NURS 165 Study Guide - Final Guide: Calcitriol, Lisinopril, Vancomycin
Chronic Kidney Disease
• Epidemiology
o 9th leading US cause of death
o 13.1% of population has it, 65% are in 3rd or 4th stages
o 2/3 of these patients are on dialysis, 1/3 with kidney transplant
o 101,170 people waiting kidneys in US (Sept. 2014)
o More common in women, but men progress more often to ESRD
▪ End-stage renal disease
o Greater progression to ESRD in:
▪ Older adults
▪ African Americans, Latinos, Asian
▪ Smokers!
o Rare in children but possible
o Diabetes is #1 cause, hypertension #2
• Kidney Function
o Maintain stable volume and composition of body fluids
▪ Water
▪ Sodium
▪ Potassium
▪ Calcium
▪ Phosphorus
▪ Acid-base balance
o Reabsorb filtered nutrients
o Retain blood cells/proteins in bloodstream
▪ Don’t permit to leak into kidney
o Excretion of wastes
▪ Creatinine – muscle metabolism product
▪ Urea – amino acid metabolism product
▪ Metabolic end products from drugs
▪ Acid (esp. from meat consumption)
• Meat proteins have more amino acids that generate
acid. Most comes from sulfur-containing AA’s
o Endocrine function
▪ Produce erythropoietin
• RBC growth factor → binds w/ bone marrow receptors
→ stimulates RBC production
▪ Convert Vitamin D to active form
• Second hydroxylation of Vitamin D to active form
needed for calcium absorption
▪ Produce renin
• Regulates blood volume and blood pressure via RAAS
o Renal Blood Flow
▪ ~ 20-25% of cardiac output, even though kidneys are 1% of
body mass
find more resources at oneclass.com
find more resources at oneclass.com
▪ Glomerular Filtration Rate (GFR) is 10%
▪ RBF is 180L/day (125 mL/min)
▪ Actual urine production is 1.5L/day
• That’s a LOT less than RBF!
▪ Nephron is functional unit
o The Glomerulus
▪ Site of filtration from the blood
▪ Basement membrane and proteins in podocytes of Bowman’s
capsule prevent passage of cells and large proteins
▪ Formed by glomerular capillary tuft, podocytes of
Bowman’s capsule, and basement membrane
▪ Mesangial cells in basement membrane
• Provide structural support for glomerular capillaries
• Contract and relax → alter avail surface area for
filtration → affect GFR
▪ ~10% of renal blood flow leaves circulation → gets filtered →
enters glomerular space
• Ultrafiltrate of plasma – has water, ions, small
molecules (glucose, amino acids, etc.)
▪ Blood cells and proteins retained in bloodstream
▪ Negative charges in basement membrane and podocytes
REPEL proteins
• Key factor in ability of glomerulus ability to prevent
plasma proteins from leaking into urine
• HOW?!?!
▪ Remaining structures process that fluid and return 99% of
filtered water/substances to bloodstream
▪ Glomerular filtrate leaves vascular space → enters urine space
at glomerular capillaries → water, electrolytes, glucose, etc.
reabsorbed by renal tubules → return to circulation by
peritubular capillaries → remaining fluid excreted into urine
o Glomerular Filtration Rate
▪ Method to express kidney function (about 125 mL/min)
▪ High filtration rate (compared to other systemic capillaries)
• Due to high net filtration pressure, high surface
area, and high permeability.
• Filtration allowed by glomerular capillaries, basement
membrane, and podocytes
▪ Regulation of GFR
• Proportional to number of nephrons
• Tends to decline with age
find more resources at oneclass.com
find more resources at oneclass.com
o Mechanisms of Kidney Injury
▪ Acute vs. Chronic
▪ Glomerular abnormalities (acute OR chronic)
• Sclerosis (hardening) of basement membrane
• Scarring and deposit of immune complexes (infection)
• Loss of basement membrane negative charges
o Normally repel protein filtration
• Change in morphology (effacement) of podocytes
o Diabetes
▪ Tubular injuries (more acute)
• Ischemic damage to deep medullary interstitium
• Increased vulnerability to reactive oxygen species
• Hyperfiltration
o Often with protein leakage
▪ Glomerular capillaries more permeable than other
capillaries – increased risk for bacteria to enter (ex.
streptococcus
→
glomerulonephritis); or entrance of
damaging antibodies (IgA
→
nephropathy)
• Also Systemic Lupus Erythematosus (SLE); antigen-
antibody complex deposited in glomerular basement
membrane
o Loss of nephrons → loss of GFR
▪ Diabetes is #1 cause of ESRD
▪ Chronic hyperglycemia → hyperfiltration → glomerular
overload
▪ Chronic hyperglycemia modifies glomerulus and alters
filtration barrier → weak kidneys → ESRD
find more resources at oneclass.com
find more resources at oneclass.com
