Using NodeJS to send an mongodb data through to Jade

Im currently using nodejs, express, jade and mongodb to create a website. Its been going well so far however im currently trying to place a small box on the side of every page on the site that displays any updates/information/notifications. I understand in nodejs you can use res.render to show a page and pass a variable through to Jade(in the past using res.render ive passed through an array of mongodb data to jade). However since i want this notifications bar to show up on every page of the site i want to be able to go: "extends notifications" to pull the jade code for the notifications bar from a separate jade file. Therefore i was wondering how do i pass through a variable to jade(in this case an array from the mongo database of notifications to show) without having to render the page(eg res.render)

Extends Layout just brings through the code, therefore using a res.render on the initial page and putting a variable through will also work for any code within the "extends notifications"