoagulation 24h/d
DISADVANTAGES
• Vascular access• Complicated• Large extracorporeal
volume• Adapted equipment• ? Poorly tolerated
Pediatric CRRT: Vicenza, 1984
CRRT for Infants: A Series of Challenges
• Small patient with small blood volume
• Equipment designed for bigger people
• No specific protocols
• Complications may be magnified
• No clear guidelines
• Limited outcome data
Potential Complications of Infant CRRT
• Volume related problems
• Biochemical and nutritional problems
• Hemorrhage, infection
• Thermic loss
• Technical problems
• Logistical problems
Role of RRT in different clinical situations
• Sepsis
• Congestive heart failure
•Miller's Anesthesia, 7th ed. 2009
RRT in congestive heart failure
• Slow continuous ultrafiltration (SCUF) effective for fluid removal in decompensated CHF..
Costanzo et al J Am Coll Cardiol 2010 49:675-683.
Discontinuation of RRT
• Until “evidence of recovery of kidney function”– Improved UOP in oliguria– Decreasing creatinine– Creatinine clearance minimum 12 mL/min,
some say 20 mL/min
Thanks!