FORM & FUNCTION (Acid Base Disturbances)

Question 1

4 types of disturbances

Answer 1

1. Metabolic ([HCO3-]) or Respiratory (PCO2)
2. Acidosis or Alkalosis

Question 1

Acidemia

Answer 1

-pH<7.4
-caused by acidosis
-higher PCO2/lower HCO3-

Question 2

alkalemia

Answer 2

-pH>7.4
-caused by alkalosis
-lower PCO2/higher HCO3-

Question 3

normal ratio of HCO3-/0.03xPCO2

Answer 3

=20
-less than 20: acidemia
-more than 20: alkalemia

Question 4

Le Chatelier’s principle

Answer 4

-disturbance to a system equillibrium shifts the equilibrium in the direction that counteracts the changes
*system always wants to re-establish equilibruim

Question 5

If CO2/H2CO3 increases

Answer 5

-shift will favour formation of H+ and HCO3-
-as H goes us, the environment becomes more acidic

Question 6

If H+/HCO3- increase

Answer 6

-shift will favour increase in CO2/H2CO3

Question 7

Respiratory acidosis

Answer 7

1. Causes: hypoventilation (reduced rate and depth of breathing)
2. Change: increase in CO2 ->increase in PCO2
3. Shift: to the right=increase H+ and HCO3- (decreases pH)
   *renal compensatin via increased HCO3- reabsorption (slow process

Question 8

Respiratory alkalosis

Answer 8

1. Cause: hyperventilation (increased rate and depth of breathing)
2. “Change”: decreased CO2 (decrease PCO2)
3. Shift: left=decrease H+ and HCO3- (more basic)
   *renal compensation to reduce HCO3- reabsorption (slow process)

Question 9

metabolic acidosis

Answer 9

1. Cause: overproduction of lactic acid from exercise
2. “Change”: increase H+ (decrease in HCO3-)
3. Shift: left
   *respiratory compensation via in depth and increased rate (hyperventilation) to reduce PCO2 ->reduces H+ formations

Question 10

Metabolic alkalosis

Answer 10

1. Causes: vomiting->loss stomach acid->increase HCO3- in plasma
2. “Change”: increased HCO3-
3. Shift: right, going to get more proteins deficit as HCO3 will deplete it due to high levels
   *chemoreceptors detect a drop in H+ ->respiratory suppression to increase PCO2 ->increases H+ formation

Question 11

respiratory vs. renal compensation

Answer 11

-respiratory is faster

Question 12

additional underlying factors that hinder compensation responses

Answer 12

-renal failure
-pulmonary disease
-depressant drugs of the respiratory center

Question 13

mixed disturbances

Answer 13

-two or more acid-base disturbance together
Ex. unregulated diabetic animals

Question 14

anion gap

Answer 14

-difference in concentration of major cations and anions
-due to various organic cations, anions and proteins
*totatal charge is neutral

Question 15

cations

Answer 15

Na+
K+

Question 16

anions

Answer 16

-Cl-
-HCO3-

Question 17

anion gap ratio

Answer 17

-allows for estimation of unmeasured molecules
-can provide info on the type of metabolic disturbance

Question 18

increase in anion gap

Answer 18

-useful indicator of metabolic acidosis
Ex. excess lactic acid in blood
>increased from the decrease in HCO3-
>total charge still neutral since lactate anion also increase
*due to increased organic anions (“randoms”)

Question 19

decrease in anion gap

Answer 19

-could signal cation anomally (cation disturbance) or metabolic alkalosis (increase bicarbonate)

Question 20

anion gap, but normal

Answer 20

-metabolic acidosis (ex. diarrhea cause HCO3- loss)
>kidney compensates increases Cl- reabsorption to maintain a neutral charge
*hypercholremia metabolic acidosis

Question 21

Metabolic acidosis determinaion

Answer 21

+increased anion gap=caused by excess organic anion (lactic acid)
+no change in anion gap=loss of HCO3- compensated by Cl- (diarrhea)