Fluids and Electrolytes Flashcards
In a 70kg male, water constitutes _____% of total body weight, which equates to ___L
60% of TBW, or 42L
ICV accounts for what percentage of TBW?
40% or 28L
ECV accounts for what percentage of TBW?
20% or 14L
ECV consists of:
Plasma: 15% of TBW
Interstitial: 5% of TBW
Which population has the highest TBW?
Neonates
Which population has the lowest TBW?
Females
Obese
Elderly
What are starling forces?
Hydrostatic and oncotic forces that determine movement of plasma between the capillaries and the interstitial space
What is the glycocalyx?
The protective layer on the inside of blood vessel walls that controls what can and cannot pass through pores in the vessel. Disruptions in the glycocalyx=capillary leak
What is hematocrit?
The percentage of the blood volume that’s occupied by erythrocytes
Where is the interstitial space?
It’s the space between cells, filled with a gel
The lymphatic system is the ______ of the body
scavenger system
What is osmolarity?
Number of moles per LITER of solution
What is osmolality?
Number of moles per KG of solution
“L is not for Liter”
How does albumin impact inflammation?
It actually has anti-inflammatory properties
Which colloid has the highest risk for anaphylaxis?
Dextran
How does albumin impact Ca?
It binds calcium, so it can cause a reduction in ionized calcium
Crystalloids expand ______ whereas colloids expand _______
Crystalloids expand the ECF
BUT colloids ONLY expand plasma volume
Excessive NS can lead to what metabolic derangement?
Hyperchloremic metabolic acidosis
What is the black box warning for colloids?
Renal injury
HYPERkalemia ________ cell membranes
depolarizes
In order for cellular excitation to occur, potassium efflex has to DECREASE. When extracellular K is high, less K leaves the membranes
HYPOkalemia _______ cell membranes
hyperpolarizes
In order for cellular inhibitio to occur, K efflux must INCREASE. Hypokalemia causes more K to shift out of the cell
How does potassium derangement impact EKG?
Which electrolyte derangement is the most common in clinical practice
Hypokalemia
How quickly should serum sodium derangement be corrected?
Slowly. No more than 1-2 mEq/L/hr
Treating hyponatremia too quickly causes:
central pontine myelinolysis
Treating hypernatremia too quickly causes:
cerebral edema
Surgery should be cancelled if serum Na is less than:
130
What is the most abundant electrolyte in the body?
Calcium
Nearly all of calcium is stored:
in bone
Calcium is responsible for which phase of the cardiac cycle?
Phase 2
Ca is factor ____ in the coagulation cascade
4
An increase in calcium leads to the release of:
Calcitonin from the thyroid, which inhibits bone break down and decreases Ca reabsorption in the kidney
A decrease in calcium leads to the release of:
Parathyroid Hormone (PTH), which stimulates osteoclasts to break down bone and increases reabsorption of Ca from the kidney
Chvostek’s Sign is:
Trousseau’s Sign is:
Chvostek and Trousseau are signs of ______calcemia
HYPOcalcemia
Magnesium antagonizes the effects of which electrolyte?
Calcium
at the NMJ, in the bronchioles etc.
What can cause an Anion Gap metabolic acidosis?
What can cause a non-anion gap metabolic acidosis?
How does acidosis impact ICP?
Acidosis increases ICP and CBF
Alkalosis decreases ICP and CBF
Massive transfusion can cause:
metabolic alkalosis BECAUSE the liver changes all of that citrate into bicarbonate!
What does acetazolamide do?
Inhibits carbonic anhydrase, which increases renal excretion of bicarb
What is the adult shortcut for the 4-2-1 rule?
Weight + 40 ml
