כליה Flashcards
(237 cards)
Glomerular filtration pressures?
Hydrostatic-
afferent arteriole- 55mmHg
fluid pressure created by back propagation of water in capsule of bowmen- (-15)mmHg
[colloid- (-30)mmHg]
net filtration pressure-10mmHg
clearance definition?
volume of plasma from which a substance is completely removed per unit time
stages of chronic kidney disease?
stage 1: Kidney damage with normal or increased GFR (>90 mL/min/1.73 m 2)
stage 2: Mild reduction in GFR 60-89
Stage 3: Moderate reduction in GFR 30-59
stage 4: severe reduction in GFR 15-29
chronic renal failure (end stage) GFR <10-15
GFR measurement?
inulin
nuclear medicine lab
BUN-Blood Urea Nitrogen
Creatinine
inulin?
100% clearance in urine
no reabsorption
no metabolism
nuclear medicine lab?
can differentiate between two kidney
BUN-Blood Urea Nitrogen?
urea production rate not constant
proximal massive reabsorption
Creatinine?
serum creatinine
men 0.74 to 1.35 mg/dL (65.4 to 119.3mmoles/L)
women 0.59 to 1.04 mg/dL (52.2 to 91.9 mmoles/L)
100% renal clearance- GFR dependent
fast buildup at low kidney function, almost no reduction from basal line at higher kideny function
secreted in proximal tubuli- Cr.clearance> GFR
serum lvl- normal distribute across population
thus steady-state indicator of function,
and is not a sensitive marker of injury
women:
Ccr- 95 ± 20 ml/min
men:
Ccr- 125 ± 25 ml/min
Estimated Cr clearance?
Cockcroft-Gault formula?
(140 - age) x (IBW in kg) Est. CCr = ------------------------------ [x 0.85 women] 72 x Pcr (gr/dl)
IBW = ideal body weight
Tenofovir renal dosing?
by Creatinine Clearance
50>
300mg every 24H
30-49>
300mg every 48H
10-29>
300mg every 72-96
less than 10, no hemodialysis- no recommendations
less than 10, with hemodialysis
300mg every 7d or total of 12h dialysis
Gabapentin renal dosing?
by Creatinine Clearance
30-59 700mg
30-49> 300mg ever 48H
10-29> 300mg ever 72-96
less than 10, no hemodialysis- no recommendations
less than 10, with hemodialysis> 300mg ever 7d or total of 12h dialysis
Total body water composition and distribution?
- TBW = 60% ~ 42 Liter
1.1 ICF= 66%
~ 28 Liter
1.2 ECF= 33%
~ 14 Liter
- 2.1 ISF = 3/4 ECF
(10. 5 L) - 2.1 IVF = 1/4 ECF
(3. 5 L)
Posm – Plasma Osmolarity calculation?
Posm = 2(Na) + Glucose/18 + BUN/2.8
(in mg/dl)
שאר עולם
Posm = 2(Na) + Glucose + BUN
(in milimol/liter)
הדסה
effective blood volume definition?
blood volume on the arterial side of the circulation
part of IVF
Volume Regulation physiology?
Renal sodium handling
Na excretion stand in direct proportion to EBV (GFR)
Sympathetic tone (reveres proportion to EBV, carotic bodeis)
RAAS (reveres proportion to EBV, Afferent arteriole)
ANP (direct proportion to EBV)
Osmoregulation physiology?
Normal plasma osmolality = 275 to 290mosmol/kg.
osmolarity sensors in anterior hypothalamus:
ADH > thirst sensitivity
Volume/Osmoregulation in CHF?
blood concentrated in veins 🡪 EBV down
🡪 kidney + carotid bodies sensing 🡪 RAAS < ADH secretion 🡪 Posm down but EBV still down 🡪 ADH secretion (although low osmolarity)
EBV signal overcomes the Osmolarity signal
PNa is low but the Total Body Na is high = Edema
Hyponatremia definition?
Plasma Na+ concentration < 135 meq/L
usually reflects impaired renal Water excretion
situations of Hyponatremia with normal H2O excretion?
Primary polydipsia Reset Osmostat (pregnancy)
Isotonic (280-290) Hyponatremia mechanism?
HyperProteinemia, Hyperlipidemia 🡪 H2O fraction of TBW lowers + hyponatremia 🡪 [Na] is kept normal.
Hypertonic (<295) Hyponatremia mechanism?
- Posm = 2(Na) + Glucose/18 + BUN/2.8 (in mg/dl)
NA has the major influence but not a single player.
diabetes 🡪 Posm of blood is up (Hypertonic) 🡪 water moves form ISF TO ECF 🡪 [Na] goes down 🡪 “pseudohyponatremia” / dilutional hyponatremia
A 2.4-meq/L reduction in the plasma sodium concentration for every 100-mg/dL elevation in the plasma glucose
- mannitol
hypotonic hyponatremia (remember it represents concentration and not total mg) mechanism and Treatment?
hypovolemia-
TBW↓ Total Na ↓↓
U[na]> 20- renal losses, diuretic excess
U[na]< 10- extra renal losses, diarrhea/ vomiting
Give Salt & water == 0.9% saline
euvolemia-
TBW↑ Total Na –
U[na]> 20- SIADH
Vasopressin receptor antagonists
hypervolemia-
TBW↑↑ Total Na↑
U[na]> 20- Renal failure (acute/ chronic)
U[na]< 10- cardiac failure (keep secrete ADH)
Diuretics, Low salt diet
SIADH - Criteria?
Hyponatremia & Hypoosmolarity
Uosm inappropriatly high>100 mosmol/kg
Una >40 mosmol/kg*
Normovolemia
SIADH - ETIOLOGY?
Increased production-
Neuropsychiatric disorders Drugs- thiazides Pulmonary Disease Post operative Severe nausea
Ectopic production (Carcinoma)
Exogenous administration (Oxytocin; Vasopressin)
etc…