FEN/Renal Flashcards
What is the percentage of body water at 24 weeks?
What percent is extracellular vs intracellular?
90%
65% Extracellular
What is the percentage of body water at 24 weeks?
What percent is extracellular vs intracellular?
90%
65% Extracellular 25% Intracellular
What is the percentage of body water at term?
What percent is extracellular vs intracellular?
80%
45% Extracellular 35% Intracellular
What is the percentage of body water at 1 year of age?
What percent is extracellular vs intracellular?
65%
20% Extracellular 45% Intracellular
TBW and ECF _______ with increasing gestational age.
decreases
ICF _________ with increasing gestational age.
increases
Normal UOP is _____ml/kg/hr
Stool water content is _______ ml/kg/d
1-3
5-10
Hypernatremia correction:
_____ for Na over ______
_____ for Na over ______
4ml/kg free water for every 1mEq/L Na >145
3ml/kg free water for Na >170
Where and at what proportion does evaporative water loss occur?
1/3 via respiratory tract
2/3 via skin
Factors increasing insensible water loss
Increased environmental and body temperature Decreasing gestational age Skin breakdown Congenital skin defects Radiant warmer Phototherapy
Factors decreasing insensible water loss
Humidity
Plastic heat shield
ADH produced by fetus at
11 weeks
ADH is produced _______ and stored in the _______
Hypothalamus
Posterior pituitary gland
Osmolality calculation:
2(Na) + glucose/18 + BUN/2.8
Nephrogenic DI is caused by
Renal tubule ADH insensitivity
Congenital nephrogenic DI is due to either
Vasopressin- receptor defect (X-linked recessive)
Aquaporin defect (autosomal)
Increased urine concentration is accomplished in nephrogenic DI through administration of
Thiazides
Body fluid with the highest potassium content is
Diarrheal stool
Body fluid with the highest chloride content is
Stomach
Body fluids with the highest sodium content are
Small intestine
Bile
False hypernatremia can occur with
Hyperlipidemia
Hyperproteinemia
Hyperglycemia
Na correction calculation
(Na desired - Na current) x 0.6 x weight
Carbonic anhydrase is an enzyme that contributes to
Acid base balance
pH is _________ correlated to potassium level.
Inversely
Acid base balance is regulated by transportation of _____ by the ________ and increased clearance of _____ by the ______
HCO3 - kidneys (to increase base)
CO2 - lungs (to decrease acid)
Renal tubular acidosis is caused by
Decreased renal tubular H+ secretion
OR
Decreased HCO3 reabsorption
Electrolyte abnormalities in RTA are
Hypercalciuria Hypokalemia (d/t increased aldosterone)
RTA 1 is identified by:
Autosomal dominant
Genetic/autoimmune disease
Inability to secrete H+ in distal tubule
Urine pH >6.2
RTA 2 is identified by:
Autosomal recessive
Fanconi, cystinosis, tyrosinemia, Lowe
Prematurity
Decreased original tubular HCO3 reabsorption
Urine pH <5.3
RTA 3 is identified by:
Aldosterone deficiency/resistance
Hyperchloremic/hyperkalemic
Metabolic acidosis
Poor growth, FTT
Renal juxtaglomerular hyperplasia/hypertrophy is
Bartter syndrome
Bartter syndrome is marked by
Defective ascending loop chloride transport–>
Increased renin
Increased aldosterone
Hypokalemic metabolic acidosis
Kidneys are formed from
Mesoderm
Three morphologic stages of embryonic kidneys are
Pronephros, mesonephros, metanephros
Nephrogenesis continues until
35 weeks
Urine production begins at
10 weeks
Preterm infant maximum osmolality is 500 due to
Tubule insensitivity to vasopressin-
Short loop of Henle
Limited na reabsorption in thick ascending loop
Renal blood flow shifts from ____ of cardiac output in utero to ____ after birth
3%
12%
Neonatal GFR doubles by
2 weeks of age
Most sodium is reabsorbed in the
Proximal tubule
Remaining in ascending loop and distal tubule
FeNa calculation
Urine Na x plasma creatinine/
Urine creatine x plasma Na x100
FeNa suggestive of prerenal failure is
1-2.5%
Potassium is reabsorbed in
Proximal tubule and ascending loop of Henle
Bicarbonate in excess of the threshold is secreted in the
Proximal tubule
Calcium reabsorption occurs in the
Proximal tubule and loop of Henle (passive)
Distal tubule and collecting ducts (active)
80% phosphorus is reabsorbed in
Proximal tubule
Tubular reabsorption of phosphorous calculation:
1- ((UrPh x PCr)/ (UrCr x PPh)) X100
65% magnesium reabsorption in
Proximal tubule and thick ascending loop
RAAS pathway is
Angiotensinogen vasoconstriction, ADH
Aldosterone –>^ Na, Cl, K, H, retain water
Pseudohypoaldosteronism
X linked recessive
Renal tubule aldosterone resistance
Incr aldosterone, renin but still with low Na, high K
Large placenta associated with
Congenital nephrotic syndrome (+ incr AFP)
Syphilis
GFR calculation
0.45 x height (cm)/
PCr
Preterm, 0.33 instead of 0.45
Protein reabsorption occurs
Proximal tubule
Myoglobinuria is due to
Rhabdomyolysis
Kidney length is approximately equal to
Gestational age in weeks
Congenital nephrotic syndrome signs
Proteinuria
Hypoproteinemia
Hyperlipidemia
Edema
Autosomal recessive
Finnish (CNF) - 19q13.1, NPHS1- large placenta
Diffuse mesangial sclerosis (DMS) - normal placenta
AR PKD signs
Chr 6p21 Snowstorm cysts Liver involvement increases with age Hepatic fibrosis Biliary dysgenesis Severe hypertension
AD PKD signs
Chr 16,
- PKD1 16p13.3 polycystin 1
- PKD2 4q. Polycystin 2
Cysts: renal, liver, pancreas, spleen
Hypertension
Cerebral aneurysms
Fanconi syndrome signs
Autosomal dominant Associated with Lowes syndrome Proximal tubule dysfunction --> urinary losses Polyuria Low phosphorous, potassium
Autosomal recessive defective cystine transport is
Cystinosis
Progression of cystinosis is from ____ in infants to _____by ____ age
FTT, V/D
ESRD
9 years
Findings in cystinosis are
Normal plasma cystine
Increased cystine in lysosomes and crystals in slit lamp
Oculocerebrorenal syndrome is also called
Lowe’s syndrome
Lowe’s syndrome is inherited
X linked recessive
Lowe’s syndrome is caused by
Enzyme deficiency due to gene defect, defective Golgi
Lowe’s syndrome signs
Cataracts, glaucoma Mental deficiency Hypotonia Renal tubular dysfunction \+/- Congenital nephrotic syndrome Cryptorchidism
Neonatal UTI is associated with
40% risk of reflux
Ectopic ureterocele is
Duplicated renal pelvis and ureter
Renal upper pole drained by duplicate ureter abnormally developed
Demonstrated on VCUG
Excision indicated
Females 6:1
Cloacal exstrophy is caused by
Failed cloacal septation with ureters, ileum and rudimentary hindgut connected to common cloaca
Clinical signs of cloacal exstrophy are
Bladder exstrophy omphalocele hydromelia cryptorchidism GU anomalies Limb deformities Hip dislocation
Bladder exstrophy causes
Defect in infraumbilical mesoderm migration with exposed posterior bladder wall, epispadias, +/- inguinal hernia
Male»female
Sacral/lumbar hypoplasia, neurogenic bladder, VUR, and renal agenesis can be
Caudal dysplasia syndrome
Cerebrohepatorenal syndrome is also
Zellweger syndrome
Glaucoma, brain anomalies, chrondrodystrophy, and cortical renal cysts describe
Zellweger syndrome
Autosomal recessive
An autosomal recessive syndrome with small thoracic cage and pulmonary hypoplasia, cystic tubular dysplasia and glomerulosclerosis is
Jeune syndrome
Polycystic or dysplastic kidneys with encephalocele, polydactyly, cryptorchidism and cardiac anomalies is ____, inherited ____
Meckel-Gruber
Autosomal recessive
Tuberous sclerosis is inherited _____ and includes
Autosomal dominant
Fibrous angiomatous lesions, intracranial calcifications, polycystic kidneys and renal angiomyolipomata
Congenital cause of nephritic syndrome is
Nail-patella syndrome (autosomal dominant)
Hypoplastic-absent patella
Palpable kidney, hematuria, and renal failure suggest
Renal vascular thrombosis
Hypercalciuria can contribute to nephrocalcinosis in ____% of neonates >____ weeks
25-60%
32 weeks
Risk factors for nephrocalcinosis
Loop diuretics Williams syndrome Type 1 RTA primary hyperparathyroidism Bartter's syndrome
