Renal Flashcards
Where do the kidneys sit
retroperitoneal between T12 and L3 (Right slightly more caudal to accommodate the liver).
primary functional unit of the kidney
nephron
Kidneys receive how much CO?
receive 20-25% of the cardiac output (1-1.25L)
Primary Functions of The Kidney
Maintenance of Extracellular volume and Composition (helps to concentrate and dilute)
Blood Pressure Regulation (Intermediate and Long term)
Excretion of toxins and metabolites
Maintenance of Acid-Base balance along w/ the lungs
Hormone Production
Blood glucose hemostasis
Hormones kidneys produce
erythropoietin (EPO),
calcitrol,
prostaglandins
What does low blood calcitrol cause
increases parathyroid hormone release, which increases the serum calcitriol level (active vit D) level. As serum calcium level rises it feeds back to reduce the serum level of PTH, which reduces the serum level of calictriol (negative feedback loop).
medications related to hormones that long term dialysis patients are on
iron and synthetic epo because dialysis negates the RBC’s
What is azotemia?
abnormally high levels ofnitrogen-containing compounds (such asurea,creatinine, various body waste compounds, and other nitrogen-rich compounds) in theblood. It is largely related to insufficient or dysfunctional filtering ofbloodby thekidneys.
What amount of body wt in non obese adult is total body water
60%
ICF vs ECF relationship
ECF is ½ the volume of ICF; kidneys effect ECF.
Two main components of ECF
plasma and interstitial fluid(IF)
Osmolality sensors in ant. hypothalmus
cause what?
Stimulate thirst
Vasopressin release; stop diuresis
sodium normal and cut-offs
normal 135 -145
cut-offs;
low; 125
high; 155
What percent of hospitalized patients have hyponatremia
15% …due to us giving IVF.
Causes of hyponatremia
Prolonged sweating- volume loss
Vomiting/diarrhea- GI disturbances
Insufficient aldosterone secretion- water overdose
Excessive intake of water; psych patients
Populations that we are concerned about hyponatremia with?
neuro and kids
forget about volumes-> too much fluid in kids neuro- regulate swelling/ brain edema, limit na or water
Causes of AMS
BG, Drugs, electrolytes, stroke
s/s for 130-135 meq/L na
asytmomatic
ha
n/v
fatigue
confusion
muscle cramps
depression reflexes
s/s 120-130meq/L na
malaise
unsteadiness
ha
n/v
fatigue
confusion
muscle cramps
s/s na <120meq/L
ha
restlessness
lethargy
sz
brain-stem herniation
respiraory arrest
death
most severe consequences of hyponatremia
sz, coma, death
Hypertonic saline dose
1meq/L/hr
Hyponatremia tx
Underlying cause
Normal saline- resuscitative
Hypertonic saline
Lasix- concentrate fluid ( get rid of free water)
Mannitol
130-135 = gatorade
max correction rate for hypona
6 mEq/L in 24 hours
What does rapid correction of na cause
osmotic demyelination syndrome-> sz, coma, death
Close-to-death dose for 3%
About to die; 3-5ml/kg of 3% of 15-30 minutes till seizures/ symptoms resolve; killing brain cells if don’t correct quickly.
Hypernatremia causes
Excessive evaporation – no volume
Insufficient ADH
Poor oral intake…very young, very old
Overcorrection of hyponatremia
Excessive sodium bicarb/acidosis
what can we give with bicarb to buffer our acidosis correction?
THAM; trometamol
helps to avoid raising na w/ sodium bicarb
Effects of hypernatremia
Orthostasis- synopsize w/ standing
Restlessness
Lethargy
Tremor- spastic muscles
Muscle twitching/spasticity
Seizures
Death
Hypernatremia vital signs to check / assess volume status
vs; tachy and hypo, urine output, skin turgor, svv, cvp, ivc, labs, pap, tongue, us ICV.
treatment for hypernatremia
treatment based on the cause;
Hypovolemic: normal saline
Hypervolemic: diuretic
Euvolemic: water replacement (po or D5W)- free water
correction rate for hyperna
slower reduction rate of no more than 0.5 mmol/L per hour, with an absolute change of 10 mmol/L per day to avoid cerebral edema, seizure, and permanent neurologic damage from rapid correction
K+ normal and cut offs
normal; 3.5-5
cut-offs;
low; 3
high; 5.
How does DKA affect K+?
get acid out of the body by breathing and frequent urination of large volumes of urine -> hypokalemia
Hypokalemia causes
Excessive release of aldosterone
Diuretic drugs; should be taking K+ replacement
Kidney disease; our fault for over-dialysis?
Excessive intake of licorice
Diabetic ketoacidosis; diuresis out so much fluid.
At what level do we see arrhythmias with hypokalemia
2meq/L
Effects of hypokalemia
Dysrhythmias; U wave
Muscle weakness; treat w/ banana or lyte replacement
Cramps
Paralysis
Ileus – loss of peristalsis.
dig
chf ( chronic diuretic therapy)
IV dose for IV K replacement
Generally 10-20meq/hr IV.
10meq/ L/ Hr IV will increase hypokalemia by 0.1 or about by ~0.25 meq/L for each 20 meq K.
What does hydrocholothiazide cause
hypokalemia and increase in phos clearance, a decrease in tubular reabsorption of phosphate, and hypophosphatemia
When does phos correction occur
A decrease in phosphate clearance and a return of the plasma phosphate concentration to normal levels occurred after correction of the potassium deficit.
G tube color
stomach and clear
peritoneal dialysis tube color
white and smaller
Hyperkalemia causes
Renal disease- long term hd.
Insufficient secretion of aldosterone
Acidosis
Tissue/muscle damage
Use of depolarizing NMBD
Hypoventilation
blood products; large amount of free K
low flow states; tourniquet, arrest…
Why is sux contraindicated in hyperkalemia
increased K by 0.5meq.
Ph changes with potassium
pH 0.1 change causes 0.4-1.5 mEq/L shift
what does stored blood do to ca++
citrate lowers ca levels and loss of cell stability because of kelation of ca that we have available
Effects of hyperkalemia
Potentially asymptomatic…GI upset..malaise
Progresses to Skeletal muscle paralysis
Lowers resting membrane potential
Decreases action potential duration
Peaked T wave-> sine waves.
Treatment of hyperkalemia
Insulin 10 units to D50 25grams
Bicarbonate- secondary tx
fastest tx ; ca++ (stabilize cell membrane)
Dialyze day of surgery if possible
Increase respiratory rate
Albuterol; blow off K
Treatment of hyperkalemia
Insulin 10 units to D50 25grams
Bicarbonate- secondary tx
fastest tx ; ca++ (stabilize cell membrane)
Dialyze day of surgery if possible
Increase respiratory rate
Albuterol; blow off K
Glomerular filtration rate
Best measure for trend, not good for acute.
125-140 mL/min
Creatinine Clearance
Not reabsorbed
Most Reliable measure of GFR
Serum Creatinine normal values and what it does?
Estimate of GFR….75% below normal
0.6-1.0mg/dL - female
0.8-1.3 mg/dl- male
SERUM CREATININE produced
produced by skeletal muscle and is a byproduct of creatine breakdown.
Creatinine production is constant and directly proportional to muscle mass
Creatinine undergoes renal filtration but not reabsorption, making it a useful indicator of GFR.
increase in creatinine indication….
100% increase in creatinine indicates a 50% reduction in GFR. 1.2-> 2.4 = big drop in GFR.
Protein in urine
Large amounts of protein suggest glomerular injury (750mg/day or 3+ on dipstick) ….also seen in UTI’s
Blood urea nitrogen normal
Misleading…diet, intravascular volume
Normal 8-20mg/dL
Specific gravity normal and what its measuring
Compared to 1ml distilled water; 1 ml of ruine
Normal 1.001-1.035
more concentrated = more product retained
BUN:Creatinine ratio
generally 10:1
primary metabolite of protein metabolism
Urea is the primary metabolite of protein metabolism in the liver. (amino acids->ammonia->urea)
Urea undergoes…..
filtration and reabsorption, it’s a better indicator of uremic symptoms than as a measure of GFR.
BUN < 8 mg/dl causes
think dilution
overhydration
decrease urea production; malnutrition, severe liver diseases
BUN 20-40mg / dl causes
dehydration
taking in large amount of protein
GI bleeds
hematoma breakdown
catabolic state; trauma, sepsis,
decreased GFR