Chemistry 1 - Exam 2 Flashcards
What are the clearance tests for renal disease?
- Para I amino hippurate
- Inulin
- Creatinine
Describe Para-amino hippurate.
- Exogenous substances used to examine Renal Plasma Flow (the amount of blood passing through the kidney)!!
- PAH is both filtered and secreted to such an extent that > 90% of the substances removed from the blood in a single pass through the kidney.
- Carrier protein mediated excretion (has to be bound to protein).
- PAH clearance (ml/min) = Ux(X)(V/Px)
Describe Inulin.
- Exogenous substance
- Reference Molecule for freely accessing GFR (must be infused).
- Freely filtered by glomerulus and is neither reabsorbed or secreted.
- Insulin clearance (ml/min) = Ux(X)(V/Px)
Describe Creatinine.
- Next best convenient tool is creatinine clearance (cystatin C) because PAH and Inulin are not quick lab measurements.
- Endogenous substance and tests are easy to perform.
- Results are a good estimate for GFR. Tubular secretion of creatinine prohibit it from being perfect marker for GFR.
- Results closely parallel inulin until renal failure progresses where [creatinine]serum increases significantly and then creatinine clearance decreases as renal function fails.
- Creatinine clearance is used to diagnose renal failure.
What are renal diseases? What are they?
- Chronic renal failure
- Acute renal failure
- Acute glomerulonephritis
- Nephrotic syndrome
- Renal tubular defects
- UTI (pyelonephritis/cystitis)
- Nephrolithiasis
- Renal hypertension
Characteristics of Chronic renal failure (CRF) and Uremic syndrome.
- Symptoms = weakness, fatigue, loss of appetitie , nausea, vomiting, muscle wasting, tremors, abnormal mental function, shallow respiration, and metabolic acidosis!!
- Symptoms related to inability of kidney to maintain adequate excretory, regulatory, and endocrine function.
- GFR < 60 ml/min/1.73m^2:
- GFR < 15 ml/min/1.73m^2: failure
Describe kidney damage.
- Structural or functional abnormality other than just decreased GFR.
> albuminuria
> urine sediment abnormalities
> electrolyte & other abnormalities due to tubular disorder
> abnormality detected by histology
> structural abnormalities detected by imaging
> history of kidney transplant
Describe the progressive stages of chronic renal failure.
Differentiated by NPN compounds.
1. Initial deterioration may be silent, kidney function decreased, but BUN and creatinine are normal. Remaining renal function = 50-75%.
2. Slight renal insufficency. > 50% renal function must be reduced before BUN & creatinine increase and reference ranges reflect pathology. Remaining renal function = 25-50%.
3. Many signals of impending failure. (Decreased erythropoietin > increased anemia, increased systemic acidosis). Remaining renal function = 10-25%.
4. Onset of Uremic syndrome, which leads to death. Remaining renal function < 10%.
* decreased glomerular filtration & tubular function leads to increased NPN, hyperphosphaturia, hypocalcemia, and acidosis in hyperkalemia.
What is the relationship between calcium and phosphate?
As calcium increases, phosphate decreases and vice versa.
Overall picture of Chronic renal failure & uremic syndrome.
- Uremia-acidosis caused by inability to secrete normal H+ production.
- Retained nitrogenous waste: increased BUN & creatinine in serum.
- Loss of tubular reabsorption > inability to concentrate urine is reflected in decreased urine osmolality.
- Serum: decreased HCO3-, Na+, Ca2+, pH. Increased K+, Cl-, P-, Mg2+.
- Abnormal endocrine function: 2’ (secondary) hyperparathyroidism/anemia (EPO).
- Diabetes mellitus
- Increased proteinuria
Why is this true with chronic renal failure & uremic syndrome?
Serum: decreased HCO3-, Na+, Ca2+, pH. Increased K+, Cl-, P-, Mg2+.
What is diabetes mellitus?
What is diabetes insipidis?
Describe acute renal failure.
Rapid & severe reduction of GFR with oliguria & edema.
Caused by pre-renal, renal, and post renal effects. (I.e. hypovolemia, heart failure, acute tubular necrosis, or urinary tract obstruction.
Clinical findings of Acute renal failure.
