RENAL FAILURE LEARNING OBJECTIVES At the end of the lecture, student should be able to: • Know the quick overview of anatomy, physiology of urinary system. • Know the classification of renal failure. • Know the clinical picture and presentation of renal failure. ANATOMY • • • •

2 Kidneys 2 Ureters Bladder Urethra KIDNEY FUNCTION

• Detoxify blood • Increase calcium absorption – Calcitriol • Stimulate RBC production – Erythropoietin • Regulate blood pressure and electrolyte balance – Renin ASSESSMENT OF RENAL FUNCTION Glomerular Filtration Rate (GFR) • It is the fluid filtered from the plasma per unit of time. • Gives a rough measure of the number of functioning nephrons. • Normal GFR: • Men: 130 mL/min./1.73m2 • Women: 120 mL/min./1.73m2 Cannot be measured directly, so we use creatinine and creatinine clearance to estimate.

CLASSIFICATIONS OF RENAL FAILURE • Acute renal failure. • Chronic renal failure ACUTE VERSUS CHRONIC • Acute – sudden onset – rapid reduction in urine output – Usually reversible – Tubular cell death and regeneration • Chronic – Progressive – Not reversible – Nephron loss • 75% of function can be lost before its noticeable ACUTE RENAL FAILURE • Pre-renal = 55% • Renal parenchymal (intrinsic)= 40% • Post-renal = 5-15% • • • •

RISK FACTOR FOR ARF Advanced age Preexisting renal parenchymal disease Diabetes mellitus Underlying cardiac or liver disease URINE OUTPUT IN ARF

• Oliguria – daily urine output < 400 mL – Most deaths are associated with the underlying disease process and infectious complications. • Anuria – No urine production

– probably time for dialysis CAUSES OF ARF • Pre-renal – vomiting, diarrhea, poor fluid intake, use of diuretics, and heart failure – liver dysfunction, or septic shock. • Intrinsic – Interstitial nephritis, acute glomerulonephritis, tubular necrosis, ischemia, toxins • Post-renal – prostatic hypertrophy – cancer of the prostate or cervix – retroperitoneal disorders – neurogenic bladder – bilateral renal calculi – papillary necrosis – coagulated blood – bladder carcinoma – fungus

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SYMPTOMS OF ARF Decrease urine output (70%) Edema, esp. lower extremity Mental changes Heart failure Nausea, vomiting Pruritus Tachypenic Cool, pale, moist skin

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MANAGEMENT OF ARF Make/think about the diagnosis Treat life threatening conditions Identify the cause if possible – Hypovolemia – Toxic agents (drugs, myoglobin) – Obstruction Treat reversible elements – Hydrate – Remove drug – Relieve obstruction CHRONIC KIDNEY DISEASE • Progressive, irreversible damage to the nephrons and glomeruli • a GFR of < 60 for 3 months or more. • Most common causes: • Diabetes Mellitus • Hypertension CHRONIC RENAL FAILURE

Causes • Diabetic Nephropathy • Hypertension • Glomerulonephritis • Reflux nephropathy in children • Polycystic kidney disease • Kidney infections & obstructions

• Malaise • Weakness • Fatigue • Neuropathy • CHF • Anorexia • Nausea • Vomiting

Stage 1 2 3 4 5

CRF SYMPTOMS • Seizure • Constipation • Peptic ulceration • Diverticulosis • Anemia • Pruritus • Jaundice • Abnormal hemostasis

STAGES OF CHRONIC KIDNEY DISEASE Description GFR (mL/min/1.73 m2) Kidney damage with ≥ 90 normal or increased GFR Kidney damage with mildly 60-89 decreased GFR Moderately decreased GFR 30-59 Severely decreased GFR 15-29 Kidney Failure < 15

ASSOCIATED PROBLEMS AND TREATMENT 1. Immunosuppression • Patients with CRF, even pre-dialysis, are at increased risk for infection • Cell mediated immunity is particularly impaired • Hemodialysis seems to increase immunocompromise • Complement system is activated during hemodialysis • Patients with CRF should be vaccinated aggressively 2. Anemia: • Due to reduced erythropoietin production by kidney • Occurs when creatinine rises to >2.5-3mg/dL • Anemia management: Hct goal @ 33% 3. Hyperphosphatemia: • Decreased excretion by kidney • Increased phosphate load from bone metabolism (by high parathyroid hormone levels) • Increased PTH levels leads to renal bone disease. 4. Hypertension: • Blood pressure • Targetted mean pressure 92-98mm Hg in patients with renal failure and proteinuria. • Patients with HTN and albuminuria >1gm/day, blacks, diabetics have higher ESRD risk.

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DIALYSIS ½ of patients with CRF eventually require dialysis Diffuse harmful waste out of body Control BP Keep safe level of chemicals in body 2 types – Hemodialysis – Peritoneal dialysis

HEMODIALYSIS • 3-4 times a week • Takes 2-4 hours • Machine filters blood and returns it to body

PERITONEAL DIALYSIS • Abdominal lining filters blood • 3 types – Continuous ambulatory – Continuous cyclical – Intermittent

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