I'm outside Canada and my PR card is coming up for expiration. I maintain permanent resident status because I am outside Canada with my spouse who is a Canadian citizen. Can I apply to renew my card from outside Canada?

Here is some information to obtain your PR Card.
First obtain a travel document from the nearest Embassy.
After you land back in Canada please apply for your PR Card or if you have enough time in, then your Citizenship and a Passport, IF YOU WISH.

Accompanying a Citizen: http://www.cic.gc.ca/english/information/applications/guides/5445EA.asp

Travel document: http://www.cic.gc.ca/english/information/applications/guides/5445E.asp

Hope this helps.

Freddie.