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Management of Management of Acute Renal FailureAcute Renal Failure
Dr. Sachin Verma MD, FICM, FCCS, ICFCDr. Sachin Verma MD, FICM, FCCS, ICFC
Fellowship in Intensive Care MedicineFellowship in Intensive Care Medicine
Infection Control Fellows Course Infection Control Fellows Course
Consultant Internal Medicine and Critical CareConsultant Internal Medicine and Critical Care
Web:- Web:- http://www.medicinedoctorinchandigarh.com
Mob:- +91-7508677495Mob:- +91-7508677495
ReferencesReferences Brenner & Rector’s The Kidney, 7Brenner & Rector’s The Kidney, 7thth ed. ed. Harrison’s Principles of Internal Medicine, 16Harrison’s Principles of Internal Medicine, 16thth ed. ed.
29/9/0529/9/05
DefinitionDefinition
Acute renal failure is a syndrome Acute renal failure is a syndrome characterized by a rapid (hours to week) characterized by a rapid (hours to week) decline in GFR and retention of decline in GFR and retention of nitrogenous waste products such a BUN nitrogenous waste products such a BUN and creatinineand creatinine
Etiology & Classification of ARFEtiology & Classification of ARF
A. Pre renal azotemia (55-60%)A. Pre renal azotemia (55-60%) Intravascular volume depletionIntravascular volume depletion Decreased cardiac output Decreased cardiac output Renal vasoconstrictionRenal vasoconstriction
B. Acute intrinsic renal azoteniaB. Acute intrinsic renal azotenia Disease involving large renal vesselsDisease involving large renal vessels Diseases of glomeruli and renal microvasculature Diseases of glomeruli and renal microvasculature Injury to renal tubules. Exogenous toxins and Injury to renal tubules. Exogenous toxins and
endogenous toxins endogenous toxins Acute disease of tubulo interstitium. Acute disease of tubulo interstitium.
C. Post renal azotemiaC. Post renal azotemia Ureteric obstruction (Intraluminal, intramural, Ureteric obstruction (Intraluminal, intramural,
Extraureteric, periureteric)Extraureteric, periureteric) Bladder neck obstruction Bladder neck obstruction Uretheral obstruction Uretheral obstruction
Etiology & Classification of ARFEtiology & Classification of ARF
Clinical Approach to the Clinical Approach to the Diagnosis of ARFDiagnosis of ARF
History (Drug history)History (Drug history)↓↓
Physical examination (Fundus & Weight)Physical examination (Fundus & Weight)↓↓
UrinanalysisUrinanalysis↓↓
Flow chart of serial BP, Wt, BUN, S. Cr. Flow chart of serial BP, Wt, BUN, S. Cr. Major clinical events interventionsMajor clinical events interventions
↓↓Routine blood chemistry Routine blood chemistry
↓↓Radiologic evaluation (plain abdominal film)Radiologic evaluation (plain abdominal film)
Renal USG, IVP, renal angiography, MR angiography Renal USG, IVP, renal angiography, MR angiography ↓↓
Renal Biopsy Renal Biopsy
Clinical Assessment Clinical Assessment
Pre renalPre renal Fluid loss in any formFluid loss in any form Symptoms of thirstSymptoms of thirst Orthostatic dizziness and hypotension Orthostatic dizziness and hypotension TachycardiaTachycardia Decreased skin turgor dry mucus membrane Decreased skin turgor dry mucus membrane Decreased axillary sweatingDecreased axillary sweating
Definitive diagnosisDefinitive diagnosis Resolution of ARF after restoration of renal Resolution of ARF after restoration of renal
perfusionperfusion
IntrinsicIntrinsic Increased muscular activity (Rhabdomyolysis)Increased muscular activity (Rhabdomyolysis) Recent transfusion (Hemolysis) Recent transfusion (Hemolysis) Flank pain Flank pain Hyperreflexia and asterixisHyperreflexia and asterixisPost renalPost renal Suprapubic pain (Acute distension of bladder)Suprapubic pain (Acute distension of bladder) Colicky flank pain radiating to groin Colicky flank pain radiating to groin Definitive diagnosisDefinitive diagnosis Radiologic investigation and rapid improvement Radiologic investigation and rapid improvement
in renal function after relief of obstruction in renal function after relief of obstruction
UrinanalysisUrinanalysis1. Urine volume1. Urine volume
2. Urine sediment 2. Urine sediment Acellular / Transparent hyaline cast (pre renal)Acellular / Transparent hyaline cast (pre renal) Pigmented “muddy brown” granular cast, tubule epithelial Pigmented “muddy brown” granular cast, tubule epithelial
cell cast (renal)cell cast (renal) Benign sediment, hematuria, pyuria (post renal)Benign sediment, hematuria, pyuria (post renal) Broad granular cast characteristics of chronic renal disease Broad granular cast characteristics of chronic renal disease
and reflect interstitial fibrosis and dilatation of tubulesand reflect interstitial fibrosis and dilatation of tubules Granular cast Granular cast
ATN, GN / vasculitis, Interstitial nephritis ATN, GN / vasculitis, Interstitial nephritis RBC cast RBC cast
GN / Vasculitis, Malignant hypertension GN / Vasculitis, Malignant hypertension
WBC cast WBC cast Acute interstitial nephritis, Severe pyelonephritis, Acute interstitial nephritis, Severe pyelonephritis,
Marked leukemic or lymphomatous infiltration Marked leukemic or lymphomatous infiltration
3. Eosinophiluria (>5%)3. Eosinophiluria (>5%) Drug induced allergic interstitial nephritis Drug induced allergic interstitial nephritis
4. Crystalluria4. Crystalluria Uric acid crystals (pleomorphic), oxalate (envelop Uric acid crystals (pleomorphic), oxalate (envelop
shaped), Hippurate (needle shaped)shaped), Hippurate (needle shaped)
5. Tubule proteinuria (<1g/d)5. Tubule proteinuria (<1g/d) : proximal tubule cell injury, : proximal tubule cell injury, glomerular proteinuria (>1g/d)glomerular proteinuria (>1g/d) injury to glomerular injury to glomerular ultrafiltration barrier ultrafiltration barrier
6. Haemoglobinuria6. Haemoglobinuria
7. Myoglobinuria7. Myoglobinuria
Confirmatory testConfirmatory test
Plain abdominal film Plain abdominal film USG USG CT Scan CT Scan Radio nuclide scan Radio nuclide scan MRAMRA
Doppler USG and Spiral CTDoppler USG and Spiral CT Contrast angiography (Gold standard)Contrast angiography (Gold standard) Renal biopsy Renal biopsy
FENa (Fractional Excretion FENa (Fractional Excretion of Na+(%) of Na+(%)
Most sensitive index to differentiate pre renal Most sensitive index to differentiate pre renal azotemia from ATN azotemia from ATN
UNa X PcrUNa X Pcr <1 prerenal <1 prerenal
PNa X UcrPNa X Ucr >1 ATN>1 ATNX100
TreatmentTreatment
Pre renal azotemiaPre renal azotemia Correction of Hypovolemia by packed red cells, Correction of Hypovolemia by packed red cells,
isotonic saline, Hypotonic saline (0.45%)isotonic saline, Hypotonic saline (0.45%) Loop blocking diuretic, (Frusemide high dose 20 Loop blocking diuretic, (Frusemide high dose 20
– 160 mg orally or IV twice daily) to effect – 160 mg orally or IV twice daily) to effect adequate diuresis and convert oliguric to non-adequate diuresis and convert oliguric to non-oliguric RF. oliguric RF.
ARF with cirrhosis (fluid challenge) paracentesis ARF with cirrhosis (fluid challenge) paracentesis with albumin administrationwith albumin administration
Renal dose dopamine (1-3 mg/kg/min) Renal dose dopamine (1-3 mg/kg/min)
TreatmentTreatmentIntrinsic ATNIntrinsic ATN Optimization of CV function & intravascular Optimization of CV function & intravascular
volume volume Prophylactic oral acetylcysteine (600 mg BD 24 Prophylactic oral acetylcysteine (600 mg BD 24
hour before and after procedure) hour before and after procedure) Use of less nephrotoxic contrast agent Use of less nephrotoxic contrast agent
(Gadolinium and CO(Gadolinium and CO22)) Cautious use of diuretics, NSAIDs, ACE inhibitorsCautious use of diuretics, NSAIDs, ACE inhibitors Lipid encapsulated formulation of amphotericin B Lipid encapsulated formulation of amphotericin B Allopurinol (Acute urate nephropathy)Allopurinol (Acute urate nephropathy) Amifostine an organic thiophosphate (Cisplatin) Amifostine an organic thiophosphate (Cisplatin)
Forced diuresis and alkanization of urine Forced diuresis and alkanization of urine (Rhabdomyolysis)(Rhabdomyolysis)
N Acetylcysteine within 24 hour N Acetylcysteine within 24 hour (Acetaminophen)(Acetaminophen)
Dimercaprol (Chelating agent) (heavy metal)Dimercaprol (Chelating agent) (heavy metal) Ethanol (ethylene glycol toxicity)Ethanol (ethylene glycol toxicity) Plasma pharesis (Myeloma cast nephropathy) Plasma pharesis (Myeloma cast nephropathy) Systemic arterial pressure control (malignant Systemic arterial pressure control (malignant
htpertensive nephrosclerosis)htpertensive nephrosclerosis) Acute GN (pulse glucocorticoid therapy)Acute GN (pulse glucocorticoid therapy)
ANPANP 28 amino acid polypeptide. Synthesized in cardiac 28 amino acid polypeptide. Synthesized in cardiac
atrial muscle. Increased GFR by triggering afferent atrial muscle. Increased GFR by triggering afferent arteriolar vasodilatation and increasing ultrafiltration. arteriolar vasodilatation and increasing ultrafiltration. Inhibits Na transport and lower oxygen requirement. Inhibits Na transport and lower oxygen requirement.
Post renal ARFPost renal ARF Transuretheral or suprapubic placement of bladder Transuretheral or suprapubic placement of bladder
catheter (obstruction of urethra or bladder neck) catheter (obstruction of urethra or bladder neck) Percutaneous catheterization of dilated renal pelvis or Percutaneous catheterization of dilated renal pelvis or
ureter (ureteric obstruction) ureter (ureteric obstruction) Removal of obstructing lesion percutaneously or Removal of obstructing lesion percutaneously or
bypassed by insertion of ureteric stentbypassed by insertion of ureteric stent
Management of complicationManagement of complication
Intravascular volume overloadIntravascular volume overload Salt (1-2 gm/day) and water (<1 lt/day) restrictionSalt (1-2 gm/day) and water (<1 lt/day) restriction Diuretics, usually loop Diuretics, usually loop ++ thiazide thiazide Ultrafiltration or dialysis Ultrafiltration or dialysis
HyponatremiaHyponatremia Restriction of enteral free water intake (<1lt/day)Restriction of enteral free water intake (<1lt/day) Avoid hypotonic intravenous solution (including Avoid hypotonic intravenous solution (including
dextrose)dextrose)
HyperkalemiaHyperkalemia Restriction of dietary KRestriction of dietary K++ intake (<40 mmol/day) intake (<40 mmol/day) Eliminate KEliminate K++ supplement and K supplement and K++ sparing diuretic, sparing diuretic, Potassium binding ion-exchange resin (Na Potassium binding ion-exchange resin (Na
polystyrene sulphonate)polystyrene sulphonate) Glucose (50 ml of 50% Dextrose) and insulin (10 Glucose (50 ml of 50% Dextrose) and insulin (10
U regular) U regular) NaCONaCO33 (50-100 mmol) (50-100 mmol) Calcium gluconate (10 ml of 10% solution) over 5 Calcium gluconate (10 ml of 10% solution) over 5
minuteminute Dialysis (with low KDialysis (with low K++ dialysate) dialysate)
Metabolic acidosisMetabolic acidosis Restriction of dietary protein (0.6 g/Kg/day of high Restriction of dietary protein (0.6 g/Kg/day of high
biologic value)biologic value) Na bicarbonate (maintain serum bicarbonate >15 Na bicarbonate (maintain serum bicarbonate >15
mmol/L or arterial pH >7.2) mmol/L or arterial pH >7.2) Dialysis Dialysis
HyperphosphatemiaHyperphosphatemia Restriction of dietary phosphate intake (<800 Restriction of dietary phosphate intake (<800
mg/day)mg/day) Phosphate binding agents (Ca carbonate, Phosphate binding agents (Ca carbonate,
Aluminium hydroxide)Aluminium hydroxide)
HypocalcemiaHypocalcemia Calcium CarbonateCalcium Carbonate Calcium gluconate (10 – 20 ml of 10% solution) Calcium gluconate (10 – 20 ml of 10% solution)
HypermagnesemiaHypermagnesemia Avoid MgAvoid Mg2+2+ containing antacids containing antacids
HyperuricemiaHyperuricemia Treatment usually not necessary (<15 mg/dl)Treatment usually not necessary (<15 mg/dl)
NutritionNutrition Restriction of dietary protein (0.6 g/kg/day)Restriction of dietary protein (0.6 g/kg/day) Carbohydrate (100 g/day)Carbohydrate (100 g/day) Enteral / Parenteral nutritionEnteral / Parenteral nutrition
Indication for DialysisIndication for Dialysis
Clinical evidence (signs & symptoms) of uremia Clinical evidence (signs & symptoms) of uremia Intractable intravascular volume over loadIntractable intravascular volume over load Hyperkalemia Hyperkalemia Severe acidosis (resistant to conservative Severe acidosis (resistant to conservative
measures)measures) Prophylactic dialysis when urea >100-150 mg/dl Prophylactic dialysis when urea >100-150 mg/dl
or creatinine >8-10 mg/dlor creatinine >8-10 mg/dl
OutcomeOutcome
Mortality rate approximately 50%Mortality rate approximately 50% Poor prognosis – Oliguria (<400 mg) or serum Poor prognosis – Oliguria (<400 mg) or serum
creatinine (>3 mg/dl), older debilitated patient creatinine (>3 mg/dl), older debilitated patient and multiple organ failure at the time of and multiple organ failure at the time of presentation presentation
50% subclinical impairment of renal function 50% subclinical impairment of renal function 5% never recover (require dialysis or 5% never recover (require dialysis or
transplantation)transplantation) 5% progressive decline in GFR5% progressive decline in GFR