renal disorders Flashcards
How are the causes of renal dysfunction catergorized?
causes of kidney dysfunction are divided into 3 categories based on the mechanism of injury; prerenal, intrarenal, & postrenal
What are prerenal injuries related to?
decrease in blood flow & perfusion
What are intrarenal injuries related to?
secondary to actual injuries to the kidney itself
What are postrenal injuries related to?
related to obstruction of urine outflow from the kidneys
list possible causes of prerenal injury
- hypotension
- shock
- diarrhea (severe)
- vomiting (severe)
- bleeding/hemorrhage
- diuretics
- diabetes insipidus
- burns
- HF/MI
- cirrhosis
- sepsis
list possible causes of intrarenal injury
- vasculitis
- venous occlusion
- pre-eclampsia
- acute tubular necrosis
- multiple myeloma
- hypercalcemia
- IV contrast dyes
- pyelonephritis
- certain meds: NSAIDS, ACEI, heavy metals
- transfusion reaction
- rhabdomyolysis
list possible causes of post renal injury
- renal calculi
- enlarged prostate
- cancer
- diabetes
- functional obstruction due to drugs
- blood clot
- trauma
What is the most common cause of acute kidney injury?
acute tubular necrosis (ATN)
What occurs when acute tubular necrosis is present?
damage to renal tubules causing cells to slough into the tubular lumen and lumen becomes blocked
- fluid unable to go thru lumen; decreased urine formation ; ultimately no urine if untreated
- blocked lumen exacerbates ischemic injury to cells & causes additional intrarenal injury
What are possible causes acute tubular necrosis?
post - ischemia (all causes of severe pre-renal disease)
nephrotoxins
is acute tubular necrosis permanant or reversible?
permanent injury if not reversed
What 3 things were mentioned to cause nephrotoxicity?
aminoglycosides
IV contrast dye
multiple myeloma
What is creatinine clearance (100-150cc/min) in prerenal azotemia vs ATN?
prerenal azotemia - 15-80cc/min
ATN - less than 5-10cc/min
What is urine sodium (10-20mEq/L) in prerenal azotemia vs. ATN?
prerenal azotemia - less than 10 mEq/L
ATN - greater than 20 mEq/L
What is specific gravity(1.005-1.025) in prerenal azotemia vs ATN?
prerenal azotemia - greater than 1.015
ATN - 1.010 fixed
What is urine osmolality (200-1200mOsm/kg) in prerenal azotemia vs ATN?
prerenal azotemia - concentrated >450mOsm/kg
ATN - isomotic = 300mOsm/kg
What is serum BUN (10-20)/ creatinine in prerenal azotemia vs ATN?
prerenal azotemia - greater than 15:1
ATN - 10:1 fixed
What is the UA like in prerenal azotemia vs. ATN?
prerenal azotemia - normal
ATN - red/qhite cells, casts & epithelial cells
What is oliguria?
urine output <400 ml/day
What is anuria?
urine output < 30-40 ml/day
What are the 4 stages of an AKI?
initial onset
oliguria
late diuretic
recovery
What happens in the initial onset phase of an AKI?
- 0-2 days
- initial insult to point when BUN/Cr rise and/or urine output drops
What happens in the oliguria phase of an AKI?
- 1-2 days to 6-8 weeks
- drop in GFR, rention of urea, potassium, sulfate & creatinine
- decrease urine output & edema
What happens in the late diuretic phase of an AKI?
- 2-8 days
- begins with a slow, gradual increase in urine output, then high output (up to 10L in 24 hr)
What happens in the recovery phase of an AKI?
- 2-4 months
- labs return to pre-morbid state (full reovery; diabetics might not fully return)
What are the most common AKIs?
septic & cardiac shock
What should you do to help during the recovery phase of an AKI?
- low sodium diet
- fluid restriction (either IV or PO)
- low potassium diet?
What clinical manifestations will an AKI have regardless of cause?
oligura and fluid overload
What are the clinical manifestations of an AKI?
oliguria
fluid overload
edema
build up of nitrogenous waste
- uremia
- metabolic acidosis
- thrombocytopenia
- neuromuscular irritability
What labs & imaging are used to dx an AKI?
- UA
- serum electrolytes
- BUN/ Creatinine
- ABG
- CBC
- CT scan
- renal biopsy
What is tx of an AKI depend on?
depends on cause
What is the goal of AKI tx?
to restore normal chemical balance, prevent further complications until repair of renal tissue and restoration of renal function
How is an AKI treated?
- fluid administration
- loop diuretics (lasix)
- monitor electrolytes → potassium
- cardiac monitoring → tele; step down or ICU
- hemodialysis → helps maintain a homeostatic state
- monitor I & Os
- might need to do daily weights
- monitor BP
What is the leading cause of death in AKIs and why?
hyperkalemia; potassium plays a role on muscles and neves → supposed to be in ICF not ECF, do when gets ut into the ECF levels become too hight & heart will be affected
Is dialysis longterm or shortterm in AKI?
should be shortterm; hope is as you recover from AKI → to get off of dialysis; non compliant pts are usually on life-long dialysis
list indications for dialysis
- volume overload
- potassium greater than 6mEq/L → should be < 5.5 mEq/L
- BUN greater than 120mg/dL → should be between 10-20 mg/dL
- other signs of uremic intoxication (N/V, decreased appetite, weight loss, fatigue, impaired cognition, mucle cramps, metallic taste, seizure, coma)
What is an irreversible and progressive disease?
chronic kidney disease
chronic kidney disease is often ____________ initially until disease is far advanced
asymptomatic
What classifies chronic kidney disease?
kidney damage or a GFR <60mL/min/1.73m^2 for 3 months or longer
What are the causes of chronic kidney disease?
*hypertension
*diabetes
obesity
glomerulonephritis
SLE (lupus)
polycystic kidney disease
What happens during chronic kidney disease?
loss of functioning nephrons, progressive deterioration of glomerular filtration, ability of tubules to reabsorb, endocrine functions
as nephrons are destroyed the remaining function ____________ to take on the work of the destroyed nephrons
hypertrophy
What are the tx for chronic kidney disease?
- lifelong dialysis
- kidney transplant (will get you off of dialysis)
How many stages of renal dysfunction are there?
5
What is stage 1 of renal dysfunction?
- damage with normal or increased GFR (>90ml)
What is stage 2 of renal dysfunction?
- mild reduction in GFR (between 60-90ml/min)
What is stage 3 of renal dysfunction?
- moderate reduction in GFR (between 30-59ml/min)
- decreased function because <50% of nephrons are working
- will see lab changes
- no longer able to compensate
What is stage 4 of renal dysfunction?
- severe reduction in GFR (15-29ml/min)
- renal insufficiency is evident
- nephrons no longer able to do the job
- diet restriction of proteins
What is stage 5 renal dysfunction?
kidney failure (less than 15ml/min); kidney can not longer remove waste product or maintain their normal function to sustain life; need dialysis and/or transplant
stage 1 & 2 renal dysfunction
- often asymptomatic & creatinine will be normal
- compensation will occur for damaged nephrons
list clinical manifestations of CKD
- accumulation of nitrogenous waste
- hyperkalemia
- hypocalcemia
- normochromic/normocytic anemia
- low albumin
What occurs due to the accumulation of nitrogenous waste in CKD?
- encephalopathy
- anemia & thrombocytopenia due to lysis
Why does hypocalcemia occur in CKD and what can it cause?
hypocalcemia occurs because vitamin D is not able to be acitvated; can cause:
- hyperparathyroidism
- bone breakdown
- hyperphosphatemia
What may the skin look like when someone has CKD?
grayish undertone b/c of the waste products & from the filtrated stuff used in dialysis; thin skin
What is the tx for CKD?
- treat underlying cause
- monitor labs
- smoking cessation → vasoconstriction
- manage hyperglycemia → if diabetic
- manage anemia
- excercise program
- decrease sodium
- avoid alcohol
- dialysis
- kidney transplant
What is glomerulonephritis?
inflammation of the glomerular capillaries
What causes about 25-30% of all ESRD cases?
glomerulonephritis
is glomerulonephritis acute or chronic?
can be acute or chronic
What is the most common cause of glomerulonephritis?
post-streptococcal glomerulonephritis
What are the sx of glomerulonephritis?
- pink or cola-colored urine
- proteinuria
- hematuria
- hypertension
- fluid retention/edema
- decreased urine
- N/V
- muscle cramps
- fatigue
What are complications of glomerulonephritis?
- accumulation of waste or toxins in the bloodstream
- poor regulation of essential minerals & nutrients
- loss of RBCs
- loss of blood proteins
What causes glomerulonephritis to begin with?
begins with an antigen-antibody reaction
What does the antigen antibody complex do in glomerulonephritis?
damages structures of the glomeruli which causes nephron dysfunction
What does nephron dysfunction in glomerulonephritis cause?
- decreased filtration of blood
- decreased urine production
- hypervolemia
- hypertension
What are the clinical manifestations of glomerulonephritis?
- oliguria often 1st sx
- followed by hematuria, proteinuria → cola colored urine
- edema often in face & hands
- HTN
- elevated anti-strep antibodies (ASO)
- increased creatinine
- decreased serum albumin
- cast in urine
What are casts in urine?
tiny tube-shaped partickes that can be found when urine is examined under the microscope; may be made up of WBC, RBC, kidney cells, or substances such as protein or fat
What is the goal of tx for glomerulonephritis?
- increase urine output
- decrease urinary protein
What types of medications are used to tx glomerulonephritis?
- corticosteroids
- antibiotics, if needed
- antihypertensives, if needed
- antipyretics
What diet modifications should be made for a patient who has glmomerulonephritis?
- low sodium
- low protein
What complications should you monitor for during glomerulonephritis tx?
- HTN
- encephalopathy
- HF
- pulmonary edema
What is nephrotic syndrome?
damage to the glomerulus; the filter is damaged and things which should stay in are able to leak out through the pores which become bigger due to the damage
What does damage to the glomerulus lead to?
increased permeability of proteins & other substances in the blood
What is the most common type of nephrotic syndrome?
diabetic nephropathy
What are the top 3 causes of nephrotic syndrome?
- diabetic nephropathy
- lupus
- amyloidosis
What percentage of cases do the top 3 causes of nephrotic syndrome account for?
90%
list other possible causes of nephrotic syndrome
- vasculitis
- allergies
- preeclampsia
- HTN
- other infections
What are the clinical manifestations of nephrotic syndrome?
- albuminuria (AKA proteinuria) → often also have WBC in urine
- edema
What is used to dx nephrotic syndrome?
- UA → proteinuria, hematuria
- elevated BUN/Cr
- low serum albumin
- test for lupus & HepB & C may be performed
- 24 hr urine
- renal ultrasound
- renal biopsy
What is the tx for nephrotic syndrome?
- diet → low protein & sodium
- adequate fluid intake but avoid overload
- pneumococcal & flu vaccines
- ACEI or ARBs
What are complications related to tx of nephrotic syndrome?
- hyperlidemia
- thromboembolism
nephrotic syndrome (slide)
- increase in glomerular permeability
- massive loss of plasma proteins in the urine
- generalized edema
- elevated triglycerides & LDL
- Na & water retention
- ascites +/-
nephritic syndrome (slides)
- inflammatory response r/t immune complexes & antibody-antigen complexes lodged in capillary
- immune response develops against the antigens
- occlusion of glomerular capillary lumen & damage of capillary wall
- damage allows RBC to escape into urine
- decreased GFR, fluid retnenion & nitrogen waste accumulation
- protein uria & oliguria
post-strep glomerular nephritis (chart)
- seen ages 4-7
- 10-14 days after strep inf.
- anti-streptolysin titer→ pos
- urine → cola-colored
- hematuria → massive
- proteinuria → minimal
- HTN
- edema → moderate
- hyperkalemia
- elevated BUN
