Coding CPR

I work for a pulmonologist, he does rounds in the hospital. He tended to a patient in ICU and had to perform CPR 2x same visit. I billed 99291-25, 92950-76, 92950 and 31500 (intubation). Medicare denied 92950-76 as invalid modifier. Can someone please tell me what modifer needs to be billed, or what I did wrong? Thank you.

re: Coding CPR

Probably should only bill 92950 only once, same encounter