1.ACUTE RENAL FAILURE Trish Keresztes, PhD, RN, CCRN

2. ARF: REVIEW RENAL FUNCTION

Regulate fluid volume.

Regulate electrolyte balance.

Regulate acid-base balance.

Regulate blood pressure.

Excrete nitrogenous waste products.

Produce erythropoietin.

Metabolism of vitamin D.

3. 4. ACUTE RENAL FAILURE

Precipitous and significant (>50%) decrease in glomerular filtration rate (GFR) over a period of hours to days with an accompanying accumulation of nitrogenous wastes in the body.

5. ACUTE RENAL FAILURE

Glomerulus: tuft of capillaries. The wall of the glomerular capillary serves as a filtration membrane with three layers

• Inner capillary endothelium

• Middle basement membrane

• Outer layer of capillary epithelium

6. ACUTE RENAL FAILURE

The glomerular filtrate passes through the three layers of the glomerular membrane and forms the primary urine.

GFR: the filtration of the plasma per unit of time. Directly related to the perfusion pressure in the glomerular capillaries.

7. ACUTE RENAL FAILURE

Process of urine formation:

• Glomerular filtration-> tubular reabsorption->tubular secetion->excretion.

• Proximal tubules reabsorbs 60-70%sodium and water and 90% other electrolytes.

• Distal tubules reabsorb sodium, secrete potassium and hydrogen ions (regulate acid base balance.

8. ACUTE RENAL FAILURE 9. ACUTE RENAL FAILURE 10. ACUTE RENAL FAILURE 11. ARF: RISKS FOR DEVELOPMENT

Hx DM, HTN, CV disease, calculi.

Family history calculi, HTN.

Hypotensive episodes.

Drugs with potential for nephrotoxicity.

Major trauma, crushing injuries, severe allergic reactions.

12. Acute Renal Failure

Occurs in 4% of all hospital admissions.

Occurs in 20% of those admitted into critical care units.

Mortality rate 50% overall.

Mortality rate for hospital acquired ARF is 70%.

13. Pathophysiology

Glomerular pressure is primarily dependant upon renal blood flow.

Depressed renal blood flow eventually leads to ischemia and tubular cell death.

As tubular cells die, they slough off into the tubules and form obstructing casts which further decrease GFR and lead to oliguria.

14. ACUTE RENAL FAILURE

Azotemia: refers to an abnormally high level of nitrogenous wastes (urea nitrogen, uric acid, creatinine) in the blood related to a decrease in the GFR.

Uremia: a clinical syndrome that comprises the signs and symptoms associated with end stage renal disease.

15. ARFCAUSES

Prerenal: decreased blood flow to the kidney.

Intrarenal: Direct damage to the kidney parenchyma.

Postrenal: Obstruction to the flow of urine which may cause hyronephrosis.

Before-within-after the kidney.

16. ARF PRERENAL CAUSES

Inadequate intravascular volume:hypovolemia

• Fluid loss from N/V

• Hemorrhage

• Excessive diuresis

Redistribution of blood volume

• Peripheral vasodilation with sepsis

• Third spacing

17. ARF PRERENAL CAUSES

Reduced cardiac output

• Acute MI -> cardiogenic shock

• CHF

• Cardiac tamponade

Renal artery thrombosis

Interruption of blood flow during surgery

18. ARF INTRARENAL CAUSES

Acute Tubular Necrosis most common form

ATN: Prolonged ischemic damage: MAP