Fluid therapy

Question 1

What are the 7 steps used to work out the fluid requirements + drip rate for a dehydrated patient?

Answer 1

Work out…

1. Maintenance (ml/kg/day)
2. Deficit (mls/day)
3. Total fluid (mls)
4. Rate (ml/hr)
5. Ml/min (ml/min)
6. Drops p/min (Drops p/ml)
7. Giving set (Drop p/sec)

Question 2

Work out the fluid maintenance for 4kg cat

Answer 2

Maintenance = 50ml/kg/day
= maintenance x weight
= 50 ml x 4kg
= 200 ml/kg/day

Question 3

Work out the fluid requirement (Deficit) for a 3% dehydrated 4kg cat

Answer 3

Deficit = 10 ml/kg/day x % dehydration
= 10 ml x weight x % dehydration
= 10 m l x 4kg x 3
= 120 mls/day

Question 4

Calculate the fluid requirement for a 4kg Cat that is 3% dehydrated.

At what rate should the fluid be set?

Answer 4

1. Maintenance = 50 ml/kg/day
   = M x BW(kg) = ml/kg/day
   = 50 ml x 4kg
   = 200 ml/kd/day
2. Deficit = 10 ml/kg/day x w x % dehydration
   = 10 ml x 4kg x 3
   = 120 mls/day
3. Total fluid = maintenance + deficit
   = 200 ml + 120 ml
   = 320 ml/day
4. Rate (ml/hr) = fluid volume/day /24hrs
   = 320/24hrs
   = 13.33 ml/hr
5. Rate (ml/min) = fluid volume/hr /60min
   = 13.33/60min
   = 0.22 ml/min
6. Rate (ml/sec) = fluid volume/min x drops/ml
   = 0.22 x 20
   = 4.4 drops/min
7. Giving set = 60 sec/drops/p/ml
   = 60/4.4
   = 13.63
   (round up to 14)
   = 1 drop, per 14 seconds

Question 5

• A 25kg Dog comes in with severe V+ + D+.
• It has V+ 6 times + D+ 4 times.
• It is now 5% dehydrated.

Work out how much fluid it needs + at what rate the drip should be set at?

At what rate should the fluid be set?

Answer 5

1. Maintenance = 50 ml/kg/day
   = M x BW(kg) = ml/kg/day
   = 50 ml x 25kg
   = 1,250 ml/kd/day
2. Deficit = 10 ml/kg/day x BW x % dehydration
   = 10 ml x 25kg x 5
   = 1,250 mls/day
3. Volume of Ongoing losses = 4ml/kg x BW(kg) p/episode of V+ + D+/Burn %
   = 4 ml/kg x 25kg x 10 (times) - (6 + 4 = 10)
   = 1,000 ml/day
4. Total fluid = maintenance + deficit + losses
   = 1,250 ml + 1,000 ml
   = 3,500 ml/day
5. Rate (ml/hr) = fluid volume/day /24hrs
   = 3,500/24hrs
   = 145.83 ml/hr
6. Rate (ml/min) = fluid volume/hr /60min
   = 145.83/60min
   = 2.43 ml/min
7. Rate (ml/sec) = fluid volume/min x drops/ml
   = 2.43 x 20
   = 48.6 drops/min
8. Giving set = 60 sec/drops/p/ml
   = 60/48.6
   = 1.234..
   (round up to 14)
   = 1 drop, per 1 second

Question 6

Calculate the fluid requirement for a 15kg Dog that is 2% dehydrated.

At what rate should the fluid be set?

Answer 6

1. Maintenance = 50 ml/kg/day
   = M x BW(kg) = ml/kg/day
   = 50 ml x15kg
   = 750 ml/kd/day
2. Deficit = 10 ml/kg/day x w x % dehydration
   = 10 ml x 15kg x 2
   = 300 mls/day
3. Total fluid = maintenance + deficit + losses
   = 750 ml + 300 ml
   = 1,050 ml/day
4. Rate (ml/hr) = fluid volume/day /24hrs
   = 1,050/24hrs
   = 43.75 ml/hr
5. Rate (ml/min) = fluid volume/hr /60min
   = 43.75/60min
   = 0.73 ml/min
6. Rate (ml/sec) = fluid volume/min x drops/ml
   = 0.73 x 20
   = 14.58 drops/min
7. Giving set = 60 sec/drops/p/ml
   = 60/14.58
   = 4.115..
   (round up to 14)
   = 1 drop, per 4 seconds