Perioperative Fluid therapy Flashcards
(101 cards)
1
Q
% tbw in the average adult
A
60% water
2
Q
Low % of water in _______ tissue
A
adipose
3
Q
intracellular fluid compartment %
A
55%
4
Q
Extracellular fluid compartment %
A
25%
5
Q
Extraceulllar componenets
A
Interstitial: lymphatics and protein-poor fluid around cells
Intravascular: plasma volume
Transcellular: GI tract, urine, csf, joint fluid, aqueous humor
6
Q
Describe diffusion (5)
A
-Solute particles fill solvent volume
-High to low concentration
-Speed is proportional to distance squared
-Can occur across permeable membranes
-Can relate to electrical gradients
7
Q
types of solutes
A
Glucose, proteins, electrolytes
8
Q
Primary extracellular cation
A
Sodium
9
Q
Primary intracellular cation
A
Potassium
10
Q
Describe osmosis
A
A semipermeable membrane separates pure water from water with solute
Diffuses from low to high concentration
11
Q
Osmotic pressure formula
A
P = nRT/ V
N = number of molecules
R= constant
T= Temperature
V= Volume
12
Q
Osmotic pressure definition
A
Pressure that resists the movement of water through osmosis
13
Q
number of osmotically active particles/L of solvent
A
Osmolarity
14
Q
_____osmolarity…_____“pulling power”
A
Higher osmolarity…higher “pulling power”
15
Q
Number of osmotically active particles per kg of solvent
A
Osmolality
16
Q
normal osmolality
A
Normal: 280-290 mOsm
17
Q
The component of total osmotic pressure due to colloids
A
Oncotic pressure
18
Q
Colloids types
A
Albumin (most), globulins, fibrinogen
19
Q
Albumin % responsible for oncotic pressure
A
65-75% from albumin
20
Q
Average intake (3)
A
750 ml of solids
350 ml from metabolism
1400 ml liquid intake
21
Q
Average ouptuts (3)
A
1000 ml insensible loss (tears/vapor)
100 ml GI loss
0.5-1 ml/kg/hr urine output (60%)
22
Q
ADH response
A
Antidiuretic Hormone (ADH) – renal H2O excretion in response to plasma tonicity.
23
Q
ANP response
A
Atrial Natriuretic Peptide (ANP) – activated with ↑ fluid volume
↑ atrial stretch = ↑ renal excretion.
24
Q
Aldosterone response
A
Aldosterone – regulates Na+ and K+ levels
If Na+ and fluid volume ↓ aldosterone is released causing Na+ and H2O conservation.
25
Urine output is regulated by
adh
ANp
aldosterone
26
Urine section = ____ of dailty water loss
60%
27
Sensory for fluid balance (3)
Hypothalamic osmoreceptors
Low pressure baroreceptors; large veins and RA
High pressure baroreceptors; carotid sinus and aortic arch
28
Triggers for fluid balance
Increased thirst or adh release
29
The compensatory mechanism for disturbances in circulating volume (5)
Venoconstriction
Mobilization of venous reservoir
Autotransfusion from ISF to plasma
Reduced urine production
Maintenance of CO…tachycardia, increased inotropy
30
Sensors for disturbances in circulating volume
low and high pressure baroreceptors
RAA axis
31
RAA axis
Renin
ang 1 becomes 2
aldosterone released from adrenal cortex
32
Renin facts
Released from juxtaglomerular cells
Cleaves angiotensinogen to make angiotensin I
33
Angiotensin I becomes II causes
vasoconstriction and aldosterone release
34
Aldosterone released from adrenal cortex causes_____
salt and water retention
35
IN the absence of ongoing loss RAA axis and compensatory mechanisms restores ______
Restores volume in 12-72 hours
Restores RBC numbers through erythropoiesis in 4-8 weeks
36
NS na, cl, osmolarity
na; 154
cl; 154
osmolarity; 308
37
LR; na, k , cl , lactate, osmolarity
na; 130
k; 4
cl; 109
lactate; 28
osmolarity; 274
38
Isolyte P; na, k, cl, mg, acetate, glucose, posphate
na; 26
k; 21
cl; 21
mg; 3
acetate; 24
glucose; 5
phosphate; 3
39
Plasmalyte A; na, k, cl, acetate, osmolarity
na; 140
k; 5
cl; 98
acetate; 27
osmolarity 295
40
D5 glucose and osmolarity
gluose; 5
osmolarity; 252
41
Albumin 5% na; k, cl, osmolairty
na; 145 + 15
k; <2.5
cl; 100
osmolarity 330
42
Hetastarch 6% na, cl , osmolairty
na 154
cl; 154
osmolarity; 310
43
Solutions of electrolytes in water
Crystalloids
44
Called balanced solutions
Crystalloids
45
Most balanced crystalloid
LR
46
indications for crystalloids
Replacement of free water and electrolytes
Volume expansion
47
Distribution of crystalloids volume through entire ecf
70% intravascular after 20 minutes
50% after 30 minutes
48
Too much crystalloids can cause____ and where?
Tissue edema
Lung, gut, soft tissues
49
Cyrtalloids side effect
Hypercoagulable…anticoagulant factors diluted (at low dilution)
50
effects of ns (0.9%) (3)
-Dilutes hct and albumin
-Increases cl- and K+ concentrations
-Late onset of diuresis
51
Side effect of NS (2)
Causes hyperchloremic metabolic acidosis
Increased AKI and RRT in critical care patients
52
Pulls water out of ICF to ECF including plasma
Hypertonic saline (3%)
53
Hypertonic saline used for _____
Treats hypoosmolar hyponatremia
Treats increased ICP
54
Much lower osmolarity than NS
LR; Lower Na+ and Cl- concentrations (close to plasma)
55
Lr has ___ added as a buffer
Lactate added as buffer
56
What relies on hepatic metabolism?
Lactate (dont use LR for liver insufficiency)
57
Lr Excretes excess water faster than ns
by____
Suppresses adh secretion/allows diuresis
58
Indications for Dextrose solutions
A source of free water (5%)
Could be used for caloric intake in diabetics (10%)
59
Dextrose is not suitable for _____
Not suitable for volume expansion; water moves freely between all compartments
60
Large molecules of a homogeneous, non-crystalline substance that cant be separated
Colloids
61
Types of colloids
Semisynthetic colloids; hetastarch, hespan
Human plasma derivatives; FFP
62
Colloids dispersion facts
Large molecules of a homogeneous, non-crystalline substance (in a balanced solutions (crystalloid).
Cant be separated. Disolved in crystalloid
dispersed in a second substance (typically a balanced crystalloid)
Particles cannot be separated (through filtration or centrifuge
63
effects of colloids
Increased cop = increased potential plasma volume expansion
Cause hemodilution
Uncertain effect on immune, coag, renal systems
64
What are the effects of colloids causing hemodilution (2)
Decrease plasma viscosity
Inhibit rbc aggregation
65
when are Uncertain effect on immune, coag, renal systems of colloids seen?
Maximum recommended dosages
66
Hydroxyethly starch is Modified natural polymers of ____
Modified natural polymers of amylopectin
67
where is hydroxethyl starch deterived from
Modified natural polymers of amylopectin
Derived from potato or maize
Substitution onto glucose
68
Hydroxyethyl starch metabolism is dependent on_____
Metabolism dependent on molecular weight of molecules
69
Hydroxyethyl starch effects
Plasma volume effects last longer
70-80% larger at 90 minutes
70
side effects of Hydroxyethyl starch
Side effects r/t MW
Coagulopathy…vwf, factor VIII and clot strength (at high dilution)
Renal dysfunction
71
Highly branched polysaccharides
Dextrans
72
Dextrans highly branched polysaccharides are procduced by _____
Produced by leuconostoc mesenteroides
73
Dextrans plasma volume is similar to______
Plasma volume similar to the starches (6-12 hours)
74
When is dextrans used and what are the effects
Dextran-40 used for microvascular surgery
Inhibits factor VIII, vWf factor, platelet aggregation
Coats rbc…may interfere with cross-matching
75
Types of human plasma derivatives
Albumin 5%, FFP, immunoglobulin solution
76
Physiologic COP with plasma derivatives indications_____ (4)
Volume replacement
Trauma, sepsis, replacement following paracentesis
77
indications for preop fluids (9)
Disordered Na+ distribution
Requirement for dialysis
Chronic use of diuretics
Diagnosis of hypertension
Preop fasting
Bowel prep
Acute hemorrhage
N,V,D and/or suction
3rd space redistribution
78
indications for intraop fluids (6)
Vasodilation from anesthetics
Sympathetic blockade
Autoregulatory responses
Acute hemorrhage
Insensible losses
Inflammation related redistribution
79
Assessments of low intravascular volume (5)
-Signs of hypovolemia; Tachycardia, ↓ pulse pressure, hypotension, ↓ capillary refill
-urine output; Inadequate as end-organ due to raa
-CVP; Measures central venous volume but distensible
-Tissue perfusion; lactate, mixed venous O2
80
Assessments of high intravascular volume (5)
Excessive crystalloids/colloids;
-↑ capillary hydrostatic pressure
-Excessive fluid development in lungs, bowel, muscle
-Reduced tissue oxygenation
-Poor wound healing
-Hypo/hyper coagulation
81
Uses for classic fluid therapy
NPO deficit
ongoing maintenance
anticipated surgical loss
82
Npo status
Clear liquids: 2 hours
Breast milk: 4 hours
Infant formula: 6 hours
Light meal: 6 hours
Meat/fatty, fried: 8 hours
83
classic approach for NPO/ maintainance formula (4-2-1)
1st 10 kg = 4ml/kg/hr
2nd 10kg = 2 ml/kg/hr
Each 1kg > 20kg = 1 ml/kg/ hr
calculate total deficit
(multiply by number of hours of NPO)
84
How to replace a NPO deficit
½ in the 1st hour of surgery.
¼ in the 2nd hour.
¼ in the 3rd hour.
85
Estimating Blood loss possiblities
Suction
Lap sponges 100ml
Raytech’s 20ml
4x4’s 10ml
86
Lap sponges thats saturated holds
100 ml
come in packs of 5
87
Raytechs comes in packages of ____
10
88
why do sponges have markings?
x ray able
89
Hypovolemic replacement
Preoperative bleeding
Crystalloid traditionally 3:1
May replace prbc’s, ffp, cryo using TEG/ROTEM
90
Average fluid with bowel prep
2000ml average
91
Everage fluid loss with fever
10% deficit q1degree Celsius
92
evaporative/redistribution losses
Minimal= 0-2 ml/kg/hr
Moderate = 2-4 ml/kg/hr
Severe = 4-8 ml/kg/hr
93
Parkland Burn resuscitation formula; what to use, when to use, and how much to give
Based on “rule of 9’s”
Adjusted due to obesity
Lactated ringers
use formula if; 20% TBSA of 2nd/3rd degree burns
4ml/kg/%BSA burn
½ over 1st 8 hours
½ over next 16 hours
94
Rule of 9s
Head; 9
chest ; 9
abdomen; 9
upper back; 9
lower back; 9
legs; 9 and 9
arms together; 4.5 and 4.5
perineum; 1%
95
Goal directed therapy fluid administration is based on_____
Cvp
Co
sv
Svv
96
What do the studies show about goal directed therapy
Studies: less aki, respiratory failure, wound infection, mortality
97
Goal-directed therapy allows decisions to use:
More fluid
Vasopressors
Inotropes
Blood products
98
Goal-directed therapy principles (3)
-Maintenance of 1-3 ml/kg/hr of crystalloid
-Fluid challenges of 250cc to increase sv
-Colloids 1:1 with blood loss or blood products
99
Normal svv
10-15%
100
Shows difference in arterial pulse pressure during inspiration/expiration
(SPV, PPV, SVV)
101
Limits to arterial waveform pressure monitoring
SVV >15% = fluid responsive
Low hr/rr
Irregular heartbeats
Mechanical ventilation (with low tidal volume)
Increased abdominal pressure
Thorax open
Spontaneous breathing
