Act on user meta updated, but only once

If you can assume that user profile is edited all at once (Users Role, Organisation ID and Organisation name), you can hook on only one meta_key (say Organisation name) and send all infos at this moment. By the time this action is fired, all 3 metas are already in database.

add_action('updated_user_meta', 'when_user_meta_updated', 10, 3);

function when_user_meta_updated( $meta_id, $object_id, $meta_key, $_meta_value ) {
    // we do this only on one meta not all three    
    if ($meta_key == 'organisation_name' ) {
            $organisation_name = $_meta_value;
            // get other fields from db
            $user_role         = get_user_meta( $object_id, 'user_role', true );
            $organisation_ID   = get_user_meta( $object_id, 'organisation_id', true );


            // HTTP Call

        }
    }