Exam 2: Lecture 13/14: Fluid Therapy Flashcards
1
Q
T/F: fluid therapy is a common practice in veterinary medicine and a standard of care during the perioperative period
A
true!
2
Q
Why can fluid therapy be risky?
A
because of fluid overload!
3
Q
T/F: All fluid therapies are based on human models, even in vet med
A
true! after the cholera epidemic
4
Q
What are the 3 things considered in fluid physiology
A
distribution, circulations, eliminations
5
Q
IMPORTANT! Why should we give fluids?
A
perfusion, O2, electrolytes, and acid base disoders
6
Q
T/F: Dosing of fluids should be uniform regardless of the context of the case
A
FALSE! It should be individualized looking at the type of anesthesia and the disease severity
7
Q
What is the only accurate way to monitor fluids given
A
fluid responsiveness
8
Q
Historically, how did we know that we gave too much fluids?
A
because the patient would have pulmonary edema
9
Q
if you have >10% increase in body weight, what does that mean for our patient?
A
this is the zone where death can occur from fluid overload
10
Q
T/F: All fluids dilute what they dont contain
A
true!!!
11
Q
what are the 7 things that can happen from fluid overload
A
- pulmonary edema
- cerebral edema
- myocardial edema
- increased renal venous pressure and rental interstitial edema
- gut edema
- tissue edema with impaired lymphatic drainage and microcirculatory derangements
- hepatic congestion
12
Q
What % of the patients body weight is their blood volume
A
8%
13
Q
what % is total body water
A
60% (40 intracellular and 20 extracellular)
14
Q
what 2 things does extracellular fluid break down into and what are the %’s
A
15% interstitial
5% plasma
15
Q
how is the extracellular fluid separated in the body
A
via a vascular wall (capillary wall)
16
Q
what is the avg blood volume for dogs
A
80 ml/kg
17
Q
what is the avg blood volume for cats
A
60 ml/kg
18
Q
what is the avg blood volume for horses
A
70 ml/kg
19
Q
what is the avg blood volume for cows
A
55 ml/kg
20
Q
T/F: There is also another distribution of fluids called transcellular fluids and they make up about 2%
A
true!
21
Q
how does the lymphatic circulation get back into the systemic circulation
A
through the thoracic duct
22
Q
For the starling equation, what are the 2 biggest contributors of effect on fluid flux
A
Pc = capillary hydrostatic pressure
πc = capillary colloid osmotic pressure
23
Q
what is important to remember about the revised starling principle
A
Fluid is NOT normally reabsorbed from capillaries except in the gut and kidney or during acute hypotensive episodes
24
Q
What is the endothelial glyucocalyx
A
a slimy-like wall that lines the blood vessels
25
what is the purpose of the endothelial glycocalyx
It helps to keep fluid in the vascular system
26
what happens if you destroy the endothelial glycocalyx and how can you damage/destroy it
you can damage/destroy it via if you are diseased or giving too much fluids
this no longer allows you to keep fluids in the vascular system leading to edema and higher likelihood of fluid overdose
27
What is the interstitium
a series of fluid filled spaces made of flexible connective tissue
28
Why is the interstitium like a slinky
you have to use force to get it to stretch but if you stretch it toooo far it wont come back together completely
29
In the interstitial fluid, what compartment has rapid exchange and is working around normal pressure
Vt1
30
In the interstitial fluid, what compartment has slow exchange and is usually over stretched
Vt2
31
what are the 8 reasons to use IV fluid therapy
1. maintain hydration (30-60ml/kg/day)
2. treat/prevent dehydration
3. treat/prevent hypovolemia
4. treat hypotension
5. normalize acid-base balance
6. normalize electrolytes
7. supply calories
8. provide access to a vein
32
What is something important to remember when we are giving fluids to prevent or treat dehydration
must be VERY careful on how fast you give them! It can take 16 hours to 1.5 days to get fluids back into vessels
33
what are the 7 most common problems with general anesthesia
1. arousal and breakthrough pain
2. hypoventilation
3. hypotension
4. arrhythmia
5. temp regulation
6. airway complications
7. recovery delirium
34
What are some of the causes for hypotension
1. volume deficiency
2. drugs
3. hypothermia
4. hypercarbia
5. acidemia
6. hyperkalemia
7. heart failure or arrhythmia
8. sepsis
35
How does anesthesia produce hypotension when there is MINIMAL or NO blood loss
Because almost every drug is a vasodilator which takes blood from the arteries and puts them into veins leading to a drop in BP
36
What is the golden hour in vet med
the period of time after an injury when there is the highest likelihood that medical/surgical treatment will prevent death
37
What is a compensatory response to hypovolemia
suppression or loss of lymphatic return
38
If there is blood loss, what happens once MAP gets below about 45 mmHg
the body starts to pick what organs it can stop supplying blood to, to maintain vital function
39
T/F: Healthy animals should not be able to compensate for up to 10-15% loss of their blood volume
false! They should be able to compensate for that % of blood loss
40
T/F: Hypotension due to hemorrhage happens when blood loss is > 10 to about 30 ml/kg
true!
41
What % of blood volume loss is class I of hemorrhagic shock and what are the key components
Less than or equal to 15% of blood volume lost
usually fully compensated by transcapillary refill, blood volume is maintained, and clinical findings are absent or minimal
42
What % of blood volume loss is class II of hemorrhagic shock and what are the key components
15-30% blood volume lost
clinical findings may include in HR and BP, BP and perfusion of vital organs is maintained, urine output may decrease to <1.0 mL/hr and splanchnic flow may be compromised
43
What % of blood volume loss is class III of hemorrhagic shock and what are the key components
30-40% blood volume lost
onset of uncompensated hypovolemia, hypotension, and reduced urine output
44
What % of blood volume loss is class IV of hemorrhagic shock and what are the key components
>40% blood volume lost
profound hypotension and oliguria, changes may be irreversible
45
At what class or classes of hemorrhagic shock will we most likely see death
III or IV
46
What is osmolarity
refers to the number of solute particles per 1L of solvent
47
what is tonicity
the ability for water to move in or out of a cell by osmosis
48
what is colloid osmotic pressure
osmotic pressure exerted by large soluble molecules referred to as oncotic pressure
49
Why are fluids technically considered drugs
because a drug is a medicine or other substance which produces a physiological effect when introduced into the body and thats what fluids do
50
what is maintenance fluid therapy
daily metabolic requirements
51
what is replacement fluid therapy
replace lost fluids, includes insensible losses from respiratory, skin, and water excreted in the stool
52
what is resuscitative fluid therapy
acute restoration of hemodynamics, tissue perfusion, and oxygen delivery
53
what are the types of crystalloid fluids
saline vs balanced solution
54
what are colloid fluids
gelatin vs dextran vs hydroxyethyl starch vs polyethylene glycol
55
What is the normal PCV in a healthy animal
hemoglobin > 7- 10 g/dl
56
Who was sydney ringer (1834-1910)
made ringers solution
57
who was hartog jacob hamburger (1859-1924)
hamburgers solution aka normal saline solution
58
who was alexis f hartmann (1898-1968)
made hartmanns solution aka lactated ringers
59
What are crystalloids
Na, Cl, K, and others solution that may contain metabolizable small molecules in water
60
what are balanced crystalloid solutions
physiological normal electrolytes, pH
61
what are colloid solutions
a solution that contains large molecules which are retained within the vascular endothelium
62
what are colloid solutes
metabolizable large molecules that should not pass through semipermeable membranes so that when infused they remain in the vascular system for prolonged periods of time
63
what determines the ability of colloids to remain in the vascular space
1. molecular size (30-40kD up to >700kD)
2. rate of degradation
3. permeability of the endothelium
64
how much salt is in one L of saline
9000 mg/L (its 0.9%)
65
what % of water do most tissues contain
>60%
66
what % of water does bone contain
about 30%
67
what % of water does fat contain
10-20%
68
T/f: Lean tissue contains less water than fatty tissue
FALSE! fatty tissue contains less water than lean muscle
69
What % of cardiac output does the vessel rich group get
about 75%
70
What % of cardiac output does the muscle group get
18%
71
What % of cardiac output does the vessel poor group get
2%
72
What % of cardiac output does the fat group get
5%
73
what are the best fluids?
depends on what is wrong!
74
what are the 4 things we should ask/consider for fluid therapy
1. what type of fluid?
2. what rate? (ml/kg/hr)
3. what volume? (ml/kg)
4. when? and for how long?
75
What was the original shock dose and why did we change it
80-90 ml/kg/hr and we changed it because that high of a dose can kill the patient
76
what is the new shock dose
40-60 ml/kg/hr
77
what is the one question to ask yourself when monitoring fluid therapy
are they fluid responsive??
78
what is central venous pressure good for when monitoring fluids
it is a good guide if you have given too much fluid volume but NOT if you have given enough
79
T/F: CVP does not always correspond to RA (right atrial??????) pressure
true!
80
T/F: CVP can correlate and predict cardiac output/stroke volume in response to fluid administratino
false! CVP can NOT correlate or predict cardiac output or stroke volume
81
T/F: Monitoring CVP to determine fluid administration almost always leads to fluid overload
TRUE!
82
Why doesn't arterial blood pressure accurately monitor fluid infusion during anesthesia
because arterial BP is a LATE indicator of hypovolemia so by maintain arterial BP to me greater than or equal to 70mmHg with high fluids can produce fluid overload!
83
T/F: Volume therapy is not always effective in anesthetized animals and many animals are partially or completely fluid non-responsive
true! In about 25-75% of animals
84
what are some causes of fluid non-responsiveness
vasoplegia, heart failure, sepsis, or anesthetic overdose
85
how can we treat hypotension without producing fluid overload?
1. decrease anesthetic depth
2. utilize dynamic monitoring
3. administer vasoactive drugs
86
how can we decrease anesthetic depth
by using multimodal anesthesia
87
what is multimodal anesthesia
using different things to help with anesthetic plane rather than just IV drugs (ex: nerve blocks, pain control)
88
what are some vasoactive drugs
norepinephrine, vasopressin, or dobutamine
89
how many ml/kg of packed RBCs will raise PCV by 0.1%
1ml/kg
90
how many ml/kg of packed RBCs will raise the hemoglobin by 0.3g/dl
1ml/kg
