WPF calling commands via events

Is it possible to call a command via an event in WPF?

I have a save button that when pressed calls a command, this is pressed when you have finished editing a textbox, it also passes an object as a command parameter

 <Button Content="Save"  Command="{Binding DataContext.SaveQueueTimeCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}}" CommandParameter="{Binding}" />

What I would ideally like to do is call this command and pass the object as a parameter when the textbox loses focus, rather than having to press the button, something like:

 <Button LostFocus="{Binding SaveQueueTimeCommand}" />

And still somehow pass the object as a parameter. Is there a way to acheive this without using code behind as I am using the MVVM pattern

Thanks for your time