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Coexisting and Basic Principles Orals > Fluids > Flashcards

Flashcards in Fluids Deck (28)
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1
Q

Body fluid distribution?

A

Intracellular: 40% 24 L
Interstitial: 16% 9.6 L
Plasma: 4% 2.4 L

2
Q

How to assess for fluid volume status

A
Skin turgor 
Mucous membrane
Edema
Lung sounds
Vital signs
Urine output
HCT
Urine specific gravity
BUN/Creatinine
3
Q

Sources of intraoperative fluid requirements

A
Maintenance
         Fluid deficit
         Blood loss
         Evaporative loss (3rd space loss)
4
Q

Insensible loss sources?

A

the respiratory tract
perspiration
urine and feces
GI fluids

5
Q

Maintenance fluid calculation?

A

4-2-1 rule
4cc/kg/hr for 1st 10kg
2cc/kg/hr for 2nd 10kg
1cc/kg/hr for each additional kg

6
Q

What is fluid deficit?

A

The maintenance requirement multiplied by the number of hours patient NPO
If patient receiving maintenance IV fluids there is no NPO deficit but consider other losses
If baseline hypovolemia exists consider overall deficit larger than just NPO deficit
fluid should be replaced to restore mean arterial pressure , heart rate, and filling pressures prior to induction.
Normal urine output is also desirable

7
Q

Fluid deficit replacement strategy?

A

Replacement strategy
½ deficit replaced in 1st hour of surgery
¼ deficit replaced in 2nd hour of surgery
Remaining ¼ replaced in 3rd hour of surgery

8
Q

What is allowable blood loss?

A

Determines how much blood you can lose to reach a particular HCT
Helps anesthetist design appropriate plan and time to transfuse patient

ABL= EBV x (pts HCT – allowable HCT)
pts HCT

9
Q

Evaporative loss and 3rd space loss?

A

Evaporative loss related directly to surface area of surgical wound and duration of exposure
3rd space loss due to massive fluid shifts and intravascular volume deficit caused by redistribution of fluids
Trauma, infection, burns

10
Q

Replacing evaporative/3rd space loss: Minimal, moderate, severe, emergency?

A

Minimal (eye cases, lap chole : 0-2ml/kg/hr
hernia, knee scope)
Moderate (open cholecystectomy): 3-5ml/kg/hr
appendectomy
Severe (bowel surgery, THR): 6-9ml/kg/hr
Emergency (gun shot, MVC): 10-15ml/kg/hr

11
Q

Blood loss replacement strategy

A

replace 3:1 crystalloid

Replace 1:1 blood

12
Q

Name the crystalloids and their osmolarity

A
  1. Hypotonic solutions (253)
    Replaces water loss, called maintenance fluids examples: D5W
  2. Isotonic solutions (300)
    Replaces water and electrolyte loss, called replacement fluids examples: LR, NS
  3. Hypertonic solutions
    For hyponatremia or shock examples: D51/2NS (432), 3% NS (1026)
  4. LR
13
Q

Describe the characteristics of LR

A

Isotonic, provides 100cc free water per liter of solution, tends to lower Na+
Lactate converted to bicarbonate
Most physiologic solution (most similar to ECF)
Avoid in ESRD as contains K+

14
Q

Describe LR and its electrolyte contributions

A
Sodium130 meq/liter
Potassium4 meq/liter
Calcium2.7 meq/liter
Chloride110 meq/liter
Lactate27 meq/liter
15
Q

Describe NS

A

0.9% NS
Isotonic solution
In large volumes produces high Cl- content dilutional hyperchloremic acidosis
Preferred solution for diluting PRBCs

16
Q

Describe D5W

A

D5W
Hypotonic solution
Has little place perioperatively (except as 2nd line- DM Rx with insulin)
Causes free water intoxication and hyponatremia

17
Q

Describe albumin?

A
Blood colloid
Obtained from fractionated human plasma
Does not contain coagulation factors or blood group antibodies
Available as 5% or 25% solution
5% solution common in OR
18
Q

Describe Dextran

A
Synthetic colloid solution
Water soluble glucose polymers
Enzymatically degraded to glucose
Dextran 70 used for volume expansion
Dextran 40 used for prevention of thrombosis
Side effects include 
anaphylactoid reaction, 
platelet inhibition, 
noncardiac pulm edema
Interference with crossmatching
19
Q

Describe Hetastarch

A

Synthetic colloid solution
(hespan 6%)
As effective as albumin for volume expansion
Nonantigenic
Less expensive than albumin
Stored in the reticuloendothelial system for several hours and renally excreted
Coagulopathy d/t dilutional thrombocytopenia

20
Q

Crystalloids vs. Colloids

A

Crystalloids:
Crystalloids equally effective as colloid in restoring intravascular volume if given in sufficient amounts
Support u/o better
Less likely to cause pulmonary edema, colloids associated with coagulation and antigenic problems
Inexpensive

Colloids:
Colloids better at restoring severe intravascular volume deficits by maintaining plasma oncotic pressure
Intravascular half life is 3-6 hours for colloid 20-30 minutes for crystalloid
Fluid of choice with hypoproteinemia
More tissue edema occurs with crystalloids

21
Q

What are the 4 blood components?

A

PRBC
Platelets
Fresh frozen plasma
Cryoprecipitate

22
Q

ASA guidelines for blood transfusion

A

Rarely indicated if HBG >10g/dl and almost always indicated if HGB

23
Q

Indications for blood transfusion

A
  1. Expand intravascular volume
  2. Increase oxygen carrying capacity
  3. Hemoglobin and hematocrit
Clinical judgment based on certain factors
Cardiovascular status
Age
Anticipated blood loss
Arterial oxygenation
Cardiac output and blood volume
24
Q

PRBCs

A

Type specific ABO and Rh factor alone is sufficient in 98.9% of patients (incompatibility seen in 1 in 1000)

Further testing if antibodies present or patient has had numerous blood products

1 unit PRBC increase HGB 1gm/dL
HCT of one unit of PRBC is 70%

Autologous Unit

Reconstituted with  
0.9%Normal Saline
5% dextrose in 0.4%saline
5%dextrose in 0.9% saline
Normosol-R (ph of 7.4)

Citrate toxicity
Hypocalcemia
Monitor ionized calcium

25
Q

Autologous Blood

A

Complications of autologous transfusion include:
anemia
pre-op myocardial ischemia from the anemia
administration of the wrong unit (1:100,000)
need for more frequent blood transfusion
febrile and allergic reaction

26
Q

Platelets

A
One unit obtained by centrifuging single unit of whole blood
Uses include:
thrombocytopenia 
dysfunctional platelets, 
active bleeding 
platelet count
27
Q

FFP

A

Contains clotting factors and plasma proteins (no platelets)
VOLUME 200-250CC
MUST BE ABO Compatible
Uses:
Emergent reversal of warfarin
Known coagulation factor deficiencies
Correction of microvascular bleeding in the presence of increased PT or PTT
Correction of microvascular bleeding in the patient transfused with more than one blood volume when PT and PTT cannot be obtained in a timely fashion

Each unit increases each clotting factor level by 2-3%

FFP is contraindicated for augmentation of plasma volume or albumin concentration

28
Q

Cryoprecipitate

A
Derived from precipitate remaining after FFP is thawed
Contains:
 factor VIII 
fibrinogen
vWF 
XIII
Used in the treatment of 
von Willebrand’s disease 
fibrinogen deficiencies
ABO compatible
Administer through a filter rapidly (200ml/h) and complete within 6 hours