Nephrology Flashcards
Main cause of cystitis
E. coli #1 cause
Enterobacteria
Typical signs of cystitis
dysuria, frequency, urgency, +/- hematuria
Antibiotic treatment for cystitis
Nitrofurantoin
Fluoroquinolones (Cipro)
TMP-SMX (Bactrim) becoming less effective due to resistant organisms
An ascending urinary tract infection
pyelonephritis
How does patient with pyelonephritis present differently than cystitis?
Fever, radiating flank pain, abd pain, nausea and vomiting
CV tenderness
UA results of pyelonephritis
Pyuria
WBC casts
Pyelonephritis treatment
- Abx per urine culture: Cipro, Cephalosporins, gentamycin, Bactrim
- Nephrectomy
Most common presenting symptom of bladder carcinoma
hematuria
Treatment of bladder carcinoma
Surgery: transurethral resection of bladder tumor (TURBT), partial or radical cystectomy
Adjuvant chemotherapy and radiation may be used
Hematuria + palpable abdominal mass + smoker
renal cell carcinoma
Child with hematuria and palpable abd mass or distended abd
Wilms tumor
1 risk factor of bladder cancer
smoking
I came in to see my physician assistant because of…
Nocturia Hesitancy Decreased urine flow Incomplete bladder emptying Frequency Firm enlarged prostate on rectal exam Negative urine culture
Benign Prostatic Hyperplasia (BPH)
How to treat BPH?
Behavior modification: decrease fluids before bed, decrease alcohol and caffeine, routine voiding schedule
Meds:
Alpha blockers - relax smooth muscle; Tamsulosin (Flomax), Prazosin, Terazosin
5 alpha reductase inhibitors - block DHT production which causes BPH; Finasteride, Dutasteride
Surgery:
Transurethral resection of the prostate (TURP)
Prostatectomy
3 types of urinary incontinence
Stress incontinence – Leaking of urine due to physical stress. Coughing, jumping, laughing etc. This is often due to urethral incompetence.
Urge incontinence – A sudden feeling of urgency and an associated loss of urine. Often associated with an overactive detrusor muscle. This may be due to neurologic disease
Overflow incontinence – Involuntary voiding without an urge to urinate typically secondary to urinary retention. This is often due to an outlet obstruction (think BPH) or an underactive detrusor muscle
I came in to see my physician assistant because of…
Sudden onset of severe flank pain
Nausea and vomiting
Hematuria
Nephro/urolithiasis (kidney stone)
Most kidney stones composed of what
calcium
Treatment of nephrolithiasis
Prevention: increased fluid intake
Meds: alpha blockers (Flomax, Prazosin), NSAID, corticosteroids
Ureteroscopic stone extraction
Extracorporeal shock wave lithotripsy
Normal GFR
100-130 mL/min/1.73 m^2
Symptoms of uremia may include…
Anorexia, Fatigue, Malaise, Dyspnea, Orthopnea, Change in mental status, restless legs, Weakness, Pruritis, Insomnia, Irritability, Cramping, etc
3 categories of AKI
Prerenal (decreased blood flow to kidney)
Intrinsic (kidney is having the problem)
Postrenal (urinary tract obstruction)
Prerenal causes of AKI
Renal artery stenosis Renal artery thrombosis Heart failure Severe dehydration NSAIDS
Intrinsic causes of AKI
Crush injury Antibiotic reaction Contrast dye Glomerulonephritis ATN AIN
Postrenal causes of AKI
OBSTRUCTIONS!
BPH
Kidney stone
Most common types of AKI
prerenal and ATN
BUN/CR greater than 20:1 in ________.
acute GN, prerenal and postrenal AKI
BUN/CR less than 20:1 in ___________.
ATN, AIN
Lab findings of AKI
elevated BUN:Cr
hyperkalemia
anemia
decreased GFR
How is AKI treated?
Treat underlying cause
- Correct CHF
- Fluids if dehydrated
- Avoid nephrotoxins
- Treat post renal problem
- Stenting of renal arteries
Dialysis
Transplant
How long until AKI becomes chronic?
over 3 months
Most CKD is secondary to what?
HTN or DM
Lab findings of CKD that are not seen in AKI
Broad waxy casts
Proteinuria
HTN
- both have elevated Cr/BUN, decreased GFR, hyperkalemia, anemia
CKD treatment
Aggressive treatment of HTN and DM
Treat hyperkalemia with calcium chlorid or bicarb
Diet: protein restriction, salt and water restriction, K+ restriction, Phos restriction
Hemodialysis if GFR below 15
I came in to see my physician assistant because of…
- Edema (periorbital or scrotal area)
- Dark (Tea Colored) urine
- Red cell casts
glomerulonephritis
Causes of glomerulonephritis
Berger disease (IgA nephropathy)
Endocarditis
Lupus
Strep infection
Glomerulonephritis treatment
high dose corticosteroids
proteinuria > 3.5g/day, high cholesterol, edema
nephrotic syndrome
causes of nephrotic syndrome
Primary renal disease SLE, rheumatoid etc Post infectious causes DM NSAIDS Lithium Toxins Pregnancy Multiple myeloma
UA results of nephrotic syndrome
fatty casts, oval fat bodies
Nephrotic syndrome treatment
Diet - increase proteins to match loss of proteinuria, salt restriction
Diuretics - ACE or ARB
Steroids
How to differentiate nephrotic syndrome and nephritis?
proteinuria levels (3.5 nephrotic syndrome)
UA results (RBC casts in nephritis, fatty casts in nephrotic syndrome)
Causes of nephritic syndrome
Specific strains of Group A strep
Bacterial or viral infection
Lupus
Goodpasture’s syndrome
I came in to see my physician assistant because of…
Hematuria (coca cola urine) Proteinuria HTN Oliguria Edema Pruritus Loss of appetite
nephritic syndrome
Nephritic syndrome treatment
Treat HTN
ACEI or ARB
Corticosteroids
Causes of hydronephrosis
Abnormal anatomy leading to poor outflow (often congenital)
Obstruction of any kind
Compression of the bladder causing reverse urine flow
How is hydronephrosis detected?
Renal ultrasound during prenatal testing
I came in to see my physician assistant because of…
Flank pain
History of UTIs and kidney stones
Kidneys may be large and palpable
polycystic kidney disease
50% of patients with PCKD have ________ by 60 years old
end stage renal disease
PCKD treatment
Supportive care and pain meds Cyst decompression Antibiotics if cyst is infected Decreased caffeine intake Dialysis Renal transplant
Granular or muddy brown casts on UA =
acute tubular necrosis
Broad waxy casts on UA =
Chronic kidney failure
Fatty casts on UA =
nephrotic syndrome
Red blood cell casts on UA =
glomerulonephritis/nephritic syndrome
WBC casts on UA=
infection, pyelonephritis
Epithelial casts on UA =
acute tubular necrosis
Nephrotic syndrome consists of huge losses of ________.
protein
Maltese crosses indicates _______.
nephrotic syndrome
Tea colored urine indicates __________.
glomerulonephritis
Causes of hypernatremia
Hypervolemic: iatrogenic (hypertonic saline), hyperaldosteronism
Hypovolemic: extrarenal loss (diarrhea, sweating, burns), urinary/renal loss (diuretics, renal disease)
Euvolemic: Diabetes Insipidus (ADH deficiency or insensitivity), hypodipsia
Normal sodium levels
135-145
Signs/sx’s of hypernatremia
Thirst, Lethargy, Irritability, Weakness, Change in mental status, dry mucous membranes, lack of tears (infants), hyperreflexia
When should dialysis be done in hypernatremia?
Na > 200
How should hypernatremia be treated based on circulating volume?
ISOTONIC IV FLUIDS
Hypovolemia: 0.9% NS, D5W
Normal volume: Drink water, D5W
Hypervolemia: Loop diuretic, D5W
Causes of hyponatremia with hypervolemia
CHF, nephrotic syndrome, cirrhosis
Causes of hyponatremia with euvolemia
SIADH (high ADH release)
Adrenal insufficiency
Hypothyroidism
Polydipsia
Causes of hyponatremia with hypovolemia
Sodium loss (renal or extrarenal)
Signs/Sx’s of hyponatremia
Nausea, Malaise, Headache, Lethargy, Mental status changes, Muscle cramps, Seizures
Hyponatremia treatment
Fluid restriction Hypertonic saline (D5 1/2 or D5 NS), but be very careful
Normal serum pH
7.35-7.45
Normal PCO2
35-45 mmHg
Normal serum bicarb
22-26 mEq/L
Acid-base imbalances of respiratory causes show up with changes in _______ and metabolic causes with changes in ________.
carbon dioxide
bicarb
Metabolic acidosis treatment
Treat underlying cause
Give bicarbonate
Metabolic alkalosis treatment
Stop diuretics or nasogastric suctioning
Give IV Normal saline
Describe mneumonic “ROME” for acid-base disorders
Respiratory will be opposite (the RO in rome)
- so pCO2 will be opposite the pH (so in respiratory acidosis the pH is low but the pCO2 is high)
Metabolic always relate with Bicarb & if pH is alkalosis the bicarb will be the same (ME for metabolic equal)
- so for metabolic alkalosis pH is high and bicarb is also high
Functions of the kidneys
Blood filtration
Regulation of blood volume and pressure
Activation of Vit D
Production of erythropoietin
How does CHF contribute to renal failure?
inadequate heart pumping -> effective blood volume depletion -> decreased renal perfusion -> prerenal failure
How does cirrhosis contribute to renal failure?
scarring of the live -> portal HTN -> blood pools in gut’s venous system -> effective blood volume depletion -> decreased renal perfusion -> prerenal failure
How do the kidneys react to low blood volume?
kidneys reabsorb sodium and water in attempt to replenish intravascular volume
What is elevated serum creatinine a sign of?
GFR is inadequate and renal function is impaired
What is lab that distinguishes prerenal from intrinsic renal failure?
BUN/Cr >20:1 in prerenal and less than 20:1 in intrinsic AKI
Why is BUN/Cr not as elevated in intrinsic AKI?
renal reabsorption is defective
Urine changes in intrinsic AKI
reabsorption defective so wastes both water and sodium in urine -> urine dilute with high sodium
Urine changes in prerenal AKI
reabsorbs Na and water to increase intravascular volume -> urine very concentrated with low sodium
Function of ADH
increases water reabsorption from renal tubules to blood
How can postrenal AKI be dx’d?
ultrasound of ureter, bladder, or urethra for possible obstruction
Two categories of glomerulopathies
nephrotic and nephritic syndromes
Signs of nephrotic syndrome
edema, proteinuria, hyperlipidemia
Pathophysiology behind nephrotic and nephritic syndrome
damage or inflammation to filtering mechanism of glomerulus, allowing proteins through
Signs of nephritic syndrome
HTN, hematuria, proteinuria
Changes in the serum that occur with chronic kidney failure
increase: Na, K, H, Mg, Phos, ammonia, PTH
decrease: Vit D, calcium, erythropoietin
Why does calcium concentration decrease in CKD?
In renal failure, Vit D activation decreases. Without Vit D, calcium cannot be absorbed from the diet and calcium in serum decreases
What hormone increases serum calcium by releasing it from bone?
PTH
Why does renal failure cause anemia?
kidneys are responsible for erythropoietin production
Urethritis most often caused by what?
Gonorrhea and Chlamydia
What is the significance of cells vs casts on UA?
cells with normal morphology -> lower GU tract disease
cells with abnormal morphology -> renal disease
casts are conglomerates of protein and cells -> glomerular or tubular disease
White cells from kidney =
White cells from lower UG =
AIN
infection - cystitis or urethritis
Red cells from kidney =
Red cells from lower UG =
glomerulonephritis
nephrolithiasis, hemorrhagic cystitis, or bladder cancer
What kind of casts occur in ATN and pyelonephritis?
white and epithelial casts
Which IV solution increases sodium in blood to increase intravascular volume?
hypertonic saline (D10W, 3% NS)
Which IV solution dilutes sodium in blood vessels and causes water to leave bloodstream and enter cells?
hypotonic saline (1/2 NS)
Which saline causes intravascular volume increase without any fluid shifts?
isotonic saline
Which IV saline should be used in hypovolemic patient?
isotonic (0.9% NS, D5W, LR)
What can occur if electrolyte imbalances are corrected too quickly with IV fluids?
central pontine myelinolysis; brain does not have time to re-equilibrate
Function of aldosterone
reabsorption of sodium and secretion of potassium
______ is the main extracellular cation and _____ is the main intracellular cation.
sodium
potassium
How are “-volemias” (hyper, hypo, euvolemia) determined?
based on perceived clinical exam (edema, dryness, skin tenting, etc.)
Hypervolemic hypernatremia most commonly caused by what?
iatrogenic - administration of sodium bicarb or dialysis solutions
How can renal and extrarenal losses of water and/or sodium be distinguished in hypovolemic hypernatremia?
renal - higher concentration of sodium in urine
extrarenal - kidneys hold on to as much sodium as possible, so lower concentration in urine
Central vs Nephrogenic diabetes insipidus
central - decreased production of ADH from posterior pituitary
nephrogenic - decreased sensitivity of kidneys to ADH
Well known med that causes renal toxicity
lithium
Main signs of diabetes insipidus?
excess and dilute urine (ADH is not absorbing water)
How do diabetes insidious and polydipsia present similarly in clinic? How can they be differentiated?
both have polyuriaserum [Na]
will be low in polydipsia and high in DI
What is SIADH and what does it cause to happen in body?
inappropriate and excessive secretion of ADH, which dilutes serum and causes hyponatremia
What would you expect on UA of SIADH?
concentrated urine, elevated urine [Na]
Pathophysiology behind pseudohyponatremia?
- increase in glucose, lipids, proteins, or urea in blood causes increased water reabsorption
- dilutes intravascular space and causes hyponatremia even though there is actually no change in serum sodium
_________ is a net gain in sodium or a net loss in water.
hypernatremia
3 basic mechanisms that cause hyperkalemia:
increased intake
decreased urinary excretion
increased movement of K+ from cells into bloodstream
Hyperkalemia on ECG
peaked T waves
Shifts of K+ and H+ in acidosis and alkalosis
acidosis: H+ into cell, K+ out of cell = hyperkalemia
alkalosis: H+ out of cell, K+ into cell = hypokalemia
Which drugs cause H+ to rush into cell and cause hyperkalemia?
beta blockers
How does insulin affect H+ shift into and out of cells?
low insulin = H+ into cellhigh insulin = H+ out of cell* opposite for K+
______ and ______ are main players in acid-base balance.
kidney and lungs
Respiratory acidosis is caused by elevated _____.
CO2
How does body compensate for respiratory acidosis?
kidney reabsorbs more HCO3- to buffer
How does body compensate for metabolic alkalosis?
lung retains more CO2 to buffer
What causes respiratory acidosis?
decreased expiration of CO2: obstruction, damage to lungs or chest wall, problem with respiratory muscles
What causes respiratory alkalosis?
hyperventilation
What causes metabolic alkalosis?
hyperaldosterone
vomiting
diuretics
Causes of acid gain in metabolic acidosis
"MUD-PILES" Methanol Uremia DKA Paraldehyde Isoniazid or Iron Lactic acid Ethylene glycol Salicylates
How to determine the cause of metabolic acidosis?
Calculate serum anion gap: Na - (Cl + HCO3)
- Over 10-12 (another acid present) -> MUD-PILERS
- Normal -> diarrhea or renal
Calculate urine anion gap: Na + K - Cl = -NH4
- Negative -> diarrhea
- Positive or zero -> renal tubular acidosis
