Fluid Therapy

Question 1

aims of fluid therapy

Answer 1

Maintenance of normal physiology

Improvement of organ function

Correction of electrolyte disturbances

Correction of hypovolemia

Correction of acid-base disturbances

Total parenteral nutrition

Replace surgical losses – evaporative, haemorrhage

Question 2

blood volume

Answer 2

dog - 88 ml/kg
cat - 66ml/kg

Question 3

% fluid deficits and clinical signs

Answer 3

No signs - <5%

Tacky mm - 5-6%

Skin tenting, sunken eyes - 6-8%

Increased pulse rate, cold peripheries - 8-10%

Weak pulses - 10-12%

Collapse - 12-15%

Question 4

maintenance rate

Answer 4

60 ml/kg/hr

Question 5

total deficit =

Answer 5

% deficit + losses (+maintenance)

Question 6

rate to replace acute loss

Answer 6

1/2 over 1-2 hour, then fluid over 24-48 hours (monitored)

Question 7

rate with shock

Answer 7

60-90 ml/kg for max 1 hour then normal rates

Question 8

rate to replace chronic loss

Answer 8

replace over 3-4 days

Question 9

surgical rates

Answer 9

start at -

3 ml/kg/hr cat
5 ml/kg/hr dog

+ maintenance

Question 10

fluid types

Answer 10

Crystalloid –

Isotonic - Lactated Ringers – shock, diruesis, anaesthesia – default choice

Hypotonic – saline – probably not

Hypertonic – different saline – draws water from interstitial space – severe life threatening ICP

Colloids -

Eg hetastarch - Support circulating blood volume – severe hypovolemia, haemorrhage, hypoproteinemia

Blood product – natural colloids – match fluid to type lost