Kidney Physiology Kidney Functions: activate vitamin D (renal 1-alpha hydroxylase)activate vitamin D (renal 1-alpha hydroxylase) produces erythropoietin which stimulatesproduces erythropoietin which stimulates RBC formation helps regulate blood pressurehelps regulate blood pressure ELIMINATES METABOLIC WASTEELIMINATES METABOLIC WASTEPRODUCTS HELPS MAINTAIN FLUID, ELECTROLYTE,HELPS MAINTAIN FLUID, ELECTROLYTE, AND ACID-BASE IMBALANCES

Kidney Diseases of Note n Glomerulonephritis (acute or chronic) n Nephrotic Syndrome n Acute Renal Failure n Chronic Renal Failure n Dialysis n Urinary Calculi

Renal Filtrate:fluid from the blood filtered by the kidneys that forms urine. GFR:Glomerular Filtration Rate the rate at which the kidney forms renal filtrate. Normal: ml/min Renin:enzyme secreted by kidney in response to low blood flow; results in adrenal signal (aldosterone) to cause kidney to retain Na and water.

Nephrotic Syndrome: a cluster of symptoms proteinuria low serum albumin edema hyperlipidemia Sometimes an early sign of renal failure. Caused by:infections, certain drugs, toxins, DM, renal blood clots.

Proteinuria Albumin Albumin Immunoglobulins (immunity) Transferrin (anemia) Transferrin (anemia) Vitamin D-BP (rickets) Low serum proteins fluid shift into interstitial spaces Low Blood Volume Edema Kidneys Respond Retain Na and fluids!!!!

Energy:35 kcal/ kg Protein: g / kg Fat:< 30% of kcals; low in saturated fatty acids. Sodium:During edematous phase 250 mg/day As edema resolves to ~ 1500 mg/ day

Prerenal Postrenal Intrarenal LOW RENAL OBSTRUCTION KIDNEY DAMAGE BLOOD FLOW IN URINARY TRACT TRACT SUDDEN PRECIPITOUS DROP IN GFR, URINE OUTPUT

UREMIA/ AZOTEMIA:Build-up of urea nitrogen in the blood (BUN). Normal:10-20 mg/dl Uremia: mg/dl ESRD: mg/dl ARF Phases:1. Oliguric= reduced urine volume; 2. Diuretic= large fluid/electrolyte losses; 3. Recovery= NL renal function

Build-up of toxic waste products in the blood (e.g., urea, potassium) (e.g., urea, potassium) Symptoms:Weakness, Fatigue “Dull” mental state Anorexia, N/V/D, altered taste, subdermal hemorraging

Causes of Chronic Renal Failure n Diabetic or HIV-Related Nephropathy n Recurrent Glomerulonephritis or Pyelonephritis n Acute Non-Responsive Kidney Failure n Nephrosclerosis n Cardiac Failure n Extensive Atherosclerosis n Malignant Hypertension

Early & Accurate Assessment n Anthropometrics (< 20 BMI or < 80% body weight n Biochemistry (albumin, prealbumin, cholesterol, K, creatinine, BUN) n Clinical Assessment (edema, GIT) n Dietary Intake( protein, calories, K, PO4)

Without Adequate Protein/ Kcals : Hypermetabolic state= Break down visceral protein stores; protein stores; Hyperkalemia worsens. Hyperkalemia worsens. Kcal needs:30-50 kcal/kg (depending on level of catabolism) (depending on level of catabolism) Oliguric phase:Diuretics, restrict fluids, Na and K. Diuretic phase:Fluids and K supplements

Measuring fluid needs: Measure urinary output, then add 500 ml for insensible losses.

Non-Dialyzed PtsDialyzed Pts 0.6 to 1.0 g/ kg g/ kg Feeding in Enteral and Parenterally-Fed Patients Less Protein, ElectrolytesLower amino acid [ ] High Kcal DensityHigher Dextrose [ ] Insulin may be used to control hyperglycemia Insulin may be used to control hyperglycemia

Medications  Hyperkalemia - Exchange resins (po or enema) e.g.polystyrene sulfonate to increase fecal potassium losses by exchanging sodium.  Hyperphosphatemia - Phospate binders e.g. Phosphlo & Tums (Ca based); Magnabid (Mg based); Amphogel (Al based); Renagel (polymer)  Anemia - Iron  Edema - Diuretics

Removal of blood waste products through a semi-permeable membrane via diffusion/osmosis. Hemodialysis Large blood vessel tapped,blood routed through dialysis machine, excess fluid/ electrolytes are removed. Dialysed blood returned to body. Peritoneal Dialysis Dialysis is accomplished using peritoneal cavity as the semi-permeable membrane.