acute renal failure

ACUTE RENAL FAILURE

Vimar A. Luz, MD, FPCP, DPSN

OUTLINE Definition Incidence Causes/Pathophysiology Phases Evaluation Management Outcome

RENAL FAILURE Acute

Rapid decline in GFR (Over Hours To Days)

Usually Reversible

Chronic Kidney Damage for

> 3 months Irreversible

INCIDENCE 5% to 7% of hospital admissions 30% of ICU admissions

ACUTE RENAL FAILURE

CATEGORIES

<5%55% to 60% 35% to 40%

Prerenal

Due to decreased blood flow

in the kidneys

ACUTE RENAL FAILURE

ACUTE RENAL FAILURE

PATHOPHYSIOLOGY

Phases of Ischemic ARFPhases of Ischemic ARF

begins with renal insultbegins with renal insulthypothetical period of time hypothetical period of time

S/S: Urine 400ml or less/24 hrs,S/S: Urine 400ml or less/24 hrs,Increasing BUNIncreasing BUN


Period of ongoing renal failurePeriod of ongoing renal failureand lasts 7-14 daysand lasts 7-14 days

S/S: Urine Output is Lowest S/S: Urine Output is Lowest


Gradual return of renal functionGradual return of renal functionS/S: Can be complicated my marked S/S: Can be complicated my marked

diuretic phasediuretic phase

NEPHROLOGICAL EVALUATION Risk factors for ARF Underlying CKD Exposure to potential nephrotoxins Recent disturbance of renal perfusion

RISK GROUPS/FACTORS Hemodynamic instability Nephrotoxins Sepsis Post surgical Cardiovascular Elderly, HPN, Diabetics Trauma, Burns Neoplasia Pulmonary Muskuloskeletal Injury/Poisoning Gastrointestinal

Chertow GM et al, Toward and evidence based definition of hospital-acquired acute renal failure. J Am Soc Nephrol 2003; 8:1042A

MANAGEMENT PRIORITIES (I) Search for and correct prerenal and

postrenal factors Review medications and stop nephrotoxins Optimize cardiac output and renal blood flow Restore and/or increase urine flow Monitor fluid intake and output, daily weight

MANAGEMENT PRIORITIES (II)

Search for and treat acute complications (hyperkalemia, hyponatremia, acidosis hyperphosphatemia , pulmonary edema)

Provide early nutritional support Search for and aggressively treat infections Initiate dialysis before uremic complications

emerge Dose drugs appropriate for their clearance Stop and repair ongoing intracellular injury

MANAGEMENT Preventive Resuscitative/Supportive

Factors affecting choice of RRT modality

Patient factors:- Hypercatabolism and abdominal surgery: no PDa.The underlying disease process

isolated ARF: IHDMODS and hemodynamically unstable: CRRT, IHF,

SLEDCerebral edema: continuous formsARF and respiratory failure: continuous forms, SLED

b. The indications for dialysisRapid removal of solutes (life-threatening

hyperkalemia):IHDFluid removal in unstable patient: continuous forms

c. Location of the patient and duration of treatmentPatient mobility: SLEDICU: Continuous, SLEDCardiac ICU: CRRT, SLED

Factors affecting choice of RRT modality

Technique factorsa. Solute and water clearance

need for high urea clearance:IHD, SLEDdrug overdoses: drugs with large DV and easy

dialysability: IHD, but rebound, thus: IHD followed by CRRT

b. Ease of application and local possibilitiesnumber of nurses, machines, training of nursesrisk of bleeding: preferably IHD or SLED, PD?

ACUTE RENAL FAILURE Increase hospital length of stay Associated with more than doubling of the

cost of hospital care Increased morbidity and mortality

Chertow, et al. Toward and evidence-based definition of hospital acquired acute renal failure. J am Soc Nephrol 2003; 8:1042 A

OUTCOME 50% MORTALITY Irreversible in about 5% of cases About 5% suffer progressive deterioration

in renal function 50% have subclinical functional defects

*Dose of renal Replacement Therapy – The higher dose the better the survival

Ronco C et al. Effects of different doses in continous veno-venous hemofiltration on outcomes of acute renal failure: a prospective randomized trial. Lancet 2000;356:26-30

RECOVERY Severity of Creatinine Elevation Requirement for Dialysis Other organ system involvement

Morgera et al. Long-term outcomes in acute renal failure patients treated with continous renal replacement therapies. Am J Kidney Dis 2002; 40:275-279

Bhandari S et al. Survivors of acute renal failure who do not recover renla function. Qjm 1996;89:415-421

Salmanullah M et al. The effects of acute renal failure on long term renal function. Ren Fail 2003; 25:267-276

GOOD DAY!

acute renal failure

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