Hospitals around the country are scrambling to stockpile vials of a critical drug — even postponing operations or putting off chemotherapy treatments — because the country’s only two suppliers have run out.

The medicine? Sodium bicarbonate solution. Yes, baking soda.

Sodium bicarbonate is the simplest of drugs — its base ingredient, after all, is found in most kitchen cabinets — but it is vitally important for all kinds of patients whose blood has become too acidic. It is found on emergency crash carts and is used in open-heart surgery and as an antidote to certain poisons. Patients whose organs are failing are given the drug, and it is used in some types of chemotherapy. A little sodium bicarbonate can even take the sting out of getting stitches.

“As I talk to colleagues around the country, this is really a problem we’re all struggling with right now,” said Mark Sullivan, the head of pharmacy operations at Vanderbilt University Hospital and Clinics in Nashville.

Hospitals have been struggling with a dwindling supply of the medicine for months — one of the suppliers, Pfizer, has said that it had a problem with an outside supplier but that the situation worsened a few weeks ago. Pfizer and the other manufacturer, Amphastar, have said they don’t know precisely when the problem will be fixed, but it will not be before June for some forms of the drug, and in August or later for other formulations.