Fluid And Blood Flashcards
1
Q
Reasons for fluid management
A
- Maintain intravascular volume
- Augmenting CO
- Maintain tissue perfusion
- Promoting O2 delivery
- Correcting/maintaining electrolyte balance
- Enhancing microcirculatory flow
- Facilitating delivery of nutrients
- Clearance of metabolic waste
2
Q
Total body water percentages
A
60% of total body weight
Intracellular volume (24L) -40% total body weight
Extracellular volume
-20% total body weight
Extracellular volume/fluid compartment
-interstitial fluid volume: 75% of ECV (9.6L)
-plasma volume: 25% of ECV (2.4L)
3
Q
Total body water percentages of males/females/infants
A
Males: 55%
Females: 45%
Infants: 80%
- obese individuals have less TBW per weight than non-obese. Fat does not have as much water so lower calculation for them
- elderly have less water, but don’t change calculation
4
Q
Fluid compartments are divided by what?
A
Water permeable membranes
- intracellular space is separated from the extracellular space by the cell membrane
- capillary membranes separates the components of the extracellular space. In between the interstitial and plasma volume
5
Q
The intracellular fluid compartment has a high concentration of what electrolytes?
A
Potassium (primary cation)
Phosphate (primary anion)
Magnesium
6
Q
What maintains the high concentration of K in the intracellular fluid?
A
Sodium-potassium pump
Uses ATP for active transport
3 Na out per 2 K in, uses 1 ATP
7
Q
The extracellular fluid compartment has a high concentration of what electrolytes?
A
Sodium (primary cation)
Chloride (primary anion)
8
Q
This makes up about 1/4 of the extracellular volume and has a high concentration of what?
A
Intravascular fluid or plasma
Albumin
9
Q
T/F: Capillary membrane is essentially impermeable to plasma proteins?
A
True
They create an osmotic pressure to pull fluid in to try to dilute solute and balance concentrations.
10
Q
This makes up 3/4 of the extracellular fluid compartment and is fluid in tissue spaces
A
Interstitial fluid
11
Q
Fluid movement across fluid compartments is affected by:
A
-Properties of membranes separating the compartments
Concentration of osmotically active substances within a compartment
12
Q
This fluid space is the chief focus of our fluid therapy, why?
A
The intravascular fluid space bc this is an accessible fluid compartment
13
Q
What are the 4 things that determine starling forces?
A
- Hydrostatic pressure in the capillary
- Hydrostatic pressure in the interstitium
- Oncotic pressure of the capillary
- Oncotic pressure of the interstiitium
14
Q
This is used to calculate the overall pressure of a compartment to find the need driving pressure
A
Starling equation
15
Q
What 3 factors affect fluid movement?
A
- Osmolarity: expression of the number of osmolality of a solute in a liter of solution
- Osmolality: expression of the number of osmolality of a solute in a kilogram of solution
- Tonicity: how a solution affects cell volume
16
Q
Hypovolemia
A
AKA: volume depletion
- loss of extracellular fluid
- absolute loss of fluid from the body
- reduced circulating volume
*balance is there, just less volume
17
Q
Dehydration
A
- concentration disorder
- insufficient water present in relation to sodium levels.
*can be caused by different things, not just fluid loss. Balance also off
18
Q
Hypervolemia
A
- excess fluid volume in an isotonic concentration
- not usually a problem with surgical patients
19
Q
Hypervolemia may be seen in surgical what patients?
A
CHF
Renal failure
Over hydration with isotonic IVF
20
Q
What is the most abundant electrolyte in the ECF?
A
Sodium
21
Q
What is responsible for normal osmotic activity of the ECF?
A
Na+ and accompanying anion Cl-
22
Q
All sodium gain/loss is accompanied by what?
A
Water gain/loss
23
Q
What are the extracellular and intracellular sodium levels?
A
ECV: 140 mEq/L
ICV: 25 mEq/L
24
Q
Causes of hyponatremia
A
Vomiting Diarrhea Diuretics Adrenal insufficiency Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) Renal failure Water intoxication CHF Liver failure Nephrotic syndrome
*you’re either losing sodium or gaining too much water
25
What is the most common electrolyte abnormality is hospitalized patients?
Hyponatremia
26
Clinical manifestations of hyponatremia
Neurologic
- HA
- malaise
- agitation
- coma
- cerebral edema
- confusion
GI
- anorexia
- N/V
Muscular
- cramps
- weakness
27
What is most significant risk of hyponatremia?
Cerebral edema
Na can’t cross BBB. Great increases Na and will pull fluid in causing the brain to swell
28
Treatment of hyponatremia
- fluid restriction
- hypertonic saline and an osmotic loop diuretic
* correction of serum sodium levels too fast can result in neurological damage and myelinolysis
* see Nagelhout pg 362 on how to correct
29
How rapidly should a low sodium level be corrected?
No more than 1-2 mEq/L/hr
30
Causes of hypernatremia
*not as common
- most common cause is water deficiency d/t:
- excessive loss
* *inadequate intake
- exogenous Na load
- primary hyperaldosteronism
- diabetes insipidus
- renal dysfunction
31
Clinical manifestations of hypernatremia
Neurologic
- thirst
- weakness
- seizure
- hallucinations
- irritability
- disorientation
- coma
- intracranial bleeding
CV
-hypervolemia
Renal
- polyuria or oliguria
- renal insufficiency
32
Treatment of hypernatremia
- replacing the water deficit *see nagalhout p363
- plasma sodium should be decreased by 1-2 mEq/hr until the pt is clinically stable
- correction should progress gradually over a 24 hr time frame
33
This makes up 87% of the body’s potassium supply and how is it balanced?
Intracellular electrolyte
Balanced by GI absorption and renal excretion
34
Intracellular and extracellular K levels
Intracellular: 150-160 mEq/L
Extracellular: 3.5-5.0 mEq/L
Largely responsible for resting membrane potential
35
Causes of hypovolemia
```
GI losses
Systemic alkalosis
Diabetic ketoacidosis
Diuretic therapy
Sympathetic nervous system stimulation
Poor dietary intake
```
36
What is the most commonly seen electrolyte abnormality is our clinical practice?
Hypokalemia
37
Clinical manifestations of hypokalemia
CV
- ST-segment depression
- presence of U wave
- flattened or inverted T waves
- ventricular ectopy
Neuromuscular
- weakness (respiratory muscle)
- decreased reflexes
- confusion
* <2.5 pt will likely have parisesias and decreased reflexes
38
Treatment of hypokalemia
-slow IV potassium supplements
39
Anesthesia concerns with hypokalemia
- increased risk of myocardial irritability (K < 2.6)
- avoid hyperventilation of the lungs
- avoid glucose containing IV solutions
- avoid rapid infusion of IV K supplements
*normal replacement rate is 10-2- mEq/hr
40
Causes of hyperkalemia
Increased total body potassium
- renal failure
- k-sparing diuretics
- excessive IV K supplements
- excessive use of salt substitutes
Altered distribution of potassium
- metabolic or respiratory acidosis
- digitalis intoxication
- insulin deficiency
- hemolysis
- tissue and muscle damage after burns
- admission of succinylcholine
41
Clinical manifestations of hyperkalemia
CV
- tall, peaked and elevated T wave
- widened QRS complex
- prolonged PR interval
- flatted or absent P wave
- ST segment depression
- cardiac arrest
42
Treatment of hyperkalemia
Primary goal
- avoid adverse cardiac effects
- insulin and glucose to shift K into cells
- IV calcium to antagonize cardiac effects: 1st line of defense bc it helps to generate an action potential
43
What is the upper K limit for elective procedures?
5.5 mEq/L
44
Percentage of magnesium stored in muscle/bone, cells, and serum
Muscle/bone; 40-60%
Cells: 30%
Serum: 1%
45
What regulates magnesium levels?
Intestines had kidneys
46
What role does magnesium play in the body?
Cofactor in enzymatic reactions
- energy metabolism
- protein synthesis
- neuromuscular excitability
- function of Na-K-ATPase
47
What is considered hypomagnesemia?
Serum mag < 1.7 mEq/L
48
What causes hypomagnesemia?
Inadequate dietary intake
TPN w/o mag supplementation
Starvation
GI loses
- diarrhea
- fistulas
- NG suctioning
- vomiting
Chronic alcoholism
49
Clinical manifestations of hypomagnesemia
ECG
- flat T-waves
- U-waves
- prolonged QT interval
- widened QRS
- atrial and ventricular PVCs
*low mag has an inhibitory effect on ATPase pump and alters resting membrane potential
50
Treatment of hypomagnesemia
IV administration of mag sulfate
- 1-2g over 5 minutes with EKG monitored
- followed by continuous IV infusion 1-2 g/hr
51
What is considered hypermagnesemia?
Serum mag > 2.5 mEq/L
52
Causes of hypermagnesemia
Iatrogenic administration
- preeclampsia
- antacids/laxative
Renal failure
Adrenal insufficiency
53
Clinical manifestations of hypermagnesemia based on labs (mEq/L)
```
3-5: flushing n/v
4-7: drowsiness, decreased deep tendon reflexes, weakness
5-10: hypotension, bradycardia
7-10: loss of patellar reflex
10: respiratory depression
10-15: respiratory paralysis, coma
15-20: cardiac arrest
```
54
Treatment of hypermagnesemia
D/C supplemental mag
Use calcium as an antagonist in urgent situations
- bradycardia
- heart block
- respiratory depression
55
What does magnesium do to resting membrane potential?
Decreases it
56
What does calcium do to resting membrane potential?
Increases it
57
What will magnesium do to non-depolarizing neuromuscular blockers?
It will potentiate them
58
Where is calcium stored in the body?
99% found in bones
| 1% found in plasma and body cells
59
Functions of calcium in body?
Structural integrity of bones
* second messenger that couples cell membrane receptors to cellular responses
- muscle contraction, hormones, neurotransmitters, coagulation, myocardial contractility
60
This is the best lab to determine physiologically active calcium
Ionized calcium
Normal: 9.0-10.5
61
Calcium level is maintained/regulated by what 2 things?
Calcitonin: drives calcium into bones
Parathyroid hormone: pulls it out
62
Causes of hypocalcemia
Hypoparathyroidism
Malignancy
Chronic renal insufficiency
63
What are the 2 most common causes of intra-operative hypocalcemia?
Hyperventilation (leads to alkalosis which causes protein binding to calcium)
Massive transfusion (due to citrate in blood products binds to calcium)
64
Manifestations of hypocalcemia
Neuromuscular irritability
- cramps
- weakness
- Chvostek sign: clinal sign of hyperexcitability. Abnormal reaction to stimulation of facial nerve
- Trousseau sign: carpal spasm when upper arm is compressed. Indication of latent tetany
- seizure
- numbness
- tingling
65
Clinical manifestations of hypocalcemia
CV
- dysrhythmias
- prolonged QT interval
- T-wave inversion
- hypotension
- decreased myocardial contractility
Pulmonary
- laryngospasm
- bronchospasm
- hypoventilation
66
Treatment of hypocalcemia
Infusion of calcium salts
Calcium chloride
- more bioavailable
- more rapid correction (best)
Calcium fluctuate
- slower (has to be altered by body first)
- 3 grams = 1 gram calcium chloride
67
Causes of hyperkalemia
Hyperparathyroidism (>50% cause)
Tumors/malignancy
Calcium mobilization from bone due to immobility
68
Clinical manifestations of hypercalcemia
CV
- HTN
- heart block
- shortened QT interval
- dysrhythmias
Neuromuscular
- muscle weakness
- decreased deep tendon reflexes
- sedation
69
Treatment of hypercalcemia
Treat underlying cause
Volume expansion with normal saline
Intraoperative hypercalcemia should be managed with administration of adequate fluids and maintenance of urine output
Loop diuretics to enhance the renal excretion of calcium
70
Factors influencing intraoperative fluid management
```
Pts perioperative fluid status
Co-existing disease
Intra-op fluid shifts
Intra-op blood loss
Selection of appropriate fluids for replacement of intra-operative losses
```
71
Historical replacement of intra-op fluid loss takes into account what 2 things?
Insensible loss
Third space loss
Blood loss
72
What does insensible loss include and how do we replace?
Urine
Feces
Sweat
Respiratory tract
*correct with 2 mL/kg/hr of crystalloids solution
73
What is 3rd space loss and how do you replace?
A redistribution of fluid from the intravascular space to the interstitial space
The volume of fluid transferred corresponds to the degree of manipulation of tissues intraoperatively
* replacement is dependent of the surgical procedure
- minimal trauma: 3-4mL/kg
- moderate trauma: 5-6mL/kg
- severe trauma: 7-8mL/kg
74
3rd space losses are mobilized on what day and manifest as what?
About 3rd day post-op
May see an increase in intravascular volume on that day
*pts with limited cardiac reserve or renal dysfunction may have hypervolemia or or pulmonary edema if fluid mobilization is significant
75
What is the aim of perioperative goal-directed fluid therapy (PGDT)
Utilize individualized hemodynamic end-points to support O2 transport and balance
Minimize: O2 demand
Optimize: CO, tissue oxygenation, capillary and macrovascular flow, oxygen and nutrient deliver, and end-organ perfusion
76
PGDT hemodynamic Monitoring uses what mechanism?
Frank-starling mechanism
- LVEDV: myocardial contractility
- An increased in preload will increase myocardial contractility and thus >CO
- there is an endpoint to the stretch
* clinically must be able to determine which pts can tolerate fluids
- ex: CHF, vent dysfunction
77
For PGDT hemodynamic monitoring, you can measure cardiac output with a PAC by using what technique?
Dilution technique
78
What is pulse contour?
```
Emerging technique
Minimally or non-Invasive
Examples include
-plethsmography variability index
-stroke volume variation
-systolic pressure variation
-pulse pressure variation
```
*use this in ERAS cases
79
Other methods of PGDT hemodynamic Monitoring
- esophageal Doppler and echocardiography
- real-time measures of LV function and aortic compliance
- Measures of tissue oxygenation
- integrated invasive technologies combine invasive lines with software inputs of blood gas data to calculate oxygenation
80
PGDT protocol steps
- baseline assessment of target hemodynamic measures
- administration of small fluid bolus (200-250mL) to assess Frank-Starling curve
- ends-points identified and fluid given to maintain
81
Why use crystalloids intra-op
- used to maintain normal body fluid composition and replace losses
- contain water and electrolytes
- cross plasma membranes easily and may dilute plasma proteins resulting in a reduction of plasma oncotic pressure
- are effective at increasing the intravascular fluid volume
*associated with an increased risk of pulmonary edema if administer in large volumes
82
What does ERAS stand for?
Enhanced Recovery After Surgery
83
How much crystalloid do you use to replace blood loss?
The volume of crystalloids used to replace intraoperative blood loss should be 3x the EBL
*this is bc the volume replacement must replenish both the volume lost from the intravascular space and the volume transferred from the extravascular space to the intravascular space to maintain the plasma volume during times of acute hemorrhage
84
Do we usually use glucose containing solutions during surgery?
NO
Surgical stress response normally induces hyperglycemia
The exception would be for prevention of hypoglycemia in diabetic pts who have received insulin
85
Examples of colloids
Albumin
Plasmanate
Hetastarch
Dextran
86
What are colloids?
Large molecules that do not readily cross plasma membranes
Can be used 1:1 to replace blood loss
May be advantageous bc they remain in the intravascular space longer than crystalloids
*no evidence they are superior to crystalloids for replacing intravascular volume
87
Advantages and disadvantage of colloids
| Compared to blood
Advantages
-lack of disease transmission
Disadvantages
Lack of O2 carrying capacity
Lack of coagulation factors
Increased cost
88
Negatives to hetastarch
Infusion of large volumes can cause dilutional coagulopathy
Can cause a decrease in factor VIII when given in a volume greater than 1000mL in a 70kg pt
*FDA study showed increased mortality in critically ill adult pts
89
Negatives of dextran
Infusion of large volumes can cause dilutional coagulopathy
Appears to decrease platelet adhesiveness
Potential for anaphylactic/anaphylactoid reactions
Interferes with ability to cross match pts blood secondary to agglutination of RBCs
90
What is most common colloid used?
5% albumin
Used fro rapid expansion of intravascular fluid volume
*some Jehovah Witnesses won’t want
91
What is the primary indication for 25% albumin
Hypoalbuminemia
92
Clinical stings of intra-op blood loss
```
Tachycardia
Hypotension
Decrease CVP
Decrease mixed venous O2
Oliguria
```
*will notice tachycardia and hypotension first
93
What is oliguria?
Urine output of 0.5-1 mL/kg/hr
*diuretics will interfere with the utility of intra-op urine output as a measure of fluid volume
94
What does a variation of SBP with respiratory cycle of mechanically vented pts mean?
Normally a 8-10mmHg variation d/t decrease venous return that occurs with inspiration
Variations greater than 10mmHg may indicate hypovolemia
95
Young healthy pts may lose _________% of circulating blood volume without demonstrating clinical signs
20
96
Vasoconstriction of ________ and ______. ______ vessels in response to blood loss
A blood volume loss of _______% can be masked by this compensatory response
Splanchic
venous capitance
10
97
T/F: anesthesia may interfere with body’s physiological response to acute blood loss
True
98
What is the primary indication for blood transfusion?
To increase oxygen carrying capacity o father blood
*typically Hgb concentration if basis on which decision to transfuse is made?
99
At what hemoglobin level would you typically decide to transfuse?
Almost always justified when Hgb is less than 6g/gL
* consider blood when Hgb: 6-7
* transfusion rarely justified when Hgb is greater than 10g/dL
100
T/F: If pt has acute anemia, you should still transfuse if Hgb 6-7
False
Consider pt’s age, medical status, and co-morbities.
Is the current anemia acute or chronic?
The decision to transfuse must be made on an individual bases
101
During acute hemorrhage, administration of crystalloid volumes necessary to replace the intravascular fluid loss will result in an _________ oxygen carrying capacity of the blood
Inadequate
102
_____ ______ is preferred to PRBCs in acute hemorrhage to expand the circulating blood volume and the red cell volume
Whole blood
103
Ways to evaluate the adequacy of blood volume replacement
```
SBP
HR
CVP
Urine output
Arterial oxygenation
Arterial pH
Base deficit
Serial Hct levels
```
104
What is the purpose of typing the pts blood
To avoid the transfusion of incompatible blood
*this may occur if the pts has antibodies to A or B, or A and B, in their serum and they receive a transfusion of RBCs that have the corresponding antigen
Also analyzed for the presence of the Rh(D) antigen
105
Transfusion reactions may cause what?
Rapid intravascular hemolysis
106
What is crossmatching of blood?
Tests for serious transfusion reaction before the administration of the blood to the recipient
Accomplished by incubating the pt’s plasma with the donor’s RBCs
*3 step process, takes about 45 minutes
107
What it the universal donor?
O-negative
Lack A, B, and Rh(D) antigens
Will not be hemolyzed by antigens anti-A, and anti-
B antibodies that may be present in pts blood
108
What is a concern of transfusing pt specific blood after the transfusion of O-negative blood?
May result in major intravascular hemolysis of O-negative blood by increasing titers of transfused anti-A and anti-B antibodies
Risk of continuing with O-negative blood is minor hemolysis and hyperbilirubinemia
109
Info about type specific blood
- blood that has already been typed for the A, B and Rh antigens
- the first phase of the crossmatch process
- requires 5 minutes to perform
- chance of significant hemolytic transfusion reaction is 1 in 1000
- often used in emergent situations when time does not allow for formal cross match
* type and screen: general, not cross matched
* type and cross: mix 2 bloods and make sure it doesn’t coagulate
110
What is a type and screen?
- in addition to being typed for A, B, and Rh antigens, it is screened from the most common antibodies
- pt’s blood is not matched to a specific unit of donor blood
- allows for a unit of blood to be available for more than one pt
- ordered for surgical procedures where risk of transfusion is remote
- if pt need the blood, the immediate phase of the crossmatch is performed
- chance of significant hemolytic reaction is 1 in 10,000
111
Solutions used to preserve donated blood and their purpose
Phosphate: acts as a buffer
Dextrose: provides energy to the RBCs
Adenine: allows RBCs to resynthesize ATP to fuel their metabolic requirements and increase survival time in storage
112
How long can good be stored?
21-35 days
Duration of storage is determined by the requirement that at least 70% o the RBC be viable for more than 24 hrs after transfusion
113
Blood is stored at what temp? Why?
1-6 degrees Celsius
This slows the rate of glycolysis in RBCs and increases their survival time in storage
114
A unit of whole blood is how many mL? The volume of citrate-containing preservative is how many mL? What is the hematocrit?
450mL
65mL
40%
115
What are the components derived from whole blood?
```
PRBCs
Platelets
Fresh Frozen Plasma (FFP)
Cryoprecipitate
Albumin
Plasma protein fraction
Leukocyte poor blood
Factor VIII
Antibody concentrates
```
116
What are some advantages of component therapy?
- pt specific deficits can be corrected
- allows for prolonged storage of blood components
- retention of unnecessary components for other pts who may need them
- avoids transfusion of unnecessary components that could potentially contain antigens and antibodies
117
One unit of PRBCs is how many mLs. What is its hematocrit?
300mL
70%
118
Hemoglobin concentrations will increase by approximately __________per unit PRBC in a 70kg adult
1g/dL
119
Reconstitution of PRBC with _________mL of saline does what>
50-100
Facilities the administration
* do not use hypotonic solution to reconstitute PRBCs
- included glucose contains solutions and plasmanate
- can result in RBC swelling and cell lysis
* reconstituting PRBCs in solutions containing calcium may result in clotting
120
Advantages of PRBCs
- Decreases potential citrate toxicity as compared to whole blood
- decreased risk of allergic reaction as compared to whole blood
121
When is the administration of platelets during surgery usually indicated?
Platelet count less than 50,000 cells/mm3
*severe trauma, bleeding into the brain, eye, or airway, transfusion at a higher platelet level may be warrented
122
Platelet count will increase by _________ to________cells/mm3 with each unit of platelets administered to a 70kg adult
5,000-10,000
123
Risks associated with platelet administration?
-transmission of viral diseases
-sensitization to human leukocyte antigens present on platelet cell membranes
-bacterial infections in 1 of 12,000 transfusion
-small risk of platelet-related sepsis
(Pt develops fever after platelet therapy)
124
FFP contains all coagulation factors except what?
Platelets
*it includes factors V and VIII
125
FFP is the plasma portion of _____ unit donated blood.
The plasma is frozen within ______ hours of collection
1 unit
6 hours
126
When is FFP indicated during surgery?
When the prothrombin time and/or partial thromboplastin times are greater than 1.5x normal and there is a clinical indication of the need to transfuse.
* indicated for reversal of warfarin
* indicated for correction of known factor deficiencies
127
Risks associated with FFG transfusion
Sensitization to foreign proteins
Transmission of viral diseases
Allergic reactions
128
What is cryoprecipitate?
The plasma fraction that precipitates when PPF is thawed
129
Cryoprecipitate contains high concentrations of what?
```
Factor VIII
Von willebrand factor
Factor XIII
Fibrinogen
Fibronecitn
```
*there is more von willebrand factor in FFP, but higher concentration in cryoprecipitate
130
Indications for cryoprecipitate
Factor VIII deficiency (hemophilia A)
Von Willebrand factor deficiency
Fibrinogen deficiency
131
What is the ratio of replacement for blood products?
4 units PRBC
1 unit FFP
1 super-pack platelets
132
Complications of blood therapy
```
Transfusion reactions
Metabolic abnormalities
Citrate intoxication
Transmission of viral diseases
Microaggregates
Hypothermia
Coagulation disorders
Acute lung injury
Immunosuppression
```
133
3 types of transfusion reactions
Febrile
Allergic
Hemolytic
134
This is the most frequently occurring transfusion reaction and thought to occur when antibodies in the recipients serum interact with antigens from the donor’s cells
Febrile transfusion reaction
135
Signs and symptoms of febrile transfusion reaction
```
Fever
Chills
HA
Myalgia
Nausea
Nonproductive cough
```
136
How can you distinguish between a febrile and hemolytic transfusion reaction?
Evaluate the pt’s serum and urine for hemolysis
137
Treatment for febrile transfusion reaction
Slow rate of transfusion and give antipyretics
*can still give transfusion
138
This occurs due to presence of incompatible plasma proteins in donor blood
Allergic transfusion reaction
139
Signs and symptoms of allergic transfusion reaction
Urticaria
Pruritus
Occasional facial swelling
*severe anaphylactic reactions (without RBC destruction) occur due to transfusion of IgA to pt’s who are IgA deficient
140
Treatment of allergic transfusion reaction
Stop infusion
| IV antihistamines
141
How can you differentiate between allergic and hemolytic transfusion reactions?
Check pt urine and plasma for free hemoglobin
142
What causes a hemolytic transfusion reaction?
Result from giving an erroneous unit of blood to a pt
-transfused donor cells are attacked by the recipient’s antibody and compliment, resulting in intravascular hemolysis
* as little as 10mL of donor blood can result in a hemolytic reaction which can be fatal
- severity of transfusion reaction is proportional to the volume of blood transfused
143
Clinical signs of hemolytic transfusion reaction
```
Fever
Chills
Chest pain
Hypotension
Nausea
Flushing
Dyspnea
Hemoglobinuria
```
*all clinical signs are masked by anesthesia except hemoglobinuria and hypotension
144
How do you diagnose a hemolytic transfusion reaction?
Direct antiglobulin test
Should also do plasma and urine hemoglobin and bilirubin analysis
- plasma bilirubin will eat 3-6 hours after starting blood transfusion
- hemoglobinuria or hemolysis in the presence of a transfusion should be treated as a hemolytic transfusion reaction until proven otherwise
145
Treatment of hemolytic transfusion reaction
STOP THE TRANSFUSION
Maintain urine output of 100mL/hr through administration of L and mannitol and/or furosemide
-renal failure occurs as a result of precipitates in the renal tubules
-prevent renal failure by maintaining UO
-bicarb may be used to alkalinize the urine
-labs: plasma Hgb, baseline coag studies, diagnostic urine
*return unused blood to blood bank along with repeat type and crossmatch sample
146
What labs can increase due to blood therapy
Increased hydrogen and potassium (bc there are higher in stored blood)
*will cause acidosis in the pt, but body will compensate and cause metabolic alkalosis
147
What labs may decrease due to blood therapy?
2,3 DPG -> causes shift to left
Hypocalcemia: citrate binds to free calcium so levels drops.
- usually offset by mobilization of calcium stores from blood.
- hypocalcemia after blood transfusion rarely occurs to the extents that it requires treatment
148
What is the pH of a unit of blood?
7. 1 after collection
6. 9 after being stored for 21 days
* this is due to a high PCO2 of stored blood and to the addition of acidic preservatives
- pt’s pH actually increased after transfusion
149
Why does arterial pH increase with blood product administration?
- elevated PCO2 of blood is quickly corrected through ventilation
- blood products
- citrate metabolizes to bicarb upon transfusion -> increased arterial pH and can cause metabolic alkalosis with transfusion of large volumes of blood
150
What is potassium level of stored blood?
Potassium level of stored blood may be as a high as 20-30 mEq/L
- serum K levels rarely increase with transfusion
- this is bc the high concentration of K exists in a small volume and the total K content is small
- large volumes of blood transfused greater than 120mL/min can occasionally cause hyperkalemia
151
Is there a significant decrease of oxygen delivery due to shift to the left with decreased 2,3 DPG and hypothermia?
No
152
______gram calcium chloride = _______gram calcium gluconate
1g calcium chloride = 3 grams calcium gluconate
153
Transmission rates of HIV and hepatitis with blood therapy
HIV: 1:1 million
Hepatitis: 1:60,000
154
What may accumulate in the lungs, cause vascular obstruction, and contribute to ARDS?
Microaggregates in whole blood (include platelets and leukocytes)
* this is why don’t want whole blood stored long
- whole blood should be transfused through filter to prevent
- 10-40 um filters preferred
155
Blood should be warmed between ________ and ______ degrees Celsius. Why?
37-38
- RBCs hemolyze if overheated
- hypothermia is a major source of increased O2 demand and cause cardiac irritability and shivering
156
Coagulation disorders with blood therapy
- dilutional thrombocytopenia
- dilutional coagulation factors
- DIC
157
Labs you’ll see with DIC
Prolonged prothrombin time
Prolonged partial thromboplastin tie
Decreased serum fibrinogen
Increased level of fibrin split products
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Treatment of DIC
Treat underlying cause
Administer platelets and FFP
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What is transfusion-related acute lung injury (TRALI)
- acute, noncardiogenic pulmonary edema associated with dyspnea and arterial hypoxemia that occurs with in 6hrs of transfusion
- treatment is supportive
- most spontaneously recover
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Is immunosuppression that can occur with blood therapy a concern for most pts?
No
- may be beneficial for transplant pts
- may be a concern for pts with malignancy
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Benefits of autologous blood
Decreased risk of complications
Reserves blood bank resource
*will still get increase in H+ and K if it was stored
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Contraindications of intraoperative salvage
Malignancy
Presence of blood-borne disease
Blood contaminated with bowel contents
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What is the hematocrit of cell saver blood?
50-60%
FFP and platelets all spun off
The pH is alkaline
-bc not stored
Hct of PRBCs is about 70%
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Complications of intraoperative salvage
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Dilutional coagulopathy
Re-infusion of blood treated with anticoagulants
Hemolysis
Air embolism
Fat embolism
Sepsis
DIC
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What is hemodilution technique?
Removed pt blood prior to procudure starting. Replace with crystalloid or colloid. Blood is stored in OR and transfused to pt after major blood loss has ceased
- avoids issues with K and Ca bc not stored
* contraindicated is pts with anemia, severe cardiac disease, severe neurologic disease
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Advantages of hemodilution
- Less expensive
- doesn’t require pt cooperation
- decreased number of RBCs lost during surgical procedure
- blood has platelet and coagulation factors that is lost in stored autologous blood
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Transfusion thresholds of each product
Blood:
-Hgb = 7 with cv or pulmonary disease and 65 y/o
-Hgb = 6 in pts undergoing cardiopulmonary bypass
-loss > 30% blood volume or 1500 mL cumulative losses
Platelets:
-count = 50 x 10 to the 9th
FFP:
-INR > 2.0
-PT 1.5 times normal
-aPTT > 2 times normal
Cryoprecipitate;
-fibrinogen concentrations < 80-100 mg/dL
