If you’ve identified metabolic alkalosis, congratulations: you’ve already done 50% of the work! Assuming you also have accounted for concomitant acid-base disturbances…
What remains is figuring out the cause of the metabolic alkalosis. Be aware that metabolic alkalosis can be associated with severe electrolyte derangements like hypokalemia, hypomagnesemia, and hypoalbuminemia. Think about processes that would deplete bicarbonate or potassium.
- Vomiting and diarrhea.This is unlikely to land a patient in the ICU, but villous adenomas can excrete bicarbonate and cause a hyperchloremic alkalosis!
- Severe potassium depletion
- Post-hypercapnic alkalosis, seen in COPD patients who have their PaCO2 corrected. This may be associated with a concomitant respiratory acidosis.
- Iatrogenic: diuretics and steroids are two common players. Think about your patients on a lasix drip. Remember that if you resuscitate someone with ONLY normal saline, they are at risk for a non-gap metabolic ACIDOSIS.
- Underlying endocrine problems: hyperaldosteronism and Cushing’s syndrome
How is the alkalosis then treated? Correcting the underlying problem is best. There is some data that using acetazolamide, no matter what the cause, is a quick and relatively safe way to correct alkalosis.