Admin password/email changed and he still logged in and carried operations

Hello,
A  system developed with  Codeigniter is It is giving us admin log issues.

When Admin  password is changed  in DB, the  Admins is still logged in and carry operations
When  the admin  email is changed in DB , the same admin is still logged on and carry operations.
When both email and password is changed  in DB , the still logged on and carried operation.

Please, how can we resolve this?
How can the admin be logged of immediately hiw password or Email is Changed? 

Any suggestion will be help.


Thank you in advance.