Using Store Procedure with an OUT parameter in Laravel

Im having a problem calling an store procedure that has two OUT parameters. I cannot get them.

Here is my procedure first line:

PROCEDURE `validate_reservation`(IN people INT, IN r_date DATETIME,IN place_id INT,IN max_people INT,IN more_people TINYINT(1),OUT r_status CHAR(20),OUT message CHAR(100))

And here is how I call it from laravel 5:

DB::statement("call validate_reservation(4,'2016-04-26 20:30',1,10,1,$status,$message)");

I dunno if I have to pass two empty variables and they will turn the values of the output or if that is the return of the statement.

If I pass two empty variables laravel tells me they are not defined. If I don't pass them, laravel tells me the procedure is waiting for 7 parameters intead of 5.

Thanks for helping me,

via Chebli Mohamed