$this->db->query("SET @q=''"); //set q variable

$sql    = "CALL some_procedure('$param1','$param2','$offset','$length',@q)"; //Call procedure

$arr['query']   = $this->db->query($sql) or die($this->db->error);

$sql    = "SELECT @q as q"; //select out parameter (@q) dari some_procedure

$qry    = $this->db->query($sql) or die($this->db->error); // muncul #2014 Commands out of sync; you can't run this command now
$row    = $qry->fetch_object();