acid base control

Question 1

what buffers control acid base balance

Answer 1

haemoglobin
bicarbonate
carbonic acid
proteins

Question 2

what is normal pH

Answer 2

7.35-7.45

Question 3

what is normal O2 pp

Answer 3

12-13 kPa

Question 4

what is normal pCO2

Answer 4

4.5 – 5.6 kPa

Question 5

what is normal bicarbonate concentration

Answer 5

22 – 26 mmol/l

Question 6

what is standard bicarbonate

Answer 6

used to indicate metabolic acid base balance

assumes standard temperature and CO2 pp

Question 7

what is the first step of assessment of ABG

Answer 7

assess PO2 and oxygenation

Question 8

what is a healthy P/F ratio

Answer 8

> 50

Question 9

what P/F ratio indicates acute lung injury

Answer 9

> 40

Question 10

what P/F ratio indicates ARDS

Answer 10

26.6

Question 11

if the pH and pCO2 are changing in different directions what does that indicate

Answer 11

respiratory problem

Question 12

if the pH and pCO2 are changing in the same direction what does that indicate

Answer 12

metabolic problem

Question 13

if pCO2 and bicarb are moving in the same direction what does that indicate

Answer 13

compensation is occuring

Question 14

what is the anion gap

Answer 14

the sum of routinely measured cations in
venous blood minus routinely measured
anions
([Na+] + [K+])- ([Cl-] +[HCO3-])

Question 15

what is normal pH

Answer 15

7.35-7.45

Question 16

what is normal O2 pp

Answer 16

12-13 kPa

Question 17

what is normal pCO2

Answer 17

4.5 – 5.6 kPa

Question 18

what conditions will cause lactic acidosis

Answer 18

hypoperfusion of the whole body or a part
increased anaerobic metabolism producing increased lactic acid

Severe acute hypoxia
Severe convulsions (resp arrest)
Strenuous exercise (dehydration)

Question 19

what is standard bicarbonate

Answer 19

used to indicate metabolic acid base balance

assumes standard temperature and CO2 pp

Question 20

what is the first step of assessment of ABG

Answer 20

assess PO2 and oxygenation

Question 21

if the pH and pCO2 are changing in different directions what does that indicate

Answer 21

respiratory problem

Question 22

if the pH and pCO2 are changing in the same direction what does that indicate

Answer 22

metabolic problem

Question 23

if pCO2 and bicarb are moving in the same direction what does that indicate

Answer 23

compensation is occuring

Question 24

if pCO2 and bicarb are moving in the different directions what does that indicate

Answer 24

mixed problem

Question 25

what anions are measured

Answer 25

protein, phosphate, Cl, sulphate bicarbonate

Question 26

what cations are measured

Answer 26

Ca, Mg, K, Na

Question 27

what does an increased anion gap indicate

Answer 27

metabolic acidosis -

Question 28

what is the normal anion gap

Answer 28

16

Question 29

what conditions will cause lactic acidosis

Answer 29

hypoperfusion of the whole body or a part

Question 30

how is lactic acid broken down

Answer 30

in the liver using oxygen

Question 31

how will anions change in lactic acidosis

Answer 31

same cations increase in unmeasured anions decrease in bicarb

Question 32

what conditions can cause ketoacidosis

Answer 32

decreased insulin diatbetes alcoholic ketoacidosis starvation

Question 33

what substances might be ingested which increase the anion gap

Answer 33

methanol | ethylene glycol

Question 34

what is Renal tubular acidosis

Answer 34

accumulation of acid due to failure of kidneys to acidify the urine normal anion gap

Question 35

how does the anion gap change in renal failure

Answer 35

increase

Question 36

what conditions involve acidosis but no anion gap

Answer 36

diarrhoea | renal tubular acidosis

Question 37

how is the ionogram changed with metabolic acidosis but an unchanged anion gap

Answer 37

decreased bicarbonate only due to it being combined with H+

Question 38

how does the kidney correct metabolic acidosis

Answer 38

secretes more acid into the urine | makes new bicarbonate

Question 39

what is Kussmaul respiration

Answer 39

laboured, deep rapid pattern of breathing

Question 40

what is the most common cause of metabolic alkalosis

Answer 40

loss of H+ ions from the stomach or kidney | e.g. pyloric stenosis

Question 41

what diuretics can cause loss of H+ ions

Answer 41

furosemide | thiazide

Question 42

what can cause loss of H+ ions in babies

Answer 42

pyloric stenosis

Question 43

what to situations lead to metabolic alkalosis

Answer 43

an initiating process and a maintaining process

Question 44

how is alkalosis maintained

Answer 44

kidneys ability to excrete excess bicarb is impaired

Question 45

what is chloride depletion

Answer 45

if chloride is low in the kidneys then bicarb must be reabsorbed leading to alkalosis