Acid Base

Question 1

What is acidemia

Answer 1

when blood has elevated H+

Question 2

What is alkalemia

Answer 2

When blood has decreased H+

Question 3

What is respiratory acidosis?

Answer 3

when hypoventilation causes hypercapnia

Question 4

What is respiratory alkalosis?

Answer 4

when hyperventilation causes hypocapnia

Question 5

What is metabolic acidosis?

Answer 5

when an acid is produced or a base is lost

Question 6

What is metabolic alkalosis?

Answer 6

when a base is added or an acid is lost

Question 7

What kind of acids/bases are counteracted by the bicarb buffer system?

Answer 7

metabolic acids or bases

requires ventilation and gas exchange to allow for CO2 excretion

Question 8

What are extracellular examples of nonbicarb buffers?

Answer 8

plasma proteins, phosphate and ammonia

Question 9

What are intracellular examples of nonbicarb buffers?

Answer 9

dibasic phosphate, proteins, and bone bicarb

Question 10

Define the isohydric principle

Answer 10

the acid/base ratio of a buffer is determined by it’s Ka and [H+]
i.e. a change in [H+} changes ALL acid/base ratios in all buffers

Question 11

What is the henderson hasselbach equation

Answer 11

pH = Pk + log (bicarb/0.03xPCO2)

Question 12

What is the first defense to changes in pH

Answer 12

physical and chemical buffers

Question 13

What is the second defense to changes in pH over a scale of minutes?

Answer 13

respiratory compensation

Question 14

What is the long term solution to changes in pH?

Answer 14

renal excretion and or metabolism

Question 15

An immediate and pronounced drop in bicarbonate and a transient increase in PaCO2 would indicate what process?

Answer 15

uncomplicated metabolic acidosis

Question 16

A pronounced increase in bicarb with a transient increase in PaCO2 would indicate what process?

Answer 16

uncomplicated metabolic alkalosis

Question 17

What are respiratory processes buffered by?

Answer 17

non bicarbonate buffers only!

Question 18

the change in bicarb concentration is always equal to the change in what value?

Answer 18

the H+ taken or added to the system

Question 19

With increasing hemoglobin concentration, what happens to the buffer value?

Answer 19

it increases

Question 20

What is the natural response to metabolic acidosis?

Answer 20

respiratory alkalosis via increase in ventilation, dropping concentration of both bicarb and non bicarb buffers

Question 21

What is the natural compensation for metabolic alkalosis?

Answer 21

respiratory acidosis

Question 22

The rapid intravenous infusion of bicarbonate into a 70 kg male initially increased arterial pH from 7.40 to 7.51 and [bicarb] from 24 to 32 mEq/L. However, over the next 3 hr the arterial [bicarb] decreased to 27 mEq/L and pH decreased to 7.45. What caused the fall in bicarbonate and pH over the 3 hr period?

Answer 22

equilibration of bicarbonate will cause an increase in pH that has a tendency to decrease breathing by increasing arterial PCO2, which in turn will increase brain PCO2, dropping brain pH and causing respiratory stimulation. This will drop PCO2 and pull the reaction away from production of bicarbonate by expiring CO2

Question 23

The rapid intravenous infusion of bicarbonate into a 70 kg male initially increased arterial pH from 7.40 to 7.51 and [bicarb] from 24 to 32 mEq/L. However, over the next 3 hr the arterial [bicarb] decreased to 27 mEq/L and pH decreased to 7.45. How will acid-base balanced be restored?

Answer 23

excretion of bicarbonate in the urine

Question 24

If a patient’s PaCo2 is consistently at 40 mmHg, what factors determine how much extracellular pH changes in response to an increase in acid load?

Answer 24

The concentration of extracellular and intracellular buffers will determine the magnitude of the change in extracellular pH.

Long term, there may be compensation in excretion by the kidneys.

Question 25

A patient has a low pHa, low bicarb, and low PaCo2. Are they in respiratory or metabolic acidosis?

Answer 25

metabolic acidosis (both pH and CO2 are low)