Flashcards in Fluids Deck (117):
Body weight is what % water?
Intracellular space contains how much of the total body water?
2/3 (about 40% of body weight)
Extracellular space contains how much of the total body water?
Extracellular space can be divided into what 3 compartments?
Which compartment contains 3/4 of the extracellular fluid?
- Interstitial (3/4 extracellular fluid)
- Intravascular (within blood vessels)
- Transcellular (specialized fluid/areas)
What is the fluid component of blood?
What are 3 reasons to give fluids?
What are maintenance fluids?
The required volume of fluid needed per day to keep the patient in balance, with no change in total body water.
What is the maintenance fluid dose range?
What is dehydration?
Decreased fluid in intracellular or interstitial spaces.
What is seen with shock?
Decreased fluid in intravascular space.
Fluids are most commonly given via what route?
T/F: The type of fluids given depends on the situation as to why they are being given.
What are the 2 basic types of non-blood fluid?
If the diagnosis is unknown and there are no lab work results, which type of fluid should be used?
Crystalloid replacement fluid
Solutes (electrolytes and non-electrolytes) that can move freely around the fluid compartments are known as what?
Crystalloids can be divided into 3 groups based on tonicity (ability to shift water across semipermeable membranes), what are these 3 groups?
What is hypotonic crystalloid fluid composed of?
0.45% NaCl, 5% dextrose and water
Where is fluid drawn with a hypotonic crystalloid solution?
Into the cells.
Where is fluid drawn with a hypertonic crystalloid solution?
Into the intravascular space.
With which type of crystalloid fluid is the osmolality the same as the blood cells and plasma so that the fluids neither exit or enter the cells?
What are 2 things isotonic crystalloid solutions used for?
- Perfusion support
- Volume replacement
Which have a larger molecular weight, crystalloids or colloids?
Where do colloids remain?
How does this affect fluid?
- In intravascular space.
- Keeps fluid in intravascular space.
What are 2 examples of natural colloids?
- Whole blood
What are 4 examples of synthetic colloids?
What are 3 uses for crystalloids?
- Correct dehydration
- Expand vascular space in shock
- Correct electrolyte/acid-base imbalances
After about a half hour of equilibration, how much crystalloid solution will still be within intravascular space?
Where did the rest go?
What can this lead to in large volumes?
- Interstitial space
- Peripheral edema
What are the 2 major purposes isotonic fluids are designed for?
- Fluid replacement
- Fluid maintenance
What is the most commonly used type of crystalloid?
With isotonic fluids used for fluid replacement, the Na+ concentration is close to what?
The normal plasma Na+ concentration of about 140 mmol/l.
With isotonic fluids used for fluid maintenance, the Na+ concentration is close to what?
The normal total body concentration of about 70 mmol/l.
What type of crystalloid is Ringers?
What type of crystalloid is LRS?
What type of crystalloid is Normosol M?
What type of crystalloid is Normosol R?
What type of crystalloid is 0.45% NaCl with 2.5% dextrose?
What type of crystalloid is 0.9% saline?
What type of crystalloid is PlasmaLyte?
What type of crystalloid is PlasmaLyte 56?
What are isotonic replacement fluids designed to replace?
What are isotonic maintenance fluids designed to replace?
Daily Na+ losses without Na+ overload.
Which type of isotonic fluid has a K+ concentration similar to that of plasma?
Which isotonic solution can be given rapidly?
Since maintenance fluids have lower Na+ which do not stay in vascular space and are poor at expanding blood volume, they are often combined with what in patients with low albumin?
Which type of isotonic fluid can not be given rapidly?
What are 2 examples of non-buffered replacement fluids?
- 0.9% saline
- Ringers solution
What are 3 examples of replacement fluids that are buffered?
- Normosol R
What are 3 things that replacement fluids can be buffered with to maintain physiologic pH?
What is an example of a buffered maintenance fluid?
What is an example of a non-buffered maintenance fluid?
If replacement has to be used for maintenance, what must be added?
What must be monitored?
- K+ must be added
- Serum Na+ must be monitored
What is the most frequently used replacement fluid?
LRS (lactated ringer solution)
Do all maintenance fluid have K+?
No, so it must be added to those that do not.
Which type of colloid is used when the goal is to restore RBCs, clotting factors, AT III or albumin?
Which type of colloid is used when the goal is to rapidly improve perfusion in a patient that does not have obvious blood loss or clotting problem?
If albumin, AT III or clotting factors are needed, which type of natural colloid is used?
If RBCs are needed, which type of natural colloid is needed?
What is the most commonly used synthetic colloid in veterinary medicine?
What is dextran composed of?
What are 3 advantages of Dextran?
- Stored at room temperature
- Increases plasma volume 1.38x the volume infused.
What are 4 disadvantages of Dextran?
- Increase in BMBT
- PTT but no clinical bleeding
- Fibrinogen concentration decreases
- Blood glucose level may increase
What is the most common type of hydroxyethyl starch (HES)?
What is a synthetic high molecular weight starch made from maize or sorghum?
Which colloid should be used in cases that need oncotic support but don't need clotting factors?
What is an example of such a case?
- Cases with low albumin.
How is hetastarch formulated?
As a 6% solution in saline.
How much does hetastarch increase plasma volume?
By 1.37% of the volume infused.
Which lasts longer in circulation, hetastarch or dextran?
What is the bolus dosing for hetastarch?
The CRI dosing?
- 5-10 ml/kg over 5-10 min for hypovolemia
- 10-20 ml/kg/day = this is the maximum daily dose
What is a contraindication of hetastarch?
What are 2 possible side effects of hetastarch that can be seen in cats?
What are 4 possible side effects of colloids in general, both natural and synthetic?
- Fluid overload and pulmonary edema
- Renal failure
- Human albumin: could cause life threatening allergic reaction in dogs
You first correct for dehydration by giving what?
Can this be given rapidly?
- Isotonic replacement fluid
When do you switch from a replacement fluid to a maintenance fluid?
After water and electrolyte deficits have been corrected (usually 24 hours).
What can happen to patients on a replacement fluid for several days?
Is this usually a serious clinical problem with patients with normally functioning kidneys?
When can it become a problem?
- May become mildly hypernatremic.
- When Na+ levels become greater than 170 mmol/l
Can colloids and crystalloids be combined in dehydration or shock cases?
Are colloids used to replace dehydration deficits?
- You need crystalloid to get into interstitial and intracellular spaces.
What are 4 conditions colloids are used in since they keep fluids in intravascular spaces?
- Low albumin
- Peripheral edema
What are 2 benefits of combining colloids and crystalloids?
- Decrease the amount of crystalloid being used.
- Restore the fluid deficit of intravascular space more rapidly.
Why do you have to be careful if using replacement fluids in patients with known or suspected cardiac disease?
The high sodium load can unmask pre-clinical congestive heart failure, as water follows sodium, and volume overload can result.
Which fluid is classically used for cardiac patients?
How is it modified?
- 0.45% NaCl
- Made isotonic through addition of dextrose.
Due to obligate renal K+ loss, what can happen to patients who are not eating?
They can become hypokalemic within days.
Too much K+ can lead to what?
What is used to determine the amount of K+ to be added?
What measuring devise is used?
- Based on the patients existing K+ level.
- Sliding scale of Scott
What is the Kmax for how rapidly you can give fluids with K+ added?
Life threatening hyperkalemia can result in what?
Even though hypertonic saline is technically a crystalloid, what is notable about its osmolality?
It is much higher than replacement or maintenance crystalloids.
How does hypertonic saline act?
It pulls fluid into vascular space from interstitial and intracellular spaces.
Are the effects of hypertonic saline short-lived or long-lived?
How does hypertonic saline act in hypovolemic shock?
It replaces volume deficit with less fluid and improves blood flow.
What type of fluid is useful in patients that need to receive a large amount of fluid quickly but for which it is difficult to administer quickly enough?
For large dogs that are in shock due to gastric dilatation-volvulus, what fluid should be used?
Patients who should not receive large volumes of fluid, such as those with head trauma or cerebral edema, should receive what type of fluid?
Hypertonic saline comes in what 2 forms?
What has to be done to 23% hypertonic saline before it can be administered?
How can this be done?
- It has to be diluted to a 7.5% solution.
- Add 17 ml of 23% hypertonic saline solution to 43 ml of a colloid solution in a 60 ml syringe.
What is hypertonic saline solution normally diluted with?
A colloid solution.
What are 2 examples of when hypertonic saline should be used?
- Cases of hypovolemic shock that do not have dehydration or hypernatremia.
- Head trauma cases.
What are 2 contraindications for the use of hypertonic saline?
What are 3 side effects that can be seen with rapid administration of hypertonic saline?
What is the recommended dose of hypertonic saline for dogs?
- 4 to 7 ml/kg over a 20 minute period
- Half this dose.
What is the most physiologic route of fluid administration?
Which route of fluid administration is used in mild dehydration cases if GI function is normal (no vomiting), if the airway is controlled and if mental status is ok?
Which route of fluid administration is used mainly in pediatrics?
Where are 2 common locations of needle placement with this route?
- Femur (trochanteric fossa) or humerus (greater tubercle)
Where are 3 common locations for IV fluid administration?
You may occasionally have to do a "cut down" to find a vein with what route of fluid administration?
Which route of fluid administration is most appropriate for dehydration and shock?
What is the most commonly used route of fluid administration used in chronic renal failure cases?
Don't swab the site of administration with alcohol with which route of fluid administration?
You should warm fluids in warm water prior to giving them with which route of fluid administration?
Avoid solutions with glucose with which route of fluid administration?
- It is a great medium for bacteria.
How do you administer fluids enterally in large animals?
Through a tube.
What is one way to administer fluid to a cat enterally?
Add water to food.
Which route of administration should be avoided in a severely dehydrated patient?
What are 6 perfusion parameters?
- Heart Rate
- Capillary refill time
- Mucus membrane
- Pulse pressure
- Blood pressure
Ideally how often should you weigh an animal when administering fluids?
One pound is equal to how much fluid?
What are 4 things that should be monitored when administering fluids?
- Urine output