If your stored procedure only returns OUTPUT parameters,
then you can use this shorthand:

$sth = $dbh->prepare('...');
$sth->execute;
@results = $sth->func('syb_output_params');

This will return an array for all the OUTPUT parameters in
the proc call, and will ignore any other results. The
array will be undefined if there are no OUTPUT params, or
if the stored procedure failed for some reason.

The more generic way looks like this:

$sth = $dbh->prepare(
   "declare \@id_value int, \@id_name
   exec my_proc @name = 'a string', @number = 1234, @id = @id_value
   OUTPUT, @out_name = @id_name OUTPUT"
);

$sth->execute;
do {
   while($d = $sth->fetch) {
      if($sth->{syb_result_type} == 4042) { # it's a PARAM result
         $id_value = $d->[0];
         $id_name  = $d->[1];
      }
   }
 } while($sth->{syb_more_results});