Fluids and Blood (Connie) Flashcards
Intravascular half-life of a crystalloid solution is ____.
20 – 30 minutes
Intravascular half-life of most colloid solutions is ____.
3 – 6 hours
In anesthetized patients, an acute HTR (hemolytic transfusion reaction) is manifested by ___.
hyperthermia, tachycardia, hypotension, hemoglobinuria (1st sign), oozing in surgical field.
Allogenic transfusion of blood/blood products may diminish ___.
immunoresponsiveness and promote inflammation.
The most common cause of nonsurgical bleeding following massive transfusion is ____.
dilutional thrombocytopenia
Total body weight = ____water.
60%
(40% intracellular, 20% extracellular)
Extracellular is further divided into interstitial (15%) and plasma (5%) fluid outside of the cells.
The most severe transfusion reaction you will see is from ___.
ABO incompatibility
Major ICF cations
Potassium (K), Magnesium (Mg), Phosphate (P04)
Major ECF cations
Sodium (Na+), Calcium (Ca), Chloride (Cl-), Bicarbonate (HCO3-)
Fluid Movement within the body (general facts)
Constant circulation to maintain homeostasis
Exchange between compartments to compensate for gains or losses
Dependent on hydrostatic and osmotic pressures
- Tonicity versus osmotic activity
- Isotonic, hypotonic, and hypertonic solutions
What is the calculation of osmolarity?
Osmolarity = (Na+ x 2) + (Glucose/18) + (BUN/2.8)
Isotonic Solutions
LR, 0.9% NaCl, Plasmalyte A, 5% albumin, Voluven 6%, and Hespan 6%
Hypotonic Solutions
D5W, 0.45% NaCl – no colloids
Hypertonic Solutions
NaCl 3%, D5 NaCl 0.9%, D5 NaCl 0.45%, D5 LR, and Dextran 10%
What are three main mechanisms of fluid/electrolyte imbalances?
1) Disorders of intake or elimination impairment
* Resulting imbalance exceeds body’s compensatory ability
2) Kidney
* Primary organ regulating electrolyte and fluid imbalance
3) Systems serving as a catalyst for imbalance
* Neurologic, cardiovascular, liver
Fluid distribution will vary based on what factors?
gender and age, muscle mass, fat composition, and body water
How do we evaluate intravascular volume in our patients?
Patient history (Intake & output)
Physical examination (Skin turgor, Vital signs, UOP)
Laboratory evaluation (H&H – ABGs – urinary specific gravity or osmolality – electrolytes – BUN & creatinine)
Hemodynamic monitoring (CVP - PA)
What is GDFT?
Goal directed fluid therapy
- LIDCO – Vigileo – Flo Trak
- Esophageal doppler
- TEE or TTE
(these noninasive devices use arterial pulse contour to provide an estimate of stroke volume variation to provide you with an understanding of whether the patient will be responsive to fluid)
What is the link between water and sodium?
Chloride attraction to sodium
Sodium (General Facts)
- Most significant cation
- Most prevalent electrolyte within ECF
- Controls serum osmolality and water balance
- Helps maintain acid-base balance when combined with bicarbonate
- Regulated by kidneys and sympathetic nervous system
- Sodium-potassium pump for transport across cell membrane
- Primarily brought into body through dietary intake
- Consider plasma osmolarity and ECF volume
Clinical Manifestations of Hypernatremia
Lethargy, headache, confusion, irritability, seizures, and coma
Osmosis is defined as ___.
The movement of water across a semi-permeable membrane
Hyponatremia
Similar neuromuscular manifestations
Gastrointestinal symptoms with 130 mEq/L
Most common electrolyte disturbance in hospitalized patients
Osmolality
The # osmoles per kilogram of a solvent
Osmolarity
The number of osmoles per liter of a solvent
Diagnosis of sodium imbalances is based on ___.
serum levels
Management of sodium imbalances focus on ___.
- focused on treating underlying cause
- Rapid correction of hyponatremia may lead to osmotic demyelination syndrome (“locked-in” syndrome, acute paralysis, inability to speak, issues with myocardial contractility)
Potassium (general facts)
- Primary intracellular cation
- Role in electrical conduction, acid-base balance, and metabolism
- Serious issues from fluctuation
- Diet as main source
- Imbalance affects several body systems
- Chemistry panel as diagnostic test
- Determining reason for alteration
If we exhaust our body’s physiologic system, it becomes __.
Pathophysiologic (which is what it refers to when we say the body couldn’t compensate any longer)
Hyperkalemia > 5 mEq/L management
Increase excretion
Treatment of acidosis
Management of Hypokalemia < 3.5 mEq/L
Increasing potassium
Oral or intravenous administration
Crystalloids
Initial resuscitation fluid
*If you give too much NS it may cause hyperchloremic metabolic acidosis & may contribute to perioperative acute kidney injury)
LR and PlasmaLyte
Colloids
Albumin (fluid resuscitation in hemorrhagic shock and in the presence of hypoalbuminemia or in conditions where there is large protein loss)
Which patients have large protein loss? Burns and septic
Hydroxyethyl Starch
- Polysaccharide (6% and 10% solution)
- Volume expansion
- Acute normovolemic hemodilution
- Improve blood rheology
•Side effects = Coagulopathy (dose-dependent decrease in factor VIII and vWF)
Dextran
Water soluble glucose polymer
•Clinical use
- Colloid osmotic pressure of 350 mOsm/L
- Remains in intravascular space for 12 hours
- Replacement of intravascular volume
•Side effects
- Allergic reactions
- Increased bleeding time (decreases platelet adhesion)
- Non-cardiogenic pulmonary edema
Universal Donor
RBC = 0- (because it does not contain any antigens)
Plasma = AB+ (also no antibodies)
Universal Acceptors
RBC = AB+
Plasma = O-
If you have a change in sodium, you will also have a change in ___
chloride
Once you determine an electrolyte imbalance, what other factor is key to obtain before making a plan to correct the imbalance?
Whether the patient is euvolumic, hypovolemic or hypervolemic
Most common electrolyte imbalance in hospitalized patients =
hyponatremia
Magnesium (general facts)
- Intracellular cation mostly stored in bone and muscle
- Functions of magnesium (regulates many of the biochemical reactions in the body such as protein synthesis, muscle and nerve function, helps control blood glucose levels, BP regulation)
- Diet as main source
Clinical manifestations
- Neuromuscular and cardiovascular system effects
Diagnostic procedures
- History, physical exam, blood chemistry
Hypermagnesemia
> 3.0 mg/dL
Results from renal failure or excessive intake
Treatment = Diuretics and IVF administration
You’ll see loss of DTR (deep tendon reflex)
Hypomagnesemia
<1.8 mg/dL
Inadequate intake or decreased absorption
Treatment Oral or IV replacement
Rapid administration of Magnesium can result in ___.
Hypertension
Antigens are AKA ____
surface markers on our RBC
The ABO antigens are sugars
The RhD antigen is a very large protein
How long does it take to crossmatch blood?
45 minutes
In an emergency transfusion with no time for 45 minute crossmatch, you can give___.
- Type-specific partially crossmatched blood
- Type-specific uncrossmatched blood
- Type O uncrossmatched blood (remember that the PRBCs will contain some of the anti-A and anti-B antibodies found in the plasma of type O blood
•After two or more units of type O blood are transfused, you must continue to use type O blood even if the patient is identified to be a different blood type.
•Once is has been identified that the transfuse anti-A and anti-B antibodies have decreased to a safe level, you may give the patient type specific blood.
Massive Tranfusion Protocol suggests what ratio of blood products for patients to receive?
PRBC: FFP: Platelet at a 1:1:1 ratio
10 units of cryoprecipitate generally increases a person’s fibrinogen by __.
75mg/dL
Dosing of TXA during MTP
1 gm during transfusion then 1 gm q8 hours
*TXA has proven NOT to increase clotting post-op (that was an old concern)
One “round” of MTP = ___ RBC.
How much calcium do we give per round?
One round = 6 units PRBC
Give 1 gm calcium chloride or 3 gm calcium gluconate
Calcium chloride delivers 3 times more elemental calcium than calcium gluconate.
You prefer to administer intravenous calcium gluconate over calcium chloride because it causes less tissue necrosis if extravasated.
Goals for Massive Tranfusion Protocol
Avoid acidosis – treat with standard approaches
Avoid hypothermia
Hemodynamic management
Source control
Components, Indications, and Key Points for Packed RBCs
Components: RBCs
Indications: RBC replacement
Key Points: Hbg >10 rarely indicated, Hgb <6 tranfusion is often indicated
Components, Indications, and Key Points for Whole Blood
Components: RBCs, WBCs, Plasma, Platelet debris & Fibrinogen
Indications: RBC replacement & Blood volume replacement
Key Points: Rarely used in the OR
Components, Indications, and Key Points for Fresh Frozen Plasma
Components: All coagulation factors, Fibrinogen & Plasma proteins
Indications: Coagulopathy, Warfarin reversal, AT III deficiency, Massive transfusion, DIC, C1 esterase deficiency (causes angioedema)
Key Points:
Warfarin reversal = 5-8 mL/kg
Coagulopathy = 10-20 mL/kg
Complete transfusion within 24 hours of thawing
Patients who receive massive transfusion are at risk for ___. Why?
Hypocalcemia
(Because bags of blood contain citrate which binds to calcium).
Components, Indications, and Key Points for Platelets
Components: Platelets
Indications:
- < 50,000 µL
- Invasive procedures, neuraxial blockade or most surgeries (< 100,000 µL)
- Eye and neurosurgery
- Qualitative platelet defect
- TEG
Key Points:
- 1 pack per 10 kg/wt.
- Stored at room temp for 5 days
- Highest risk of bacterial contamination
- Recommended to not go through a blood warmer
Components, Indications, and Key Points for Cryoprecipitate
Components: Fibrinogen, Factor 8, Factor 13 & vWF
Indications:
- Fibrinogen deficiency
- < 80 – 100 mg/dL
- vWB disease
- Hemophilia
Key Points:
- 5 bag pool
- Administer through filter
- Complete infusion within 6 hours of thawing
Which signs of a tranfusion reaction will be observed in the patient under general anesthesia?
Which signs are masked by anesthesia?
Observed under anesthesia = Hemoglobinuria, Hypotension & Bleeding
Masked by anesthesia
- Fever ?
- Chills
- Chest pain
- Dyspnea
- Nausea
- Flushing ?
Describe how an AKI can occur with a transfusion reaction
- Free hemoglobin precipitates in the renal tubules = mechanical obstruction
- Acidic urine increases precipitation
Describe how DIC can occur with a transfusion reaction
•Erythrocin is released from the RBC and activates the intrinsic clotting cascade
Lab abnormalities reflect consumption of clotting factors and enhanced fibrinolysis: DECREASED platelets, fibrinogen, prothrombin, factor 5, 8, 13 and INCREASED fibrin degredation products
Describe how hemodynamic instability occurs with a transfusion reaction
- Free hemoglobin activates the the kallikrein system = bradykinin
- Vasodilation
Treatment of Transfusion Reaction
- Stop transfusion
- Maintain UOP (need to make sure the kidneys are getting perfusion)
- IVF
- Mannitol (add Lasix if IVF and mannitol fail to provide adequate response)
- Alkalinize the urine with NaHCO3 (Sodium Bicarbonate)
- Send urine and plasma hemoglobin samples to blood bank
- Check platelets, PT and fibrinogen
- Send unused blood to blood bank (recheck cross match)
- Support hemodynamics
Negative Events that can occur from a blood transfusion
- Alloimmunization (platelets – Leukocytes - RBC) (your body gains immunity against your own cells)
- HLA – antigens (Granulocyte – platelet – RBC specific)
- Allergic reactions
- Febrile reactions
- ABT (allogenic blood transfusions)– related mortality (TRALI – TAS – HTRs – TTI) TAS = transfusion associated sepsis, HTR = hemolytic transfusion reaction, TTI = transfusion transmitted infections
- Intravascular hemolysis – coagulopathy – renal impairment and failure - death
What is a TRALI?
Transfusion Related Acute Lung Injury
Can occur from all plasma containing blood products (HLA antibodies). Can also occur from storage of banked blood which develops biologically active lipids which can go across the vessels into the lung vessels and draw fluid into it.
- Non-cardiogenic pulmonary edema
- Typically seen 1-2 hours post-transfusion
- Symptoms = Dyspnea -cough - fever
What is TACO?
TACO = transfusion associated circulatory overload
- Volume overload
- Cardiogenic pulmonary edema
- Multiparous donors become HLA sensitive (thus they’re at higher risk)
Hemolytic Transfusion Reaction occurs mostly from ___
ABO antigens and/or antibodies to other RBC antigens.
Can be Acute = 24 hours or Delayed > 24 hours
If it’s Non-ABO = RBC antibodies (Jkb, Jka, Kell, Fya, Fyb, E, Jsa, I)
Usually due to exposure (can occur during pregnancy as well).
For transfusion transmitted infections, list the viral ones in order of most prevalent to least prevalent?
1 Cytomegalovirus (CMV) (prevent with leukoreduction)
Human T-cell lymphotropic virus (HTLV)
Bacterial contaminated has been seen to occur with which blood products?
RBCs and platelets
What is TRIM?
Transfusion Related Immunomodulation
APCs (Antigen Presenting Cells) and plasma. Can cause:
- Non-specific immunosuppression
- Antigen-specific immunosuppression
- Impaired T-cell mediated immunity
- Decreased macrophage
- Altered cytokine
Renal allografts – better outcomes
Tumor recurrence (occurs when pt received blood during the tumor removal case)
Reduction in survival
Which cells have negative consequences from receiving a blood transfusion?
WBCs – HLA – CD4 – Helper T-cell
Patients who are chronically anemic ___.
Adapt appropriately. Even though oxygen carrying capacity is decreased, tissue oxygenation is preserved at Hgb levels below 10.
THESE MACHANISMS ARE WHY THIS HAPPENS:
Shift in oxyhemoglobin dissociation curve to the right which increases synthesis of 2,3-DPG (diphosphoglycerate).
Hemodynamic alterations (increased CO)
Microcirculatory alterations = Vascular tone- Helps drive bringing the blood to the tissues in need.
Renin-angiotensin-aldosterone system- promotes better BP responses and helps absorb Na in water so that we have more volume in vasculature
What is the function of 2,3 DPG?
To unload O2 off of cells into the tissues.
Explain DO2 and VO2
DO2 = delivery of oxygen
VO2 = utilization of that oxygen
What factors impact the efficacy of a blood transfusion?
Delivery. Stored RBCs contain:
- low p50- shifting the oxygen dissociation curve to the left
- Depletion of 2,3 DPG
- Depletion of ATP (which undergoes anaerobic metabolism which causes bad changes)
Oxygen Utilization
- Very few studies can confirm improved hemodynamics and O2 transport parameters in critically ill patients after receiving RBCs
Biochemical Changes that occurs in stored blood?
Metabolic acidosis
- Lactate increased = 1.6 - 30.1 mmol/L
- K+ increased = 3.9 - 80 mEq/L
- Increased Free Hemoglobin (a marker for hemolysis which can cause problems which vascular tone)
- pH decreased = 7.2 - 6.6
- 2,3-DPG decreased
- ATP decreased
- GSH (glutathione) is decreased (this decreases your ability for the vasculature to expand)
- Ionized Calcium and magnesium = 0
- (SNO-Hb decreased)
What is the function of GSH (glutathione)?
Modulates vascular tone
What are the biomechanical changes that occur to stored blood?
- Hemolysis
- Membrane area decreases
- Osmotic fragility
- RBC adhesion
- 30% DOA (dead on arrival)
- Deformability decreases
only good for 42 days
What are the oxidative changes that occur with stored blood?
Hemoglobin oxidation which leads to Hemoglobin denaturation & Lipid peroxidation (production of free radicals)
•Bioactive Substances (they’re all bad)
- Cytokines
- Histamines
- Lipids
- Soluble HLA
What are the benefits of blood transfusion?
- Hemorrhagic shock
- Critically ill do not tolerate anemia
Goal to Increase DO2 and Increase VO2
Transfusion of 1-2 units does not ____.
Increase Oxygen Delivery!!
Study done by Suttner et al. (2004)
The influence of allogeneic RBC transfusion compared with 100% oxygen ventilation on systemic oxygen transport and skeletal muscle oxygen tension after cardiac surgery
•O2 - not the blood transfusion increased tissue oxygen levels
What are the goals for blood transfusion?
- Reduce hemolysis
- Reduce dead-on-arrival RBC (Iron toxicity, Vasoconstriction via NO scavenging)
- Maintain deformability / prevent aggregation (prevent capillary blockage)
- Maintenance of high ATP – 2,3, DPG – SNO-hb
- Minimize oxidative damage
- Prevent release, and/or remove bio-active substances
- Prevention of TRALI
- Leukoreduction, irradiation, pathogen-reduction, etc.
Platelets
Clinical uses = Platelet count < 50,000 or Known platelet dysfunction (TEG)
General Facts
- Multiple or single donors
- One unit increases platelet count by 5000-10,000 cells/mL3
- Platelets loose ability to aggregate when refrigerated
- A typical pack of platelets includes 6 units
- Stored at room temperature 20 – 24 degrees C – 5 days (because they can’t aggregate appropriately at other temps)
- Risk for bacterial growth & Sepsis. (because they need to be stored at room temp)
Fresh Frozen Plasma
Clinical uses
- PT > 1.5 times normal (18)
- PTT > 1.5 times normal (55-60)
- Coagulation factor assay of < 25% activity (TEG)
Other reasons to give
- Urgent reversal of warfarin therapy
- Antithrombin deficiency (requiring heparin)
- Massive blood transfusions (> 5000 mL)
Why do we give FFP?
Warfarin reversal
Antithrombin deficiency
Antithrombin is essential for ___
anticoagulation and Heparin admin
Therefore, the deficiency of AT III would explain a patient’s lack of response to Heparin therapy.
ACT = ____
Activated clotting time
Cryoprecipitate
Antihemophiliac factor (VIII)
Clinical uses
- Treatment of hemophilia A
- Von Willebrand’s disease
- Massive transfusion with fibrinogen concentrates
- Consumption coagulopathy
What’s a benefit of Cryo? It’s not a lot of volume
Dosing for DDAVP
0.3 mcg/kg
What is DDAVP? What does it do?
Desmopressin Acetate
Twofold to 20-fold increase in factor VIII
Speeds up activation of factor X by factor IXa
- Stimulates release of vWF
- Releases tPA
- Releases prostacyclin
Used for: Hemophilia A and vWF & ASA induced platelet dysfunction
Purified Fibrinogen concentrates
Factor I
Dose: 70 mg/kg
Adverse reaction = HA – erythema – N&V – fever – weakness
Prothrombin Complex concentrates (Kcentra)
Factor IX (II, VII, X)
Used in hemophilia B
Reversal of anticoagulant agents (warfarin)
Recombinant Factor VII
Approved for hemophilia patients
Enhances thrombin generation on activated platelets
Cost – exorbitant $15,000.00
Thrombotic complications
Dose of Aminocaproic Acid
100 mg/kg (max 5g) over 15 min (load)
10 mg/kg/hr throughout surgery
1604 mL versus 2312 mL
Aminocarproic Acid
- Synthetic lysine inhibitors of plasminogen
- Significant reductions in blood loss and transfusion requirements
- Reduced perioperative blood loss
- Decreased autologous blood donation
- Transfusion of blood products
- Overall costs and complications
Tranexemic Acid
Competitive inhibitor of plasminogen activator
Significantly reduced intraoperative bleeding by a mean of 408 mL
Decreased the probability of receiving blood transfusion by 49%
The rate of DVT was not affected by the use of TXA when compared to controls
What are other autologous transfusions?
Preoperative blood donation
- Hgb not less than 11 g/dL or Hct 33%
- May donate 10.5 mL/kg
Intraoperative blood collection
- Cell saver – shed blood
- Lacks coagulation properties
Postoperative blood collection
- Shed blood
- Coagulation/fibrinolysis/hemolysis
Acute Normovolemic Hemodilution (ANH)
Technique that involves removing whole blood from patient shortly after induction. Overall goal = decreasing blood viscosity.
Benefits = Conserved RBC Mass, Improved Oxygenation, Preservation of Hemostasis, Improves rheology (tissue perfusion)
Criteria
- High likelihood of transfusion
- Hb > 12
- No significant comorbidities
- Absence of infection
Transfusion of allogeneic blood represents a major risk for ____.
immunosuppression and adverse outcome
The #1 predictor of intraoperative transfusion requirement is __.
Pre-operative anemia
(She gave the example of cancelling an urgent but not emergent case so that the patient can go to the clinic and receive IV iron and epogen and then come back to have their surgery done).
