In script : ssh and then sudo rootsh root

Can't find the solution. I need in the script - ssh to a server then change to root via sudo /usr/bin/rootsh -i -u root. Then make some action then go back and carry on with script... Something like

...
ssh -t myserver 
EOF
...

If I do it this way - doesn't work. If done in the way

ssh -t myserver 'sudo /usr/bin/rootsh -i -u root ;whoami'

I can do ssh and then switch to root, but then script wait until session/shell closed.