Advanced Fluid Management Flashcards
Intravascular hydrostatic pressure drives fluid ___ blood vessels
out of
Interstitial hydrostatic pressure drives fluid ____ blood vessels
into
Intravascular oncotic pressure pulls fluid ___ blood vessels
into
Interstitial oncotic pressure pulls fluid ___ blood vessels
out of
What leads to edema?
Decreased intravascular oncotic pressure
How does edema occur in pregnancy?
Plasma volume increases, plasma albumin concentration decreases, capillary oncotic pressure decreases, fluid in the interstitial space increases
Helps maintain fluid balance and protects the body from producing WBCs from lymphocytes
Lymphatic system
Number of osmoles per kg
Osmolality
Number of osmoles per liter
Osmolarity
Plasma osmolarity
280-290 mOsm/L
What regulates osmolarity?
- Hypothalamus
- Carotid baroreceptors
- kidneys
Has a higher concentration of total solutes than other side of the membrane
Hyperosmolar
Has a lower concentration of total solutes than other side of the membrane
Hypoosmolar
Means water moves toward the solution
Hypertonic
Means water moves away from the solution
Hypotonic
Osmolarity of a hypertonic IV solution
> 375 mOsm/L
What happens to a patient that receives hypertonic IV fluid?
- The cells of the body shrink
2. Blood volume increases/expands
Examples of hypertonic IV solutions
- Mannitol
- 3% NS
- D5 solutions (except D5W)
How much dextrose is in a D5 solution?
5%
50mg/mL
How much dextrose is in a D50 solution?
50%
500mg/mL
Dextrose doses for hypoglycemia
Pediatric = 0.25-0.5 g/kg Adult = 0.5-1 g/kg
How many grams of glucose are in 1 amp (50ml) D50?
25g
How many grams of glucose are in 1000mL D5W?
50g
How many grams of glucose is 500 mL D5W?
25g
Indications for hypertonic IV fluids
- 3% NS can be indicated to correct hyponatremia
- Glucose solutions to treat hypoglycemia
- Mannitol can increase renal perfusion and diuresis or decrease ICP
Complications of hypertonic IV fluids
- Brain cells can shrink and cause “central pontine myelinolysis” and death
- Osmotic diuresis, loss of electrolytes, intracellular dehydration and coma
Osmolarity of hypotonic IV solution
<250 mOsm/L
Effects of hypotonic solutions
- Cells expand
2. Blood volume decreases
Examples of hypotonic IV fluids
- D5W after glucose metabolizes
- 0.45% NS
- 2.5% dextrose in water
Indications for hypotonic IV fluids
- hypernatremia
Complications with hypotonic fliuds
- Phlebitis (administer through central line if possible)
2. Cerebral edema if large volumes are administered
Osmolarity of isotonic solution
250-375 mOsm/L
Examples of isotonic solutions
- LR
- NS 0.9%
- Normosol/Plasmalyte
- 5% albumin
Osmolarity of LR
273 mOsm/L
Contents of LR
Na+, K+, Ca+2, Cl-, lactate
Contraindications to lactated ringers
- Liver disease/liver failure (lactate is converted to bicarb by the liver)
- Neurosurgery and/or patients with increased ICP
- W/rocephin in newborns
4? Metabolic alkalosis/pyloric stenosis
5? giving blood
6? diabetes
7? renal failure
Osmolarity of 0.9% NS
308 mOsm/L
Amount of sodium in 1 L of 0.9% NS
154 mEq
Administration of large volumes of NS leads to
Non-anion gap metabolic acidosis
Contents of plasmalyte
K+, Mg+2, Cl-
Osmolarity of plasmalyte
294 mOsm/L
Indications for plasmalyte
- Blood transfusions
2. Liver failure
Preferred fluid in patients with metabolic acidosis
Plasmalyte, it has 50 mEq bicarb per L compared to 28 mEq/L in LR
Contraindications for plasmalyte
None
Most common colloid used in the OR for treating hypovolemia patients
5% albumin
When are 20 and 25% albumin considered?
In large blood volume deficit or an oncotic deficit resulting from hypoproteinemia
Colloid used as an alternative to albumin
Hespan (6% Hetastarch)
What is the black box warning for hespan?
Increased mortality and severe renal injury in critically ill adult patients, as well as increased risk of bleeding with use of CPB
Circulating blood volume for preterm infant
90-100 mL/kg
Circulating blood volume for pregnant patient at term
90-100 mL/kg
Circulating blood volume for full term neonate
90 mL/kg
Circulating blood volume for infants
80 mL/kg
Circulating blood volume for adult males
70-75 mL/kg
Circulating blood volume for adult females
60-65 mL/kg
Circulating blood volume for elderly and obese
15% less than adults
Total body water in healthy males
60%
Total body water in obese males
50%
Total body water in geriatric males
50%
Total body water in healthy females
50%
Total body water in obese females
40-45%
Total body water in geriatric females
40-45%
Total body water in neonates
80%
Total body water in infants
70%
1st step of total body water
1 L of water = 1 kg
Percentage of TBW that is intracellular fluid
65%
Percentage of TBW that is extracellular fluid
35%
Percentage of extracellular fluid that is interstital
70-75%
Percentage of extracellular fluid that is intravascular
25-30%
Percentage of TBW that is interstitial fluid
25%
Percentage of TBW that is intravascular fluid
10%
Complication of acetazolamide
It is a carbonic anhydrase inhibitor, causing patients to urinate bicarbonate, causing metabolic acidosis
Uses for acetazolamide
- Diuretic for heart failure related edema
- Treat glaucoma and lower intraocular pressure
- Treat altitude sickness
Uses for lasix
- Fluid overload
- Chronic hypertension
- Offsetting increased production of ADH during surgery
True/false. Lasix is renal protective
False
Causes diuresis through increased blood flow to the kidney
Mannitol
Kidney disorder that causes the body to excrete too much protein in the urine
Nephrotic syndrome
Symptoms of nephrotic syndrome
- Proteinuria
- Hypoalbuminemia
- Fluid overload (edema)
Treatment for nephrotic syndrome
Treat underlying conditions
Percentage to classify a major burn injury in adults
> 20% or face, airway, and/or genitalia are burned
Percentage to classify a major burn injury in kids and elderly patients
> 10% or face, airway, and/or genitalia are burned
TBSA for burns on a child compared to an adult
9% more in the head
8% less in the legs
1% less in the genitalia
Physiology of patients after thermal injury (9)
- Hypovolemia and decreased cardiac output
- Massive leak of fluid and electrolytes from intravascular space into interstitial space (edema, hypovolemia)
- Hypothermia
- Anemia and thrombocytopenia
- Hypercoaguable state
- Proliferation of nicotinic receptors after 24 hours
- Possible acute renal failure
- Altered pulmonary physiology
- Hypermetabolic phase
What causes hypovolemia and decreased cardiac output in burn patients?
- Drainage and evaporation from burn wounds
2. An intense inflammatory response, leading to vasodilation and increased capillary permeability
Proliferation of nicotinic Ach receptors causes:
- Resistance to nondepolarizers
2. Sensitivity to Sux
What happens with hypermetabolic phase in patients with a burn injury?
- Massive surge in catecholamines and corticosteroids
- Increased myocardial oxygen consumption and work
- Insulin resistance
- Fever
- Liver dysfunction
First priority after thermal injury
Immediate airway assessment
Safest intubation option
Awake fiberoptic intubation with maintenance of spontaneous ventilation
Why are lower drug doses required in the initial burn shock phase? (1st 48 hours)
Renal and hepatic flow is decreased
-vasodilation and increased vascular permeability lead to large fluid shifts to the interstitial space, leading to low blood volume, increased hematocrit and low cardiac output
Drug dosing requirements in the hypermetabolic phase (48-72 hours)
MAC requirements are higher
Fluid overload can lead to higher drug dosing requirements
Succinylcholine guidelines for burns
- Can be safely administered within 24 hours
- Should be avoided for 24-48 hours after thermal injury
- May consider using 1-2 years after thermal injury occurred
Intraoperative goals for thermal injury
- Rapid and effective intravascular volume replacement
- Low tidal volumes should be used with mechanical ventilation (6ml/kg Vt and <30cmH2O PIP)
- Efforts to minimize heat loss should be implemented
What is the parkland formula for burn patients?
4 ml/kg LR per percentage of TBSA burned within the first 24 hours
-first half of the volume should be administered within the first 8 hours
Are colloids useful for burn resuscitation?
No, they can cause the vessels to become so vasodilated that they leak
Potential infectious causes of sepsis
- CNS infections
- Cardiovascular infections
- Respiratory infections
- Gastrointestinal infections
- UTIs
- Generalized abscesses
Potential non-infectious causes of sepsis
- Severe trauma or hemorrhage
2. Acute systemic disease (MI, PE, pancreatitis)