Salt substition aids high risk levels

Dear Dr. Roach: Ina recent column, you said that using salt substitutes can reduce blood pressure and that, across a population, this would result in far fewer heart attacks and strokes.

While lowering blood pressure would have that effect, my understanding is that there is no significant research showing benefits from lowering salt intake in individuals with normal or lower blood pressure. Is that the case?

R.L.

Answer: Interventional trials of salt substitutes and low sodium diets have only been done on people at a high risk, such as people with a history of stroke or with high blood pressure. It would be very hard to prove a benefit in people who are at low risk, since it would require many people to be followed for many years. It is thought that the primary way salt restriction (or substitution of sodium with potassium) works is through lowering blood pressure, so it seems unlikely that there would be a major benefit for people with normal blood pressure.

Dear Dr. Roach: Iam79 and in quite good health. Recently, I have had two procedures that required light sedation (a colonoscopy and endoscopy). Both times when I woke up, I began sneezing violently, which would sometimes go on for hours.

My symptoms were those of a severe allergic reaction.

The contact nurse checked with the anesthesiologist, who said he had never known sneezing to be a reaction. He said it could have been related to the oxygen drying out the nasal passages. Now I have anxiety about ever having oxygen administered. Have you ever seen a reaction to oxygen like this?

W.I.K.

Answer: This is not a rare occurrence. It even has a (somewhat droll) published name: “PRAISE SNOG,” which stands for “Postprocedural Rhinitis After Intravenous Sedation with Supplemental Nasal Oxygen.” It is thought to be partly due to a nonallergic rhinitis (nose inflammation) of cold and dry oxygen. In addition, the prongs of the nasal oxygen tube can irritate the lining of your nose.