9th lecture - fluid therapy Flashcards
The purpose of fluid therapy is to compensate
for the loss of fluids caused by pathology (dehydration),
or to correct overhydration, electrolyte and/or acid-bace imbalance.
What is Degree of dehydration
How is it expressed
Loss of fluids resultingin reduction of body mass due to this loss of fluids.
Expressed in percentage terms (% of body mass).
This is not super precise but adequate.
How is degree of dehydraton determined?
Determined visually:
- the humidity and colour of mucous membranes
- sunken eyes and skin turgor
Skin can be dry and wrinkled and skin elasticity disappears in the event of dehydration.
Laboratory parameters such as hematocrit
Anamnesis.
Patients that vomit/diarrhea, have no appetite or have reduced consumption of liquids for some other reason, should be treated as how dehydrated?
4-5% dehydrated.
Signs of dehydration are:
low amounts of concentrated urine/oliguria,
thirst,
fever,
tacky mucous membranes,
constipation,
loss of body mass,
muscle tremors and eventually death.
Normal sources of physiological water loss (4)
Urine output,
evaporation from skin surface,
natural sweating,
evaporation from respiratory tract.
a rise in body temperate by 1 degree above the normal level increases the excretion of liquids by
500 ml per 24-hour period (in humans).
normal liquid requirement per 24-hour period
55-132ml/kg
Third space fluic losses
Extravasation of fluid from the vascular compartment into extravascular spaces.
“Third-space fluid loss, also known as third-spacing, is an excessive fluid accumulation in compartments that typically have little or no fluid.
For instance, pleural effusion and ascites are excessive fluid accumulations that develop pathologically within the pleural and peritoneal cavities, respectively.”
Products for fluid therapy (4)
Crystalloids
Colloids
Blood replacements
Nutritional solutions
Additional supplementary K+ where needed.
In what type of situation might colloids be utilized?
In case of a loss of blood, administer colloidal solutions, plasma substitutes (dextrans).
Particles of high molecular weight, absorb slowly from the blood vessels, quickly restore the blood volume.
Each gram of dextran that is administered is capable of binding up to 18 ml of water.
Critical dehydration is how much
10-12%.
In the case of critical fluid loss, how should fluids be administered
Fluids must be administered first IV.
Fluids administered subcutaneously, intraperitoneally and through the oral route are not absorbed by highly dehydrated patients.
The blood volume has been reduced, blood has concentrated into the organs of vital importance within the trunk, peripheral blood vessels are empty and fluids administered in such regions will not be absorbed so IV is important to start them off.
Intraosseous can also be utilized.
Sites of intraosseous administration are the following:
tuberosity of the tibia,
medial proximal portion of tibia that is 1-2 cm further from the tuberosity of the tibia, hole between the trochanters of the femur.
What tonicity of fluids can be administered SC and IP?
only isotonic
(hypo-and hyper- only IV)
