Metabolic alkalosis is usually categorized as either chloride responsive or nonchloride responsive. Common causes for chloride-responsive metabolic alkalosis in the intensive care unit (ICU) setting include diuretic therapy, vomiting (or from excessive nasogastric suctioning), and diarrhea. Nonchloride causes include alkali administration (with sodium bicarbonate or rapid infusion of more than eight units of blood that contain large quantities of citrate), mineralo-corticosteroid excess (corticosteroid administration), chronic respiratory acidosis (secondary to permissive hypercapnea from mechanical ventilation), and hypokalemia.

Therapy for metabolic alkalosis in most patients involves discontinuing the causative factor for alkalosis and undertaking volume and electrolyte repletion. Patients in an edematous state, however, follow a different principle since it may be desirable to avoid volume repletion. Treatment with acetazolamide (Diamox) may be indicated in this setting. Acetazolamide is a carbonic anhydrase inhibitor that acts by promoting the renal excretion of bicarbonate anions and hence reversing the metabolic alkalosis.