Question

A 26-year-old woman reports that she has a severe migraine and has taken six times more than the recommended dose of aspirin for the past 3 days to relieve her headaches. Her plasma pH is 7.24. Which of the following would you expect to find compared with normal?

Answer 1

the patient is suffering from aspirin toxicity:

The following features can be seen in this condition:

Arterial blood gas:

• pCO2 - low ( less 45 mmHg - this could be due to two reasons
  1. High levels of salicylates can stimulate respiratory centers (central) and cause hyperventilation. This would cause respiratory alkalosis
  2. Low pCO2 levels may be due to compensatory hyperventilation secondary to metabolic acidosis.
  3. As the pH given is 7.24, it means the patient acidosis. the second cause seems more likely
  4. Salicylate poisoning promotes glycolytic pathways and inhibits the Kreb's cycle (uncoupling oxidative phosphorylation.
  5. There is an accumulation of lactic acid (a byproduct of the glycolytic pathway).
• Low bicarbonate - This can occur due to :
  1. As compensation for the response to respiratory alkalosis
  2. It may be due to metabolic acidosis
• Low or normal potassium - This can occur due to loss of potassium into the urine
  1. to compensate for respiratory alkalosis, the body loses bicarb.
  2. It also losses sodium with it
  3. the loss of sodium stimulates the release of aldosterone - this increased sodium and water retention.
  4. The body loses H+ and K+ the process
• High Anion gap - due to high acid in the blood
• Acidic urine - low urinary pH