Exam 1 - Fluid Therapy Flashcards
dehydration affects the _______ where volume depletion affects the ______
ICF - affected by dehydration
ECF - affected by volume depletion
what are the hallmarks of dehydration?
occurs over time - along a continuum
ICF volume is lost when insensible losses are not replaced
simple dehydration has mild clinical signs
severe dehydration mimics volume depletion
what are the hallmarks of volume depletion?
acute injury or disease
ECF volume is lost acutely - ICF volume can be normal
negative impact on cardiovascular parameters
EMERGENCY
what clinical signs/parameters are seen in a patient with dehydration when trying to differentiate between it & volume depletion?
simple dehydration
heart rate: mild tachycardia
mucus membrane/CRT: tacky mucus membranes & increased CRT
jugular vein fill: normal
peripheral pulse pressure: normal
extremity temperature: WNL/cool
mentation: BAR/QAR
skin tenting: +/- present
what clinical signs/parameters are seen in a patient with volume depletion when trying to differentiate between it & dehydration?
volume depletion/decreased ECV
heart rate: moderate to severe tachycardia
mucus membrane/CRT: +/- moisture/increased CRT
jugular vein fill: prolonged
peripheral pulse pressure: reduced
extremity temperature: cool/cold
mentation: +/- obtunded
skin tenting: +/- normal
what are the 4 phases of fluid therapy?
- resuscitation
- rehydration
- maintenance
- ongoing loss
when do you need to pursue resuscitation in a patient? what does that mean physiologically?
when they are showing signs of decreased effective circulating volume - patient is volume depleted
patient is losing body water & electrolytes
what is the goal of resuscitation in fluid therapy?
improve circulating volume & blood pressure
prevent circulatory collapse
improve O2 delivery to tissues
what is the body’s homeostatic response to volume depletion? what is the purpose of them?
decreased ECF volume leads to decreased venous return to the right atrium -> decreased cardiac output
activation of the autonomic nervous system, RAAS, & AVP
strive to maintain O2 delivery to tissues in the body, but these mechanisms are short-lived
what is the shock dose of fluid used for companion animals? how is it given?
80-90 ml/kg - given 1/4 bolus at a time using isotonic fluid
T/F: in fluid therapy for volume depletion, your goal is reaching the ECF quickly
true
what percentage of dehydration do you see clinical signs with?
5%
what lab abnormality is the hallmark of dehydration?
hypernatremia
what is the body’s homeostatic response to dehydration?
CNS osmoreceptors sense a change in plasma osmolality - increase in serum sodium triggers central osmoreceptors
stimulates thirst!!!
what is the mechanism of dehydration in the body?
on a daily basis, ICF contributes water to prevent dehydration
with decreased water consumption, hypertonicity of ECF occurs (increase in effective osmols) which stimulates water movement from the ICF
what is the formula for calculating a patient’s dehydration deficit for fluid therapy?
deficit (L) = % dehydration X BWT (kg)
what clinical signs are seen in an animal with 5-7% dehydration?
mild dehydration
decreased skin turgor & slightly tacky mucus membranes
what clinical signs are seen in an animal with 8-10% dehydration?
moderate dehydration
depressed mentation, tacky mucus membranes, & CRT > 2-3 seconds
what clinical signs are seen in an animal with >10% dehydration?
severe dehydration
cool extremities, poor perfusion, & CRT > 4 seconds
T/F: loss of body water is not an acute event
true - not like blood loss/hemorrhage
it occurs over time
use ____________ to replace body water over time
% dehydration of your patient
how is rehydration done in fluid therapy for a dehydrated patient?
initial bolus (1.2 of the deficit) is patient dependent & many small animal patients may not require a bolus
replace remaining 1/2 (or whole amount) over the next 12 hours (or may be able to deliver entire deficit over time period without a bolus)
what route of fluid administration is appropriate for resuscitation efforts?
intravenous
what route of fluid administration is appropriate for rehydration efforts?
in reality - depends on % dehydration but probably intravenous in small animal patients
what is phase 3 of fluid therapy?
maintenance
what are the daily fluid requirements for dogs, cats, & horses?
dogs - 60 ml/kg/day
cats - 45 ml/kg/day
horses - 50 ml/kg/day
when should you provide maintenance fluid therapy for a patient?
patient is unable to intake the appropriate amount of their daily water from:
sickness, physical inability, or reduced dietary/forage intake (horses)
what is included in maintenance fluid therapy?
daily water requirements & necessary electrolyte supplementation when necessary (dependent on patient needs, so monitor bloodwork for electrolytes and renal function)
what is ongoing loss when it comes to fluid therapy?
most difficult replacement to predict in fluid therapy
fluid loss through blood loss, vomit, diarrhea, feces, manure, gastric reflux, etc
what is the most common type of solution used for fluid therapy in veterinary medicine? what is it? what are some examples?
crystalloids
fluids that mimic the composition of the ECF with Na/Cl being the primary electrolytes
LRS, normosol-r, & 0.9% saline