Download Diseases of the Kidney

Kidney Physiology
Kidney Functions:
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activate vitamin D (renal 1-alpha hydroxylase)
produces erythropoietin which stimulates
RBC formation
helps regulate blood pressure
ELIMINATES METABOLIC WASTE
PRODUCTS
HELPS MAINTAIN FLUID, ELECTROLYTE,
AND ACID-BASE IMBALANCES
Kidney Diseases of Note
Glomerulonephritis (acute or chronic)
 Nephrotic Syndrome
 Acute Renal Failure
 Chronic Renal Failure
 Dialysis
 Urinary Calculi
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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: 90-120 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
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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
Immunoglobulins (immunity)
Transferrin (anemia)
Vitamin D-BP (rickets)
Low serum proteins
Low Blood Volume
Kidneys Respond
fluid shift into interstitial
spaces
Edema
Retain Na and fluids!!!!
Energy:
35 kcal/ kg
Protein:
0.8-1.0 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
LOW RENAL
BLOOD FLOW
Postrenal
OBSTRUCTION
IN URINARY
TRACT
Intrarenal
KIDNEY DAMAGE
SUDDEN PRECIPITOUS DROP IN GFR, URINE OUTPUT
UREMIA/
AZOTEMIA:
Build-up of urea nitrogen in the blood
(BUN).
Normal:
Uremia:
ESRD:
ARF Phases:
10-20 mg/dl
50-150 mg/dl
150-250 mg/dl
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)
Symptoms:
Weakness, Fatigue
“Dull” mental state
Anorexia, N/V/D, altered taste,
subdermal hemorraging
Causes of Chronic Renal
Failure
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Diabetic or HIV-Related Nephropathy
Recurrent Glomerulonephritis or
Pyelonephritis
Acute Non-Responsive Kidney Failure
Nephrosclerosis
Cardiac Failure
Extensive Atherosclerosis
Malignant Hypertension
Early & Accurate Assessment
Anthropometrics (< 20 BMI or < 80%
body weight
 Biochemistry (albumin, prealbumin,
cholesterol, K, creatinine, BUN)
 Clinical Assessment (edema, GIT)
 Dietary Intake( protein, calories, K,
PO4)
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Without Adequate Protein/ Kcals:
Hypermetabolic state= Break down visceral
protein stores;
Hyperkalemia worsens.
Kcal needs:
30-50 kcal/kg
(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 Pts
Dialyzed Pts
0.6 to 1.0 g/ kg
1.1-2.5 g/ kg
Feeding in Enteral and Parenterally-Fed Patients
Less Protein, Electrolytes
High Kcal Density
Lower amino acid [ ]
Higher Dextrose [ ]
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
Peritoneal Dialysis
Large blood vessel
tapped,blood routed
through dialysis
machine, excess fluid/
electrolytes are removed.
Dialysed blood
returned to body.
Dialysis is accomplished
using peritoneal cavity as
the semi-permeable
membrane.