Fluid Management

Question 1

What percent of your body is fluid? What’s the distribution of the fluid?

Answer 1

60% fluid

2/3 intracellular, 1/3 extracellular

3/4 extravascular, 1/4 intravascular

Question 2

What is the “third space”?

Answer 2

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

Question 3

Isotonic saline: what percent? Where does it go?

Answer 3

0.9% saline

Goes to extracellular space

Question 4

Where does 5% dextrose go?

Answer 4

Goes to both ECF and ICF

Question 5

Where does 5% albumin go?

Answer 5

only to intravascular compartment!

most efficient way to bring up bp

it’s expensive, not always available

Question 6

Normal saline v. albumin: pros/cons

Answer 6

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

Question 7

Volume deficits: intravascular v. extracellular v. total body

Answer 7

• *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

Question 8

Colloids v. Crystalloids

Answer 8

Crystalloids: dextrose in water, saline, combo, ringer’s lactate

Colloids: albumin, dextrans, hetastarch

Question 9

What are the consequences of shock?

Answer 9

Organ dysfunction

Parenchymal damage if prolonged & severe: ATN, watershed CNS infarction (around cortical rim), “shock” liver (infarction), ischemic colitis

Question 10

How do you calculate water deficit?

Answer 10

Osm * Normal body water = Osm * Current body water

Current body water:
Men: 60% of body weight
Women: 50% of body weight

Question 11

How do you treat a patient who has ascites but has a low intravascular fluid volume?

Answer 11

This is the only case when albumin is preferred!

If you gave saline, it would quickly make him decompensated

Question 12

How do you treat someone who has massive bleeding?

Answer 12

It’s blood loss, so choose normal saline at 1L/hour

Question 13

How do you treat someone with lots of diarrhea and vomiting? poor skin turgor, low bp

Answer 13

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

Question 14

How do you treat a patient with a hyperosmolar state? i.e. high Na, low bp, decreased skin turgor

Answer 14

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