Final- Perioperative Fluid Therapy Flashcards
1
Q
What percentage of total body weight is water?
A
- 60%
- Elderly and Obese patients will have lower percent of water in the body.
- Pediatrics will have HIGHER percent of water in the body (Table 47.1)
S2
2
Q
what perecent of water is in adipose tissue?
A
low percentage in adipose tissue
S2
3
Q
What are the two main fluid compartments?
A
- Intracellular Fluid (ICF) makes up two-thirds of total body water
- Extracellular Fluid (ECF) makes up one-third of total body water
S2
4
Q
What are the different compartments of the ECF?
A
- Interstitial: lymphatics and protein-poor fluid around the cell.
- Intravascular: plasma volume
- Transcellular: GI Tract, Urine, CSF, Joint fluid, aqueous humor.
S2
5
Q
List the different ways of fluid/electrolye movement
A
- Diffusion
- Osmosis
- Osmolarity
- Osmolality
- Oncotic pressure
S3-7
6
Q
What is diffusion?
A
- Solute particles moving or filling solvent volume
- High to Low concentration
- Speed is proportional to the distance squared
- Can occur across permeable membranes
- Can relate to electrical gradients
S3
7
Q
What are examples of the type of solutes that are in our body?
A
- Glucose
- Protein (Albumin)
- Electrolytes
S3
8
Q
What is the primary extracellular cation?
A
- Sodium (Na+)
S3
9
Q
What is the primary intracellular cation?
A
- Potassium (K+)
S3
10
Q
What is osmosis?
A
- A semipermeable membrane that separates pure water from water with dissolved solute.
- Osmosis is just the movement of WATER
- Diffuses from low to high solute concentration
S4
11
Q
What is osmotic pressure?
A
- Pressure that resists the movement of water through osmosis
S4
12
Q
- What is osmotic pressure affected by?
A
- Temperature
- Number of Molecules
- Volume
S4
13
Q
What is the equation for osmotic pressure?
A
P = nRT/V
* V=volume
* N= number
* T=temperture
S4
14
Q
What is osmolarity?
A
- Number of osmotically active particles per L of solvent
- Higher osmolarity, higher “pulling power”
S5
15
Q
Patient A has serum glucose of 600mg/dl
Patient B has serum glucose of 250mg/dl
Who has higher osmolarity?
A
- Patient A
Pt with glucose of 600 has more particles
S5
16
Q
What is osmolality?
A
- Number of osmotically active particles per Kg of solvent
S6
17
Q
What is normal osmolality?
A
- 280-290 mOsm
S6
18
Q
What is oncotic pressure?
A
- The component of total osmotic pressure due to colloids
S7
19
Q
List examples of colloids
A
- Albumin
- Globulins
- Fibrinogen
S7
20
Q
What percentage of oncotic pressure is due to albumin?
A
- 65-75%
S7
21
Q
What makes up our daily fluid intake?
A
- Solids (750 mL)
- Liquids (1400 mL)
- Metabolism (350 mL)
S8
22
Q
What makes up our daily fluid output?
A
- Insensible Loss (1000 mL)
- GI loss (100 mL)
- Urine output (0.5-1 mL/kg/hr)
S8
23
Q
How do we regulate intake and output of fluid?
A
- We are responsible for:
- intake: oral fluids & food
- Output: urinary secretion
S9
24
Q
Urine secretion accounts for ____-% of daily water loss.
A
- 60%
S9
25
What hormones regulate urine output?
* Antidiuretic hormone [ADH]
* Atrial natriuretic peptide [ANP]
* Aldosterone
| S9
26
How does ADH regulate urine output?
* Renal H2O excretion in response to plasma tonicity
*tonicity: a measure of effective osmolarity*
| S9
27
How does ANP regulate urine output?
* ANP is activated by ↑ fluid volume
* ↑ Atrial Stretch = ↑ Renal Excretion
| S9
## Footnote
A&P: ANP/ANF talk to the kidney to increase prostaglandins [PG] production in the kidneys.
-More PG result in increases RBF—> increases GFR —>increase UO to get rid of fluid and electrolytes to reduce strain/stretch on atria.
28
How does Aldosterone regulate urine output?
* Regulates sodium and potassium levels
* Aldosterone is released if sodium and fluid volume decreases, causing sodium and water conservation.
| S9
29
What are the sensors for fluid balance?
* Hypothalamic osmoreceptors
* Low-pressure baroreceptors
* large veins and RA)
* High-pressure baroreceptors
* carotid sinus and aortic arch
| S10
30
What is the trigger for fluid balance?
* Increased thirst or increase ADH
| S10
31
What are the compensatory mechanisms for acute disturbances in circulating volume?
* Venoconstriction
* Mobilization of venous reservoir
* Autotransfusion from ISF to plasma
* Reduced urine production
* Maintenance of CO…tachycardia, increased inotropy
**happens in minutes to hours**
| S11
32
For compensatory mechanisms to occurs for acute disturbances in circulating volume, what sensors must be present?
* low and high pressure baroreceptors
* RAA Axis
| S11
33
Overview of RAAS
* Renin relased
* Angiotensinogen → Angiotension 1
* Angiotensin 1 → Angiotension 2
* Vasocontriction + aldosterone release
34
* Where is Renin released?
* What does Renin do to angiotensinogen?
* Released from juxtaglomerular cells
* Cleaves angiotensinogen to make angiotensin I
| S12
35
When ANG I → ANG II, what will this cause?
* Vasoconstriction and aldosterone release
| S12
36
Where is aldosterone released from and what does it cause?
* Aldosterone is released from the adrenal cortex
* causes salt and water retention
| S12
37
In the absence of ongoing fluid loss, volume loss is restored within how many hours?
* 12-72 hours
| S12
38
In the absence of ongoing fluid loss, how is RBC restored? How long does this take?
* through erythropoiesis in 4-8 weeks
| S12
39
What are the Electrolytes and Osmolarity of Normal Saline (0.9%)?
* Na+: 154 mEq/L
* K: -
* Chloride: 154 mEq/L
* Osmolarity: 308 mOsm/L
| S14
40
What are the Electrolytes and Osmolarity of LR?
* Na+: 130 mEq/L
* K+: 4 mEq/L
* Chloride: 109 mEq/L
* Lactate: 28 mEq/L
* Osmolarity: 274 mOsm/L
| S14
41
What are the Electrolytes and Osmolarity of Plasmalyte?
* Na+: 140 mEq/L
* K+: 5 mEq/L
* Cl-: 98 mEq/L
* Acetate: 27 mEq/L
* Osmolarity: 295 mOsm/L
| S14
42
What are the Electrolytes and Osmolarity of Albumin 5%?
* Na+: 145 +/- 15 mEq/L
* K+: < 2.5 mEq/L
* Cl-: 100 mEq/L
* Osmolarity: 330 mOsm/L
| S14
43
What are the Electrolytes and Osmolarity of Hetastarch 6%?
* Na+: 154 mEq/L
* K: -
* Cl-: 154 mEq/L
* Osmolarity: 310 mOsm/L
| S14
44
What are crystalloids?
* Isotonic
* Solutions of electrolytes in water
* The are called balanced solutions (not really though, misnomer)
* *LR is probably considered the most "balanced" crystalloid*
| S15
45
What are indications of using crystalloids?
* Replacement of free water and electrolytes
* Volume expansion
| S15
46
* With crystalloid administration and distribution throughout the EFC what percentage will be in the intravascular space:
* after 20 minutes?
* What about after 30 minutes?
* 70% in the intravascular space after 20 minutes
* 50% in the intravascular space after 30 minutes
| S16
47
What are the negative effects of crystalloids?
* Tissue Edema
* Lungs, GI Tract, Soft Tissues
* Hypercoagulability
* Anticoagulant factors diluted
* *micro emboli*
| S16
48
List the different types crystalloids
* Normal saline (0.9%)
* Hypertonic saline (3%)
* Lactated Ringers
* Dextrose solutions
| S17-20
49
NS 0.9% is the most commonly fluid, but what are the negative consequence of this fluid?
* Dilutes Hct and Albumin
* Late onset of diuresis
* Increase AKI and dialysis in ICU patients
* Causes hyperchloremic metabolic acidosis if too much is given resulting in:
* ↑ Cl- and K+ concentraions
| S17
50
* How does hypertonic saline (3%) work?
* What does it treat?
* pulls water out of ICF to ECF including plasma
* Treats:
* hypoosmolar hyponatremia
* increased ICP
* TURP
| S18
51
In comparison to NS, what does the osmolarity, Na, and Cl look like in LR?
* lower osmotarity
* lower Na+
* lower Cl-
| S19
52
What is added to LR to act as a buffer?
* Lactate
| S19
53
how does LR excreter excess water faster than NS?
suppresses ADH secretion which allows for diuresis
| S19
54
Why would you not want to use LR on a liver pt?
* LR relies on hepatic metabolism
* *This can cause an increase build of lactate in the patient.*
| S19
55
What happens to dextrose solution when the glucose is metabolized?
* Dextrose becomes a hypotonic solution/a source of free water
* Does not say in the vascular space
* Water moves freely between all compartments
| andy?
56
* What percent dextrose is a source of free water?
* What is this not suitable for and why?
* D5
* not suitable for volume expansion bc water moves freely between all compartments
| S20
57
What fluid could be used for caloric intake in diabetic patients?
* Dextrose 10%
* Better options out there
| S20
58
What are colloids?
* Large molecules of a homogeneous, non-crystalline substance
* dispersed in a second substance (usually a balanced crystalloid).
* Particles cannot be separated (through filtration or centrifuge)
| S21
59
What are the two main types of colloids?
* Semisynthetic colloids (Starches)
* Human plasma derivatives (FFP, Albumin)
| S21
60
How do colloids work?
* Colloids work by increasing colloid oncotic pressure (pulling force), which increases potential plasma volume expansion
| S22
61
What are the negative effects of colloids?
* Causes hemodilution
* Decreases plasma viscosity
* Inhibit RBC aggregation
* Uncertain effect on immune, coag, and renal system (AKI)
* maximum recommended dosages
| S22
62
* What is hydroxyethyl starch?
* where is is derived from?
* what is it substituted on?
* modified natural polymers of amylopectin
* dervied from potato or maize
* substitution onto glucose
*This is a man made colloid*
| S23
63
The metabolism of hydroxyethyl starch is dependent on?
* Molecular weight of molecules (small, medium, large)
* 70 to 80% of larger molecules are still in the intravascular space at 90 minutes.
* Plasma volume effect last longer
| S23
64
What are the S/E of Hydroxyethyl Starch r/t molecular weight?
* Coagulopathy through dilution effects, leading to reduction in VWF, Factor VIII, Clot Strength.
* Renal Dysfunction
| S23
65
Dextrans are a type of colloid. Where are the derive from?
* highly branched polysaccharide
* produced by a bacteria called Leuconostoc Mesenteroides
| S24
66
Describe the plasma volume of dextrans.
* Plasma volume similar to the starches
* duration: 6-12 hours [stays in vascular space for a long time]
| S24
67
What is Dextran-40 used for?
Why?
How?
* Microvascular Surgery (limb reattchement, breast flap)
* Inhibits factor VIII, VWF, Platelet Aggregation prevent coagulation
* Coats the RBC...may interfere with cross-matching
| S24-lecture
## Footnote
Dextran-40 will coat the RBC and may interfere with cross-matching
68
What are examples of human plasma derivative colloids?
* Albumin 5%
* FFP
* Immunoglobulin Solution
| S25
69
Human plasma derivates: physiologic colloid oncotic pressure [COP]
* Volume replacement
* trauma
* sepsis
* replacement following paracentesis
| S25
70
Fluid alterations in the preoperative settings (long list, common sense).
* Na+ distribution disorder
* Dialysis requirement
* Chronic use of diuretics
* Dx of HTN
* Preop Fasting
* Bowel Prep
* Acute Hemorrhage
* NVD, Suction
* 3rd space redistribution
| S26
71
Fluid alterations in the intraoperative settings (alterations caused by CRNA).
* Vasodilation from anesthetics
* Sympathetic blockade (narcotics)
* Autoregulatory response
* Acute Hemorrhage
* Insensible Loss
* Inflammation related redistribution
| S26
72
Assessment of Low Intravascular Volume
* **Signs of Hypovolemia** - ↑HR, ↓Pulse Pressure, ↓BP, ↓Cap Refill (25% of volume must be lost)
* **Decreased Urine Output**
* inadequate as end-organ d/t RAA
* **CVP**
* measures central venous volume but venous system distensible
* **Tissue Perfusion**: Lactate, Mixed venous O2
| S27
73
What are the signs of hypovolemia for low intravascular volume? how much volume must be lost for these s/sx to occur
* ↑HR
* ↓Pulse Pressure
* ↓BP
* ↓Cap Refill
* 25% of volume must be lost
74
What factors do you need to consider as a CRNA when assessing urine output for intravascular volume?
* Low UO can be d/t stress hormone release from anesthetic
* Low UO can be d/t low intravascular volume and inadequate perfusion to the kidney
* Low UO can be d/t the patient's position, Steep Trendelenburg
| S27 lecture
75
Assessment of High Intravascular Volume
* Increase capillary hydrostatic pressure
* Excess fluids in lungs (Crackles/edema), bowels, muscle
* Decreased gut motility
* Reduced tissue oxygenation
* Poor wound healing
* Hypo/Hyper Coagulation
If he is fluid overloaded, HE DRIP
| S28
76
A study of 13 patients (11 adults and 2 peds) all died from what? Why?
post-op pulmonary edema
-we give way too much volume in surgery historically speaking
| S28
77
what is the 4-2-1 plan?
What does it take into account?
* it is the "classic" fluid therapy
Takes into account:
* NPO deficit
* ongoing maintenance (hourly)
* anticipated surgical loss (blood & insensible)
| S29
78
NPO Status:
* Clear Liquids
* Breast Milk
* Infant Formula
* Light Meal
* Meal/Fatty, Fried
* Clear Liquids: 2 hours
* Breast Milk: 4 hours
* Infant Formula: 6 hours
* Light Meal: 6 hours
* Meal/Fatty, Fried: 8 hours
| S30
79
How is ERAS protocol changing NPO status?
* Maintain homeostasis by allowing NPO status to be delayed
* Can have carbohydrated 2 hours before surgery.
| S30-lecture
80
# Classic approach for **NPO/MAINTENANCE**
Formula for Classic Fluid Therapy.
* 1st 10 kg = 4 mL/kg/hr
* 2nd 10kg = 2 mL/kg/hr
* Each kg over 20 kg = 1 mL/kg/hr
| S31
81
Mr. Cartman's Weight is 80 kg. Calculate Total NPO deficit for 8 hours using the classic fluid therapy.
Cartman is 80kg, using the 4-2-1 Rule.
4 mL/kg for 1st 10 kg = 40 mL
2 mL/kg for 2nd 10 kg= 20 mL
1 mL/kg for last 60 kg = 60 mL
120 mL/ hr x 8 hours = 960 mL deficit
| S32
82
How do we replace the deficit in the OR?
Mr. Cartman's has a 960 ml deficit. How would you replace this?
* ½ in the 1st hour of surgery
* *480 m*l
* ¼ in the 2nd hour.
* 240 ml
* ¼ in the 3rd hour.
* 240 ml
| S33
83
If Cartman's fluid deficit is 960 mL and fluid maintenance is 120 mL/hour, what is the fluid plan for this patient?
| S33/34
Add blood loss...could easily exceed 1L in the 1st hour
| S34-36
84
How much blood would the following hold when estimating blood loss in surgery:
Suction:
Lap Sponge:
Raytech:
4x4 Gauze:
* **Suction**: be sure to subtract the irrigation fluids
* **Lap Sponge (packs of 5)**: 100 mL
* **Raytech** (pack of 10): 20 mL
* **4x4 Gauze**: 10 mL
| S37
## Footnote
dont argue with what the surgeon says the blood loss is...just chart what you know!
85
How much fluid can be loss with a bowel prep?
* 2000 mL
| Andy?
86
What is the fluid deficit for a fever?
* 10% fluid deficit for every 1 degree Celsius above 38C
| andy?
87
What are the different categories of evaporative/ redistribution losses?
* **Minimal**: 0-2 mL/kg/hr
* (robotics case, sinus)
* **Moderate**: 2-4 mL/kg/hr
* **Severe**: 4-8 mL/kg/hr
* (open belly, bowel)
| S38, lecture
## Footnote
**controversial**
88
The parkland formula is based on what?
what is it adusted due o?
* Rule of 9's
* 20% TBSA of 2nd/3rd degree burns
* Adjusted due to:
* obesity
* kids
| S39
89
What is the Parkland Burn Formula?
* 4 mL x kg x % BSA burn (whole number) = Fluids to replaced
* 1/2 over the first 8 hours
* 1/2 over the next 16 hours
*Formula adjusted for obese patients and children*
| S39
90
What is the percent body surface area of the following: (front and back of body)
* front/back of head:
* Each arm
* Each leg
* Chest:
* Abdomen:
* Groin:
* Front/back of head: 9%
* Chest: 18%
* Each arm: 9 %
* Each leg: 18%
* Abdomen: 18%
* Groin: 1%
| S39
91
What is the percent body surface area of the anterior trunk? (includes upper and lower)
Posterior trunk?
* 18%
* 18%
| S39
92
What fluid is used to replace burn patients?
* Lactated Ringers
| S39
93
When is the Parkland Burn formula used?
* 20% of TBSA is burned
* 2nd and 3rd degree burns only
| S39
94
If an 80kg patient has 40% of their TBSA burned, what would be the total fluid needed to be replaced in this patient?
* 4mL x kg x TBSA (%)
* 4 x 80kg x 40 =12800 mL total
* 6400 mL replaced in the first 8 hours
* 6400 mL replaced in the next 16 hours
| S39 lecture
95
4-2-1 is an old estimation for fluid replacement. What is goal directed theraphy and fluid administration is based on?
* Goal: keep CO at a level that delivers appropriate amounts of oxygen to the tissues
**Fluid administration based on**:
* CVP- not specific
* CO
* **SV** -determines if they are fluid responsive
* **SVV** -determines if they are fluid responsive
* SWAN- use declining
* SVO2- measures O2 extraction
* TEE- quantify LV cavity size/EF (not a standard of care)
* lactate levels: decreasing level signals successful resuscitation
*Patient will either be fluid responsive or unresponsive. If fluid responsive, a bolus will be administered. Fluid replacement is individualized.*
| S40
96
What are the reasons for using GDT (goal directed therapy)?
Allows decisions to use:
* more fluid
* vasopressors
* inotropes
* blood products
| S41
97
What have studies shown about the results of goal directed therapy?
* Less AKI
* Less Respiratory Failure
* Decrease Wound Infection
* Decrease Mortality
| S41
98
What is the maintenance dose for goal directed therapy?
* 1-3 mL/kg/hr of crystalloid
| S42
99
For goal directed therapy, a fluid challenge of ___________ mL will be used to increase SV.
* 250 mL
| S42
100
What is used in goal directed therapy with blood loss or blood products?
* Colloids 1:1 (1 colloid for every blood product)
* *Did 3:1 in the past*
| S42
101
What are the LIMITS to arterial waveform pressure monitoring (SVV Monitoring)?
* **L**ow HR/RR
* **I**rregular rhythms
* **M**echanical Ventilation w/ Low Vt
* **I**ncreased Abdominal Pressure
* **T**horax Open
* **S**pontaneous Breathing
*Any of these factors will result in an inaccurate reading on the monitor. Need normal on all of these factors to have SVV*
| S43
## Footnote
its ironic that patients we would need to measure this on are the patients that this information will not be accurate with, haha
102
What are the 3 different types of monitoring using an aterial line for fluid responsiveness?
* Systolic Pressure Variation
* Pulse Pressure Variation:
* Stroke Volume Variation
| S44 and lecture
103
How do you utilize Systolic Pressure Variation
* Max systolic pressure -min systolic pressure
* during one cycle of mechanical breath
*Normal: 7-10 mmhg*
*Increase: volume responsive or have residual prelaod reserve*
| S44
104
How do you utilize pulse pressure variation?
* **The difference between the lowest systolic pressure and the highest diastolic pressure**
* *Over entire RR cycle*
* *Normal <13-17%*
* *>13-17% = positive respone to volume expanson*
105
How do you utilize stroke Volume Variation?
* variation of SV in 30 seconds
* The area under the "curve" (*still highest and lowest values)*
106
What is normal Stroke Volume Variance (SVV)?
* 10-15%
(erikson: 10-13%)
| S44
107
* For SVV, what do you do if its >15%?
* What do you do if pt is hypotensive but SVV is normal or low?
* If >15%, patient will be responsive to fluid (give fluid bolus)
* Pt will not be fluid responsive. Give ionotrpes
| S44 lecture
