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
What are the limitations of Gravity Fed Systems? (3)
- Infusion pressure dependent on how high fluids are above the patient.
- Flow limited by ambulatory patient & catheter placement
- Patient limb must be fully extended when changing flow rate.
What is a Burette or Buretrol? (1)
A measuring chamber that can added to gravity fed systems.
What are the benefit of using a Burette or Buretrol? (3)
- Accurate delivery of small volumes (holds 100 – 150mls)
- Reduces risk of fluid overload in small patients
How do Mechanical Delivery Systems work?
They use a mechanical pumping system to deliver fluids
What are the two main types of Mechanical Delivery systems? (2)
- Syringe pumps
- Fluid infusion pumps (NIKI pump)
What are syringe pumps best used for? (2)
- Administering IV medications at a constant rate.
- Administering fluids to small patients.
How do Syringe Pumps work? (3)
- A syringe is filled with appropriate fluid or medication.
- Syringe is placed in the pump.
- The plunger is automatically pushed at a constant rate.
How do Fluid Infusion Pumps (NIKI pumps) work? (1)
They use peristaltic action (intermittent squeezing of IV tubing) to pump fluid into the patient.
What is a possible complication of Fluid Infusion Pumps? (2)
- They can infuse fluids at a high pressure
- Therefore, may pump fluid into perivascular tissues
What information should be included when Labeling Fluid Bags?
- Date & time of when bag was hung.
- Initials of who hung the bag.
- Concentration of additives in the bag.
Why is placing Labels on fluid bags important? (4)
Shows all staff:
* The contents of the bag
* When the bag was hung
* Staff member that hung the bag
What is an additional way to label gravity fed fluid bags? (1)
Place tape on bag to monitor how much fluid is given over time.
