How Much Fluid? (ASAN002/4) Flashcards
To determine how much fluid is required, we need to calcuate how much fluid is needed to: (3)
- Replace (rehydrate) fluid loss
- Maintain normal hydration
- Predict any ongoing losses
What do we need to calculate to determine how much fluids we need for Rehydration? (2)
Calculate the amount of missing fluids or Fluid Loss.
How do we calculate fluid loss (L)? (1)
Weight kg x % dehydration = L fluid loss
eg: 10kg patient with 5% dehydration
10 x 5/100 = 0.5L = 500mls
What is the quick formula to give Fluid Loss in ml? (1)
% dehydration x weight kg x 10 = mls
eg: 10kg patient with 5% dehydration
5 x 10 x 10 = 500mls
What do we need to calculate to determine how much fluids we need for Maintenance? (2)
Insensible fluid losses (GIT, Resp, Skin)
+
Sensible fluid losses (urine, faeces)
What are Insensible Losses? (3)
Fluids lost through:
* Gastrointestinal Tract
* Respiratory Tract
* Skin / Sweating
What is the calculation for Insensible losses? (1)
20mls/kg/day
What are Sensible Losses?
Fluids lost through:
* Urine
* Faeces
What is the calcuation for Sensible losses? (2)
1–2ml/kg/hour = 24–48mls/kg/day
What is the calculation to estimate Combined Maintenance Volume? (1)
40 – 60ml/kg/day
Why do large dogs typically have lower maintenance volume requirements than small dogs? (1)
Due to lower surface area : body mass ratio
What does Ongoing Fluid Losses refer to? (1)
Fluid loss > maintenance req of normal patient
What are some examples of Ongoing Fluid Losses? (4)
- Vomiting
- Diarrhoea
- Bleeding
- Wound exudate
How do we calculate Ongoing Fluid Losses? (1)
Need to estimate as difficult to predict & calculate exact amt.
How do we Calculate Fluid Requirements? (4)
Fluid Requirement
fluid deficit
+ maintenance requirements
+ ongoing losses
What fluid rates do Fluid pumps use? (1)
hourly fluid rates
What fluid rates do Gravity fed adminstration systems use? (1)
Rates calculated at drops per second.
What is the drop rate for most common admin sets? (1)
20 drops/ml
Example 1:
10kg dog, 8% dehydrated. Has diarrhoea & estimated further loss of 140mls over 24hrs
(Image)
Example 2:
20kg dog, 10% dehydrated. Has V & D, and estimated further loss of 360mls over 24hrs
(Image)
What are the two types of Fluid Delivery Systems? (2)
- Gravity fed systems
- Mechanical delivery systems (pumps)
How do Gravity Fed Systems work? (1)
Rely on gravity to create flow of fluids.
How do you calculate & adjust fluid rates on Gravity Fed Systems?
- Roller pinches line to regulate flow.
- Drip chamber to calculate flow/drip rate (must know drops/ml of admin set)
What are the different drop/ml admin sets most commonly available? (4)
Available in 10, 15, 20 or 60 drop/ml