Fluid Management Flashcards
What percent of your body is fluid? What’s the distribution of the fluid?
60% fluid
2/3 intracellular, 1/3 extracellular
3/4 extravascular, 1/4 intravascular
What is the “third space”?
Acute sequestration in a body compartment that’s not in equilibrium with ECF
Examples: intestinal obstruction, severe pancreatitis, peritonitis, major venous obstruction, capillary leak syndrome, burns
Isotonic saline: what percent? Where does it go?
0.9% saline
Goes to extracellular space
Where does 5% dextrose go?
Goes to both ECF and ICF
Where does 5% albumin go?
only to intravascular compartment!
most efficient way to bring up bp
it’s expensive, not always available
Normal saline v. albumin: pros/cons
Saline: most of the time prefer this, cheaper
Albumin: if you don’t have a good IV line and are p ushing a small volume to bring up fluid pressure, becasue you need a smaller volume to bruing up the intravascular volume since it only goes to the intravascular compartment
Volume deficits: intravascular v. extracellular v. total body
- *Intravascular** = blood i.e. acute hemorrhage
- hemodynamic effects: BP, HR, flat JVP; cool extremities, sweating, dry mucus membranes, low filling pressures (CVP, PCWP)
- *Extracellular** = intravascular + extravascular = salt and water loss i.e. secretory diarrhea, ascietes, edema, third spacing
- skin turgor, sunken eyeballs, weight + same hemodynamic effects as above
- *Total body**: water loss = hypertonic situation i.e.diabetes insipidus, osmotic diarrhea
- thirst, hypernatremia
Colloids v. Crystalloids
Crystalloids: dextrose in water, saline, combo, ringer’s lactate
Colloids: albumin, dextrans, hetastarch
What are the consequences of shock?
Organ dysfunction
Parenchymal damage if prolonged & severe: ATN, watershed CNS infarction (around cortical rim), “shock” liver (infarction), ischemic colitis
How do you calculate water deficit?
Osm * Normal body water = Osm * Current body water
Current body water:
Men: 60% of body weight
Women: 50% of body weight
How do you treat a patient who has ascites but has a low intravascular fluid volume?
This is the only case when albumin is preferred!
If you gave saline, it would quickly make him decompensated
How do you treat someone who has massive bleeding?
It’s blood loss, so choose normal saline at 1L/hour
How do you treat someone with lots of diarrhea and vomiting? poor skin turgor, low bp
Both intravascular and extravascular fluid loss: accounts for both poor turgor and sunken eyeballs
Give them salt + water i.e. normal saline, or even better D5W+Na+bicarb
How do you treat a patient with a hyperosmolar state? i.e. high Na, low bp, decreased skin turgor
It’s intravascular volume loss (drop in bp), loss of interstitial fluid (loss of turgor), and water deificit (low Na)
Acutely: give saline until the bp comes back to normal
Then correct the water deficit
