My mentally impaired 96 yr old father is extremely depressed,my brother who likes people?

to know that he cares very much for his father,but is this the way to care for him? my mom is 91 and in the hospital recovering from an amputation of the left leg at the knee,im hpome with bronchitis and cannot get my father to the hospital to visit my mom,my brother promises my dad hed take him and conveiniently forgets what hes promised my dad,leaving my dad to sulk and get deeper into depression.hes gone to bed and i think in his little mind thinks people forgot him and his needs.which is what my brother has done many many times before.i wouldnt trust my brother for anything.hes half the problem why my dad is the way he is.