Fluid's electrolytes, acid-base physiology Flashcards
exam 1
Henderson-Hasselbaclch euation
CalculatespH
relationship pH, PaCO2, serum bicarbonate
pH = 6.1+log (HCO3)/0.03 x PaCO2
solubility coefficitent in blood of CO2
0.03
pKa of carbonic acid
6.1
Normal pH
7.35-7.45
What divides intravascular fluid (IVF) ad interstitial space (ISF)
capillary membrane
Starling forces role
determine motion across the membrane in the microcirculation
Starling forces (4)
1.Capillary Pressure
2. ISF pressure
3. ISF colloid osmotic pressure
4. Plasma colloid osmotic pressure
Most significant starling force is
plama colloid osmotic pressure
Plasma colloid osmotic pressure is determined by
plasma protien concentration and serves to maintain the circulating fluid volume within the intravascular space
How can you increase or decrease plasma protien concentration depending on
type and volume of IV Fluids
Fluid movement betwenen intravascular space and interstitial space is determined by: (2)
- Starling forces
- glycocalyx (protective layer on interior wall of blood vessel) (gatekeeper of what can pass from vessel into interstitial fluid)
Lymphatic system role
fluid scavenger- removes unwanted things that enter interstitium
Hypovolemia is most often from
Loss of ECF leading to decreased circulating volume
How to treat hypovolemia
isotonic crystalloids (NS, LR) because they are most similar to ECF
Serum osmlality and osmolarity measure
balance between water and solutes in blood
evaluates hyponatremia etiology
Normal serum osmolality
275-295 mmol/kg
Normal plama osmolarity
280-290 mOsm/L
Tonicity compares
osmolarity of a solution relative to osmolarity of the plasma
transfer of water move in direction of less solute concentration
Isotonic
same as plasma, not water transfer
Hypotonic
water enters and cell swells (leaves plasma)
Hypertonic
Water exits and cell shrinks (enters plasma)