急性肾衰竭急性肾衰竭

Acute Renal Failure

（ ARF ）

DEFINITIONS AND DEFINITIONS AND INCIDENCEINCIDENCE

Acute renal failure (ARF) is a syndrome characterized by rapid decline in glomerular filtration rate(GFR) and retention of nitrogenous waste products such as blood urea nitrogen (BUN) and creatinine.

ARF complicates approximately 5% of hospital admissions and up to 30% of admissions to

intensive care units.

CLASSIFICATIONCLASSIFICATION

Prerenal azotemia Intrinsic renal azotemia Postrenal azotemia

ETIOLOGY OF ARFETIOLOGY OF ARF

Prerenal Azotemia Intravascular Volume Depletion

Decreased Cardiac Output

Systemic Vasodilatation

Renal Vasoconstriction Pharmacologic Agents (ACEI or NSAIDs)

ETIOLOGY OF ARFETIOLOGY OF ARF

Postrenal Azotemia

Ureteric Obstruction

Bladder Neck Obstruction

Urethral Obstruction

ETIOLOGY OF ARFETIOLOGY OF ARF

Intrinsic Renal Azotemia

Diseases Involving Large Renal Vessels

Diseases of Glomeruli And Microvasculature

Acute Tubule Necrosis

Diseases of the Tubulointerstitium

急性急性肾小管坏死肾小管坏死

Acute Tubule Necrosis

（ ATN ）

ETIOLOGY OF ATNETIOLOGY OF ATN

Renal Ischemia （ 50% ） Nrphrotoxins （ 35% ） Exogenous

Endogenous

PATHOPHYSIOLOGY OF ATNPATHOPHYSIOLOGY OF ATN

Intrarenal Vasoconstriction

Tubular Dysfunction

Role of Hemodynamic alterations Role of Hemodynamic alterations in ATNin ATN

Reduction in Total Renal Blood Flow Regional Disturbance in Renal Blood Flow and Oxygen Supply Edothelin (ET) / NO (EDNO) Other Endothelial Vasoconstrctors The Tubulo-glomerular Feed Back

Role of Tubule DysfunctionRole of Tubule Dysfunction in ATN in ATN

Two Major TubularAbnormalities:

Obstrction

Backleak

Metabolic Responses of Metabolic Responses of Tubule cells to InjuryTubule cells to Injury

ATP Depletion Cell Swelling Intyacellular Free Calcium↑ Intyacellular 　 Acidosis Phospholipase Activation Protease Activation Oxidant Injury Inflammatory Respose

PathologyPathology

Clinical Presentation of ATNClinical Presentation of ATN

The Clinical Course of ATN ： The Initiation Phase

The Maintenance Phase

The Recovery Phase

The Initiation PhaseThe Initiation Phase

GFR↓

Lasting Hours or Days

Evidence of true Volume Depletion

Decreeced Effective Circulatory Volume

Treatment with NSAIDs or ACEI

The Maintenance PhaseThe Maintenance Phase

GRR 5 ~ 10 ml/minLasting 1 ~ 2 WeeksOliguric ARF high catabolismNonoliguric ARFUremic Syndrome

High Catabolic StateHigh Catabolic State

Daily Increase in BUN >10.1~17.9 mmol/L

Daily Increase in Serum Creatinine >176.8μmol/L

Daily Increase in Serum Potassium >1~2 mmol/L

Daily Decrease in Serum HCO 3 － >2 mmol/L

The Uremic SyndromeThe Uremic Syndrome

General Complications of ARF ： Gastrointestinal

Cardiovascular

Respiratory

Neurologic

Hematologic

Infectious

The Uremic SyndromeThe Uremic Syndrome Homeostatic Disorder of water ， Electr

olyte and Acid-alkali Balance ： Volume Overload

Metabolic Acidosis

Hyperkalemia

Hyponatremia

Hypocalcemia

Hyperphosphatemia

The Recovery PhaseThe Recovery Phase

The Period of Repair and Regeneration

of Renal Tissue:

Gradual Increase in Urine Output

“Post-ATN” Diuresis

Fall in BUN and Scr

Recovery of GFR/ Tubule function

Lab ExaminationLab Examination

Blood Routine Test and Chemistry Assays:

Animia, RBC ↓, Hb ↓

BUN and Scr↑

Na ＋ ↓ ， K ＋↑ ,Ca2 ＋↓， P3+ ↑

pH ↓ ， AG ↑ ， HCO3－ ↓

Lab ExaminationLab Examination

Diagnostic Index Prerenal Renal Specific Gravity > 1.020 ~ 1.010

Osmolality(mOsm/Kg H2O) > 500 ~ 300

Urinary Na+ (mmol/L) < 10 > 20

Ucr/Scr > 40 < 20

UUN/BUN > 8 < 3

BUN/Scr > 20 < 10-15

Renal Failure Index < 1 > 1

Fractional Excretion of Na+ < 1 > 1

Urine Sediment Hyaline Brown ranular

Lab ExaminationLab Examination

Radiologic Evaluation: Plain Abdominal film

Renal Ultrasonography

IVP

Renal angiography Renal Biopsy

Diagnosis DifferentiationDiagnosis Differentiation ：： prerenal azotemia

postrenal azotemia

Glomerulonephritis/Vasculitis

HUS/TTP

Interstitial Nephritis

Renal Artery Thrombosis

Renal vein thrombosis

Management of ARF Management of ARF (( 一一 ))

Correction of Reversible causes

Prevention of additional Injury

Maintaining Fluid balance

Management of ARF (Management of ARF ( 二二 ))

Maintaining Fluid balance

Fluid Intake ： 500ml + The Amount of Urine in The Preceding 24 Hours

Management of ARF (Management of ARF ( 三）三）

Nutrition Enegy Intake:147kj/d

Dietary Protein: 0.8g/kg.d

CRRT ( fluid > 5L/d)

Management of ARF (Management of ARF ( 四）四） Hyperkalemia K+<6mmol/L Restriction of Dietary Potassium Intake K+-Binding Ion Exchange Resins K+>6mmol/L 10%Calcium Gluconate 10-20ml 5% Sodium Bicarbonate 100-200ml 20% Glucose 3ml/kg.h+Insulin 0.5U/kg.h Dialysis

Management of ARF (Management of ARF ( 五）五）

Metabolic Acidosis HCO3

－ < 15mmol/L :

5% Sodium Bicarbonate 100-250ml

Dialysis

Management of ARFManagement of ARF

Other Electrolyte Disorder

Infection

Hart failure

Dialysis