Can cephalosporins work to treat pseudomonas aeruginosa?

Sometimes: There are several kinds or "generations" of cephalosporins antibiotics, which are antibiotics that are chemically related to penicillin. Some of the drugs in this class are highly effective against pseudomonas and some are not. In fact this can vary to some degree depending on the antibiotic sensitivities specific to the pseudomonas strains prevalent in a particular hospital or community.

Yes some: There are many different cephalosporin antibiotics. Many are not effective against ps. Aer. Those that are active against this organism are Fortaz (ceftazidime) and maxipime(cefepime).