NEPHROLOGY SN Flashcards
Fill in the blank: Problems with filtration are due to problems with _________ whereas problems with secretion and reabsorption are due to problems with _______. -what is the definition of GFR? -what is used as an estimate for GFR?
Problems with filtration: glomeruli = act as sieves to filter serum, creating ultrafiltrate Problems with secretion and reabsorption: tubules = reabsorb and secrete solutes, concentrate the urine and create and respond to endocrine signals -GFR = glomerular filtration rate = amount of ultrafiltrate produced by all of the glomeruli (ml/min). Varies with age and height -Creatinine clearance = estimate for GFR since creatinine is not significantly secreted or absorbed in the renal tubules
What level of protein on a urine dipstick warrants further testing? -what further testing can you order? (2 options) -what test can be used for tracking progression of proteinuria but not for initial diagnosis?
> 2+ protein = need to do further testing -can have false positives Further testing: 1. Protein-Cr ratio: only requires one sample but not as accurate as 24-h protein collection 2. 24 hr urine for protein = GOLD STANDARD for severity of protein loss but difficult to obtain (Microalbumin/Cr = good for tracking progression of disease but is not used for initial diagnosis)
What is the criteria for proteinuria? -What is the criteria for nephrotic range proteinuria?
-Proteinuria = > 0.2 urine spot protein/Cr ratio or >4 mg/m2/h on 24 hr urine collection -nephrotic range proteinuria = > 2.0 urine spot protein/Cr ratio or > 40 mg/m2/h on 24 hour urine collection (10x more than proteinuria) = this is NEVER benign and always warrants further evaluation
What is the differential diagnosis for proteinuria? -benign causes (6) -pathologic causes (9)
Benign causes: 1. Acute illness 2. Fever 3. Pregnancy 4. Trauma 5. Exercise 6. Orthostatic proteinuria Pathologic causes: -Glomerular: 1. Nephrotic syndrome 2. Glomerulonephritis 3. Reflux nephropathy 4. Long-standing infections -Tubular: 5. Fanconi syndrome 6. Metal poisoning 7. Ischemic injury (ie. ATN) -Increased protein burden (overwhelms tubular reabsorption) 8. Rhabdomyolysis 9. Neoplasms
What is the most common cause of persistent proteinuria in school-aged children and adolescents? -clinical features? -how is diagnosis made? -treatment?
Orthostatic proteinuria -occurs in up to 60% of children with persistent proteinuria Clinical features: -usually asymptomatic and condition is discovered on routine urinalysis -patients excrete normal or minimally increased amounts of protein in the supine position; however, in the upright position, urinary protein excretion increases up to 10 fold (1 g/24 h) once patient is up and moving. -Hematuria, hypertension, hypoalbuminemia, edema and renal dysfunction MUST BE ABSENT to make this diagnosis -diagnosis: Collect first morning urine sample (must be first voided urine immediately upon rising in the morning) = absence of proteinuria (dipstick negative or trace for protein and urine Pr:Cr < 0.2) x 3 consecutive days confirms the diagnosis -no further work-up is needed and no treatment since condition is benign
What is the work-up for proteinuria? -lab tests? -imaging tests?
Initial labs: UA with microscopy, lytes, BUN, Cr, albumin, serum protein, urine protein, urine Cr to calculate Ur Pr:Cr ratio. Consider CRP, ESR, complement -always order renal U/S to rule out structural abnormality that might lead to obstruction of renal vessels -renal biopsy may or may not be indicated depending on suspected diagnosis
What is the definition of hematuria? -definition of gross hematuria vs. microscopic hematuria?
>5 RBCs/HPF on urine microscopy -gross hematuria = visible redness of urine with > 5 RBCs/HPF on microscopy -microscopic hematuria = normally colored urine with > 5 RBCs/HPF on microscopy x 2 occasions or more
What is the differential diagnosis for hematuria?
Pre-renal: (not true hematuria) 1. Hemolysis = hemoglobinuria = positive heme in urine but NO RBCs 2. Rhabdomyolysis = myoglobinuria = positive myoglobin in urine but NO RBCs ***other causes of red urine but not hematuria: rifampin, chloroquine, beets, food coloring, etc. 3. Coagulopathy Renal: 1. IgA nephropathy 2. Postinfectious glomerular nephritis 3. Alport syndrome (hereditary nephritis) 4. Thin glomerular basement membrane nephropathy 5. Membranous nephropathy 6. Focal segmental glomerulosclerosis Multisystem disease: 7. SLE nephritis 8. HSP nephritis 9. Wegener granulomatosis 10. HUS Tubulointerstitial disease: 11. Pyelonephritis 12. Interstitial nephritis 13. ATN Vascular: 14. Arterial or venous thrombosis Malignancy: 15. Wilms, rhabdomyosarcoma, angiomyolipoma = look for abdo mass and order renal U/S Post-renal: 16. Trauma (look at urethra, genital lesions) 17. Cystitis 18. Renal calculus
What information on the microscopy can give you a clue as to where the location of defect is causing hematuria?
Look at the RBC shape! -If normally shaped, think post-renal causes -if abnormally shaped RBCs, hemoglobin, RBC casts, or proteinuria, think renal parenchymal causes
You see a patient presenting with gross hematuria. There is proteinuria and RBC casts seen on urine microscopy. Which region of the kidney is most likely involved?
Glomerulus! -will usually see brown, cola or tea colored urine -will see proteinuria, RBC casts and deformed urinary RBCs (acanthocytes)
What can give false-negative results on urinalysis for a child presenting with gross hematuria? -what can give false-positive results in a child who is not having hematuria?
False negatives: presence of formalin or high urinary concentrations of vitamin C False positives: alkaline urine, contamination with hydrogen peroxide used to clean the perineum before obtaining a specimen
What are common causes of rhabdomyolysis? (9)
- Prolonged seizures 2. viral myositis 3. Crush injury 4. Severe electrolyte abnormalities (hyperNa, hypoPO4) 5. hypotension 6. extreme exercise 7. DIC 8. toxins 9. metabolic disorders
A patient presents to you with gross hematuria. On urine microscopy, you see RBCs, leukocytes, and renal tubular epithelial cell casts. Where is the most likely location of the renal abnormality?
Convoluted or collecting tubules
What is the most common cause of gross hematuria in children?
Bacterial urinary tract infection
You find microscopic hematuria on a routine UA performed for one of your patients. They are otherwise asymptomatic, physical exam is normal, and there is no personal or family history of renal disorders. What is your management plan?
- Repeat the UA and BP in one month 2. If positive, initiate further work up at that time
What is the most common cause of renal failure in neonates?
Obstruction due to outflow anomalies
What is the differential diagnosis for acute kidney injury?
Prerenal: 1. Dehydration leading to hypoperfusion 2. Cardiogenic shock 3. Sepsis 4. Hemorrhage Renal: 1. Glomerular disease: acute glomerulonephritis (postinfectious, SLE, HSP, membranoproliferative, anti-glomerular basement membrane) 2. Tubular disease: ATN, AIN, HUS, tumor lysis syndrome 3. Vascular: vasculitis, renal vein thrombosis Postrenal: 1. acute urinary obstruction = posterior urethral valves, ureterocele, tumor, urolithiasis, neurogenic bladder
What are the clinical manifestations of acute kidney injury? (5)
- Decreased urine output 2. Fluid overload (weight gain, peripheral edema, pulmonary edema) 3. Hypertension (headaches, papilledema) 4. Electrolyte abnormalities: hyperkalemia, acidosis 5. Elevated BUN and Cr = signs of uremia (pericardial rub)
What is the pediatric rifle criteria?
RIFLE = risk, injury, failure, loss, end-stage -Risk: estimated creatinine clearance (CCI) decreased by 25%, U/O 3 mo
How do you calculate FENa? -what does FENa < 1% mean? -FENa > 2%?
FENa helps you differentiate between prerenal cause of ARF from renal cause of ARF FENa calculation: 100 x (Urinary sodium x plasma creatinine) / (plasma sodium x urinary creatinine) -think “U PE, PE U!!” Gotta pee first to get a “peeewww, it stinks!” -OR just remember that U pee sodium = urine sodium is on top (numerator) and then you can figure out the rest! -Prerenal cause: patients whose urine showed an ELEVATED specific gravity (ie. concentrated), elevated urine osmolality (UOsm > 500 mOsm/kg), low urine sodium (UNa < 20 mEq/L) and FENa < 1% =if there is a prerenal cause of poor perfusion to the kidneys, the kidneys will still try to concentrate the urine in order to reserve as much fluid for the body as possible, THUS urine will be very concentrated and urine Na will be low since body is trying to conserve it to reabsorb water -Renal cause: patients whose urine showed DECREASED specific gravity (dilute urine), low urine osmolality (UOsm < 350 mOsm/kg), high urine sodium (UNa > 40 mEq/L) and FENa > 2% = kidney is not able to concentrate urine and thus losing lots of Na and fluids
What are clinical features of acute interstitial nephritis? -Cause?
AIN = immune-mediated inflammatory response affecting renal interstitium and tubules (spares glomeruli and vasculature) -clinical features: acute renal failure, fever, flank pain, rash, arthralgias from hypersensitivity reaction and inflammation
What drugs are known to be causes of AIN? (3 groups) -abnormal lab findings in patients with AIN? -treatment?
- Antibiotics (penicillin analogs, cephalosporins, sulfonamides, rifampin) 2. NSAIDs 3. Diuretics (thiazides and furosemide) -lab findings: urinary sediment (RBCs, EOSINOPHILS, WBC casts), proteinuria, FENa > 1%, electrolyte abnormalities -treatment: usually high fluid volume to dilute and wash through the offending agent
What are main concerning clnical features of chronic renal failure?
- Anemia (decreased Epo production) 2. Growth failure 3. Fluid overload 4. Bone deformities (vit D deficiency) 5. Electrolyte abnormalities 6. Hypertension
What is the most common cause of nephrotic syndrome in young children (ie. < 8 yo)? -treatment?
Minimal change disease -always assume that young children with nephrotic syndrome have minimal change disease and treat them with steroids - only get a renal biopsy if they do not respond to steroids -steroids 2 mg/kg/day x 4-6 weeks, then taper -most patients with minimal change disease will respond within the first month of treatment with normalization of urinary protein excretion
Compare and contrast peritoneal dialysis vs. hemodialysis.
Peritoneal dialysis: -slow, small volume fluid shifts -done at home every night during sleep -need initial minor surgery to place peritoneal catheter -infection risk: peritonitis -slow toxin removal -better for growth than HD -children feel better with PD since there are no acute fluid shifts and less cytokine release as a result HD: -faster large volume fluid shifts -rapid toxin removal -needs to be done 3x/wk at medical centre -need initial minor surgery to place graft -infection risk: graft infection/bacteremia
What are the clinical features of nephrotic syndrome?
Think PALE 1. Proteinuria > 40 mg/m2/hr, Pr:Cr ratio > 2 2. hypoAlbuminemia 3. hyperLipidemia (since liver is working overtime to try to replace lost proteins ) 4. Edema ***may also have hypercoagulability from loss of protein C & S (thus increasing risk of clots) and high risk of infections from loss of complement and antibodies in urine
What is the differential diagnosis for nephrotic syndrome? (4)
- Minimal change disease 2. Membranous nephropathy 3. Focal segmental glomerular sclerosis 4. Diabetic nephropathy
What is the underlying pathophysiology behind nephrotic syndrome?
Podocyte effacement, vacuolation, appearance of microvilli on electron microscopy -unclear etiology -called minimal change disease because changes to kidneys are very subtle
What is the pathophysiology of membranous nephropathy? -usually seen in which population? -gold standard for diagnosis? -treatment? -prognosis?
Membranous nephropathy = rare but seen in older children, autoimmune or infectious cause in about 33% -gold standard for diagnosis and only way to diagnosis = renal biopsy = serum IgG complex deposition leading to glomerular basement membrane damage -on pathology: see basement membrane spikes, granular C3 and IgG deposits -treatment: immunosuppression and steroids but may not change course of illness -prognosis: 1/3 remission spontaneously, 1/3 ongoing proteinuria, 1/3 ESRD
What are the 2 main glomerular disease entities?
Nephrotic syndrome vs. Nephritic syndrome
Which children with nephrotic syndrome should receive a renal biopsy?
- Children of any age who do NOT respond to initial course of steroids or have persistent relapses despite steroids 2. Children > 8 years old with nephrotic syndrome (minimal change disease less likely in older children so gotta rule out FSGS, membranous nephropathy) 3. Presence of hypertension, renal insufficiency, RBC casts = should NOT be seeing this in minimal change disease and so biopsy
In which population do you see focal segmental glomerular sclerosis? -pathophysiology? -diagnosis? -treatment? -prognosis?
Usually see FSGS in patients with HIV, hep B, IV drug users, sickle cell disease -pathophysiology: sclerosis and scarring of glomeruli -diagnosis: renal biopsy -treatment: long-term immunosuppression and plasmaphresis -prognosis: poor (high rate of ESRD in kids)
What do you see on renal biopsy of a patient with diabetic nephropathy?
Basement membrane damage from glucose end products -thick basement membrane, Kimmesteil-wilson nodules
What are clinical features seen in nephritic syndrome?
PHAROH 1. Proteinuria (but less than nephrotic range) 2. Hematuria 3. Azotemia (elevated BUN) 4. RBC casts 5. Oliguria 6. Hypertension
What is the differential for nephritic syndrome? (10)
PIGS Always Pick the Most Wealthy Hogs 1. Postinfectious glomerulonephritis 2. IgA nephropathy 3. Alport syndrome 4. Membranoproliferative GN 5. Thin basement membrane 6. Goodpasture/anti-GBM 7. Wegener’s 8. HUS 9. SLE 10. Pauci-immune microscopic polyangitis
Which glomerulonephritidies are associated with low complement levels? (3)
- Postinfectious glomerulonephritis (C3 will normalize 1-8 wks after presentation) 2. Membranoproliferative GN 3. SLE
How can you differentiate between IgA nephropathy vs. postinfectious glomerulonephritis in terms of: -clinical presentation? -duration of hematuria in each? -what about on labwork?
-IgA nephropathy = hematuria starts within 1-2 days after a viral URTI. Duration of hematuria = short (5 days) -Postinfectious GN = hematuria starts after 7-21 days after a viral URTI or impetigo skin infection (has a latency period). Duration of hematuria = long (4-6 wks) -labwork: IgA = NORMAL C3 levels whereas in postinfectious GN, have low C3 levels
How do you diagnose IgA nephropathy? -incidence in boys vs. girls -what is the benefit of ordering serum IgA levels? -treatment? -prognosis?
Renal biopsy = see IgA deposits in glomerulus with MESANGIAL inflammation/proliferation -more common in boys -no benefit in ordering serum IgA -treatment: supportive (treat hypertension and proteinuria with ACE-I, may benefit from steroids) -prognosis: 20-40% with ESRD but MOST have benign courses. Need long term follow up
What is thin basement membrane disease? -inheritance pattern? -treatment?
A cause of glomerulonephritis = presence of persistent microscopic hematuria and isolated thinning of the glomerular basement membrane -type 4 collagen mutation -familial (sporadic or AD trait) -treatment: none needed
What gene mutation causes Alport syndrome? -inheritance pattern? -what do you see on renal biopsy?
Type 4 collagen mutation (major component of basement membranes) -inheritance: 85% are X-linked, rest are autosomal recessive -renal biopsy: mesangial proliferation, glomerular sclerosis, FOAM CELLS (lipid containing interstitial cells)
What are clinical manifestations of Alport syndrome? -investigations for work-up of Alport? -treatment? -prognosis?
- Asymptomatic microscopic hematuria -some may have recurrent gross hematuria 1-2 d after URTI 2. Proteinuria in boys more commonly than in girls 3. Bilateral sensorineural hearing loss 4. Ocular abnormalities (anterior lenticonus = extrusion of the lens into the anterior chamber is pathognomonic, corneal erosions) Investigations: 1. Urinalysis of patient and all 1st degree relatives 2. Ophtho exam 3. Hearing test 4. Skin or Renal biopsy Treatment: No treatment available although ACE-I can slow progression to ESRD Prognosis: all progress to ESRD in adulthood and eventually require dialysis or renal transplant. -15% of affected boys have ESRD before age 15. -Boys have worse prognosis than girls
A patient presents to you with gross hematuria . You do a ophtho exam and see anterior lenticonus. What is your diagnosis?
Alport syndrome! -anterior lenticonus is pathognomonic
What is the cause of Anti-GBM glomerulonephritis? -what is your diagnosis if they have this AND pulmonary hemorrhage? -renal biopsy findings? -treatment?
Anti-GBM glomerulonephritis = autoimmune condition where IgG attacks type 4 collagen in glomerular basement membrane -if pulmonary involvement = Goodpasture disease -renal biopsy: see anti-GBM antibiodies -treatment: plasmapheresis and steroids
What is the triad of HUS? -criteria for diagnosis?
- Microangiopathic hemolytic anemia -need to see acute onset anemia with microangiopathic changes on peripheral blood smear (schistocytes, burr cells, helmet cells) 2. Renal failure -need to see hematuria, proteinuria or elevated Cr 3. Thrombocytopenia -may not see initially early in the illness Criteria for CONFIRMED diagnosis: 1. Lab criteria: need both ANEMIA and RENAL INJURY (thrombocytopenia is variably seen and thus not necessary for diagnosis) 2. Acute illness that began 3 weeks after onset of an episode of acute or bloody diarrhea ****Probable diagnosis = no clear history of acute or bloody diarrhea in preceding 3 weeks but meets lab criteria
What are potential causes of HUS in terms of large classifications? (4)
- Infection: verotoxin producing E coli, shiga toxin-producing shigella, neuraminidase-producing Strep pneumo, HIV 2. Genetic 3. Diseases causing microvascular injury: SLE, HELLP, antiphospholipid antibody syndrome 4. Medication induced: cyclosporine, tacrolimus, etc.
What environmental things can be the source of verotoxin producing E coli causing HUS?
- Undercooked meat 2. Unpasteurized milk or apple cider 3. Petting farms 4. Swimming in contaminated ponds/lakes/pools
How is the diagnosis of HUS made? -pathogenesis?
Based on clinical diagnosis!!! -rarely need renal biopsy since the risk of biopsy is significant during active phase of disease -pathogenesis: toxins cause direct endothelial cell damage in the glomerulus which then activates platelets and localized thrombosis = then the RBCs being filtered through the glomerulus get sheared and you get anemia
What differs in the clinical presentation between E.coli related HUS vs. strep pneumo related HUS? -which has worse prognosis? -how crucial is stool culture for the diagnosis of HUS?
-E coli HUS = usually have diarrheal prodrome -strep pneumo = usually have pneumonia and empyema when they develop HUS -Strep pneumo has much worse prognosis (mortality 20% compared to <5% seen in E Coli) -can order stool sample but it has little utility because by the time the patient presents with HUS, usually the organism has been cleared already
What electrolyte abnormality should you monitor for in a patient with HUS?
Hyperkalemia due to renal failure AND hemolysis spilling K into the serum and not being able to pee it out
What is the incidence of CNS involvement in HUS?
Majority of patients with HUS have some CNS involvement = most are mild (irritability, lethargy, nonspecific encephalopathic features) -some have seizures and strokes (due to microvascular CNS thrombosis)
What are 3 conditions on the differential diagnosis for HUS?
Conditions causing acute kidney failure with hemolytic anemia and thrombocytopenia: 1. SLE 2. Malignant hypertension 3. Bilateral renal vein thrombosis
What is the prognosis for HUS? -mortality? -percentage requiring dialysis during acute phase? -full recovery? -chronic renal insufficiency?
<5% mortality rate -50% require dialysis during acute phase of disease -70% fully recover -30% have chronic renal insufficiency (some remain dependent on dialysis)
Are antibiotics indicated in diarrheal associated HUS? -what about antibiotics in strep-pneumo associated HUS?
NO! Antibiotics can result in increased toxin release worsening the HUS so don’t use it! -if pneumonia associated HUS, then yes use antibiotics
What type of clots can be seen in nephrotic syndrome? (3)
Nephrotic syndrome is considered a hypercoagulable condition! 1. DVT with pulmonary embolism 2. Renal vein thrombosis 3. Sinus venous thrombosis (Neuro recommends CT head in any patient with nephrotic syndrome presenting with headache)
A patient with postinfectious glomerulonephritis suddenly develops blurred vision, severe headaches, and altered mental status. What do you need to rule out?
Hypertensive encephalopathy! -take BP right away
What are 2 main complications of postinfectious glomerulonephritis?
***Overall, related to high blood pressure 1. Hypertensive encephalopathy 2. Heart failure from hypervolemia or hypertension
What is the prognosis of postinfectious glomerulonephritis? -how long does proteinuria/hypertension/hematuria last for?
Usually full recovery = acute phase resolves within 6-8 wks with normalization of proteinuria, hypertension but persistent microscopic hematuria can persist x1-2 years after initial presentation
In a patient with suspected postinfectious glomerulonephritis, what are the indications for renal biopsy?
- Acute renal failure 2. Nephrotic syndrome 3. Absence of evidence of strep infection 4. Normal complement levels
What lab findings support a diagnosis of poststrep glomerulonephritis? (3) -what is the treatment?
- Increasing ASOT titres 2. Positive streptozyme or anti-DNase B 3. Decreased C3 level -treatment: supportive
What are the clinical manifestations of unilateral renal dysplasia/agenesis if not diagnosed prenatally? (3) -what is their expected renal function? -indication for nephrectomy?
- Hypertension (due to renin production by the damaged kidney) 2. Recurrent UTIs 3. Abdominal mass (secondary to obstruction) -should have normal renal function since their one kidney works well enough for both! -indication for nephrectomy: recurrent UTIs or severe HTN not managable by medical therapy
What is the clinical manifestation of bilateral renal agenesis?
Either stillborn or die from respiratory failure -renal agenesis = cannot produce urine in utero = oligohydramnios = pulmonary hypoplasia
What are the clinical manifestations of autosomal recessive polycystic kidney disease? (6) -ultrasound findings? -prognosis? -treatment?
Presents either prenatally with oligohydramnios or early in infancy 1. Abdominal mass from cysts = SMALL CYSTS 2. Hypertension 3. Potter facies 4. Polyuria 5. Polydipsia 6. MAY see cysts in lung, pancreas, liver 7. HEPATIC FIBROSIS = can have signs of portal hypertension -see big echogenic kidneys with cysts on ultrasound -prognosis: fast progression to ESRD in 100% of patients -treatment: dialysis, growth hormone, bone growth support, eventual transplant
Why does chronic renal failure cause FTT?
- Protein loss = malnutrition 2. Poor bone growth secondary to deficient Vit D production 3. May be secondary to steroid therapy 4. Possibly anemia (not great evidence supporting this)
What are the clinical manifestations of autosomal dominant polycystic kidney disease? -associated findings? (2) -ultrasound findings? -what imaging test should all patients with ADPKD receive/ -prognosis? -treatment?
Presents in adulthood and has slower, variable course than ARPKD 1. Abdominal mass from renal cysts (big cysts) 2. Family history 3. UTIs 4. Chronic renal failure -associated findings: hepatic cysts, cerebral aneurysms (all patients with ADPKD need head imaging to rule out aneurysms) -ultrasound: can be normaly initially -prognosis: slow progression to ESRD in middle age or later, some people don’t progress to ESRD -traetment: BP management with ACE-I, occasional need for transplant
What is the pathophysiology of cystinosis? -clinical manifestations?
Autosomal recessive disease caused by a lysosomal transporter mutation = leads to intracellular cystine accumulation and subsequent Fanconi syndrome from proximal tubule damage -cystine accumulates in kidneys, thyroid, cornea, pancreas -clinical manifestations: 1. chronic renal failure (growth failure, rickets) 2. ocular abnormalities (corneal opacities, visual impairment) 3. Hypothyroidism 4. Diabetes ****THERE ARE NO STONES WITH CYSTINOSIS (only with cystinuria)
What investigations support the diagnosis of cystinosis? (4) -treatment? (4)
- Urinalysis: elevated pH, bicarb, glucose and amino acids due to Fanconi syndrome 2. Slit lamp exam = accumulation of cystine crystals in the cornea 3. Serum cystine levels are normal, urine cystine levels mildly elevated 4. Confirmation by cystine in leukocytes -treatment: 1. Oral cysteamine (enzyme that cleaves cystine) 2. Electrolyte and vit D replacement 3. Growth hormone 4. Renal transplant
What are 3 endogenous nephrotoxins?
- Uric acid 2. Myoglobin 3. Hemoglobin
What medication can cause nephrogenic DI?
Lithium
What is the most common cause of nephrolithiasis in children? -what is the most common type of renal calculi?
Idiopathic or familial hypercalciuria -most common type of renal calculi = calcium stones
What are struvite renal calculi associated with? (2)
- Proteus UTI 2. Foreign body
What investigations should you order if you are suspecfting renal calculi as a diagnosis?
- UA: may see hematuria 2. AXR first to see if you can visualize the stone, then US or CT if xray negative (calcium stones are easily seen on xray and they are the most common type) 3. BUN/Cr to evaluate renal function 4. Serum calcium to look for hypercalcemia 5. 24 hr urine collection for calcium, lytes, pH 6. Straining the urine to obtain stones for analysis
What is the treatment for nephrolithiasis? -specifically for normocalcemic hypercalciuria? -specifically for hypercalcemic hypercalciuria?
- 1.5-2x IV hydration 2. Analgesia 3. Strain urine for stones for analysis and to document stone passage 4. Surgical removal or lithotripsy if large stone > 7 mm 5. Treat underlying etiology -normocalcemic hypercalciuria: thiazide diuretics to increase tubular calcium reabsorption, mild decrease in dietary calcium, low Na, high K diet -hypercalcemic hypercalciuria = reduce serum calcium based on etiology
What are causes of increased anion gap metabolic acidosis? -normal anion gap metabolic acidosis?
Increased anion gap: CAT-MUDPILES -cyanide, carbon monoxide -aminoglycosides -toleune/theophylline -methanol -uremia -DKA, other causes of ketosis -paraldehyde -isoniazid, iron, inborn errors of metabolism -lactic acidosis -ethylene glycol -salicylate Normal anion gap: -Diarrhea -renal tubular acidosis
What are the 3 types of renal tubular acidosis? -what lab findings are expected with each? -what is the main treatment of all 3?
- Distal RTA (type I) = hypokalemia, hypercalciuria, nephrolithiasis and nephrocalcinosis, urine pH > 5.5 (cannot acidify their urine!!) -can be congenital or acquired (medications, acquired renal disease) -think HIGH things = high calcium in urine, high urine pH 2. Proximal RTA (type II) = rarely present in isolation, usually part of Fanconi syndrome -get hypoPO4, glycosuria, aminoaciduria, urine pH < 5.5 (can acidify their urine), risk of rickets due to hypophosphatemia -think LOW things = low phosphate, low urine pH 3. Hyperkalemic RTA = due to hypoaldosteronism (see low level of aldosterone since adrenal gland is not producing it) or pseudohypoaldosteronism (kidney does not respond to aldosterone thus see a high level of aldosterone trying to stimulate kidney) -see hyperkalemia, hyponatremia ***Main treatment = bicarb
Which type of RTA increases risk of rickets?
Proximal RTA! (secondary to hypophosphatemia)
What is the differential diagnosis for enuresis? -4 main categories (12 causes)
Increased urinary output: 1. DM 2. DI 3. Sickle cell disease 4. Excessive water intake Increased bladder irritability: 5. UTI 6. Constipation Structural problems: 7. Ectopic ureter 8. Epispadias (females) 9. Thickened bladder wall (males) Abnormal sphincter control: 10. Spinal cord abnormalities 11. Neurogenic bladder 12. Sphincter weakness
What is the definition of primary nocturnal enuresis? -most common cause? -most effective treatment? -other treatment options?
Night time incontinence after 6 yo with no preceding period of dryness or < 6 mo dryness at a time -alarm systems are by far the most effective treatment but needs to be motivated -other treatment options: fluid restriction, bladder exercises, caffeine elimination, DDAVP for sleepovers but not prolonged treatment
What is the definition of primary diurnal enuresis? -usual causes?
Lack of consistent daytime continence by age 4 -usual causes: stress incontinence, constipation
What is the definition of: -hypertension -hypertensive urgency -hypertensive emergency
-Hypertension: BP > 95th% on 3 separate occasions -hypertensive urgency: BP >99th% with headache or vomiting but no evidence of end organ damage -hypertensive emergency: BP > 99th% with end organ effects (encephalopathy, seizure and/or renal dysfunction)
How do you properly measure a blood pressure?
- At rest x 3-5 mins 2. Right arm at heart level resting on solid surface 3. Width of cuff bladder = 40% of mid-humoral circumference 4. Length of cuff bladder = 80% of mid-humoral circumference 5. Inflate to 20 mm Hg above point at which radial pulse is gone
Which is more likely in the following: primary vs secondary hypertension? -older children -younger children
Older children = more likely to be primary htn, especially obese or family history -younger children = more likely to have secondary htn due to an underlying etiology
What are 4 medications used to treat hypertensive urgency or emergency? -side effects of each?
***remember that for hypertensive emergency, you NEED to give IV meds and the goal is to decrease the BP by < 25% in the first 8 hrs, then normalize slowly over the next 1-2 days to ensure cerebral perfusion is still happening 1. Hydralazine (direct vasodilator) -side effect: SLE like reaction, tachycardia 2. Nifedipine (calcium channel blocker) -side effects: flushing, tachycardia, palpitations 3. Sodium nitroprusse (NO pathway dilator) -side effects: cyanide toxicity, diaphoresis, muscle twitching 4. Beta blockers (labetalol, esmolol) -side effects: heart block, bronchospasm, liver toxicity
What is the management of primary hypertension?
Start with trial of exercise, calorie reduction and sodium restriction before treating with medications
What are medications used to treat chronic hypertension? (5 main classes)
Remember that medications are used to treat refractory primary HTN and secondary HTN 1. ACE-Inhibitors 2. Beta blockers 3. Calcium channel blockers 4. Diuretics 5. Clonidine
What are signs and symptoms associated with obstructive uropathies? -5 causes of obstructive uropathy?
- Abdominal pain 2. Abdominal mass 3. Growth failure 4. UTI 5. Oliguria Causes: 1. Hydronephrosis 2. Ureteropelvic junction obstruction 3. Ureterocele 4. Posterior urethral valves 5. Duplicated collecting system
What is the most common cause of abdominal mass in a newborn?
Multicystic dysplastic kidney disease
What is the indication for prophylactic antibiotics in VUR?
Grades 4-5 VUR on VCUG
What is chordee? -treatment?
Downward curvature of erect penis due to scarring of tissue on ventral surface of penis = can be associated with hypospadias -treatment: lysis of ventral adhesions for minor repairs, tissue graft for severe cases
What is the most common penile anomaly?
Hypospadias = urethral meatus is on ventral surface of penis
What are the clinical features of prune belly syndrome? (5) -treatment?
Occurs only in males = absence of abdominal musculature 1. Complete lack of abdominal wall muscles (thus belly looks wrinkly) 2. Abdominal testes (cryptorchidism) 3. GU abnormalities with dilated urinary collecting system (unobstructed) -30% progress to end stage renal disease and end up needing renal transplant 4. Clubfeet (from oligohydramnios if kidneys are not making urine) 5. Malrotation Treatment: 1. Orchidopexy by 1 year 2. Most likely ureteral implantation due to valve incompetence and reflux leading to UTIs 3. Abdominoplasty later in life
What is the definition of micropenis? -what are 3 conditions that can cause micropenis?
<2.5 cm in term newborn or less than the age appropriate norm in older child -syndromes associated with micropenis: 1. Prader-Willi 2. Growth hormone deficiency 3. Androgen insensitivity
What is paraphimosis?
Incarceration and ischemia of the penile glans after insult or flipped retraction of the prepuce
You are examining a baby who presents with irritability and notice a blue dot on the scrotum. What is your diagnosis? -treatment?
Blue dot sign = testicular appendiceal torsion! -blue dot = engorged hypoxic appendage -treatment: need to get an ultrasound to rule out testicular torsion. If normal, then treat testicular appendiceal torsion with supportive care only since there are no complications from this condition. Give NSAIDs! Pain usually resolves within 2 weeks
What is the usual bacterial etiology of epididymitis in adolescent males vs. children? -useful screening test for epididymitis?
Adolescent males: STI Children: E coli -useful screening test = urinalysis to look for pyruria, bacteriuria
What is the treatment for labial adhesions?
Usually none since most are asymptomatic and resolve by adolescence when estrogen levels increase -can use daily estrogen cream x 1 wk followed by petroleum jelly daily x 1 mo to prevent recurrence for symptomatic or persistent adhesions -surgical lysis option also
What is Fanconi syndrome? -clinical features? (2) -causes? (4) -complications? (2)
Disease of proximal tubule of kidney = failure to reabsorb glucose, amino acids, uric acid, phosphate and bicarb! -clinical features: 1. Polyuria, polydipsia and dehydration (from glycosuria) 2. Growth failure -causes: Inherited = 1. CYSTINOSIS (most common cause) 2. Wilson’s disease 3. Galactosemia Acquired 4. Medications: tetracyclines, valproic acid, etc. -complications: 1. Type II RTA (Proximal) 2. Rickets due to hypophosphatemia
What are the grades of VUR?
- Grade I = reflux of urine into an undilated ureter 2. Grade II = reflux into ureter and collecting system without dilatation 3. Grade III = dilatation of the ureter and collecting system without blunting of the calyces 4. Grade 4 = blunting of the calyces 5. Grade 5 = Even more dilatation and tortuosity of the ureter
Orchidopexy eliminates the risk of which of the following: a. testicular malignancy b. decreased sperm count c. torsion of testes d. UTI e. epididymitis
C! Undescended testis are highly mobile and increase risk of testicular torsion! -orchidopexy improves fertility but the patient may still have reduced sperm counts
What is a varicocele?
Dilatation of the pampiniform venous plexus due to valvular incompetence of the spermatic vein
What are the symptoms of idiopathic hypercalciuria? (3) -test to confirm diagnosis?
- Recurrent gross hematuria 2. Persistent microscopic hematuria 3. Dysuria or abdominal pain -test to confirm diagnosis: urine calcium:creatinine ratio (>0.2 is diagnostic)
What is the underlying cause of Bartter syndrome? -What lab findings are seen in Bartter syndrome?
Cause: autosomal recessive condition with defect in thick ascending limb of loop of henle -usually present with persistent vomiting, polyuria/polydipsia 1. Hypokalemia 2. Hypercalciuria 3. Metabolic Alkalosis 4. Hyperaldosteronism 5. Hyperreninemia
What is the function of the proximal tubule? What is the function of the Loop of Henle? What is the function of the distal tubule?
Proximal tubule: reabsorption of 1. 66% of NaCl 2. 99% Glucose 3. 99% Amino acids 4. 99% Potassium 5. 99% Phosphate 6. 75% of bicarbonate -production of 1,25(OH)2-cholecalciferol (calcitriol) Loop of Henle: reabsorption of 1. 25% of NaCl Distal tubule (distal convoluted tubule and collecting ducts): reabsorption of 1. DCT (impermeable to water) = The rest of the NaCl via Na-K exchange (this is where aldosterone acts to reabsorb Na in exchange for K going into urine) 2. Collecting duct = responds to ADH to reabsorb water and also secretes H+
What are clinical features of multicystic dysplastic disease? -monitoring? -prognosis?
Non-heritable 1. Contralateral hydronephrosis 2. VUR in contralateral kidney 3. Late hypertension 4. Wilms tumor -monitoring: ultrasound, renal function tests and BP annually. Only obtain VCUG if contralateral hydronephrosis is found -prognosis: in 50% of patients, cysts regress by age 7 but this does NOT change the risk of developing a malignancy
What electrolyte abnormalities usually accompanies hypernatremic dehydration?
- Hypocalcemia 2. Hyperglycemia
What is the most common vasculitis in childhood? -which immunogloublin is deposited into the kidneys?
HSP -IgA deposited into the kidney
What renal monitoring is required for HSP?
- Urinalysis x 6 months 2. BP x 6 months
What are fluid management principles for syndrome with edema? (2)
- Fluid restriction if child is hyponatremic 2. If dehydrated, then give albumin and lasix
What are 3 lab findings seen with hyperaldosteronism?
- Hypernatremia 2. Hypokalemia 3. Metabolic alkalosis -remember that Na+ is coupled with HCO3- and kicks out K+
What are 4 extrarenal manifestations of autosomal dominant polycystic kidney disease?
- Aortic root abnormalities 2. Mitral valve prolapse 3. Cysts on liver, ovaries, spleen 4. Berry aneurysms in brain 5. Increased risk of renal cell carcinoma
Name 2 syndromes associated with renal cysts (other than PCKD).
- Von Hippel Lindau 2. Tuberous Sclerosis
In a patient with chronic hyponatremia, how fast can you replace their sodium?
No more than 0.5 meq increase per hour (no more than 12 mEQ/day) -1 mmol Na increases serum Na by 1 mEQ
What are the causes of: -hypovolemic hyponatremia -hypervolemic hyponatremia -euvolemic hyponatremia
-Hypovolemic hyponatremia: 1. vomiting 2. diarrhea 3. burns 4. 3rd spacing Hypervolemic hyponatremia: 1. Heart failure 2. Liver failure 3. Sepsis 4. Nephrotic syndrome Euvolemic hyponatremia: 1. SIADH 2. Water intoxication 3. Hyperosmolar (high serum glucose)
Newborn with 6 mm pelvicaliectasis documented on antenatal U/S. When do you do an ultrasound?
Any pelvicaliectasis > 5 mm requires postnatal ultrasound prior to discharge to rule out obstructive uropathy
What antibiotic is used for prophylaxis of UTI with grade 3-5 VUR in baby > 2 mo? -what about baby < 2 mo?
Trimethoprim or Septra -Babies < 2 mo: Amoxil
When do you stop antibiotic prophylaxis for history of UTI and VUR?
If UTI free > 1 yr, can stop prophylaxis antibiotics
You have a 15 yo female with 2+ protein on routine exam. What is the FIRST line of testing you should order?
First morning urine analysis x 2 to rule out orthostatic proteinuria -if this is ruled out, THEN pursue Pr:Cr ratio or 24 hr urine collection
Name 5 nonpainful testicular mass.
- Testicular cancer 2. Varicocele 3. Spermatocele 4. Hydrocele 5. Nonincarcerated inguinal hernia
What are the main differences between multicystic dysplastic kidney disease and polycystic kidney disease? (2)
- PCKD = inherited disorder; MCKD is not 2. PCKD = bilateral; MCKD = unilateral (bilateral is not compatible with life)
What is the most accurate imaging test to detect renal scarring?
DMSA! -better visualizes renal parenchymal abnormalities -can also diagnose pyelonephritis
What 2 conditions are diagnosed via VCUG?
- Posterior urethral valves 2. Vesicourethral reflux
What 3 findings predict poor prognosis in Alport syndrome?
- Development of nephrotic syndrome 2. Gross hematuria in childhood 3. Prominent glomerular basement membrane thickening on renal biopsy
A baby you examine has a single umbilical artery. There are no other abnormalities on exam. What is your next step?
Nothing! -single umbilical artery only suggests renal anomaly if associated with other
What findings on physical exam are associated with renal anomalies? (4)
- External ear anomalies 2. Imperforate anus 3. Scoliosis 4. Single umbilical artery associated with other abnormalities on exam
What is the treatment of SIADH?
Fluid restriction = 1 L/m2/day
What features of a renal cyst would warrant further work up with CT scan?
- Septations in the cyst 2. Calcifications in the cyst 3. Solid component in the cyst
When does most renal scarring occur?
Age 2-5 yo. After that, new scars are super rare. SO, if you see scarring from vesicourethral reflux, it must’ve happened when they were really young. Don’t need to repeat VCUG once kids are older and are UTI free even if they have residual VUR.
What is the management of rhabdomyolysis?
- Hyperhydration (2x maintenance) 2. Diuresis with mannitol perfusion
What is the acute management of nephrotic syndrome?
- Lasix and albumin infusion for severe edema 2. Volume restriction 3. Steroids if typical picture for minimal change disease and no indications for renal biopsy 4. May need antihypertensives 5. Restriction of salt intake
What should be your work-up for a patient with hematuria?
- Complete history and physical looking at blood pressure, optic discs, skin, abdomen, genitalia 2. Confirmation of true hematuria by urine R&M 3. Urine culture 4. Urine calcium, protein, creatinine 5. CBC, BUN, Cr, Calcium level, total protein and albumin 6. Streptozyme or ASOT titres, C3, C4 7. Renal U/S
What is the most common cause of acute renal failure in children?
ATN
What is the treatment for renal osteodystrophy secondary to CKD?
Renal osteodystrophy = related to phosphate retention from low GFR and diminished 1,25-dihydroxyvitamin D production in the kidney. Also get secondary parahyperthyroidism due to decreased calcium (from too much phosphate retention and thus loss of calcium into the urine) 1. Restrict phosphate in the diet 2. Oral phosphate binders 3. Supplemental calcium
What is the most common cause of hypertension in children?
Essential primary hypertension
What are the components of VACTERL?
Vertebral anomalies Anal atresia Cardiac defects TEF Renal dysplasia Limb defects
What is the most common cause of abdominal mass in a newborn?
Renal cause = most commonly ureteropelvic junction obstruction (according to baby nelsons) OR multicystic dysplastic kidney disease (according to mama nelsons)
What are possible causes of false positive proteinuria? (4)
- Hematuria 2. Concentrated urine 3. Alkalotic urine 4. Use of antiseptic agents
ANH What are the 5 Common Etiologies for Antenatal Hydronephrosis (ANH)?
