Renal Failure I
How does the kidney regulate endocrine function?
Renin = BP
Erytrhopoetine= RBC prod.
Ca+/Phosphorus balance = activate Vit D, incr Ca+ absorption=Calcitrol
Why do we have to urinate when we are cold?
vasoconstriction pushes excess fluid out to keep body warm and gets rid of that fluid via urine
__________ will produce concentrated urine _______ will produce dilute urine
diaphoresis + eating salty food= conc.
drinking and cold weather = dilute
kidneys can't remove urea
wastes accumulate disrupting endocrine/metabolic fx
rapid reduction in urine output
tubular cell death and regeneration
acute renal failure
Chronic renal failure
True or False
We can loose up to 75% of function before we notice kidney failure
occurs when the kidneys are unable to excrete the daily load of toxins in the urine
<400mL/day of urine
<50mL/day of urine
Oliguria + anuria + high serum creatinine + high BUN levels =
High levels of BUN
What is the most cause of acute renal failure?
Acute tubular necrosis r/t shock or chemicals
Perfusion, filtration and water balance (shock) are___________ problems
Selective reabsorption and water balance are ________ problems
Urine collection, storage and elimination are ______ problems
Vascular supply effects
Perfusion = Prerenal
Problems with the glomerulus causes
Issues in the tubules cause
Selective reabsorption, secretion, excretion=Renal
Problems between the collecting ducts and the bladder cause
urine collection and storage problems=postrenal
Urination and micturition effect
_____________ is a classic reason for drop in GFR is an early sign of___________
hypoperfusion of the kidneys
What is the key to determining how much perfusion is getting to the kidney?
MAP <80 = rapid decline
(CO X SVR) + CVP
What causes renal artery obstruction and contributes to hypoperfusion of the kidneys?
Vomiting, diarrhea, poor fluid intake, fever, diruetics and HF all contribute to _______________
shock = hypoperfusion of kidneys
What causes cardiogenic shock?
Nephron & Microcirculation are implicated in ____________ problems
Actual parenchymal damage to the glomeruli, interstitial nephritis, acute glomerulonephritis, tubular necrosis, ischemia and toxins cause problems where?
What causes tubular necrosis?
In burns and crush injuries ___________ is released causing renal toxicity, ishemia or both
(released from muscle injury)
GFR, Tubular reabsorption and tubular secretion are considered _____________
Common genetic kidney disease that becomes symptomatic after 30 with hematuria, chronic UTI's and HTN
Presents as hematuria, smokers have 2x the risk, metastasizes to lung & bone
Renal cell carcinoma
obstruction somewhere distal to the kidney is considered
If the psi rises in the kidney tubules and affects the GFR its considered
Neurogenic bladder as seen in MS, ALS, DMD and Quads
What are common causes of psi rise in the tubules?
Bilateral renal alculi
What causes calculi?
What are the sx's of calculi?
Who is at risk for calculi?
People with higher Ca+ levels
Secondary to constant UTI's which causes acute neutrophilic inflamm exudates and small abscesses
What are the sx's of acute pyelonephritis?
Water in the kidneys d/t blockage
From most to least what area of the kidneys cause acute renal failure?
Pre-renal = 55%
Renal parenchymal (intrinsic) = 40%
What is normal output?
What is normal urine replacement?
output + 600mL per 24hrs
<400mL/day urine output
>500mL/day urine output
very little or no urine output
What are the major systemic disease that cause kidney failure?
Rhabdomyolosis (ETOH, heat stroke, cocain, siezures, low Phosphate, DVT/VTE)
BUN is a measure of
products of protein breakdown
Serum creatinine is a measure of
muscle breakdown compares blood with urine
What is normal serum creatinine?
What is a normal GFR?
What is GFR affected by?
What is a normal BUN?
What causes low BUN?
low protein diet
What causes excessive proteint levels in GI tract?
If the kidneys aren't perfused what goes up and why?
b/c can't clear proteins
high metabolic rate = high fluid need and larger % of body weight that is water is characteristic of
infants and children
Who has larger fluid turnover, losses and fluid requirement/Kg?
infants and children
True or False
We have larger ECF volume until 2years of age
lower GFR, drug clearance, shorter tubules, less response to ADH
less ability to conserve and remove excess water, difficulty conserving/excreting NaCL
less ability to handle acid load and difficulty secreting solute load
What are the percent body weight as fluid for
What is the water/Kg in
What is the proportion of ECF in
Infant water loss is ____ that of an adult
What is the water turnover in an
1/5 = adult
1/2 = infant
What are s's of pediatric moderate volume deficit?
BP= normal or low
50-90mL/Kg fluid loss + gray skin + poor turgor + very dry mucous membranes + oliguria + 2-3sec cap refill
Moderate volume deficit in children
What indicates mild vol. deficit in children?
dry mucous membranes
Puls=normal or increased
drawn facial expression
Shock + change in LOC, elevated BUN, K+, Creatinine =
Severe vol deficit resulting in acidosis
What kind of fluid loss is considered severe for children?
mottled skin + very poor turgor + parched membranes + oliguria + azotemia
Severe vol deficit in children
Low BP, rapid thready pulse and cap refill >3 sec
evidence of severe vol deficit in children
What changes as we age in respect to kidney fx?
Renal blood flow
ability to concerntrate urine
less able to adjust vol, secrete solute load, bladder elasticity, weaker sphincter, decr bladder capacity, BPH
geronotological differences in fluid balance/renal fx
hypoperfusion AEB ^BUN, ^ Creatinine, decr output, urine NaCL decr <20mEq/L, ^ urine specific gravity
Parenchymal damage AEB, ^BUN, ^ creatinine, variable output often decr, urine NaCL incr >40mEq/L, low normal 1.010 spec. grav.
Obstruction AEB ^BUN, ^Creatinine, decr or sudden anuria, NaCL decr <20mEq/L, variable urine spec. grav.
All will alter GFR
Types of drugs that increase urine Sodium
Drugs that decrease urine sodium
Corticosteriods =cause NaCL retention
Why do RF patients present tired/confused?
proteins + toxins build up in brain
What are CNS s's/sx's of RF?
Muslcle twitiching d/t e- imbalance
N/V, diarrhea, ill and lethargic are s's that
They are GOING DOWNHILL
need to be treated FAST
What is the first thing to assess in ARF?
Decreased urine output
What is next to assses in ARF?
What is a late sx of ARF?
After Skin turgor check
After pruritis check
Odor of breath
After Anemia check
Cool, pale skin
metallic taste in mouth
What seems like a common sx but may be a late sx
Why do people develop Hyperkalemia in ARF?
declining GFR = can't excrete K+
protein catabolism = release of K+ into body fluids
Whats the big deal with hyperkalemia?
dysrhythmias and cardiac arrest
ARF managment includes
tx life threatening cond = K+, fluid crisis
ID cause=hypovolemia, toxicity, obstruction
Tx reversible = hydrate, remove drug, relieve obstruction
JK; Mgmt includes
maintain fluid balance
avoid fluid excess
How do we determine maintenance of fluid volume?
clin status of pt
True or false
Parenteral and oral intake, output including insensible loss are calculated and used as basis for fluid replacement