Fluid Managment (Mod 3) Flashcards
What is the division of body fluid?
Intracellular 66% and Extracellular 34%
What is the intracellular and extraceullar spaces separated by?
Water permeable cell membranes
- water based solutions contain proteins and electrolytes (and related solutes)
how many ml of fluid are in our body?
600ml/kg; our body weight is 60% fluid
Extracellular compartments (slide 4)
- Intravascular fluid
Blood volume (60-65ml/kg) - Interstitial fluid (120-165ml/kg)
Fluid that surrounds the cells of the body - Transcellular fluid (5-8ml/kg)
Fluid that is within epithelial lined spaces
Pleural fluid, aqueous humor, CSF
Review content and functions for slide 7
What component is apart of the intravascular fluid?
Plasma
- Non-cellular component of blood. Approximately 30 to 35 ml/kg
- 15% arterial circulation/ 85% venous circulation (reservoir)
- High oncotic pressure of plasma due to protein content; Approximately 20 mmHg greater than interstitial pressure)
What are the 3 main purposes of IV access
- To replace fluids and electrolytes
- To provide patients with parenteral nutrition
- To administer medications
Peripheral IV sites?
- Forearm
- Median antecubital
- Hands and feet
- Veins of the head and scalp (kids)
Central IV sites?
- Internal jugular
- Subclavian
- Femoral
3 types of fluid replacement solutions
- Crystalloids
- Colloids
- Blood
Characteristics of Crystalloid solutions?
- need to edit, slide 12 and slide 13
An aqueous solution of mineral salts and other small, water soluble molecules. Many (but not all) are isotonic to plasma (basically neutral to plasma)
- Crystalloids approximate concentrations of various solutes found in plasma and do not exert an osmotic effect
- Crystalloids function to expand intravascular volume without disturbing ion concentrations or causing large fluid shifts between intracellular, intravascular, and interstitial spaces (This depends on the patient’s status….acutely ill)
Function for Crystalloid solutions?
Crystalloids function to expand intravascular volume without disturbing ion concentrations or causing large fluid shifts between intracellular, intravascular, and interstitial spaces (This depends on the patient’s status….acutely ill)
- Crystalloids can cross rapidly from the vascular to interstitial spaces
add slide 12-17
How could saline cause metabolic acidosis?
What is the first choice for resuscitation of patients in shock?
0.9% saline
Fluid replacement solution for hemorrhagic patients?
Colloids is recommended for hemorrhagic patients (assuming no access/delayed access to blood products)
What fluid replacement solution is used for renal replacement therapy?
Colloid admin, Particularly HES
How is fluid monitoring assessed?
Monitoring fluid requirements includes tracking
- urine output (u/o)
- CVP
- PCWP
- And estimating blood loss
What is the 4:2:1 IV infusion rate/volume?
- add example from slide 20
- Formula is tested
Suggested rate of infusion for a normal patient who has no large water deficit (using crystalloids fluids)
- 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
What is the 4:2:1 IV rate formula used for?
- tested
Maintenance fluid; before any blood or fluid loss connected to the surgery is included
Intraoperative fluid strategies and considerations?
- Intra = during
- Glance over this one; its broken down into other cards.
No excessive administration of IV fluids at start of case or prior to epidural anesthesia
No fluid replacement of “third space” or U/O
Replacement of surgical blood loss on a 1:1 basis with colloid (typically albumin)
Use of colloid on a restricted bases for hypovolemia
Limit volume of crystalloids administered intraoperatively
Preference for balanced salt solutions rather than normal saline
Post op restriction of fluids and use of diuretics if weight gain exceeds 1kg
What are the levels of Fluid Deficit?
- i.e mild to severe?
How is Total Body Water (TWB) calculated?
The Watson equation
- An easier method is to multiply weight (in kg) by 0.6
What are the 3 therapeutic uses of blood or blood products in the OR?
- To correct inadequate oxygen-carrying capacity and/or delivery
- Replenishment of plasma volume
- Correction of coagulopathies
Decision to transfuse blood therapy is based on what?
- Patient blood management
- Monitoring of blood loss and potential blood loss
- Monitoring for inadequate perfusion and oxygenation of vital organs
- quantitation of IV fluid given
When is a patients blood requirement’s assessed?
Both before and during surgery
What determines whether or not blood loss is from inadequate surgical control of vascular bleeding or coagulopathy?
Clotting factors
- Platelet count
- Prothrombin Time (PT),
- INR
- Partial Thromboplastin Time (PTT),
- fibrinogen level can help
what determines if Coagulates are given?
Cross matching blood
antigen vs antibodies in relation to blood group a,b,and o?
Crystalloid group as ___balanced solutions?
- Isotonic
- Hypotonic
- Hypertonic
What are balanced Salt solutions?
A crystalloid solution that has a similar composition to extracellular fluid
- are hypotonic with respect to sodium
- The added buffer (lactate) is metabolized to generate bicarbonate
What are 3 types of Balanced salt solutions?
- Lactated Ringer solution
- Normosol
- Plasma-Lyte
Why are Balanced salt solutions like lactated ringer solutions used?
They can generate bicarbonate (bc of lactate buffer)
What is Normal Saline (0.9% NaCl) used for?
Used for hydration and as a priming/diluting solution for dialysis and med
- Resembles traits of a isotonic solution
What is hypotonic saline (0.45% NaCl) used for?
Maintenance fluid
What is hypertonic saline (3-5% solutions) used for?
Hyponatremia and aggressive volume resuscitation
- Brain injuries (increased ICP); draws the liquid out via osmotic effect
- Restricted to specific situations
What is 5% dextrose used for?
Used to treat hypoglycemia, insulin shock, dehydration (nutritional support)
- Provides free water as dextrose is metabolized into glucose (which is an energy source)
- Iso-osmotic solution
What are colloid solutions?
Colloids are based on crystalloid solutions, containing water electrolytes, but have the added component of a colloidal substance (usually a starch or protein) that does not freely diffuse across a semipermeable membrane.
- Colloids are high molecular weight substance that largely remains in the intravascular department which generates an oncotic pressure
What are 2 types of Colloids?
- Natural (Albumin)
- Artificial (Gelatin and dextran solutions)
What are the risks of using artificial colloids
Increased risk of allergic reactions.
Types of artificial would include:
- Gelatin and dextran solutions; Hydroxyethyl Starches (HES)
Why would Colloids be used in place of blood replacement products?
Colloids while more expensive than crystalloids are cheaper than blood replacement products
What are the risks of using 0.9% saline?
Increased risk of hyperchloremic metabolic acidosis if large amounts of saline are used
- Chlorine will displace bicarbonate (hyperchlorhydria occurs)
What is hyperchlorhydria?
When massive amounts of chloride entering the blood at once.
- Forces bicarbonate to move intracellularly to maintain equilibrium
When are Colloids used?
- Severely critical patients
- Hemorrhagic patients (without access/delayed access to blood products)
- Renal Replacement therapy
When would you use hypertonic vs normal saline?
hypertonic saline is primarily used for rapid volume expansion and osmotherapy to reduce intracranial pressure, while normal saline is a standard fluid for intravenous hydration and resuscitation in various clinical scenarios.
Why is the type of replacement fluid important?
Loss of fluids (esp. blood) involves the loss of electrolytes
What is the equation for fluid monitoring/resusctiation?
Total Need = Basal need + Pre-existing deficit + ongoing losses
What is the Perioperative fluid strategy?
The 4:2:1 formula
- still in use bc not very evidence based
What is the most adverse outcome with perioperative fluid strategies?
Weight gain
When is the 4:2:2 formula used?
This formula is for maintenance fluid; before any blood or fluid loss connected to the surgery is included
- based on crystalloid fluids
Why is the use of colloids restricted for hypovolemia?
while effective in expanding intravascular volume, is often restricted or used with caution due to several factors:
- Risk of Fluid Overload: They remain in the intravascular space longer compared to crystalloids. While this property can be beneficial for maintaining intravascular volume, it increases the risk of fluid overload, especially in patients with impaired renal function or congestive heart failure.
- Potential for Coagulopathy: Certain colloids like hydroxyethyl starch (HES), have been associated with coagulopathy, including impaired platelet function and altered coagulation parameters. This can pose significant risks, especially in patients with bleeding disorders, trauma, or those undergoing surgery.
- Renal Dysfunction: The administration of colloids may further exacerbate renal dysfunction and contribute to fluid retention, electrolyte imbalances, and worsened outcomes.
What ratio should surgical blood loss be treated with colloids intraoperatively?
1:1 (typically with colloids)
During operations why are balanced salt solution preferable to normal saline?
Less risk of fluid shifts and need of filtering
- Lower risk of hyperchloremic acidosis
- Reduced risk of tissue edema bc of reduced likely hood of fluid shifts into intersittal space
- Less chloride that needs to be filtered by the kidneys
why should crystalloids be restricted intraoperatively?
Electrolyte imbalances and tissue edema
- crystalloids like ringers lactate have sodium, chloride, and lactate which could lead to hyperchloremic metabolic acidosis in large volumes
- crystalloids allow liquids to diffuse across cell membranes into interstitial spaces
What should be done post op if weight gain exceeds 1 kg?
Post op restriction of fluids and use of diuretics
Traits of mild fluid deficit?
Minus 3-5% fluid
- Dry mucous membrane
- Decreased urine output u/o
- Thirst
Traits of moderate fluid deficit?
Minus 7-10% fluid
- Decreased skin turgor
- Decreased orthostatic mechanism
Traits of severe fluid deficit?
minus 11-15% fluid
- Hypotension
- Cool extremities
- dry skin
- stupor
What is the orthostatic mechanism?
- Relation to hypotension?
When gravity causes blood to pool in the lower extremities.
Hypotension occurs when enough drops to the point where venous return is compromised, resulting in decreased cardiac output and subsequent lowering of arterial pressure.
What is Blood therapy?
The therapeutic use of blood or blood products in the operating
When would blood therapy be considered in the operating room?
- To correct inadequate oxygen-carrying capacity and/or delivery
- Replenishment of plasma volume
- Correction of coagulopathies
What is assessed for a patients blood management plan?
Hemoglobin concentration aka Transfusion indicators
- Determining transfusion requirement depends on patient’s risk for complications of inadequate oxygen delivery
What are the indicators for blood transfusion’s?
Hemoglobin concentrations:
- 10g/dl rare
- 6g/dl always requires transfusion
What lowers the threshold for tranfusions?
Chronic disease; specifically ischemia or pts at risk of it may require transfusions with Hb concentrations of 8 g/dl or higher
When deciding to transfuse blood. How would you know if there is inadequate perfusion and oxygenation of vial organs?
- ECG
- Artlines
- HR (unreliable due to anesthesia)
- U/O
- SpO2
- Blood gas analysis and maintenance of MAP and CVP
What is fresh frozen plasma delivered?
PT longer than 1.5 times normal or INR > 2.0
When would plasma be transfued?
Low platelet count
What is given for low fibrinogen levels?
Cryoprecipitate, a portion of plasma, the liquid part of our blood. Cryo is rich in clotting factors
When should a transfusion reaction during anesthesia be suspected?
When the following are present
- Hyperthermia
- Increased PIP
- Acute change in urine output or color
What are the categories for Transfusion reactions?
Febrile, allergic, and hemolytic
What are important signs to monitor during transfusion?
Hypotension, tachycardia hemoglobinuria as well as signs of bacterial infection
What are Febrile Transfusion reactions?
Thought to be caused by interaction between recipient antibodies and antigens present of leukocytes and platelets of the donor
- Most common nonhemolytic reaction to occur
- Present as fever and chills
- Occur in 0.5-1% of transfusions
- Temperature rarely increase above 38 Celsius
How are Febrile Transfusion reactions treated?
Treated by slowing the infusion and the administration of antipyretics
What are Allergic Transfusion reactions?
These reactions are caused by recipient antibodies reacting against allergens in the donor blood, such as plasma proteins or residual allergens from donors
- all assuming blood type is properly crossed and matched
What are signs of a Allergic Transfusion reaction?
Increased temp, pruritus, urticaria (hives)
- more severe signs include airway edema, bronchoconstriction, and hypotension
Treatments for Allergic Transfusion reaction?
IV antihistamines
Signs of Febrile Transfusion reaction?
Present as fever and chills; leading to an inflammatory response.
- Symptoms may also include chills, rigors, and malaise, but typically resolve spontaneously without serious consequences.
What are Hemolytic Transfusion Reactions?
When wrong blood type is administered to a patient
What happens during a Hemolytic reaction?
Activation of the complement system produces intravascular hemolysis and spontaneous hemorrhage (immune response to pathogens)
- hard to identify under anesthesia
What do we rely on to identify hemolytic transfusion reactions
Appearance of free hemoglobin in urine and plasma
Why does anesthesia make it difficult to identify hemolytic transfusion reactions
Anesthesia blocks signs and symptoms, such as substernal and lumbar pain, skin flushing, dyspnea
What could be a secondary event to occur to a hemolytic reaction?
DIC
- Its a condition that causes abnormal blood clotting throughout the body’s blood vessels.
- DIC could develop if an infection or injury that affects the body’s normal blood clotting process
What are examples of infections that could occur due to transfusions?
HIV or Hepatitis
What is a citrate reaction?
A transfusion where damage occurs to red cells in the machine: if returned to you in a large volume, it can cause blood in the urine, fevers and back pain. Severe reaction to citrate can include:
- Muscle contractions or spasms
- seizures
- breathing difficulties
- disturbance of heart rhythm.
How are citrate reactions treated?
With Anti-coag preservative (ACDs)
Which transfusion problem reaction would be more likely to occur: hyperthermia or hypothermia?
Hypothermia
How is Hypothermia managed (as a result of transfusion problem)
Use blood warmers
What is TRALI?
Transfusion related acute lung injury
- Occurs within 6 hours of transfusion
- Diffuse alveolar damage and pulmonary edema
What is Transfusion related acute lung injury (TRALI) characterized by?
Characterized by non-cardiogenic pulmonary edema following a blood or blood product transfusion
- Occurs within 6 hrs of a transfusion
- Impossible to distinguish from ARDS (diffuse alveolar damage)
What is the hypothesis for Transfusion related acute lung injury (TRALI) patho?
Thought to be related to leukocyte antibodies found in the transfused plasma
What is Major crossmatch used for?
Used to assess computability of donors RBCs within the recipients plasma
What is the main function of major crossmatch?
The final check of ABO (antigen) compatibility between donor and receipt before transfusion
What does Blood group A match with and which antibodies does it produce in the plasma?
Blood group A present with type A antigen on the surface of the cells and produces Anti-B antibodies in the plasma
What does Blood group B match with and which antibodies does it produce in the plasma?
Blood group B presents with type B antigen on the surface of the cells and produces Anti-A antibodies in the plasma
What does Blood group O match with and which antibodies does it produce in the plasma?
Blood group O have not antigen on their surface of the cell but produce both Anti-A and Anti-B antibodies in the plasma
What is the optimal approach for a emergency transfusion?
- hint before compatibility testing is completed
Transfusion of type-specific, partially crossmatched blood
Donor RBCs are mixed with recipient plasma, centrifuged, and observed for macroscopic agglutination.
- This takes approximately 10 mins
- If no time, O-negative packed RBCs are given
- If time is available for cross matched blood testing; then the option is to administer type-specific, non-crossmatched blood if available
What are Autologous blood transfusions?
The collection of blood from a single patient and re-transfusion back to the same patient if required
What is the primary reason for Autologous blood transfusions?
To reduce the risk of transmission of infection and complications associated with allogenic blood and to protect an increasingly scarce resource (blood)
Why is Autologous Blood Transfusion not a practical solution?
Autologous donation is expensive and is not very effective at reducing allogenic blood transfusion
What are Intraoperative and Postoperative Blood Salvages (Washed Autotransfusion)
RBCs are collected, washed, and then delivered to a reservoir for future admin either intraop or postop
