Lecture 8

Question 1

What is most affected by acid base disturbances?

Answer 1

Proteins- may lose or gain H+, may alter function and/or structure

Question 2

What is range or pH compatible with life

Answer 2

6.8-7.8

Question 3

What are the bodies buffers

Answer 3

Bicarbonate
Proteins- hemoglobin, plasma proteins
Phosphates

Question 4

What do acids do in water? Bases?

Answer 4

Acids donate H+ in water and bases accept H+ in water

Question 5

What is the first rule of acid/base?

Answer 5

Lungs breathe off acid (CO2)

Question 6

What is the second rule of acid/base?

Answer 6

Respiratory system responds quickly (seconds to minutes)

Metabolic system takes longer (hours to days)

Question 7

Describe respiratory acidosis- causes

Answer 7

Lungs not breathing off enough acid- hypoventilation, hypercapnia

Causes:
Inhibition/dysfunction of respiratory center
Inhibition/dysfunction of respiratory muscles
Upper airway dysfunction
Impaired gas exchange at pulmonary capillaries

Question 8

Describe respiratory alkalosis- causes

Answer 8

Due to lungs breathing off too much acid- hyperventilation, hypocapnia

Causes:
Hypoxemia, pulmonary disease, stimulation of respiratory center, mechanical hyperventilation, pain/anxiety

Question 9

How do the kidneys regulate acid/base

Answer 9

Resorbs bicarb and regenerates bicarb that titrates H+ generated from metabolism

Minimal bicarb is secreted/lost

Question 10

What is metabolic acidosis? What causes it?

Answer 10

Gain of acid (titration): shock, DKA, uremia, toxins, renal tubular acidosis

Loss of base: kidney disease, GI losses

Question 11

What should you evaluate at the same time as metabolic acidosis

Answer 11

Chloride and anion

Question 12

What is metabolic alkalosis

Answer 12

Excessive loss of acid: upper GI loss, kidney dysfunction

Gain of base: can be iatrogenic

*also evaluate chloride concurrently

Question 13

What is step 1 of acid/base evaluation

Answer 13

Look at pH and determine whether it is neutral, alkalotic, or acidosis

Question 14

What is step 2 in acid base evaluation

Answer 14

Evaluate changes in bicarb and pCO2

Question 15

What does increased bicarbonate mean?

Decreased?

Answer 15

Increased= alkaline change

Decreased= acid change

Question 16

What does increased pCO2 mean?

Decreased?

Answer 16

Increased= acid change
Decreased= alkaline change

Question 17

What does it mean if pH is low and bicarb is low

Answer 17

Metabolic acidosis at least

Question 18

What does it mean if pH is high and pCO2 is low

Answer 18

Respiratory alkalosis

Question 19

What does it mean if pH is low, bicarb is high, and pCO2 is high

Answer 19

Mixed metabolic and respiratory acidosis

Question 20

What is the third step in acid/base evaluation

Answer 20

Look for compensatory change

Question 21

What does it mean is pH is low, bicarb is low, and pCO2 is low

Answer 21

Metabolic acidosis with respiratory compensation

Question 22

Do compensatory mechanisms return pH to normal?

Answer 22

No!

Also, it will never overcompensate

Question 23

What should you consider if it appears the compensatory mechanisms are exceeding or falling short expected value

Answer 23

Mixed acid/base abnormalities

Question 24

What is TCO2

Answer 24

Serum bicarbonate

It is on the chem profile, but is not an accurate marker of acid/base status

Question 25

What might cause metabolic alkalosis

Answer 25

Loss of H+ rich, Cl poor fluid: GI reflux/vomiting, proximal GI obstruction, displaced abomasum, heavy sweating in horses

Question 26

What are causes of hypochloremia

Answer 26

Sodium related decreases Failure to reabsorb chloride rich gastric secretions Iatrogenic Spurious

Question 27

Explain hypochloremic metabolic alkalosis with paradoxical aciduria

Answer 27

Upper GI disease causes dehydration, hypokalemia, and loss of HCl Dehydration causes RAAS activation- sodium and chloride resorption and potassium excretion However, because you are losing HCl, you have no chloride to resorb, so you start resorbing bicarb which further propagates the alkalosis. Additionally, you cannot excrete K because you are hypokalemic, so in an effort to conserve potassium you excrete H+ and get aciduria

Question 28

What causes respiratory alkalosis

Answer 28

Hypoxemia from any cause (low pO2) Stimulation of respiratory center (normal pO2)

Question 29

What causes respiratory acidosis

Answer 29

Respiratory center depression, pulmonary disease, neuromuscular issues, airway obstruction, restrictive/traumatic diseases

Question 30

What is pO2 levels in respiratory acidosis

Answer 30

Always low unless on supplemental oxygen

Question 31

Causes of metabolic acidosis

Answer 31

Addition of acid: ketoacidosis, lactic acidosis, ethylene glycol, renal failure, aspirin toxicity Loss of bicarb: secretional diarrhea, Addisons disease

Question 32

What is titrational acidosis and what will the anion gap be?

Answer 32

Acidosis due to increased acids, anion gap is high

Question 33

What is secretional acidosis and what is the anion gap

Answer 33

Acidosis due to loss of bicarbonate, anion gap will be normal

Question 34

What is the anion gap

Answer 34

Difference between unmeasured anions and unmeasured cations | Na + K) - (Cl + HCO3

Question 35

What will you see with high anion gap acidosis What are causes?

Answer 35

Decreased bicarb Normal Cl Causes: ketones, lactic acid, sulfates, phosphates, uremic acids, ethylene glycol

Question 36

What will you see with normal anion gap acidosis Causes?

Answer 36

Decreased bicarb, increased Cl Causes: loss of HCO3 rich fluids, proximal renal tubular acidosis, distal renal tubular acidosis, loss of saliva in ruminants **all lead to increased Cl resorption