1.2.1 Body Fluids and Electrolyte Disturbances Flashcards
Keep going.
D. 2000 mEq
Describe how the six volume and electrolyte disturbance will affect ECF osmolality, ECF volume, ICF osmolality, and ICF volume.
(Basically, fill out this chart.)
See chart.
How do you calculate sodium deficit?
Na+ Deficit = TBW x (desired [Na+] - present [Na+])
What type of volume and electrolyte distubance is: a 56 y/o man goes hiking then gets lost for 10 days. When rescued, he is barely conscious and taken to hospital. Vitals are 75/55 mm Hg and plasma osmolality of 330 mOsm.
Hypertonic contraction
Just when you thought there couldn’t be another one…
C. 7 liters
And, another one (in DJ Khaled’s voice)
B. Dextrose (5%) in Water
(If you answered this question wrong, you most likely killed your first fake patient via brainscape)
Answer this one.
C. Increased intracellular fluid volume
What are the two ways to create a hypotonic body fluid disturbance?
- by loss of impermeable solutes
- by addition of water to ECF
What are the six types of volume and electrolyte disturbances?
- Hypotonic Contraction
- Hypotonic Expansion
- Isotonic Contraction
- Isotonic Expansion
- Hypertonic Contraction
- Hypertonic Expansion
How is MAP affected by ECF expansion?
Increased
Can’t stop. Won’t stop.
E. This is an example of a hypotonic contraction
List 4 prinicipal regulators of tonicity and ECF volume.
Arginine Vasopressin (AVP or anti-diuretic hormone, ADH): senses increased body fluid osmolality, increases H2O reabsorption
Thirst: Increases when osmolality is above 290 mOsm
Aldosterone: increases Na+ reabsorption in exchange for K+
Natriuretic Peptides (BNP from ventricular cells and ANP from atrial cells): stimulated by chamber distension, increases H20 and sodium output by kidney
What are the two ways to create an isotonic fluid disturbance?
- loss of blood (hemorrhage) will not change the osmolality of the remaining blood or of the ECF
- infusion of isotonic saline will not change the osmolality of the ECF
What is central pontine myelinolysis? In what settings can it occur?
Rapid quadriplegia, basis pontis lesion,
Setting: Alcoholism, liver transplant, electrolyte imbalances
Association: Rapid sodium correction
What type of volume and electrolyte distubance is: a 60 y/o man with renal disease such that the kidney has an impaired ability to reabsorb sodium. Sodium loss in the urine is greater than water loss?
Hypotonic Contraction
Answer the question.
E. The man’s body fluid disturbance would be described as isotonic contraction
What are the two ways to create a hypertonic fluid disturbance?
- by addition of impermeable solutes (e.g. sodium)
- by loss of water from the ECF
Describe the process in which ECF contraction will lead to decreased MAP.
Decrease in ECF -> Decrease in plasma volume -> Decrease in venous return -> Decrease in preload (EDV) -> Decreased SV -> Decreased CO -> Decreased MAP
(Remember: MAP = CO X TPR)
What type of volume and electrolyte distubance is: infusion of 0.9% NaCl?
Isotonic Expansion
When the ECF is hypertonic compared to the ICF, what will water do?
Water will move out of the cells into the ECF (Volume of ICF decreases)
What is term for an increase in ECF volume? Decrease in ECF volume?
Increase: Expansion
Decrease: Contraction
What type of volume and electrolyte distubance is: 19 y/o chugs a liter soy sauce for a bet?
Hypertonic Expansion
How was the patient who drank the soy sauce treated?
Anti-seizure medication and 6L of 5% dextrose
In the two isotonic fluid disturbances, in what direction will water move b/t the ICF and ECF?
It won’t…
On the other hand, the volume of the ECF has changed
What type of volume and electrolyte distubance is: a woman drinking 2 gallons of water for a radio contest.
What type of infusion would have a similar net effect?
Hypotonic Expansion
5% dextrose infusion (b/c dextrose will ultimately be metabolized)
When the ECF is hypotonic compared to the ICF, what will water do?
Water will enter the cells (Volume of ICF increases)
What type of volume and electrolyte distubance is: a 47 y/o woman in a car accident who loses large amounts of blood?
Isotonic Contraction
What is the formula for H20 Deficit?
H20 Deficit = Present TBW {(Current[Na+]/Desired[Na+])-1}
Review: What is the standard distribution of water b/t the ECF and ICF?
ECF: 1/3 of TBW
ICF: 2/3 of TBW
Again.
B. The interstitial volume will have increased by 1.5 L
