Fluid Management and Blood Replacement Flashcards
Fluids and Electroyltes
60% of the body wieght is fluid
This water based solution contains many different types of solutes
Many of these solutes are ions (charged particles) known as electrolytes
Compartment of Body Fluid
Intracellular and Extracellular Fluids
Intracellular Fluid
Intracellular (ICF) is about 67% of body fluids in adults but only about 50% in infants
Extracellular Fluid Compartments
Of the extracellular compartment, 1/4 is plasma and 3/4 is interstitial fluid
Interstitial Fluid (ISF): Which is around cells and in the lymph
Intra-vascular (IVF): Plasma componenet of the blood
Trans Cellular Fluid (TCF): Secreted by the epithelial cells (digestive fluids, CSF, intraocular fluid)
Fluid and Elcetrolytes in Extracellular Compartment
Fluids and electrolytes move freely between ISF and IVF — interstitium and blood
Extra Cellular Fluid and Blood Volume
Blood volume consists of both plasma volume (an extracellular compartment) and an intracellular volume (red and white cell volume)
Not all extracellular water is present as “liquid” water, but is rather bound to mucopolysaccharides in connective tissue.
Blood Volume in Males
approximately 7% of total body weight (70 ml/kg).
Blood Volume in Females
55-65 ml/kg
Blood Volume in Infants
8% (80 ml/kg)
What is the most important volume to consider in the care of surgical patient s
There is a rapidly equilibrating sub-compartment of extracellular fluid which is in equilibrium with the intravascular compartment
Electroyte Transport
Organs and systems (kidneys, hormones etc.) regulate electrolyte transport in all other regions
Passive transport: diffusion, filtration, osmosis
Active transport: requires energy (e.g. sodium / potassium pump)
Total Body Water
70-50% of body weight in males
As a percentage of body weight it will decrease with age
Men have higher TBW than women which tend to mean a greater amount of fat and less muscle mass in women
Obese individuals have less TBW than lean ones. This is because the percentage of TBW decreases in inverse proportion to the percentage of body fat.
What are the Main Purposes of IV Therapy
To replace fluids and/or nutrients rapidly
To sustain pts. that are unable to take nutrients orally
To administer drugs instantly to the pt. (vein to brain)
IV Therapy can be Classified Into
IV therapy can be further classified in regards to site (peripheral or central—e.g. subclavian)
Peripheral IV Sites
Forearm
Hands and feet
Veins of the head and scalp (kids)
IV Equitment
IV administration set
IV bag. (various solutions)
Extension tubing
Filters
Infusion pumps
Five Basic Types of IV Fluids
Sources of Free Water and Calories
Crystalloids
Colloids.
Blood and blood components
Hypertonic
IV Type-Sources of Free Water and Calories
D5W: could be hypo-iso-hypertonic
Aminosyn II: 3.5% with dextrose, hypertonic, added proteins, 345 calories per 500mL.
IV Type-Crystalloids
Used to help with fluid replacement and are less expensive compared to colloids so they are used more. Balanced electroylte composition and used to expand total extracellular volume
Normal Saline: Contain sodium and maybe some dextrose
Ringers Lactate: Contains all normal electrolytes
Dextrose 5%
IV Type-Colloids
Volume expanders, used to maintain serum osmolality
Dextran®, Albumin, Plasmanate®, Hetastarch®.
IV Type-Hypertonic
Hyperosmolar solutions
Fluid for Non ‘Class-E’ patients who come into OR
These patient will have nothing by mouth for the last 8 hours, they will loose fluids due to normal pathways as well some that are lost due to nature of the procedure
The will be some degree of maintenance and replacement of fluid needed, suggested is basal ongoing requirement plus any deficit
Monitoring Fluids Requirements
Look at
Urine output
CVP
PCWP
Estimating blood loss
Loss of Fluid also results in loss of…
Loss of fluids (esp. blood) also involves the loss of electrolytes, therefore any replacement fluids should contain the proper concentrations of electrolytes.
Determining What Amount of Fluid You Need
Total need = basal need + pre-existing deficit + ongoing losses.
rate of infusion for a normal patient who has no large water deficit is
4 mL/Kg/Hr for the first 10 Kg of body weight
2 mL/Kg/Hr for the next 10 Kg of body weight
1 mL/Kg/Hr for each additional Kg of body weight
Therefore a 65 kg pt will require:
(4*10) + (2*10) + (1*45) = 105 mL/Hr.
Fluid Deficit
Remember that when a patient volume is depleted it is not only intravascular fluid but also extracellular, and intracellular fluid missing.
Thus a modestly volume depleted patient may actually 3-4L below normal TBW, nearly equal to a blood volume.
Mild Fluid Deficit
Degree of Depletion: Minus 3-5%
Body Weight Depletion: 2-3.5L
Symptons: Dry mucous membrane, decreased urine output, thirst
Severe Fluid Deficit
Degree of Depletion: Minus 11-15%
Body Weight Depletion: 7-10L
Symptons: Cool extremities, dry skin, stupor, hypotension
Moderate Fluid Deficit
Degree of Depletion: Minus 7-10%
Body Weight Depletion: 5-7L
Symptons: Decrease skin tugour, Orthostasis
The therapeutic use of blood or blood products in the operating room falls under three categories:
Replacement of lost blood cells.
Replenishment of plasma volume.
Correction of coagulopathies.
Blood Transfusion-Replacement of Lost Blood Cells
Whole blood tranfusion is rarely used due to the arrival of blood borne pathogens
Patients can tolerate a 30% loss of blood just with the use oncotically balanced fluids
Packed red cells with albumin and saline is often used as a replacement for whole blood
Blood Transfusion-Replenishment of Plasma Volume
The fluids used to replace lost volume can be colloidal or crystalloid. The difference is what compounds are used to bring the fluid up to proper blood osmotic values.
Colloids use large proteins like albumin.
Crystalloids use salt and / or sugar solutions.
Blood Transfusion-Correction of Coagulopathies
Stored blood products can be used to correct problems with the coagulation process.
Stored plasma has all the plasma proteins except Factors V and VII. It can be used to reverse anti-coagulation therapy like Coumadin.
Fresh frozen plasma has everything in it.
Platelets or cryoprecipitated Factor VIII can be given separately to treat hypo-coagulation problems.
Blood Transfusion Reactions
Febrile—-Allergic—-Hemolytic:
Serious reactions to blood products happen in about 3% of patients receiving them.
Reactions due to A-B-O incompatibility or Rh (+ -) incompatibility are potentially fatal.
Other reactions seem to be less serious or at least are treatable.
Blood Transfusion Febrile Reactions
Transfusion related fever happens in 1 to 2% of all patients receiving blood products.
The possible mechanism is reaction to lysed red cells, reaction to white cells or to cytokines released by white cells or other proteins.
These febrile reactions can be prevented by using leukocyte poor red cells or ‘washed red cells’
Blood Transfusion Allergic Reactions
Allergic reactions including rash (urticaria) occur as commonly as fever in blood transfusions. Treatment includes anti-histamines (Benadryl) given IV.
Bronchospasm, angio-neurogenic edema are rare events.
Anaphylaxis requires immediate action; stopping the transfusion, use of epinephrine, bronchodilators, antihistamine, steroids etc. and any other measures needed to maintain the circulatory system.
Blood Transfusion Hemolytic Reactions
Problems with ABO or Rh compatibility will cause hemolysis of RBCs. The immediate consequences are renal failure and DIC.
Signs include: chills, fever, headache, paresthesia (tingling extremities), N&V, chest pain, increase HR, decrease BP.
Treatment:FiO2, bronchodilators, inotropes and vasopressors to support circulation, diuretics like mannitol to increase renal tubular flow and hopefully reduce the chance of kidney failure., attempt to Tx DIC.
Reaction could be delayed if the pt has been sensitized to the red cell antigens from a previous transfusion.
Transfusion Problems
Dilutional Coagulopathies
Infection: HIV, Hepatitis, CJV, the next one?
Potassium intoxication: Too quick transfusion?
Citrate intoxication: Anti-coag preservative
Hypothermia: Use blood warmers
Acid-base abnormalities
TRALI: transfusion related acute lung injury
Transfusion Relation Acute Lung Injury
Diffused alveolar damage, increase capillary permeability, non-cardiogenic pulmonary edema
May be due to repsonse to leukocyte antigens or neutrophils
More common in multiparous women possibly due to their exposure to different fetal blood varieties.
Group Testing & Cross Matching
Identifying blood group (of the recipient & donor) involves testing for A, B type, and Rh antibodies and screening the serum for many (not all) of the irregular blood antibodies.
Cross matching implies checking the donor’s red cells and the recipient’s serum for compatibility.
A full cross match can take up to 1.5 hours whereas a quick match (less sensitive) can be done in 15-20 minutes.
In emergencies, if the patient’s blood type is known, that blood type can be given (e.g. Type A, Rh neg).
Hemolytic reaction occurrence is 1:1000 in the first time pt., down to about 1:100 in the multiple transfusion pt.
If there is no time for much of anything the pt. can be given type ‘O’ red cells with very little plasma and be relatively safe. O+ve is used in males or post-menopausal women and O –ve saved for potentially fertile women.
Identifying the patient prior to transfusion is mandatory.
Autologous Blood Transfusion
A patient’s blood is collected and then used later for a scheduled event
This can even occur during the same procedure if blood loss is anticipated
Blood Infusion Equipment
Whole blood or red cell preparations (high viscosity) should be given via an 18 gauge needle, disposable infusion set and a filter.
The calcium in Ringers’ Lactate will cause coagulation so it should not be used if it can come in contact with stored blood.
The filter will prevent clots and other debris from being transfused.
Blood pumps —- blood warmers are often used.
Blood Bank
Area is responsible for the selection and preparation of appropriate, compatible blood components (red blood cells, platelets, and plasma) that are safe for transfusion into patients.
Blood products are also tested to be sure they are free from infectious diseases such as HIV and hepatitis viruses B and C.
This laboratory also evaluates transfusion reactions by diagnosing their cause, determining whether or not it is safe to proceed with a transfusion, and selecting further components that are safe for transfusing
The blood bank may have a donor service to draw units of blood for general use and for autologous transfusions (for elective-surgery patients who wish to donate their own blood before surgery so that it will be available to them if they need it).
Types of Blood Tests
ABO Group and Rh Type
Type and Cross Match
Antibody Screening
Direct Coombs
Purspose of ABO Group and Rh Type
Type and Cross Match
Establishes blood group (A, B, O) and Rh type (positive or negative) to ensure compatibility of transfused blood between donor and recipient
Antibody Screening Test
Ensures that blood is safe for transfusion
Direct Coombs Test
Tests for antibodies on surface of red blood cells in autoimmune hemolytic anemias, transfusion reaction, and erythroblastosis fetalis (newborn hemolytic disease)
ABO System
Every person’s blood belongs to one of four ABO blood groups
Named for antigens on RBC membranes
Type A: antigen A on RBCs
Type B: antigen B on RBCs
Type AB: both antigens A and B on RBCs; known as universal recipient
Type O: neither antigen A nor B on RBCs; known as universal donor
Rh System
Rh-positive: Rh antigen is present on the RBCs
Rh-negative: RBCs have no Rh antigen present
Anti-Rh antibodies are not normally present in blood; anti-Rh antibodies can appear in Rh-negative blood if it has come in contact with Rh-positive RBCs
The complement system hekps or “complements
Complement System
Complement system helps or “complements” the ability of antibodies and phagocytic cells to clear pathogens from an organism
What is the distribution of this fluid into various body compartments?
Two thirds of TBW is intracellular, 1/3 is extracellular
Peripheral IV Needle Size
Peripheral IV therapy is accomplished through a cannula (needle) ranging in size from 14 gauge (huge) to 27 gauge (small)
IV Flow Rates and Needle Size
Flow rate is inversely proportional to cannula size. That is, the higher the number of the needle, the less flow is possible.
Large bore needles are used for blood transfusion and high flow situations. Small bore needles must be used on neonates and children
