Fluids, Electrolytes, Renal Flashcards
Role of angiotensin II
Increase Na+, H2O reabsorption (through direct tubular stimulation)
Arteriolar vasoconstriction
Stimulates release of ADH, aldosterone
Activates Vit D (by PTH), erythropoietin
Role of aldosterone
Acts on kidneys to… increase Na+ reabsorption (increase Cl- passively)
Increase K+ secretion
Increase H+ secretion
XL recessive disease with hyponatremia, hyperkalemia, metabolic acidosis, increased aldosterone, increased renin
Pseudohypoaldosteronism
- unresponsiveness of renal tubule to aldosterone
- increased urine output, polyhydramnios –> diff feeding, vomiting, FTT at 2 - 3 months
- make sure to rule out CAH!
Mgmt - give additional Na, Cl and may need indomethicin (?) to reduce urine output.
Extra sodium losses in premature infants related to…
RTA types
RTA type I - associated primary and secondary causes
RTA type II - associated primary and secondary causes
Primary - AR or AD
Secondary - Fanconi syndrome, Lowe syndrome, cystinosis, tyrosinemia
Note: High urine HCO3, normal/high H+, normal or low urine pH (b/c of distal compensation by secreting more H+), low or normal K
RTA type IV - associated primary and secondary causes
Aldosterone deficiency or resistance
- sybtype 1 - aldosterone deficient; Addison’s disease, CAH
- subtype 4 - pseudohypoaldosternoism
- subtype 5 - early childhood RTA (most common, NO salt wasting)
When does fetal kidney begin to form?
When does first glomerulus form?
2 weeks (with pronephros - > later have metonephros and mesonephros). Metonephros leads to mature kidney; other two disappear.
9 weeks -> 1st glomeruli
Describe evolution of urine production in fetus over time (in utero)
Increases, starts 10 - 12 wks -> increases from 5 mL/hr at 20 weeks to 50 mL/hr at term.
Explain reasons behind decreased ability of newborns to concentrate their urine
Newborn urine is hypo-osmolar
- tubules less sensitive to vasopressin
- short loop of Henle
- low osmolality of medulla (b/c reduced Na absorption in thick ascending loop)
- less serum urea
RTAs
RTAs
Kidney development
E
? urine Ca, urine K
Bartter
Preterm and urine concentrating ability (vs term, vs adult)
Kidney devp
Role and function ADH
Neonatal HTN - causes
Also.. mgmt of RVT
Diuretics - where they act, complications esp DIURIL
