example. when you change the status of an order to PROCESSED you could automatically open the print dialog to print it somewhere .
if you want to do something else on change of status , change as required.

add_action('admin_footer', 'wppizza_print_processed_orders');
function wppizza_print_processed_orders(){
global $current_screen;
if(isset($current_screen) && $current_screen->id=='wppizza_page_wppizza-order-history'){
echo"<script type='text/javascript'>
/* <![CDATA[ */
jQuery(document).ready(function($){
$(document).on('change', '.wppizza_order_status', function(e){
var self=$(this);
var selId=self.attr('id').split('-').pop(-1);
var selfVal=self.val();
/* do things when you change the status to PROCESSED, in this case trigger the print button **/
if(selfVal=='PROCESSED'){
var triggerTarget=$('#wppizza-print-order-'+selId+'');
triggerTarget.trigger('click');
}
});
});
/* ]]> */
</script>";
}
}