nephro Flashcards
basic filtering unit of kidney
nephron
area where you can hear a bruit
L1
3 layers fluid must go through in bowman’s capsule
Fenestrated endothelial cell Glomerular basement membrane (GBM) Epithelial cell (with podocytes and little feet)
Macula Densa in the ______ and JG cells in the ____ arteriole make up the JGA.
distal tubule, afferent
what stucutre helps regulate the GFR?
Juxtaglomerular apparatus (tubuloglomerular feedback)
what structure synthesizes pro renin?
JGA cells
when is pro renin secreted?
when decreased circulating volume or hypoperfusion
T or F: the kidney Regulats volume and composition of body fluids to maintain a constant extracellular environment for adequate functioning of cells.
T
what waste and metabolic breakdown does kidney filter?
Ammonia, urea and creatinine
Uric Acid
Drugs and toxins.
T or F: impaired kidney function will not affect insulin
F: impaired kidney function can extend half life of insulin!
what hormones does the kidney degrade?
Metabolic degradation of peptide hormones such as pituitary hormones, glucagon, insulin
Increased EPO in states of hypoxemia:
anemia, chronic lung disease, high altitudes.
when do you see decreased EPO?
Chronic Kidney Disease due to reduced EPO production by the kidney.
kideny enzyme that forms 25 oH D from vitamin D product from liver
1 alpha hydroxylase
most potent form of vitamin D that helps us absorb calcium
25 OH D
what converts angiotensinogen (made in liver) to angiotensin?
renin
what does angiotensin II do?
Systemic Vasoconstriction which raises systemic BP
Na and water reabsorption in PT helps to restore volume
Secretion of Aldosterone
vague sx in renal disease
fatigue, weight loss, anorexia.
specific sx in renal disease
hematuria, dark urine, foamy urine, peri-orbital and peripheral edema, HTN, rashes, joint pains/arthralgias, recent URI, incomplete bladder emptying
med questions in taking renal history
what meds (esp antibx) have they taken, drug abuse, hx of NSAID use
FH questions to ask in renal patients
renal dz/transplant/dialysis
PMH to ask in renal patients
hx of stones, UTIs
PE signs in renal disease patients
Signs of systemic illness: DM, HTN
Assess volume status: edema, JVP, BP.
Examine skin for rash, purpura.
Examine joints if hx of arthralgia
what can flank pain or tenderness mean?
Renal infection
Renal infarction
Glomerulonephritis
Rarely obstruction
what can severe/colicky pain mean in renal patients?
Renal or ureteric colic +/- radiation to iliac fossa, groin and genitalia
Acute obstruction of the renal pelvis and ureter by renal calculus or blood clot
sx of lower UTI
Dysuria
Frequency
Urgency
bladder outflow obsturction sx
Impaired urinary flow
Hesitancy
Dribbling
Incomplete emptying of bladder
sphincter or bladde real dysfcn a
Urinary retention
Incontinence
Enuresis
abnormal urine volume ddx
Acute renal failure or obstruction to urine flow
Anuria
Oliguria
Failure to concentrate urine (Diabetes Insipidus, CKD)
Polyuria, nocturia.
what does proteinuria suggest?
Suggest glomerular disease
Massive proteinuria causes edema
best time for UA
early AM, mid-stream clean catch specimen.
what do these colors in urine mean?
Dark yellow to green
Red to black
Purple to brown on standing to light
Dark yellow to green (Bilirubin)
Red to black (erythrocytes, hemoglobin, myoglobin)
Purple to brown on standing to light (porphyrins)
normal urine color
(yellow to amber)
normal urine ph
(Normal pH 4.6 to 6.0)
increased urine ph
Infection with urea-splitting organism (proteus)
Systemic alkalosis, renal tubular acidosis, carbonic anhydrase inhibitors
normal specific gravity
(Normal 1.003 to 1.030)
increased urine specific gravity ddx
Fasting and dehydration, glycosuria, proteinuria, radiographic contrast media.
decreased urine specific gravity ddx
Compulsive water drinking, diabetes insipidus
T or F: protein in urine is normal
F: persistent proteinuria indicates renal disease; if one time it is elevated, retake the test if no indication of a glomerular problem
Persistently positive dipstick proteinuria should be quantified how?
24 hour Urine collection or Spot albumin-to-creatinine ratio.
what do ketones in the urine mean? causes?
Ketones in urine indicate that metabolism is dependent upon fatty acids rather than glucose for energy
causes: Diabetic Ketoacidosis, starvation, fasting, alcoholic ketoacidosis.
Glycosuria in setting of normal plasma glucose:
Defect of Proximal tubule reabsoprtion such as Fanconi syndrome, myeloma, exposure to meds such as tenofovir, lamivudine, cisplatin, valproic acid and aminoglycoside
what can cause a false + blood on dipstick?
hemoglobin and myoglobin, even when no RBCs on micro
high BUN seen with…
dietary intake (high protein diet) high catabolic rate and tissue breakdown (hemorrhage, trauma, glucocorticoid therapy. Dehydration
nml or low bun seen with
Muscle wasting and liver disease.
causes of pre-renal 20:1 BUN/cr
decreased blood flow
causes of normal or post renal 10-20:1 BUN/cr
obstruction
causes of
Renal damage causes reduced reabsorption of BUN, therefore lowering the Bun: Cr ratio.
Eliminated exclusively by the kidneys and therefore can serve as an indicator of renal function
creatinine
creatinine vary according to…?
person’s size and muscle mass hence lower in women and elderly
what is a 24 hour creatinine clearance?
estimate Glomerular Filtration Rate (GFR) by comparing the level of creatinine in urine with the creatinine level in the blood
Requires serum sample and 24 hour urine collection: Ucr x Volume/ Pcr.
equation used to calculate GFR
cockcroft gault EQ
best initial test to visualize kidney
US
indications for renal ultrasound
renal masses
obstruction/hydronephrosis
fluid collections or other signs of inflammation/infection
MAY detect nephrolithiasis (but CT better)
hematuria,
Acute Kidney Injury
flank pain
safe during pregnancy
+ doppler for suspicion of renal artery stenosis
T or F: CT is better than MRI for characterizing abnormal tissues/masses especially when there is concern for malignancy
F
special test you can do if someone has frequent UTIs, hematuria, incontinence, painful urination, etc
cystoscopy or voiding cystourethrogram
can you biopsy a kidney/
no! leave that to urologists–you could create a tract for malignant cells to go
American urologic association of hematuria
> than 3 RBCs per High Power Field in 2-3 properly collected urine on two separate urinalysis over a 2 week period.
T or F: its normal for someone on warfarin to have a few RBCs in urine
F: they should not have hematuria
what is it called when RBCs may get trapped in a specific protein in the distal convoluted tubule and stick together and can be seen on microscopy
casts
causes of glomerular hematuria:
glomerulonephritis, vasculitis, Iga nephropathy, thin basment membrane nephropathy, hereditary nephritis (alport syndrome), chronic intersitial nephritis (inf
how do you distinguish extraglomerular hematuria from glomerular hematuria?
normal appearing RBCs in urine (b/c haven’t been crunched when going through glomerulus)
causes of extraglomerular hematuria
Infections Nephrolithiasis (kidney) Calculus (bladder, urethra) Malignancy Cystic disease (PKD) Vascular disorders AVM, renal vein/artery emboli/infarct, papillary necrosis (DM, Sickle Cell Disease, NSAIDs)
symptoms of extra glomerular hemauria
Dysuria, pyuria, fevers UTI, pyelonephritis, prostatitis, urethritis, malignancy Urethral discharge Urethritis, prostatitis Flank pain Pyelonephritis, stones, neoplasm, ischemia, GN Hesitancy, dribbling BPH
signs or sx of glomerular hematuria
Gross, painless hematuria :bladder cancer, post-infectious GN, Cancer
Fevers, rash, arthritis : GN associated with Vasculitis such as Systemic Lupus Erythematosus.
signs of extraglomerular hematuria
Suprapubic tenderness UTI CVA tenderness Pyelonephritis Urethral discharge Urethritis Enlarged prostate BPH Prostatitis (tender) Nodular (malignancy)
signs of glomerular hematuria
Skin lesions such as ecchymosis, petechiae, rash
Coagulopathy, vasculitis, SLE
Hypertension, periorbital edema, generalized edema.
ECF determined by
sodium and water
Plasma sodium concentration is regulated by changes in ____ intake and excretion, not by changes in sodium balance.
water
Hyponatremia is primarily due to the intake of water that cannot be ____
excreted
Hypernatremia: primarily due to :
loss of water that has not been replaced
tx of chronic moderate hyponatremia
fluid restircion
tx of sx hyponatremia
hypertonic saline (usually as a 100 mL bolus given over 10 to 15 minutes=small bolus).
causes of hypernatremia
GI losses (like osmotic diarrhea in cholera),
difference between dehydration and hypovolemia
Hypernatremia due to water loss is called dehydration. This is different from hypovolemia, in which both salt and water are lost
skin (sweat), or the urine (diabetes insipidus or an osmotic diuresis due to glucosuria (which pulls water with it) in uncontrolled diabetes mellitus or increased urea excretion resulting from catabolism or recovery from renal failure)
tx of hypernatremia
dilute fluids
most common causes of hypokalemia
most cases result from unreplenished gastrointestinal or urinary losses due, for example, to vomiting, diarrhea, or diuretic therapy
causes of hyperkalemia
increased potassium release from the cells and, most often, reduced urinary potassium excretion
how does acidosis caused by serum bicarb and pCo2
This can be caused by a fall in the serum bicarbonate (HCO3) concentration and/or an elevation in PCO2.
A disorder that reduces the serum HCO3 concentration and pH.
metabolic acidosis
A disorder that elevates the serum HCO3 concentration and pH.
metabolic alkalosis
A disorder that elevates the arterial PCO2 and reduces the pH
respiratory acidosis
A disorder that reduces the arterial PCO2 and elevates the pH.
respiratory alkalosis
definition of acute kidney injury
- Abrupt (within 48h) reduction in kidney function (usu lasts 0.3 mg/dL
- Percentage increase of > 50%
- Reduction in urine output- oliguria of 6hr
most common etiology of kidney failure
− Acute tubular necrosis 55%
Functionally, urine output less than that required to maintain solute balance (can’t excrete all solute taken in).
− Defined as urine output
oliguric renal failure
Suggests complete obstruction, major vascular catastrophy, or more commonly severe ATN, less common and indicates more severe renal failure
− Defined as urine output
anuric renal failure
causes of non oliguric renal failure
intrarenal causes – nephrotoxic ATN, acute GN, AIN.
causes of non oliguric renal failure
more common with obstruction, prerenal azotemia
how can you discriminate between acute and chronic renal failure?
➢ Oliguria supports a diagnosis of acute renal failure
clues to chronic disease: DM, HTN, age, vascular `, fatigue, nausea, anorexia, pruritus, altered taste sensation, atrophied (small) kidneys by ultrasound
pre-renal causes of renal failure
decrease in ECF volume(GI losses, hemorrhage), decreased renal blood flow (HF, renal artery stenosis), altered intra renal hemodynamics (NSAIDS, ACE, sepsis, hypercalcemia, cirrhosis)
intra renal causes of renal failure
tubulointerstitial disorders (tubular injury, ishcemic, nephrotoxic, interstitial nephritis--allergic or NSAID) and glomerular disorders (glomerulonephritis, thrombotic microangiopathies, atheroembolic disease)
post renal causes of acute renal failure
anatomic obstruction (bladder outlet, prostate, pelvic tumor, ureteral--tumor, stones, stricture) tubular obstruction (crystals (calcium oxalate--ethylene glycol poisoning), drugs (indoor, MTX), proteins (myeloma cast nephropathy)
things that can “insult” the kidneys
- Volume depletion (diarrhea, blood loss, emesis, over-diuresis), Hypotension, CHF (d/t MI or HTN).
- Drug exposure – toxin or reduction of renal perfusion (aminoglycosides, vancoymycin).
- Contrast exposure.
- Infections – inflammatory mediators v. direct infection
- Endogenous toxins/insults – myoglobin, hemoglobin, uric acid.
sx of acute renal failure
- Fever, rash, joint pains, myalgias- concern for SLE, vasculitis, acute interstitial nephritis.
- Dyspnea – heart failure.
- Hemoptysis – Goodpasture’s (genetic defect in collagen that affects basement membranes in kidneys and lungs), Wegener’s.
- Preceding bloody diarrhea – HUS.
- Preceding pharyngitis – post-Strep Glomerular nephritis (GN)-
what are some ways to assess volume status?
JVP, peripheral edema or lack of it, orthostatic vitals, signs of right sided heart disease (SOB)
what do dysmorphic hematuria/red cells casts in urine indicate?
renal cause of ARF: glomerulonephritis or atherembolic disease (albuminuria)
What do oval fat bodies and fatty casts indicate in urine?
minimal change disease focal (albuminuria)
what do muddy brown casts in urine indicate?
tubular epithethial injury–ischemic (tubular proteinuria)
what do white cells and white cell casts and eosinophiliuria indicate in urine?
interstitial nephritis, UTI (tubular proteinuria)
what does crystals in urine mean?
drug toxicity, urate, nephropathy, calcium oxalate
when do you bx kidney?
• Exclude pre- and post-renal failure, and clinical findings are not typical for ATN
• Extra-renal manifestations that suggest a systemic disorder
• Heavy proteinuria
RBC casts
urine sodium level indicative of prerenal level? Acute tubular necrosis (ATN) level?
prerenal= 40
urine/plasma creatinine ratio indicative of prerenal level? Acute tubular necrosis (ATN) level?
prerenal: >40 (higher creatinine in urine because kidney is working to excrete it); ATN
A 42 year male is admitted to the SICU after sustaining multiple trauma. His course is complicated by Enterobacter sepsis with profound hypotension requiring support with intravenous dopamine. The urine output has gradually decreased to only 300 ml per day. The urine sodium is 78. Urine sediment showing multiple muddy brown granular casts. what does he have?
- Acute tubular necrosis- tubules sensitive to low blood pressure
- How did we know?
- Sudden onset
- Hypotensive=RF for pre-renal failure
- Trauma could have led to shock and hypooperfusion
- sepsis can cause vasodilation and decrease perfusion
- Post trauma, probably sympathetic system is activated and maintaining blood flow to brain and heart but less to kidneys.
- Also renal causes:
- High urine sodium (>40), kidney is damaged and can’t reabsorb
renal failure type where kidney is reacting to some sort of irritant and is marked by non-oliguric ARF, fever in allergic and infectious types, rash in allergic types, eosinophilia, WBC casts +/- hemeaturia
acute interstitial nephritis
drugs that can cause AIN
NSAIDS
abx: PCNS, quinolones, anti-TB meds, sulfas (TMP-SMX, furosemide, thiazides), allopurinol, cimetidine, dilantin
causes of AIN
- Allergic/Drug induced
- Autoimmune: Sarcoid, SLE, Sjogren’s
- Toxins: Chinese herb nephropathy, Heavy metals, Light chain cast nephropathy
- Infiltrative: Leukemia, Lymphoma
- Infections (Legionella, CMV, HIV, Toxoplasma)
tx of AIN
withdraw offending agent (drug, etc), tx underlying disease, corticosteroids
(+) dipstick for blood but no RBCs means what?
rhabdomyolysis
Amino glycoside Nephrotoxicity Generally presents ____ after exposure
1 week
how does radioconstrast induce acute renal failure?
• Induces renal vasoconstriction
what do these major criteria indicate?
hepatorenal syndrome
most common bug in UTI
E. coli (80-90%),
RFs for UTIs
- Recurrent/previous UTIs
- Atrophy/menopause
- Obstruction, no circumcision
- Antibiotics
- Immunosuppression, DM
- Pregnancy • Incontinence
- Intercourse
- Instrumentation, inwelling catheter
- Personal hygiene
- Urinary retention
- Anatomic abnormality
- Family history
sx of UTI
- Frequency, urgency, dysuria
- Suprapubic pain/tenderness
- Odiferous urine
- Hematuria (increase index of suspicion—painless hematuria=cx)
ddx of UTI
- Urethritis
- Prostatitis
- Pyelonephritis
- nephrolithiasis
- PID/STI
- Vulvovaginitis (inflammation on outside and vaginitis on inside)
- Urethral syndrome
- Irritable bladder/interstitial cystitis
PE to do for uti
- Abdominal exam
- CVA tenderness- push on CVA before percussing, usually no pain
- Female: Vaginal/pelvic prn- suspected STI
- Males need GU and DRE- check for prostatitis
- Elderly need CV/PV/Pulm- r/o other causes of possible sepsis
UA findings indicating UTI
- Positive nitrites (bacteria can convert nitrate to nitrite)
- Positive leukocyte esterase
- Cloudy appearance
- Culture findings: Bacteriuria ≥ 105/ml, single species
- Blood + if visible, RBCs microscopic or visible
- May also see protein
- > 10 hpf WBC
- > 5 hpf RBC- hematuria detected at 20 hpf
- ↑ epithelial cells or multiple species indicate a non-clean catch
- Specific gravity: if high suggests dehydration
RFs for pyelonephritis
- Ureterovesicular reflux
- Intrarenal reflux
- Dilated/hypotonic ureters
- Indwelling catheters
- Nephrolithiasis • Immunosuppression
- Previous pyelonephritis
- Elderly, institutionalized women
- Pregnancy
- Neurogenic conditions
sx of pyelonephritis
- FAST ONSET
- Constitutional symptoms, F/C, N/V
- Dysuria, frequency, urgency
- Flank/loin/back pain or tenderness
- Elderly specific
PE findigns on pyelonephritis
- Fever
- CVAT- don’t percuss!
- Diffuse abdominal tenderness
- Female: pelvic exam if needed
- Males: GU exam b/c rare in this group
lab findings that differentiates UTI from pyelo
• WBC casts- differentiation from LUTI
ddx of pyelonephritis
- UTI
- Appendicitis
- cholecystitis
- Cholelithiasis
- Pancreatitis
- Diverticulitis
- LLL pneumonia
- Epididymitis/prostatitis
- Renal abscess
- Acute prostatitis/cystitis
- PID/STI/vaginitis
patient education for uTI/PYELO
• Describe disease • Pharmacotherapy o OTC o Antibiotics • Nonpharmacotherapy o Fluids • Advice o Frequent / postcoital void o Proper wiping o Avoid constipation (blocks urinary flow) • Follow-up o Return if…sx get worse or don’t go away (flank pain, etc) o Repeat UA if hematuria and concern for cx
Multisystem disorder
Bilateral renal cysts associated with cysts in other organs like the liver, pancreas, and arachnoid membranes
polycystic kidney disease
T or F: polycystic kidney disease is recessively interhrited
F: can be autosomal dominant or recessive
gold std for dxing PKd
imaging: US, CT
is it normal for people on warfarin to have hematuria?
no! always work up hematuria. 25% have a malignancy
complications of pKd
HTN, stones, infections, hematuria, renal failure
clinical features of PKd
- Most asymptomatic
- Flank, back, and/or abdominal pain in about 60%- massive kidney enlargement
- UTI and renal stones
- Hematuria, HTN in half
- Intracerebral aneurysm in 6-16%- intracerebral cysts are common, rupture is serious
- Most die of other things before PKD
best tx for pKD
V2 receptor antagonists (Tolvaptan)
is proteinuria > 1-2 g/24 h normal or abnormal?
abnormal
tx of people with nephrotic syndrome
anticoagulants, lipid lowering agents (statins), ACEI to protect kidneys from proteinuria
who should get a urine culture?
complicated cystitis, cystitis in a pregnancy, cystisis with clinical failure, pyelonephritis
when is post tx culture (1-2 weeks after tx) indicated?
for sure if pregnant or treatment failure
tx of acute uncomplicated cystitis: if local resistance
TMP/SMX 1 DS po bid x 3 days
alternative drugs for acute uncomplicated cystitis if sulfa allergy
nitrofurantoin, fosfomycin
drug for acute uncomplicated cystitis if local resistance of e coli >20%
cipro, levo, moxi OR nitrofurantoin or fosfomycin
options for acute UTI in pregnancy and length of tx
TMP/SMX x 7 days Amox/clav x 7 days Cephalexin x 7 days Nitrofurantoin x 7 days Note: NO FQS, beta lactams instead
tx of acute uncomplicated cysts in someone with STD risk factors
azithromycin (1st line) alt: doxy also do pelvic exam to r/o gonorrhea
young woman with >3 UTIs per year tx
TMP/SMX SS qd long term or x1 @ sx onset or post coitus
duration of UTI tx for males
10-14 days
what’s different about txing pyelonephritis pts? (outpt)
FQs 1st line, doses are double
what pathogen do you have to tx for in inpatient pyelonephritis?
pseudomonas
what’s different about txing pyelonephritis inpatiently?
FQs course twice as long (14 days, compared to 7 outpt) IV first until afebrile for 24-48 hours, includes meds for pseudomonas (pip/tazo, amp+gent, ceftriaxone)
pyridium is urinary analgesic, what can it mask?
can mask signs and sx of UTI not responding to abx
when should most UTIs sx be cleared?
12-24 hours with tx
fluids in UTIs: help or not?
little effect, may dilute antibacterial properties of urine
is cranberry use rec’d for tx of UTIs?
no, just for prevention. makes urine more acidic
clinical features of acute nephritic syndromes
1-2 g/24 h of proteinuria, hematuria with RBC casts, pyuria, HTN, fluid retention, rise in serum creatinine, reduction in GFR
1-2 g/24 h of proteinuria, hematuria with RBC casts, pyuria, HTN, fluid retention, rise in serum creatinine, reduction in GFR+ lung hemorrhage
good pastures
Heavy proteinuria (>3g/24 h), HTN, hypercholesterolemia, hypoalbuminermia, edema/anascara, microscopic hematuria, nml to declining GFR
nephrotic syndrome
Microscopic hematuria, mild to heavy proteinuria and HTN with variable serum creatinine elevations
basement membrane syndromes
Sx: impetigo or strep pharyngitis with +/- impetigo. usu develops 1-3 wks after strep pharyngitis and 2-6 weeks after impetigo skin infection. Hematuria, pyuria, RBC casts, edema, HTN, oliguric renal failure
post strep glomerulonephritis
bag of worms
varicocele
MC side of varicocele
Left
if right sided varicocele, what do you worry about?
something compressing vein or a renal mass
• Bilateral means all their veins are just not great
treatment of varicoele
surgery if assoc with small testis, fertility issues, bilateral palpable varicoceles or symptomatic
treatment of hydrocele
• Surgery for symptomatic lesions or if mass changes
testicular pain, swelling, urethral discharge. Usu gradual onset. Often unilateral. +/- fever or signs of systemic infection (chills, rigors). +/- sx assoc with urethritis or UTI. Frequency, urgency, hematuria, dysuria. cremasteric reflex intact
epidydimitis
RFs for bladder carcinoma
male, smoking, • Chemical exposure: working with chemicals dyes, aromatic amines, textiles, leather pain, dry cleaners, radiation exposure
• Chronic cystitis—increaed risk of squamous cell
MC sx of bladder carcinoma
painless hematuria
ddx of severe abdominal pain that radiates into groin
Renal or ureteral stone
Hydronephrosis (ureteropelvic junction obstruction)—does he have a tumor or mass compressing?
Bacterial cystitis or pyleonephritis
Acute abdomen (bowel obstruction, biliary, pancreas or aortic abdominal aneurysm sources)
Gynecologic (ectopic pregnancy, ovarian cyst torsion or rupture)
Radicular pain (L1 herpes zoster, sciatica)
Referred pain (orchitis, testicular torsion)
Hernia
