Fluid Therapy

Question 1

Most common causes of fluid loss/dehydration

Answer 1

Polyuria, V+, D+; anorexia

Question 2

Hct, PCV and USg in dehydrated patients

Answer 2

Increased
- except in ext. hemorrhage cases for Hct and PCV)
- USG >1.045 (assuming renal function is normal)

Obtain these values BEFORE fluid therapy!

Question 3

0.9% NaCl, Norm-R, Plasma-Lyte, and LRS are what type of fluid?

Answer 3

Isotonic crystalloid/replacement

Question 4

Indications for Isotonic crystalloid/replacement versus Hypotonic crystalloid/maintenance:

Answer 4

Isotonic crystalloid/replacement: resembles extracellular fluid –> addresses ECF loss (shock therapy, correction for fluid deficits

Hypotonic crystalloid/maintenance: less sodium, more potassium; use once dehydration has been addressed

Question 5

Hypertonic saline indications

Answer 5

not used very commonly; used for pt in shock. Short-lived effect.

Question 6

Indications for colloid therapy

Answer 6

Large MW substances restricted to the IV plasma compartment –> severe hypoalbuminemia, inadequate response to crystalloids, shock, hypotension during anesthesia, less risk of edema in pts with intact endothelium

Question 7

Intraosseous fluid therapy mechanism

Answer 7

rapid vascular access via bone marrow sinusoids and medullary venous channels
- tibial tuberosity, trochanteric fossa of the femusr wing of ilium, greater tubercle of the humerus

Bone marrow venous sinusoids: thin-walled region of inner layer of capillary vessels where passage of blood occurs b/w the EV hemopoietic compartment and systemic blood stream.

Question 8

Hydration deficit calculation and acute vs chronic loss protocol

Answer 8

• Administered in conjunction w/ maintenance requirements / ongoing contemporary losses (GI issues)
• Chronic loss: correct over 24h (slower admin to prevent diuresis)
• Acute loss: replace deficit over 6-8h (or quicker if very acutely dehyrated)

Question 9

Maintenance requirement of fluids

Answer 9

Maintenance requirement (40-60 mL/kg/day)

sensible: what we can see, insensible; what we can't really quantify

Question 10

Normal urine output and importance of monitoring when fluids are administered IV at rapid rate and renal function is questioned.

Answer 10

1-2mL/kg/hr
- to ensure that dehydration is being corrected
- Ins and outs

ins/outs: divide daily fluid therapy into six 4-hr intervals –> insensible volume + volume equal to urine output of the previous 4-hr period –> decreases risk of overhydration//fluid overload

Question 11

When should IVF therapy be discontinued?

Answer 11

• when hydration is restored and pt can maintain fluid balance with oral intake of food and water
• taper by 25% to 50% per day

Question 12

Clinical signs of hypokalemia and tx

Answer 12

Weakness, cervical ventroflexion, decreased renal concentrating ability, renal failure –> supplement potassium

Question 13

(not a question card, just the table for K supplementation)

Answer 13

Question 14

Describe body fluid compartments (sum = total body water TBW) // ratios of each

Answer 14

TBW:
- 2/3 = intracellular fluid
- 1/3 = extracellular fluid (1/4 = of plasma, 3/4 = of interstitium)