acid/base 3

Question 1

what does metabolic alkalosis require

Answer 1

both:

1. an initiator
2. impaired renal correction

Question 2

initiation of metabolic alkalosis

Answer 2

gain of alkali in ECF

• exogenous (e.g. IV NaHCO3)
• endogenous (e.g. metabolised ketoanion to produce HCO3-)

loss of H+ from ECF

• kidneys (e.g. diuretics)
• gut (e.g. vomiting)

Question 3

describe anion gap

Answer 3

• difference between cations (Na+) and anions (Cl- & HCO3-)
• normally 8-16
• used in metabolic acidosis
• if the anion of the nonvolatile acid is not Cl- then AG will increase (e.g. lactate)

Question 4

what does a large A-a gradient indicate

Answer 4

indicates impaired oxygen diffusion in the lung e.g. COPD

Question 5

describe chloride depletion

Answer 5

• Lack of Cl- = increased HCO3- reabsorption
• when Na+ & K+ are reabsorbed, Cl- balances anions to maintain electroneutrality
• thus deficiency of one = increased reabsorption of other
  e. g. diuretics (loss of NaCl)