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Flashcards in acid base 1 Deck (14):
1

what defines acidemia

pH < 7.35

2

what defines alkalemia

pH > 7.45

3

difference between acidemia and acidosis

acidemia = state of blood pH
acidosis = pathological processes that change pH

4

define a buffer

Minimises pH changes due to addition or removal of H+ (temporarily)

5

what is Henderson-hasselbach equation

pH = 6.74 + log (HCO3- / pCO2)

is determined by ratio between HCO3- and pCO2 as pKa is constant

6

describe respiratory disturbances

respiratory acidosis
- CO2 retention
- e.g. pCO2 = 9

respiratory alkalosis
- hyperventilation
- e.g. pCO2 = 3

7

describe metabolic disturbances

metabolic acidosis = low bicarbonate
metabolic alkalosis = high bicarbonate

8

name urinary buffers

phosphoric acid
ammonium ions

9

causes of metabolic acidosis

- lactic acidosis
- diabetic ketoacidosis
- renal failure
- renal tubular acidosis
- severe diarrhoea, ilieostomy

10

what is the role of the kidneys in acid-base balance

1. bicarbonate reabsorption
2. 'new' bicarbonate generation
3. H+ secretion in distal nephron (distal tubule & CD)
- via ammonia and phosphate

11

describe the role of acetazolamide

- is a carbonic anhydrase inhibitor
- causes metabolic acidosis
- used to counteract alkalosis due to hyperventilation
- inhibits reabsorption and regeneration of HCO3-

12

what plays a key role in urinary generation (not reabsorption)

urinary buffers

13

describe the role of ammonium in the nephron

1. ammonium generated from glutamine in PT cells and secreted into the lumen (produces 2x HCO3-)
2. most reabsorbed in TAL
3. CD = diffusion trapping

14

describe the response of the kidneys to acidosis

- increased HCO3- & H+ transport along the nephron
- increased ammoniagenesis
- increased availability of urinary buffers
(=more acid excretion)