Exclude Child Categories

Hi all,

I am using the following to show the lastest post on the homepage, whilst excluding a particular category:

<?php $recent = new WP_Query("cat=&exclude=134&showposts=1"); while($recent->have_posts()) : $recent->the_post();?>

The only problem is that category has child categories, I would like to exclude these too, can somebody help me achieve this?

Thanks