Fluid therapy

Question 1

Describe fluid compartments.

Answer 1

Intracellular fluid 60% (of total body water)

Extracellular fluid 40%
(intravenous 25% of the 40 & interstitial 75% of the 40)

Question 2

Total body water comprises what % of total mass.

Answer 2

60%

Question 3

Describe the 2 main points of Starling’s forces.

Answer 3

hydrostatic pressure - pushes fluids out of vessels

oncotic pressure - pulls fluids into vessels

Question 4

types of crystalloids broadly

Answer 4

iso
hypo
hypertonic

Question 5

3 attributes of Fluid disturbances to assess

Answer 5

changes in volume (dehydration, blood loss)

changes in content (e.g. hyperkalemia, protein loss)

changes in distribution (third spacing, e.g. pleural effusion)

Question 6

Signs of pleural effusion.

Answer 6

pale mucous membranes

increased respiratory rate and respiratory effort. breathes can be shallow.

later open-mouthed breathing with abdominal effort.

Question 7

Alternative to urine output measurement (when e.g. hospitalization not possible)

Answer 7

measure body weight to get an approximation of fluid retained or lost

Question 8

serum lactate shows you…?

Answer 8

tissue perfusion quality

dehydration causes tissue hypoxia which in turn causes lactate to accumulate in tissues. requires fluids to correct.

Question 9

if the lactate is high but the patient is not dehydrated, it is probably…?

Answer 9

septic

Question 10

pre-renal azotemia is usually caused by

Answer 10

fluid loss/dehydration (decreases GFR)

use urine specific gravity to check

Question 11

blood gases will allow you to assess..?

Answer 11

physiological pH, acidosis/alkalosis state

Question 12

hydration deficit =

Answer 12

dehydration % * body weight (kg)

in liters

Question 13

Maintenance equation for cats

Answer 13

80 * kg^0.75

rule of thumb 2-3 ml/kg

Question 14

Maintenance equation for dogs

Answer 14

132 * kg^0.75

rule of thumb 2-6 ml/kg

Question 15

Pediatric patients require how many ml per kg per day?

Answer 15

60-180 ml/kg/24h

Question 16

Ongoing losses can be hard to evaluate, a rule of thumb:

Answer 16

0.5-1 ml/kg/h

(Tip: vomitus or diarrhea can be weighed by weighing the bedding/absorbent pad its on)

Question 17

hypertonic solutions can be used in two situations (2)

Answer 17

hypovolemic shock (but NOT when dehydration is present!)

cerebral edema/high intracranial pressure (but mannitol is better for this if available)

(bonus: in very rare cases acute onset hyponatremia may utilize hypertonic solutions)

Question 18

hypotonic solutions can be used in what situations (3)

Answer 18

severe dehydration with no hypovolemia, so only cellular and tissue level crenation.

e.g. in some heart failure patients who have too much intravenous fluid but their cells are dehydrated (ie. CKD cats).

in severe hypER natremia cases

most common hypotonic solution 5% GLU solution (with no electrolytes in), may be administered s.c. (in exotics)

Question 19

skin turgor a bit decreased.
% dehydration?

Answer 19

5-6% dehydration

Question 20

skin turgor markedly decreased + CRT decreased, sunken eyes, tacky MMs.
% dehydration?

Answer 20

6-8% dehydration

Question 21

12-15% dehydration =

Answer 21

shock, death unavoidable.

Question 21

skin turgor markedly decreased + CRT decreased, sunken eyes, dry MMs.
signs of shock. Dehydration %?

Answer 21

10-12% dehydration

Question 22

5 main negative physiological effects of anesthesia

Answer 22

hypothermia
hypoventilation
hypotension
hypoxemia

brady-+tachyarrhythmias

Question 23

Hypovolemic shock rates (IVFT)

Answer 23

dogs: 80-90 ml/kg IV
cats: 50-55 ml/kg IV

Begin by rapidly administering 25% of the calculated shock dose. Reassess in 15-20 min. Boluses given up to 3 times.

If no change - consider colloids (no change may = septic shock which could use vasopressors as well).

Question 24

When to administer colloids?

Answer 24

When it is difficult to administer sufficient volumes of fluids rapidly enough.

Where crystalloids are not effectively improving or maintaining blood volume.

If edema develops prior to adequate blood volume restoration.

When decreased oncotic pressure is suspected.

When there is a need for longer duration of effect.

Question 25

doses for colloids

Answer 25

dogs: 20 ml/kg/24h
Divide into 5ml/kg boluses and reassess.

cats: 10-20 ml/kg/24h
Typically 10ml/kg in 2,5-3ml/kg boluses.