Week 14 - Fluid & Electrolytes Flashcards
Goals of fluid management? Maintain adequate: (5)
- Intravascular fluid volume
- Left ventricular filling pressure
- Cardiac output
- Systemic blood pressure
- Oxygen delivery to tissues
How can you assess fluid status in a patient?
- Skin turgor
- Mucus membranes
- Peripheral pulses
- Resting heart rate and blood pressure
- Orthostatic changes
- Urine output
- NPO Status
Body fluid composition percentages:
Extracellular: (33%)
- Interstitial (25%)
- Plasma (8%)
Intracellular: (66%)
Intracellular fluid (ICF) make up ___ of the body’s water and it is around _____% of your weight.
2/3;
40
The body is ___% water.
60
The intracellular fluid is primarily a solution of:
Potassium (K+)
Organic anions
Proteins
the cell membranes and cellular metabolism control these
The extracellular fluid is ____ of the body’s water and around _____% of body weight.
1/3
20%
The extracellular fluid is primarily a _____ and ____ solution.
NaCl and NaHCO3
The interstitial fluid (ISF) and Plasma are part of the _______ fluid.
Extracellular
Characteristics of the interstitial fluid (ISF):
- Surrounds the cells and does not circulate
- comprises 3/4 of the ECF
What are transcellular fluids? Characteristics?
- fluids that are outside of the normal compartments.
- 1-2 liters of fluid comprise the CSF, digestive (gastric) juices, mucus, etc/
Basic constituent of the human body
Water
Total body water (TBW) varies with age, gender and body type. What are the differences in percentages for males, females, and infants?
Males: 60%
Females: 50%
Infants: 80%
Which patients generally have less water per kg of body weight?
- Obese adults
- Patient’s with diabetes.
What are the characteristics of Hypovolemia? (7)
- Increasing Hematocrit
- Metabolic acidosis
- Urine SG >1.010
- Urine Na (less than) < 10 mEq/L
- Urine osmolality < 450mOsm/kg
- Hypernatremia
- BUN: creatinine ratio > 10:1
Signs of Hypovolemia at 5% water loss:
Mucus
LOC
Orthostatic
HR
BP
Urine output
Pulse rate
Signs of Hypovolemia at 10% water loss:
Mucus
LOC
Orthostatic
HR
BP
Urine output
Pulse rate
Signs of Hypovolemia at 15 - 20% water loss:
Mucus
LOC
Orthostatic
HR
BP
Urine output
Pulse rate
When evaluating a hypovolemic patient, keep in mind that a drop in BP does not occur in a patient that is already in the supine position until ______% of the blood volume is lost.
30
What is the intraoperative goal for urine output in normal patients? and for burn patients?
- 0.5 – 1 mL/kg/hr
- 1.5 mL/kg/hr
Decrease in urine output generally does not occur until _______% of blood volume is lost
~20
Early and later signs of Hypervolemia:
- Pitting edema
- Presacral edema
later:
- Tachycardia
- Crackles
- Wheezing
- Pulmonary edema
The Chest X-ray is reliable to evaluate for hypervolemia. What would you see on it?
- Kerly B lines: increased pulmonary and interstitial markings.
- Diffused alveolar infiltrates
What labs can you check for hypervolemia?
Blood and urinalysis
Extracellular Fluid:
Major cations (+)
Major anions (-)
Major cations (+): Sodium, Potassium and Calcium
Major anions (-): Chloride, Bicarbonate and Proteins
Intracellular Fluid:
Major cations (+)
Major anions (-)
Major cations (+): Potassium, Magnesium and Sodium
Major anions (-): Chloride, Bicarbonate and Proteins
Most important electrolytes? and why?
Potassium and Calcium
Effect excitability of nerve & muscle
K+ effects resting membrane potential (RMP)
Ca++ determines threshold potential
Sodium ( ____ - _____ mEq/L)
135 - 145
Hypernatremia is secondary to: ____________.
Lack of water;
Not because of too much salt*.
Neuro symptoms of hypernatremia (Na > _____ mEq/L):
>145
Neuro: Symptoms reflect rate of H2O movement out of brain cells
- Altered LOC
- Weakness
- Thirst
- Restlessness
- Lethargy
- Seizures
- Death
- Intracranial bleeding: ruptured cerebral veins/ focal hemorrhage (with rapid decreases in brain volume).
CV and Renal symptoms of hypernatremia:
- Hypovolemia
_________ - Polyuria, Oliguria
- Renal insufficiency
Characteristics of hypernatremia in conjunction with normal total body sodium content: (4)
- Most common cause is diabetes insipidus
- Marked impairment in renal “concentreating -ability”
- Decreased ADH secretion
or - Failure of the renal tubules to respond normally to circulating ADH (polyuria).
Characteristics of hypernatremia in conjunction with low total body sodium content:
- Patients has lost sodium and water
- Water loss is greater than sodium loss
- Losses can be renal (osmotic diuresis) or extrarenal (diarrhea or sweat).
Hypernatremia in conjuction with increased total body sodium content is most commonly caused by:
- The administration of large quantities of hypertonic NA solutions (3% NaCl or 7.5% NaHCO3).
- Cushing’s syndrome can also cause.
Treatment of hypernatremia:
- Water (fluid) deficits corrected over ~48 hours with hypotonic solution, such as D5W.
- Loop diuretic, then water deficit replacement
- Decreases in sodium concentration should not be faster than 0.5 -1 mEq/L/hour
Elective surgery should be postponed until sodium level is < ______ mEq/L and H2O deficits corrected.
150
Hyponatremia is associated with:
- Alcoholism
- Liver failure
- Severe burns
- Malignant neoplasms
- Hemodialysis
- Sepsis
Hyponatremia is serum Na < ______ mEq/L and neurologic symptoms occur with a level below < ________mEq/L
135;
120
Hyponatremia clinical manifestations include:
Neurological:
- Seizures → Coma
- Cerebral edema
- Agitation, Confusion
- Headache
Gastrointestinal:
- N & V → anorexia
Musculoskeletal:
- Cramps and weakness
Diagnosis of hyponatremia is based on the assessment of
serum osmolality and volume status
________ is the most common electrolyte disorder and may be classified as:
Hyponatremia;
Hyponatremia - isotonic or pseudo
Hyponatremia – Hypertonic
Hyponatremia – Hypotonic
What is osmolality?
number of osmoles of solute per kilogram of water (e.g., weight)
what is osmolarity?
number of osmoles of solute per liter of water (e.g. fluid)
What is tonicity?
Effect a solution has on cell volume
- Hypertonic
- Hypotonic
- Isotonic
Characteristics of Isotonic or Pseudo-Hyponatremia (3)
- Normal Osmolality (280 – 295 mOsm/kg)
- Total normal sodium
- Reflects fluid shifts from ICF –> ECF
- Decreased plasma sodium levels
Isotonic or Pseudo-Hyponatremia may occur with what conditions or medications?
Hypothyroidism
Glucocorticoid insufficiency
SIADH
______
Amitriptyline
Cyclophosphamides
Tegretol
Morphine
Pseudohyponatremia
SIADH characteristics
- clinical euvolemia
- Inappropriately elevated urine osmolality (>300mOsm - 400)
- in the face of low serum osmolality (<280 mOsm/kg)
- Urine NA> 20- 30 mEq/L
- Normal renal function
Causes of SIADH (5)
- Pulmonary carcinoma
- Brain metastases, other malignancies
- CNS disorders
- Idiopathic forms – frequent occur in older patients
- Medications
Medications that cause SIADH (6):
- Vasopressin
- HCTZ
- Antidepressants agents (SSRIs)
- NSAIDS
- Vincristine
- Oxytocin
- Neuroleptic agents
What is the acute treatment of SIADH for someone with severe hyponatremia ( <110 mEq/liter) ?
- IV lasix
- NS with 20 - 40 mEq/L KCL
- Rarely will 3% saline will be utilized
Chronic treatment of SIADH:
- Water restriction to ~1000ml per day
- Declomycin
- Vasopressin receptor antagonist: conivaptan, vaprisol, tolvaptan, samsca, lithium.
- Urea
- PO salt tablets
charactristics of Hyponatremia- Hypertonic:
High osmolality (>295 mOsm /kg)
Hypervolemia that may be caused by:
- Mannitol Excess
- Glycerol Treatment
- CHF
-Cirrhosis
Treatment to Hyponatremia- Hypertonic
Salt restriction
or
Water restriction
or
Diuretics
Characteristics/Causes of hyponatremia - hypotonic:
Low serum osmolality (<280 mOsm/kg)
Hypovolemia may be due to:
- GI losses
- Renal losses plus excess water ingestion
- Diuretics
- Ketonuria
- 3rd spacing
- Adrenal insufficiency
- N&V
Excessively rapid correction of hyponatremia has been associated with?
Demyelinating lesions in the pons ( pontine myelinolysis ) that can lead to permanent neurological damage!
S/S of pontine myelinolysis:
- Balance problems
- Confusion, delirium, ∆s in consciousness
- Difficulty swallowing, dysphagia
- Hallucinations, speech changes, poor enunciation
- Tremors, weakness in the face, arms, or legs, usually affecting both sides of the body.
- Acute progressive quadriplegia
Considerations / correction rates of hyponatremia if patient is symptomatic?
- Consider treatment with 3% NaCl
- Initial: sodium 1-2 mEq/L/hr x 2 hours then — > 0.5 mEq /L/hr
Correction rates of hyponatremia if patient is asymptomatic?
- Consider sodium 0.5mEq/L/hr
Max sodium correction rate in 24 hr:
10 mEq TOTAL rise
Max sodium correction rate in 48 hr:
18 mEq TOTAL rise
Potassium lab range:
(3.0 – 5.5 mEq)
What is hyperkalemia?
- Increase in total K content
- Altered distribution of K between intra- & extracellular sites
- Adverse effects are secondary to acute ↑ in serum concentration.
Most detrimental effects of hyperkalemia occur in cardiac conduction system. What are they?
- Prolonged PR interval
- Widening QRS complex
- Peaked T wave
Causes of hyperkalemia K+> 5.5: (9)
- Acidosis
- Hemolysis
- Tissue necrosis
- Renal insufficiency and failure
- K+ sparing diuretics
- Hypoaldosteronism
- Suppliementation
- Salt substitutes
- Rapid infusion - banked blood
Clinical manifestation of hyperkalemia? (7)
- Tall, peaked T waves
- Wide QRS
- Ventricular arrhythmias
- Muscle weakness
- Confusion
- Paresthesia
- Cardiac arrest
Treatment of Hyperkalemia (6)
- NaHCO3 (~50 mEq) promotes cellular uptake of K+ within 15 minutes (Note: cannot be used alone)
- Beta agonists
- Glucose 30-50 g + Insulin 10 units (can take up to 1 hour)
- Hyperventilation
- Hemodialysis
- Calcium
Why is calcium given for hyperkalemia? and how much?
- Administration of Ca++ will protect ♥ from hyperkalemia (1 amp = 1 gm Calcium Chloride)
- Ca++ will decrease excitability and depress the membrane threshold potential.
- Ca++ 500-1000 mg IV partially antagonizes cardiac effects; effects rapid but short-lived
Careful: Ca++ potentiates digoxin toxicity
What is hypokalemia?
Decreased total body potassium
Altered distribution
Changes in EKG with hypokalemia:
Flattened T waves and presence of U wave
__________ change in arterial ph can change plasma K+ concentration by ___________ meq ( _________ proportional relationship)
0.1;
0.6
indirectly
Causes of hypokalemia:
- Thiazide, loop diuretics
- Aminoglycosides
- Adrenal steroids
- Chronic laxative abuse
- Vomiting
- Gastric outlet obstruction
- Gastric suction
- Severe diarrhea
- Poor dietary intake
- Therapeutic alkalinization of the urine
- Hyperaldosteronism
- Cushing syndrome
- Magnesium deficiency associated with alcoholism
- Renal tubular acidosis
- Salt-losing nephropathies
Treatment of Hypokalemia:
- Oral replacement with potassium chloride : 60-80 mEq/day is safest .
- Peripheral IV potassium should not exceed >8 mEq/hr so as not to irritate veins.
- Central IV K + can be infused at 10-20 mEq/hr
Remember that NMBD dose should be decreased by _____ - ___% since hypokalemia causes increased sensitivity to NMBDs.
25-50
Normal calcium range:
8.5 - 10.5 mg/dl
Hypocalcemia causes: (6)
- Hypoparathyroid
- Pancreatitis
- Renal failure
- Decreased serum albumin levels
- Bone cancer
- Insufficient vitamin D
Why should you avoid hyperventilation with hypocalcemia?
Alkalosis should be avoided to prevent further decreases in Ca2+.
0.1 < in arterial ph can decrease ionized Ca concentration by 0.16 mg/dL
Heart effects with mild and severe hypocalcemia:
Mild: broad based tall peaking T waves
Severe:
- extremely wide QRS,
- low R wave,
- disappearance of p waves,
- tall peaking T waves
Signs of hypocalcemia: (7)
- Skeletal muscle spasm including laryngospasm/bronchospasm
- Decreased myocardial contractility
- Hypotension
- HF
- Tetany
- Trousseau’s sign
- Chvostek’s sign
Trousseau’s Sign is seen with:
Hypocalcemia
Chvostek’s Sign is seen with:
Hypocalcemia
Symptomatic hypocalcemia is a true medical emergency! What is the treatment ?
- Rule of 10’s:
- Infusion of 10ml of 10% calcium gluconate over 10 minutes (or calcium chloride). - Followed by a continuous infusion of elemental calcium 0.3 - 2mg/kg/hr
- Follow serial ionized Ca+ levels
- check magnesium: consider giving magnesium 1G
Hypercalcemia Values:
Serum Ca+ > 10.5;
Ionized >5.6 mg/dL
Hypercalcemia causes:
- Hyperparathyroidism
- Malignancy - bone
- Renal Failure
- Thiazide Diuretics
- Excess Ca+ supplements
Hypercalcemia clinical signs: 7
HTN
Dysrhythmias → Congenital Heart Block (CHB)
Shortened QT
Sedation
Polyuria
Anorexia
Pancreatitis
Treatment of Hypercalcemia
- Rehydration with NS followed by brisk diuresis (200 - 300 ml/hr) with loop diuretic to accelerate calcium excretion.
- Follow serial ionized calcium levels
- Avoid acidosis, since it may further elevate calcium levels
Normal magnesium range
1.7 – 2.2
What causes hypomagnesemia < 1.7
- Alcoholism
- Chronic diarrhea, polyuria, sweating
- Hyperaldosteronism
- Malnutrition
- Malabsorption syndromes, such as celiac disease and IBS.
- Medications:
- Diuretics
- Aminoglycoside
- Antibiotics
- Chemotherapy
Symptoms of hypomagnesemia: 7
- Abnormal eye movements ( nystagmus )
- Seizure
- Fatigue
- Muscle spasms or cramps
- Muscle weakness
- Numbness
- Dysrhythmias
Treatment of hypomagnesemia:
- IV magnesium sulfate 1- 2 grams given slowly over 60 minutes.
- Monitor labs for concomitant hypokalemia or hypocalcemia.
- Monitor EKG for arrhythmias ( similar to hypokalemia).
S/S of hypermagnesemia >2.2: (8)
- Flushing
- N/V
- Drowsiness
- Weakness
- Loss of patellar reflex, decreased DTRs
- Respiratory depression
- Cardiac arrest
- Coma
Treatment of Hypermagnesemia
- Stop all sources of Mg.
- IV calcium 1 gram - can temporarily antagonize most effects.
- Loop diuretic with rehydration of D1/2 NS enhances magnesium excretion.
What should you monitor with hypermagnesemia?
Monitor for vasodilation and negative inotropic effects
With hypermagnesemia you should decrease the dosages of NDMB by:
25- 50%
PeriOperative Fluid Therapy goals:
- Replacement of pre-existing fluid deficits
- Replace normal losses (maintenance requirements)
- Replacement NPO deficit
- Replacement of surgical wound losses (e.g., “third space losses” and blood loss)
acute chemical pneumonitis caused by the aspiration of stomach contents in patients under general anesthesia.
Mendelson syndrome
Why are NPO guidelines enforced?
due to risk of pulmonary aspiration
Prolonged fasting can contribute to:
- Hypovolemia
- Hypoglycemia
- Anxiety
Traditional NPO Guidelines for adults:
No solid food for 8 hours pre-op;
most medications can be continued with a small sip of water (excluding some cardiac and diabetic meds)
Longer fasting times should be enforced in those patients at an increased risk for aspiration:
- Renal failure
- Increased ICP
- Decreased LOC
- Cerebral palsy
- Anorexia
- Esophageal disorders
- Diabetes
- Delayed gastric emptying
- Difficulty swallowing
Traditional NPO Guidelines for pediatrics:
Up to 2 hours pre-op: clear liquids.
Up to 4 hours pre-op: Human breast milk.
At least 6 hours pre-op: Infant formula, nonhuman milk, light meal:
Up to 8 hours pre-op: “full” meal, carbonated drinks
No chewing gum or mints after midnight
refers to patient-centered, evidence-based, multidisciplinary team developed pathways for a surgical specialty and facility culture to reduce the patient’s surgical stress response, optimize their physiologic function, and facilitate recovery.
Enhanced Recovery after Surgery (ERAS®)
What is the 4-2-1 Rule?
It calculates the hourly maintenance:
4 cc/kg/hr first 10 kg of body weight
2 cc/kg/hr second 10 kg
1 cc/kg/hr for the remaining weight kg
NPO Deficit
equals the number of hours the patient is NPO x the hourly maintenance rate
After calculating NPO deficit, how are fluids administered?
Administer:
- 50% during the 1st hour.
- 25% in the 2nd hour.
-25% in the 3rd hour.
Typical fluid output sources:
- Urine (may be measured by Foley and a urometer).
- Respiratory tract
- Evaporative losses
- Losses due to surgical wound and/or bleeding
- Insensible or “third spacing” losses
Tissue manipulation & surgical trauma supports movement of fluid from the ECF compartment into non-functional compartments, and are called:
3rd space fluid losses.
Intra-operative Fluid loss
Small Incision/minimal trauma:
Moderate Incision/moderate trauma:
Large/Incision/severe trauma:
Major vascular case/extreme trauma:
- 4-6 ml/kg/hr
- 6-8 ml/kg/hr
- 8-10 ml/kg/hr
- 10-12 ml/kg/hr
Crystalloids: contain electrolytes dissolved in water or dextrose and water.
What are some examples
- 0.9% Normal saline: “isotonic”; 9 gm of NaCl per 1 liter of fluid.
- Lactated Ringer’s.
Colloids are ______ or _______ molecules, somewhat impermeable to vascular membrane.
natural or synthetic.
What do colloids do?
They determine the colloid osmotic pressure that balances distribution of water between intravascular and interstitial spaces
Examples of colloids
- 5% albumin
- 6% hydroxyethyl starch (Hespan, Hextend)
used for most neurological or renal patients; or with blood administration.
What fluid?
NaCl 0.9%
Plasmalyte contains:
Magnesium
Acetate
Gluconate
Lactated ringers contains:
Sodium
Potassium
Chloride
Calcium
Dextrose
Lactate
D5W – contains _____ gm dextrose per liter
5
used for volume expansion; each has limitations.
What fluids?
Dexran/Hespan/Hetastarch
what are Balance Salt Solutions (BSS) ?
They are fluids that have an electrolyte concentration similar to ECF.
Characteristics of Normal Saline Solution?
what happens if you give too much?
- Contains more chloride than ECF.
- Too much can cause hyperchloremic-induced metabolic acidosis
Normal Saline Solution is good choice for which patients?
Good choice for renal (diabetic) and neurosurgical patients.
When are Dextrose Containing Solutions used?
- In prevention of hypoglycemia in neonates and pediatric patients.
- In conjunction with insulin infusions.
Hyperglycemia is associated with increased risk for:
ischemic neurologic injury.
Advantages of Crystalloids (5):
- Inexpensive
- Promotes urinary flow
- Restores third - space loss.
- Used for extracellular fluid repletion
- Used for initial resuscitation.
Disadvantages of crystalloids (5):
- Dilutes plasma proteins
- Causes reduction in capillary osmotic pressure.
- Causes peripheral edema
- Has transient effect
- Potential for pulmonary edema.
Colloid advantages (6):
- Causes sustained increase in plasma volume
- Requires smaller volumes for resuscitation.
- Causes less peripheral edema.
- Tends to remain intravascular.
- causes more rapid resuscitation
- Useful in conditions of altered vascular permeability.
Colloid disadvantages (7):
- Expensive
- Can cause coagulopathy: (Dextran > hetastarch > Hextend).
- Can cause anaphylactic reaction (dextran)
- Decreases Ca2+ (albumin).
- Can cause renal failure (dextran).
- Can cause osmotic diuresis
- Can cause impaired immune response (albumin).
When is hypertonic saline beneficial?
in fluid resuscitation from shock/trauma and major surgical losses.
Hypertonic Saline is commercially available in:
2% or 3 %.
Hypertonic Saline indicated for? (6)
- Major surgical procedures: aortic, radical cancer surgeries
- Shock
- Slow correction of hyponatremia.
- TURP syndrome
- Reduce perioperative edema.
- Reduce ICP
Hypertonic Saline effects:
- Hypernatremia
- Hyperosmolality
- Hyperchloremia
- Increased cardiac output
- Increased solute to kidneys
- Improved microcirculatory blood flow
- Decreased potassium: Hypokalemia
- Decreased SVR/PVR;
- Decreased ICP
What is albumin?
Pooled plasma in saline
Albumin is:
- ________ soluble
. - _________ protein.
- Accounts for ____- ___% of the colloid osmotic pressure of plasma.
– _____ % - rapid intravascular volume expansion.
— ______% hypoalbuminemia
- Highly
- Globular
- 70 - 80%
– 5%
– 25%
Albumin has an intravascular half-life of ________ hours.
> 24 hours
Crystalloids or Colloids?
Most perioperative volume deficits are _______.
_________ solutions eventually equilibrate between plasma & interstitial space therefore more is needed to maintain intravascular volume
ECF
Crystalloid
T/F albumin and plasma derivatives:
- you need ABO compatibility
- They have no coagulation factors
- safe for critically ill patients
- False… not needed.
- True.
- False: associated with increased mortality in critically ill patients
How is the possibility of transmission of blood- borne disease eliminated for albumin?
it is heat treated at 60 degrees C for 10 hours
Dextran is composed of ________ ________ molecules.
Intravascular half-life _____ hours.
polymerized glucose;;
6
Dextran’s potential complications include: (7)
- Anaphylaxis,
- Volume overload
- Pulmonary edema,
- Cerebral edema
- Platelet dysfunction
- Acute renal failure
- PT. w/ hx of diabetes mellitus = renal insufficiency at ↑ risk.
non-ionic starch derivatives (2)
Hetastarch, Voluven
Hextend (6% in HES in ____)
LR
Hespan (6% HES in _____)
NS
Hextend & Hespan are
________ polymer and contain:
Synthetic
___________
Sodium
Potassium
Calcium
Magnesium
Hextend & Hespan intravascular half-life :
> 24 hours
Synthetic plasma expanders
Anaphylactoid reactions have been reported with both ______ and ________, but much rarer with _________.
dextran;
hetastarch
hetastarch
Ultimately indication for blood transfusion:
to maintain oxygen-carrying capacity to the tissues.
When blood loss occurs replace with _____ or _______ to maintain intravascular volume until risk of anemia outweighs the risk of the blood transfusion.
crystalloids or colloids
Healthy patient without cardiac disease: can usually tolerate decrease in Hgb to __________ or a Hct ___________.
7 - 8 g/dL
21-24%
what happens when hemoglobin is <7 g/dL?
- the resting cardiac output increases to maintain normal O2 delivery —–> myocardial strain
- Morbidity & mortality rates start to be affected.
Generally, a hemoglobin of __________ is limit for elderly and those with existing cardiac/pulmonary disease.
9 - 10 g/dL
Evaluating Blood Loss:
Soaked 4 x 4 contains:
Soaked “lap sponge” contains:
~10 ml of blood
~100 ml of blood
Fluid replacement
to blood loss ratios:
Crystalloids:
Colloid:
3:1
1:1
To Transfuse or Not to Transfuse:
what should you keep in mind?
- You must anticipate on a patient to patient basis.
- The minimum Hgb level that will avoid organ damage due to O2 deprivation.
- Balance between O2 delivery (DO2) and O2 consumption (VO2)
Factors that increase O2 demand and effect O2 delivery:
- Inability to increase CO
- Shifts to the oxyhemoglobin curve
- Inadequate oxygenation
- Abnormal Hgb
Assessment of Fluid Resuscitation includes:
- HR,
- BP,
- U/O,
- Arterial oxygenation,
- pH
In adults, _________ is an insensitive, nonspecific indicator of hypovolemia.
tachycardia
What strongly suggest adequate fluid replacement?
eservation of BP and a CVP of 6 - 12 mmHg
In procedures with large fluid losses, an arterial line is more accurate at estimating BP than indirect measures. Variations in the a-line waveform during positive pressure ventilation may indicate :
hypovolemia
EBV
Estimated blood volume
ABL
Allowable blood loss
Estimated Blood Volume (EBV)
Premature Neonates:
Term Neonates:
Infants & Children:
Adult Males:
Adult Females:
- 95 ml/kg
- 85 ml/kg
- 80 ml/kg
- 75 ml/kg
- 65 ml/kg
Allowable Blood Loss equations:
Routine typing of blood is performed to
identify antigens on the erythrocyte membranes (A, B, Rh)
Antibodies (anti-A, anti-B) are formed whenever membranes lack what?
and
what are these antibodies capable of causing?
lack A and/or B antigens
They are capable of causing rapid intravascular destruction of erythrocytes that contain the corresponding antigens.
Red cell membranes contain at least ______ different antigenic systems
300
Chromosomal locus produces 3 alleles: _ _ _.
and each represents an enzyme that modifies a cell surface _______ , producing a different antigen.
A, B, and O
glycoprotein
The Rh system is based on:
only the presence or absence of the most common, immunogenic allele, the D antigen.
________ of caucasians have the D antigen.
Individuals lacking this are called _______.
80-85%
Rh -
How can someone develop antibodies against the D antigen?
After exposure to a previous Rh-positive transfusion
or
Pregnancy (Rh-negative mother delivering an Rh-positive baby).
ABO blood grouping …exposure.
Compatibility Testing
Type Specific:
what does it do?
- ABO-Rh typing only 99.8% compatible.
- Requires 5-15 minutes
Compatibility Testing
**Type and Screen: **
and
what is the screen portion detecting?
- ABO-Rh and screen; 99.94% compatible
- Requires 15-45 minutes
-Screen (indirect Coombs test) detects presence of antibodies in serum that are most commonly associated with non-ABO hemolytic reactions.
Compatibility Testing
Type and cross match:
What does it do?
- ABO-Rh, screen, and crossmatch;
99.95% compatible - Mimics transfusion; donor cells are mixed with recipient serum
- Confirms ABO-Rh typing (in < 5 min)
- Detects antibodies to other blood group systems.
- Detects antibodies in low titers or those that do not agglutinate easily
- Takes at least 45 mins or more if patient has received prior transfusions!
For a transfusion what compatibility test:
- Always want to use:
- In an emergency – can use:
- Last resort will be:
- typed & cross-matched blood.
- type-specific, uncross-matched blood
- O negative blood.
Packed Red Blood Cells (PRBCs)contain:
- RBC’s,
- WBC’s,
- Platelets,
- Reduced plasma
Packed Red Blood Cells (PRBCs)are use for:
Used to restore oxygen-carrying capacity and for controlled surgical blood Loss.
Packed Red Blood Cells (PRBCs)usually contain a volume between:
and a hematocrit of :
250- 350 ml
70%
What is “washed PRBCs”? And who is it generally used for?
complete removal of plasma.
For neonatal transfusions
or
patients with a history of severe transfusion reaction, immunocompromised patients
1 unit PRBC increase Hgb by _____ gm/dl or Hct by ________.
- 1 g/dl
- 2- 3%
PRBCs administration steps:
- NS to decrease viscosity, increase speed of administration.
- Utilize fluid warmer to avoid hypothermia.
- Use 170 micronfilter to trap clots & debris.
PRBCs tubing should contain _____ - ______ mm filter to trap clots and debris (degenerated platelets, leukocytes, fibrin).
170 - 230 mm
PRBCS should be warmed to?
and why?
- Warm to 37*C
- Hypothermic effects and low levels of 2,3 DPG in stored blood cause leftward shift of oxygen Hgb dissociation curve –> tissue Hypoxia.
Why should PRBCs be infused with NS and not glucose or LR?
- Glucose solutions may cause RBC hemolysis
- LR contains calcium and may induce clot formation.
- NS, albumin, and FFP are all compatible with PRBC.
Whole blood volume and Hct:
Volume 450 - 500 mL
40% Hct
Whole blood is used primarily in :
- hemorrhagic shock (massive blood Loss; >25% of EBV).
Whole blood contains:
all factors:
RBC’s,
WBC’s,
Platelets,
Plasma - including factors V and VIII
Whole blood contains:
all factors:
RBC’s,
WBC’s,
Platelets,
Plasma - including factors V and VIII
Unit of whole blood will raise Hct ________ and Hgb ________ gm/dL
3-4%
1
With whole blood:
*Platelet activity decreases to < ______% after 24° storage;
If given within ______° after collection, it delivers functional platelets*.
5;
6
Cons of Whole blood:
- Not economical for routine use d/t blood shortages.
- Increased risk of allergic transfusion reaction
In Emergency Transfusions: if the type is known, what can confirm ABO compatibility?
an abbreviated cross-match can be done in 5 min. (type- specific).
universal donor
O Rh-negative
In emergency transfusions:
If > _______ or more units of O Rh-negative given, screen recipient’s blood for antibodies before own type given.
2
Old school: must continue to use O - even after type known ( True only for Whole blood, not PRBC.)
O+ can also be given in emergency transfusions, just not to:
women of childbearing age.
If > ______ units of O- given, continue with it.
Can go back to type specific blood in ___ - ____ months (RBC last ~ 120 days)
10;
3-4
Fresh Frozen Plasma contains:
plasma proteins & clotting factors.
No platelets
Fresh Frozen Plasma Utilized in:
- coagulation deficiencies.
- reversal of warfarin therapy.
- microvascular bleeding.
1 unit of FFP will increase clotting factors by _______%
3%
What could result from massive transfusion of FFP?
Hypernatremia
Thrombocytopenia (Platelet count less than <___________)
50,000
1 unit of Platelet concentrate increase platelet count by _______ to _________.
5,000 to 10,000
Each unit of platelet contains about ______ ml of ________.
50ml of plasma.
presence of plasma poses a risk of transfusion reaction
what is Cryoprecipitate?
Fraction of plasma that precipitates once FFP is thawed
Cryoprecipitate has high concentrations of what two things and help to treat what?
- High concentrations of Factor VIII to treat Hemophilia A.
- High concentrations of fibrinogen to treat Hypofibrinogenemia
Cryoprecipitate has high concentrations of what two things and help to treat what?
- High concentrations of Factor VIII to treat Hemophilia A.
- High concentrations of fibrinogen to treat Hypofibrinogenemia.
Transfusion Reactions
Febrile Reaction facts:
- Most common with a 1% incidence
- Increase in temperature by 1 degree C
Transfusion Reactions
Allergic Reaction facts:
- 2nd most common
- Pruritus, hives increase in temperature
Transfusion Reactions
What is a Hemolytic Reaction? and number of occurrences? and fatal in how many?
- ABO incompatibility
- 1 in 6000 transfusions
- Fatal in 1 in 100,000
Common cause of hemolytic reaction in a transfusion?
Patient mis-identification is the common cause
Presumptive diagnosis of hemolytic reaction is based on:
Free Hgb in urine & plasma
Steps to take if a transfusion reaction is suspected: (5)
- stop transfusion
- treat hypotension.
- consider steroids.
- send donor blood and patient blood sample for crossmatch.
- Preserve renal function by maintaining brisk urine output (IVF, Lasix, Mannitol).
After a blood transfusion reaction pt’s blood sample is sent for a crossmatch and what other tests?
- Free Hgb.
- Haptoglobin
- Coomb’s test
- DIC screening
Infection complications/occurrences with a blood transfusion:
- Hepatitis B (1: 220,00)
- Hepatitis C (1:1.6 M)
- HIV (1:1.8 M)
- rare bacterial infections
Besides infection, what other complications can occur from blood transfusions?
- Transfusion Related Acute Lung Injury (TRALI)
- Hyperkalemia
- Acidosis
- Hypothermia
Storage temp for banked blood:
1 – 6 degrees C to slow glycolysis
Biochemical changes in stored blood: (8)
- Progressive acidosis due to RBC metabolism (pyruvic and lactic acid).
- Increased K: 21 mEq
- Increased pCO2: 140 mmHg
- Increased lactate
- Decreased glucose
- Decreased 2,3 DPG
- Decreased platelets
- Decreased Factor V (15%) and Factor VIII (50%)
pH of blood at collection and 21 days later:
pH at collection 7.1; pH at 21 days 6.9
what is CPD (citrate-phosphate-dextrose)?
and what does each of its ingredients do?
and shelf life?
A banked blood preservative.
Citrate: anticoagulant that binds with ionic calcium; prevents clotting
Phosphate: acts as buffer
Dextrose: substrate used for glycolysis of RBC for energy
Shelf life: 21 days
What is CPDA (citrate-phosphate-dextrose-adenine)?
what does it do?
and shelf life?
A banked blood preservative.
Includes adenine (adenosine) for incorporation into ATP and extra glucose to prolong storage;
most common
Shelf life: 35 days
Hct 70-80%
whats a complication of MASSIVE blood transfusion? and why does it occur?
Citrate intoxication: from the addition of CPD as preservative for stored blood; can occur with rapid transfusion (>150ml/min).
Citrate is mainly metabolized by ?
what happens if rate of transfusion is too fast?
liver;
If rate of transfusion exceeds 1 unit of blood per minute in an adult, decreased calcium may result (binds calcium and magnesium)
Due to accumulation of citrate-chelating serum calcium
Pediatric patients and those with liver disease are more likely to become intoxicated
Symptoms of Citrate Intoxication
- Hypocalcemia
- Hypotension
- Increased LVEDP
- Increased CVP
- Prolonged QT interval
- Hypomagnesemia manifesting as tachyarrhythmias, TdP, or refractory V Fib
Treatment of Citrate Intoxication
- Calcium or magnesium
- Citrate will be metabolized quickly in Kreb’s cycle so symptoms may abate before treatment needed
- Supportive treatment
Transfusion blood is routinely screened for:
HIV 1/2
Hepatitis B and C
- Hepatitis C (nonA/nonB): most symptomatic (90%)
HTLV1/2 (human T-cell lymphocytic virus)
Syphilis
Request “______ Negative” blood;
it is used for immunocompromised like BMT or organ transplants, and infants.
______ is the MOST COMMONLY TRANSMITTED VIRUS in blood transfusions.
CMV;
CMV
Others Diseases That Can Be Transmitted in Blood
exposure.
What is TRALI?
Transfusion-Related Acute Lung Injury (TRALI)
is a non-cardiogenic form of pulmonary edema associated with blood product administration.
TRALI occurs more frequently with what blood products?
RBCs
FFP
Platelets
TRALI occurence and mortality rate:
- 1 in 5000 units transfused
- TRALI-mortality rate of 5 to 8%
The clinical appearance of TRALI is similar to:
adult respiratory distress syndrome (ARDS)
TRALI S/S:
- Symptoms usually begin within 6 hours after the transfusion.
Often more rapidly, the patient develops:
- Dyspnea
- Cyanosis
- Chills
- Fever
- Hypotension
- Noncardiogenic pulmonary edema.
On CXR TRALI reveals
bilateral infiltrates
Severe pulmonary insufficiency can develop
TRALI treatment:
- Supportive tx.
- Transfusion stopped.
- Oxygen and ventilatory support - with a low tidal volume strategy to prevent barotrauma.
Dilutional Coagulopathy is seen with:
Massive transfusions > 1 EBV (or >10 units)
**I don’t know what they mean by 1 EBV?
Signs of Dilutional Coagulopathy
Microvascular bleeding
Hematuria
Bleeding at IV sites
Clinically oozing
Increased PT/PTT
Decreased platelets
Treatment for Dilutional Coagulopathy
- Surgically control the bleeding.
- Keep patient warm
- Maintain perfusion and euvolemia.
- Don’t overhydrate and further dilute patient
- Consider FFP, platelets
- Consider Vitamin K, DDAVP (enhances platelet adhesiveness).
Alternatives to Traditional Blood Transfusion Therapy
- Normovolemic hemodilution
- Cell saver: 50 - 60% Hct (intraop salvage).
- Autologous donation (pre-op).
- Postop salvage (chest tube drainage system).
- Oxygen-carrying substitutes (Bovine blood/ Petroleum- based therapies).
Complication with postop salvage.
- reinfused anticoagulants,
- dilutional coagulopathy,
- air embolism
Can’t reinfuse blood if it contains pus, malignancy, or spilled GI contents
