Nephrology Flashcards
Serum sodium indicates ___
water balance
Voiding dysfunction + spinal dysraphism
myelomeningocele
Voiding dysfunction + weak stream
PUV
Daytime continence is achieved at ?
4yrs
Nightime continence is acheived at ?
5-7yrs
Abnormal bladder contraction and filling
Vincent’s Curtsy
Overactive bladder
Inability to relax sphincter and pelvic floor during voiding
Neurogenic vs. non-neurogenic (can be pathological)
What treatment has the highest rate of success for nocturesis
Enuresis alarm
What is the most appropriate follow-up for an infant with a unilateral multicystic dysplastic kidney?
VCUG to rule out reflux in contra-lateral kidney
DDx for bilateral polycystic kidneys
- ARPKD and ADPKD
- von Hippel-Lindau disease
- Tuberous sclerosis
- Acquired
- Microcysts limited to COLLECTING TUBULES
- Enlarged echogenic kidneys
- Can become massive –> pulmonary problems
- LIVER INVOLVED - congenital hepatic fibrosis, periportal fibrosis
- HTN is common and can be presenting symptom
- 99% cases of bilateral polycystic kidneys in neonates
ARPCKD
- With neonatal survival, 80% survival at 10 years with renal survival of 75% and liver fibrosis 44%
- Later presentation
- ONLY KIDNEY INVOLVEMENT
- MACROCYSTS in all segments of nephron
- Kidneys are enlarged with large cysts
- Present as abd masses, flank pain, hematuria
- HTN common
- Gene is sitting next to tuberous sclerosis gene
- Cerebral aneurysms
- Hepatic cysts later in life
- 75% with family history
ADPKD
- PKD1 and PKD2
- Oligohydramnios
- Pulmonary hypoplasia
- Limb deformities
- Flattened facies
POTTER SEQUENCE
- associated with bilateral renal agenesis
- Vertebral
- Cardiac
- TE fistula
- Renal
- Limb
VACTERL
- Renal agenesis
- Absence of upper vagina and uterus
Mayer-Rokitansky-Kuster-Hauser
Most common cause of antenatal hydronephrosis
UPJ Obstruction
2nd most common cause of antenatal hydronephrosis
Congenital megaureter
Most common cause of congenital kidney disease 2/2 obstruction
PUV
Best imaging for suspected renal trauma
CT with and without contrast
- Pelvic fracture
- Free fluid in cul-de-sac
- Gross hematuria
- Renal trauma
- Get CT scan
- Perineal/penile hematoma
- Blood at meatus
- Inability to void
- Urethral injuries
- Dx via retrograde urethrography in males, cystoscopy in females
What is the single best test for a 9y/o M with a FHx of nephrolithiasis who presents with flank pain
CT scan of abdomen without contrast - want to see stone
CT>US>Plain film
A 10y/o M is found to have HTN at a sports physical and has cafe-au-laits on exam. The next best test is…
Renal US with doppler - RAS/neurofibromatosis
Volume follows _____.
Sodium
TBW ~ Total body salt
*Serum sodium indicates water balance
Degree of dehydration:
- H/o losses
- Minimal signs
- Decreased frequency of urination
VERY MILD
- 1% infant
- 1% child
Degree of dehydration:
- Poor skin turgor
- Sunken fontanel and/or eyes
- Lack of tears and/or saliva
- Lethargy
- Tachycardia
MILD
- 5% infant
- 3% child
Degree of dehydration:
- Orthostatic Hypotension
- Significant Tachycardia
- Oliguria
- Deepening lethargy
MODERATE
- 10% infant
- 6% child
Degree of dehydration:
- Shock
SEVERE
- 15% infant
- 9% child
Rate of volume repletion
50% deficit in first 8 hours
Remainder over next 16 hours
How do you estimate serum osmolality
2Na + 2K + Gluc/18 + BUN/3
** biggest contribution to serum osmolality is sodium
- Thirst
- Fever
- Doughy skin
Hypernatremia
Lack of ADH
Central DI
- Head trauma
- Pituitary infarction
- Pituitary/hypothalamic tumors (Histiocytosis X)
- CNS infections
ADH in circulation, but kidneys not responding
Nephrogenic DI
- X-linked recessive loss of V2 receptor activity
Anorexia
Muscle Cramps
Neurologic symptoms
Hyponatremia
Rapid correction of hyponatremia
Central Pontine Myelinolysis
Rapid correction of hypernatremia
Cerebral edema
Most common cause of hyponatremia
SIADH
- Na < 280
- Uosm > Posm
- EUVOLEMIC
- NORMAL RENAL FUNCTION
6y/o w/ abd pain, v and confusion Na 125 Co2 7 Glu 900 SerumOSM 317 UrineOsm 600
DM w/ factitious hyponatremia
6y/o w/ abd pain, v and confusion Na 122 Co2 22 Glu 100 Serum osm 260 Urine osm 350
SIADH
3m/o with decreased alertness, irritability and doughy skin. H/o GBS meningitis. Na 165 CO2 24 Glu 100 Urine osm 200
DI
1y/o with polyuria and polydypsia Na 140 CO2 24 Glu 100 Urine osm 100
Perform water deprivation test
No change in Na with an increase in urine ism to 400 = psychogenic polydipsia
Serum sodium increases to 146, urine osm maxes out at 250 = DI (central or nephrogenic)
- Weakness
- Peaked T waves
Hyperkalemia
Metabolic alkalosis
Normotensive
Low urine chloride
Normal renal response - outside kidneys
- Pyloric stenosis
- Cystic fibrosis
Metabolic alkalosis
Normotensive
High Urine Chloride
Kidney - Loop of Henle
- Loop diuretics
- Lasix
- Barter Syndrome - polyhydramnios, hypercalciuria, hearing loss
- Gittelman’s - magnesium wasting
Metabolic alkalosis
Hypertension
High Urine Chloride
Liddle’s syndrome - low renin/low aldo
CAH (DOC acts like aldo)
Renal artery stenosis
Aldosterone excess
Normal anion gap
9-12
Anion gap calculation
Na - (Cl + HCO3)
Gap Acidosis
DKA, Lactic Acidosis
Non-gap acidosis
GI losses (Diarrhea, fistulas) RTA
Short stature
Nephrocalcinosis
RIckets
RTA
Hyperchloremia
Hypokalemia
Non-anion gap acidosis
Alkaline urine
RTA
- Inability to acidify the urine appropriately with spontaneous or chemically induced metabolic acidosis
- Hypokalemia
- Hypercalciuria
- SNHL
- Rickets
- Nephrocalcinosis
Distal/Type 1 RTA
- Defect in Na/H exchange mechanism leading to a defect in proximal tubular bicarbonate resorption
- Distal nephron acidifies urine appropriately
- Hypokalemia
- Acidic urine during acidosis
- Fanconi’s anemia - renal wasting of phosphate, amino acids, bicarbonate, irate and glucose
- Rickets
Type II/Proximal RTA
- D/o of distal nephron
- Hypoaldosteronism or pseudoaldosteronism and hyperkalmia
- Inability to acidify the urine
Type IV distal RTA
IDM
Hematuria
Renal Vein/Artery Thrombosis
Child with illness and hemorrhagic cystitis
Adenovirus
Hematuria and chemotherapy
Cyclophosphamide
Indications for Renal Biopsy - hematuria
- Significant proteinuria
- Persistent hypocomplementemia
- CRI
- F/h of nephritis with deafness - Alports
- Recurrent gross hematuria not explained by a non-glomerular cause
Protieinuria - Indications for Renal Biopsy
Proteinuria + FHx renal failure
Proteinuria + persistent hematuria
Steroid resistant nephrotic syndrome
Proteinuria and persistent hypocomplementemia
Proteinuria and HTN
Proteinuria associated with systemic disease
Persistent non-orthostatic proteinuria (>1-2yrs)
Proteinuria > 40mg/m2/hr
Hypoalbuminemia < 2.5g/dL
Edema
Hyperlipidemia
Nephrotic Syndrome
Most common cause of nephrotic syndrome in children
Minimal change disase
What is a common infectious complication of nephrotic syndrome
SBP - Strept pneumoniae
- Nephrotic syndrome
- No changes on light microscopy
- No immunofluorescent deposits
- Epithelial foot process effacement on EM
MCNS
MCNS - response to Prednisone
93% responders
73% respond within 14 days
94% respond within 28 days
