急性肾衰竭 急性肾衰竭 Acute Renal Failure （ ARF ）

DEFINITIONS AND INCIDENCE  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.

CLASSIFICATION Prerenal azotemia Intrinsic renal azotemia Postrenal azotemia

ETIOLOGY OF ARF Prerenal Azotemia  Intravascular Volume Depletion  Decreased Cardiac Output  Systemic Vasodilatation  Renal Vasoconstriction  Pharmacologic Agents ( ACEI or NSAIDs )

ETIOLOGY OF ARF Postrenal Azotemia  Ureteric Obstruction  Bladder Neck Obstruction  Urethral Obstruction

ETIOLOGY OF ARF Intrinsic Renal Azotemia  Diseases Involving Large Renal Vessels  Diseases of Glomeruli And Microvasculature  Acute Tubule Necrosis  Diseases of the Tubulointerstitium

急性 肾小管坏死 Acute Tubule Necrosis （ ATN ）

ETIOLOGY OF ATN Renal Ischemia （ 50% ） Nrphrotoxins （ 35% ） Exogenous Endogenous

PATHOPHYSIOLOGY OF ATN Intrarenal Vasoconstriction Tubular Dysfunction

Role of Hemodynamic alterations in 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 Dysfunction in ATN Role of Tubule Dysfunction in ATN Two Major TubularAbnormalities: Obstrction Backleak

Metabolic Responses of Tubule cells to Injury  ATP Depletion  Cell Swelling  Intyacellular Free Calcium↑  Intyacellular Acidosis  Phospholipase Activation  Protease Activation  Oxidant Injury  Inflammatory Respose

Pathology

Clinical Presentation of ATN The Clinical Course of ATN ： The Initiation Phase The Maintenance Phase The Recovery Phase

The Initiation Phase GFR↓ Lasting Hours or Days Evidence of true Volume Depletion Decreeced Effective Circulatory Volume Treatment with NSAIDs or ACEI

The Maintenance Phase GRR 5 ~ 10 ml/min Lasting 1 ~ 2 Weeks Oliguric ARF high catabolism Nonoliguric ARF Uremic Syndrome

High 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 Syndrome General Complications of ARF ： Gastrointestinal Cardiovascular Respiratory Neurologic Hematologic Infectious

The Uremic Syndrome Homeostatic Disorder of water ， Electrolyte and Acid-alkali Balance ： Volume Overload Metabolic Acidosis Hyperkalemia Hyponatremia Hypocalcemia Hyperphosphatemia

The 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 Examination Blood Routine Test and Chemistry Assays: Animia, RBC ↓, Hb ↓ BUN and Scr↑ Na ＋ ↓ ， K ＋ ↑,Ca 2 ＋ ↓ ， P 3+ ↑ pH ↓ ， AG ↑ ， HCO 3 － ↓

Lab Examination Diagnostic Index Prerenal Renal Specific Gravity > ~ Osmolality(mOsm/Kg H 2 O) > 500 ~ 300 Urinary Na + (mmol/L) 20 Ucr/Scr > 40 < 20 UUN/BUN > 8 < 3 BUN/Scr > 20 < Renal Failure Index 1 Fractional Excretion of Na + 1 Urine Sediment Hyaline Brown ranular

Lab Examination  Radiologic Evaluation: Plain Abdominal film Renal Ultrasonography IVP Renal angiography  Renal Biopsy

Diagnosis Differentiation ： Diagnosis Differentiation ： prerenal azotemia postrenal azotemia Glomerulonephritis/Vasculitis HUS/TTP Interstitial Nephritis Renal Artery Thrombosis Renal vein thrombosis

Management of ARF ( 一 )  Correction of Reversible causes  Prevention of additional Injury  Maintaining Fluid balance

Management of ARF ( 二 ) Maintaining Fluid balance Fluid Intake ： 500ml + The Amount of Urine in The Preceding 24 Hours

Management of ARF ( 三） Management of ARF ( 三） Nutrition  Enegy Intake:147kj/d  Dietary Protein: 0.8g/kg.d  CRRT ( fluid > 5L/d)

Management of ARF ( 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 ml 20% Glucose 3ml/kg.h+Insulin 0.5U/kg.h Dialysis

Management of ARF ( 五） Management of ARF ( 五） Metabolic Acidosis HCO 3 － < 15mmol/L : 5% Sodium Bicarbonate ml Dialysis

Management of ARF Other Electrolyte Disorder Infection Hart failure Dialysis