Fluid Therapy Flashcards
When administering fluids, what is it important to determine?
Whether the animal is hypovolaemic or dehydrated (or both).
What is the difference between colloids and crystalloids?
Crystalloids contain water and small molecules (e.g. electrolytes, dextrose etc.) Colloids also contain water and small electrolytes, but also have larger molecules such as RBC etc.
How do colloids and crystalloids affect the distribution of fluid between the body compartments?
Crystalloids distribute equally among compartments. Colloids hold fluid in the intravascular space and affect osmotic pressure.
How does tonicity affect distribution of fluids?
Isotonic - distribute equally
Hypertonic - draw fluid from intracellular and intersitial.
Hypotonic - fluid shifts to intracellular.
Why should fluids be used in general anaesthesia?
It causes vasodilation, so even though no fluid is lost, fluids should be give.
Which should take priority, hypovolaemia or dehydration?
Hypovolaemia
Is there a difference in the speed fluids should be administered when correcting hypovolaemia and dehydration?
Hypovolaemia is usually corrected quickly, but rehydration should be done slower so that it can distribute.
What is the difference between hypovolaemia and dehydration?
Hypovolaemia affects the plasma (intravascular) volume, but dehydration affects all extracellular fluid (intravascular and interstitial).
What are some indicators of dehydration?
Dry MM, vomiting, diarrhoea
What are some indicators of hypovolaemia?
Tachycardia, weak pulses, pale MM
Give an example of an isotonic crystaloid. What are they used for?
0.9% NaCl (normal saline) used for rehydration, resuscitation, correction of acid/base, deliver drugs etc.
Give an example of a hypertonic crystaloid. What are they used for?
7% NaCl - limited uses, small doses needed. Rapid resuss, brain oedema.
Give an example of a hypotonic crystaloid. What are they used for?
0.18% NaCl, 4% dextrose (“Devil’s fluid”) - short term use ONLY for hypernatremic patients.
What are the steps involved in determining how much fluid to administer?
Estimate deficit (evaluate skin tugor and dehydration), estimate maintenance fluid, estimate ongoing losses - add all these together.
