ACUTE RENAL FAILUREACUTE RENAL FAILURE

吳志仁 醫師馬偕醫院 腎臟內科

DefinitionDefinition

An increase Cr. 0.5 mg/dl per day≧ An increase of more than 50 %

over baseline Cr. A reduction in calculated CCr

of 50% Decrease in renal function that

results in the need for dialysis

Main Categories of ARFMain Categories of ARF

P rerena l c aus es

I s c hemia

(50% )

T ox ins

(35% )

T ubular nec ros is Intrs t it ia l nephrit is

(10% )

A c ute glomerulonephrit is

(5% )

Intrins ic c aus es P os trena l c aus es

A c ute R ena l F a ilure

Acute Tubular NecrosisAcute Tubular Necrosis

ARF is not result of primary vascular, glomerular, or interstitial disorder has to been referred to as ATN.

Neither the incidence nor the mortality and morbidity rates with ATN decreased, despite ongoing improvement of supportive Rx and renal replacement therapy.

Pathophysiology of Ischemic Acute Renal Failure Pathophysiology of Ischemic Acute Renal Failure

Vascular Factors Medullary Hypoxia Tubular - Cell Injury Neutrophils and Reperfusion Injury Role of Growth Factors in Recovery f

rom Ischemic ARF

Vascular Factors and Therapy with VsodilatorsVascular Factors and Therapy with Vsodilators

Dopamine Calcium-Channel B

lockers Atrial Natriuretic P

eptides PGE1

Endothelin receptor antagonist

Adenosine antagonist

Nitric Oxide

Lassnigg A et al, J Am Soc Nephrol 11, 2000

0.5~2 mg/kg/min -- so call renal dose dopamine

In double blind, randomized, controlled studies showed no clear experimental or clinical support for renal protective effect of dopamine.

There are potential risks associated with even low dose dopamine. These include tachycardia, cardiac arrhythmias, AMI and ischemic bowel.

Renal protection effect of dopamine ?

Osmotic Agents and DiureticsOsmotic Agents and Diuretics

Loop diuretics can only increase urine output for fluid management.

There is little evidence that conversion from an oliguric to a nonoliguric state decreases the mortality rate.

Tepel M et al, NEJM 2000

Prevention of radiographic contrast agent induced reductionin renal function by ACETYLCYSTEINE

ConclusionsConclusions

The clinical Rx of ARF is still largely supportive.

Basic research has provided many, albeit still unproved, approaches to future therapies.

Additional experimental models better reflect the multifactorial causes of clinical ARF.

Single-drug will probably never be effective, and multiple agents may be need to improve outcome.