Question

In the acid–base diagram shown in Figure 12.3, where ‘L’ and ‘U’ represent the lower and upper levels of normal respectively, a patient whose arterial blood values were found to be at point:

a. V might have a compensated metabolic alkalosis.

b. W might have an uncompensated respiratory alkalosis.

c. X might have a compensated metabolic alkalosis.

d. Y might have a partly compensated respiratory acidosis.

e. Z might be suffering from severe vomiting

Answer 1

a. False Since all parameters are within normal range, acid–base balance is normal; for a metabolic alkalosis (compensated or uncompensated) the bicarbonate level must be above normal.

b. True The rise in pH is associated with a low PCO2 but a normal HCO3- .

c. True Or a compensated respiratory acidosis; in both cases bicarbonate and carbon dioxide levels are raised proportionately, so that the ratio PCO2 to HCO3- is normal, giving a normal pH.

d. False The patient has a partly compensated metabolic acidosis (low bicarbonate); the low pH indicates incomplete compensation; for a respiratory acidosis the carbon dioxide level must be above normal.

e. True The patient has an uncompensated metabolic alkalosis caused by severe loss of gastric acid.