RENAL FAILURE LEARNING OBJECTIVES

Transcription

1 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. 2 Kidneys 2 Ureters Bladder Urethra ANATOMY 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.

2 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

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

4 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

5 Malaise Weakness Fatigue Neuropathy CHF Anorexia Nausea Vomiting CRF SYMPTOMS Seizure Constipation Peptic ulceration Diverticulosis Anemia Pruritus Jaundice Abnormal hemostasis STAGES OF CHRONIC KIDNEY DISEASE Stage Description GFR (ml/min/1.73 m2) 1 Kidney damage with normal or increased GFR 90 2 Kidney damage with mildly decreased GFR 3 Moderately decreased GFR Severely decreased GFR Kidney Failure < 15

6 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 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. 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

7 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 =================THE END====================