electrolytes, fluids and acid base

Question 1

what determines the intracellular volume?

Answer 1

K+

Question 2

what determines the extracellular fluid?

Answer 2

Na+

Question 3

volemia

Answer 3

changes in blood volume

Question 4

effective circulating volume

Answer 4

reflects perfusion status of a patient

Question 5

normal effective circulating volume

Answer 5

decreased perfusion due to any cause is counteracted by increased sympathetic tone, cardiovascular adaption and renal conservation of fluid/electrolytes

Question 6

abnormal effective circulating volume

Answer 6

increased vascular space (shock) or compromised compensation

Question 7

Fluid balance

Answer 7

intake vs losses

body perceives effective circulating volume

Question 8

fluid and electrolyte balance influenced by

Answer 8

ADH

renin angiotensin system

aldosterone

natiuretic peptides

Question 9

water loss without electrolytes

Answer 9

electrolyte levels (mostly Na) increase, usually along with protein and PCV

example: panting, restricted access to water to replace losses

Question 10

water loss with proportional electrolyte loss

Answer 10

initially electrolytes WRI

decrease as fluids are replaced by water intake and shifts from intracellular fluids

TP and PCv variable depending on losses

example: hemorrhage

Question 11

eletrolyte loss exceeds water

Answer 11

plasma eletrolytes are decreased

example: heavy sweating in horses

Question 12

dehydration laboratory abnormalities

Answer 12

pre renal azotemia

increased serum protein if no protein loss

increased PCV if no loss or decreased production of RBC

electrolyte changes variable depending on intake (K+) and type of fluid loss (all)

Question 13

increased total body water

Answer 13

indicators: weight, PCV, electrolytes, proteins

iatrogenic, pregnancy, heart failure, oliguric renal failure

Question 14

sodium physiology

Answer 14

major extracellular cation

dietary sodium usually adequate

body is efficient at retaining sodium

water follows sodium

angiotensin and aldosterone promote sodium retnetion and natriuretic peptides promote excretion

Question 15

sodium measurement

Answer 15

ion specific electrode used in reference analyzers

point of care methods vary, usually correlate with but not identical to reference analyzers

methods similar for all electrolytes

Question 16

hyponatremia-mechanisms

Answer 16

decreased intake-rare,

greater losses of Na than water: diarrhea, renal disease, sweating, diuretics

loss of H2o and elecctrolytes with replacement of H2O (exudative skin lesions, third space loss, diarrhea, hemorrahge)

dilution: increased osmotic forces that move water into the ECF and dilute Na (DM), pathological gain of water (CHF, oliguric/anuric/ post renal failure, pregnancy

Question 17

hypernatremia

Answer 17

excessive intake of sodium-rare

decreased water intake-adipsia: ritical care, loack of access, absence of thirst

loss of water in excess of sodium-GI, panting, Renal