Fluids 1 Flashcards
What makes up the interstitial space?
Lymph, Electrolytes (Na, Cl, K, HCO3-, etc.), Proteins, Water
What makes up the intravascular space?
Blood, Red blood cells, Electrolytes (Na, Cl, K, HCO3-, etc.), Platelets, White blood cells, Proteins (albumin, etc.)
What makes up the intracellular fluid?
Cell components (ex. mitochondria), Electrolytes (Magnesium, Potassium, Na), Phosphate, Water
What makes up the extracellular fluid?
The interstitial space and intravascular space
Name the five main osmotically active particles.
Electrolytes, Ketones, Glucose, Urea, Mannitol
What is a crystalloid fluid? Name some examples.
A clear solution that contains mostly electrolytes and water. Examples include 0.9% NaCl, plasmalyte, or Lactated Ringers.
What is osmolality?
The concentration of a solution expressed as a total number of solute particles.
What is the osmolality formula?
Osmolality = 2 (Na + K) + glucose + BUN
What is a hypotonic crystalloid?
A fluid that has a lower osmolality than blood.
What is an isotonic crystalloid?
A fluid that has about the same osmolality as blood.
What is a hypertonic crystalloid?
A fluid that has a higher osmolality than blood.
What is dehydration?
A decrease in (mostly) the extracellular fluid components.
When should you use isotonic crystalloids and why?
Use as a replacement fluid for hypovolemia or dehydration.
What happens when you give isotonic crystalloids IV?
It generally serves to replenish intravascular volume without causing shifts of fluid in or out of the body’s cells.
What are the three buffers commonly added to fluids and what is their function?
Lactate, acetate, and gluconate. They produce bicarbonate which limits the change in pH.
What are crystalloid fluids that contain buffers called?
Balanced crystalloids.
What are unbalanced crystalloids?
Crystalloids that contain only Na and Cl with no extra electrolytes or buffers (ex. 0.9% NaCl).
Why doesn’t 0.9% NaCl have buffers added?
It has the highest amount of chlorine and sodium, which can cause acidosis.
Crystalloid fluids increase _____________ volume.
Intravascular volume.
How long will it take for crystalloid fluids to diffuse into the interstitial space and correct dehydration?
45 minutes.
45 minutes after a bolus, ______ percent of the volume has moved into the interstitial space and _____ percent remains inside the intravascular space.
75%, 25%.
What are the three electrolytes commonly added to fluids and what is their function?
Potassium, calcium, and magnesium. They balance plasma values and improve contractility.
True or False: It is okay to give potassium in fluids as a bolus in very small quantities.
True.
What is the difference between 0.9% NaCl, Lactated Ringers, and plasmalyte?
NaCl has neither buffers or electrolytes, plasmalyte has both, and Lactated Ringers has both.
Name two contraindications of using fluids with extra electrolytes.
Do not give to patients with hyperkalemia or concurrently with a blood transfusion.
Isotonic fluids are good for ____________ dehydration but not good for ____________ dehydration.
Interstitial, intracellular.
What are six diseases that contraindicate the use of isotonic fluids?
Hypoalbuminemic patients, anuric renal failure, cardiac disease, pulmonary contusion, cerebral injury, sepsis.
What happens when you give hypotonic crystalloids IV?
They cause water to move into cells via osmosis, leading to swelling.
What are two indications for hypotonic crystalloids?
Intracellular dehydration, Maintenance fluid.
Hypotonic fluids are good for ____________ dehydration but not good for ____________ dehydration.
Intracellular, intercellular.
What is an advantage of hypotonic fluid over isotonic fluid?
The low sodium decreases risk of volume overload.
What is a major contraindication for hypotonic fluids?
Never use to treat shock!
What is the effect of dextrose in fluids?
Dextrose is immediately taken up by cells, leaving pure water.
What are the indications of giving fluids with dextrose?
Severe hypoglycemia.
Which fluids cannot be bolused and why?
KCl, due to the risk of fatal hyperkalemia.
What is a disadvantage to dextrose?
Can cause RBCs to explode and phlebitis.
What happens when you give hypertonic crystalloids IV?
There is a massive movement of water into the vascular space.
What is an indication for hypertonic crystalloids?
Hyponatremia, Cerebral edema, Extreme hypovolemia.
What are colloids?
Fluids that contain BOTH large organic macromolecules and electrolytes.
What are two natural colloids?
Albumin, Fresh frozen and frozen plasma.
What happens when you give colloids IV?
The colloid attracts a small amount of water back into the intravascular space.
What are the indications of colloids?
They may be used for short-term blood pressure support in anesthesia.
What are the disadvantages of colloids?
Causes acute kidney injury, coagulation issues, increased morbidity and mortality.
