Session 1 Renal Physiology Flashcards
Osm. Changes from Diarrheas and Burns
ECF Volume
ICF Volume
Osm.
Hct
Plasma Protein
Isosmotic volume contraction
ECF Volume: decrease
ICF Volume: No Change
Osm.: No Change
Hct: Increase
Plasma Protein: Increase
Osm. Changes from Sweating, Fever, or DI
ECF Volume
ICF Volume
Osm.
Hct
Plasma Protein
Hyperosmotic Volume Contraction
ECF Volume: Decrease
ICF Volume: Decrease
Osm: Increase
Hct: No Change
PLasma Protein: Increase
Osm. Changes from Adrenal Insufficiency
ECF Volume
ICF Volume
Osm
Hct
Plasma Protein
Hyposmotic Volume Contraction
ECF Volume: Decrease
ICF Volume: Increase
Osm: Decrease
Hct: Increase
Plasma Protein: Increase
Osm. Changes from Infusion of Isontonic NaCl
ECF Volume
ICF Volume
Osm
Hct
Plasma Protein
Isosmotic volume Expansion
ECF Volume: Increase
ICF Volume: No Change
Osm: No Change
Hct: Decrease
Plasma Protein: Decrease
Osm Changes from High NaCl Intake
ECF Volume
ICF Volume
Osm
Hct
Plasma Protein
Hyperosmotic Volume Expansion
ECF Volume: Increase
ICF Volume: Decrease
Osm: Increase
Hct: Decrease
Plasma Protein: Decrease
Osm Changes from SIADH
ECF Volume
ICF Volume
Osm
Hct
Plasma Protein
Hyposmotic Volume
ECF Volume: Increase
ICF Volume: Increase
Osm: Decrease
Hct: No Change
Plasma Protein: Decrease
What is hyponatremia?
What sx are assx with it?
serum Na levels below 130-135
decreases ECF osmotic pressure and water moves into cells
causes hypovolemia and cell swelling, edema, depression, confusion, weakness, cramps, nausea, diarrhea, hypotension, tachycardia, oligouria
What is hypernatremia?
What sx are assx with it?
Na levels above 147-150
water moves from ICF to ECF causing cells to shrink
causes edema and HTN, weakness and hyperreflexia, thirst, oligouria, confusion, coma
what is in charge of changing volume status?
What is in charge of changing Na Concentration and Osmolarity?
Na balance
H2O balance
What occurs in hyposmotic volume expansion?
gain of hypotonic fluid
assx with excessive water drinking and SIADH
increases ECF and ICF, decrease in body osm.
What occurs with hypertonic volume expansion?
ECF volume increases, ICF volume decreases, osm increases
tranisently ECF osm. increases so volume shifts from ICF to ECF until equil.
Assx with high NaCl intake
What occurs with Isotonic Volume Expansion?
ECF volume expands, ICF does not change, osm. does not change
Assx with isontonuc saline injection of Na Cl
What occurs with hyposmotic volume contraction?
ICF volume increases, ECF volume decreases, Osm decreases
Assx. with adrenal insufficiency due to loss of aldosterone leading to excessivr loss of NaCl in urine
Transient response is that ECF osm. decreases and fluid shifts to ICF until osm. equil.
What occurs with hyperosmotic volume contraction?
Hypotonic fluid loss conditions like dehydration, DI, and alcoholism
insensible water loss of ECF, solute left behind and becomes concentrated
decrease in ECF volume and ICF volume, with increase in body osm.
What occurs in isosmotic volume contraction?
acute fluid loss like hemorrhage, diarrhea, vomiting
diarrhea causes loss of isosmotic fluid from GI tract
decrease in ECF volume and no change in body osmolality and ICF volume
Crystalloid Replacement Therapy do not cross what?
Do not cross plasma membranes
Remains in the ECF
Ex: Normal Saline, Lactated Ringers, DSW
Colloids Replacement Therapy don’t pass through what?
Large molecules in colloids don’t pass through semipermeable membrane
work by drawing fluid from extravascular spaces via their higher oncotic pressure
Ex: HES, albumin
ECF volume loss results in increased plasma protein AKA
concentration
a gain in ECF volume causes a decreased plasma protein count (dilution)
Isotonic
Hypertonic (salty environment)
Hypotonic (watery environment)
Isotonic: equal movement of water in and out
Hypertonic: net movement of water out of cells, shrinks
Hypotonic: net movement of water into cells, swells
Edema can be caused by alteration in capillary hemodynamics causing fluid to move from vascular spaces into the
interstium
has to increase by 2-3 L
compensatory renal retention of Na nad water to maintain plasma volume in response to underfilling of vasculature must occur to cause the edema
Ex: CHF
Edema caused by renal retnetion of dietary Na and water causing an expansion of ECF volume is often due to
inappropriate renal fluid retention
usually increases BP, expands plasma and intersitital volume
assx with primary renal desease
causes non-pitting edema (increased ICF volume) or pitting edema (increased interstitial ICF vlume)
tx with diuretics
Gibbs Donnan Effect
Protein particles create an oncotic gradient favoring the movement of water into cells
negative charges on proteins create an electrical environment favoring movement of charges into the cell
Cumulative effect is the Gibbs Donnan Effect
Calculate Osm
2[Na] + Glucose/18+BUN/2.8
or 2xNa
60-40-20
60% of body weight is total body water
40% of body weight (2/3 of TBW) is ICF
20% of body weight (1/3 of TBW) is ECF
What are the four mechanisms that can cause polyuria?
- increased intake of fluids (psych, anxiety, stress)
- increased GFR from hyperthyroid, hypermetabolic, fever
- increased output of solutes from DM, hyperthyroid, hyperparathyroid, diuretics
- inability of kidney to reabsorb water in DCT from CDI, NDI, drugs, and CRF
What is water diuresis?
increased water excretion without correspoding increase in salt excretion
assx with polydipsia and DI
What is solute diuresis?
increased water excretion concurrent with increased salt excretion
caused by increased salt present in tubular fluid from IV NaCl, hyperglycemia, high protein intake, recovery from AKI
