According to the codex for WP_Query, you should be able to tack on some meta related arguments to your args array (this is untested):
$review_args = array(
'orderby' => 'post_date',
'order' => 'ASC',
'posts_per_page' => '1',
'cat' => 22,
'meta_query' => array(
'key'=>'reviewed_by',
'value'=> $reviewed_by_array,
'compare'=> 'NOT IN'
)
);
$review_query = new WP_Query($review_args);