One approach that is not very secure but is cheap and fast (so if you're going in for emergency surgery and only have a couple minutes to prepare) is to send a letter to yourself just before the operation. Print out your passwords, stick them between two sheets of cardboard or other sheets of paper on which you've scribbled random lines (to prevent someone from holding the letter up to the light to read the message) and send it to yourself. Add a sticker (or a painted strip of nail polish of which you've taken a picture) across the flap as a little added intrusion detection.
This avoids the problem that some people have identified with other solutions, namely remembering what you did with the passwords. ["I got a letter, I guess I should open it since that's what you do with letters."] It also makes it a federal offense (mail tampering) for others to open your mail, and it is a little bit of "security through obscurity" because that letter will look like any other letter you receive. [Security through obscurity shouldn't be your ONLY means of security, but if you have to use that approach the obscurity is a bonus.] Sure, it's not going to safeguard your passwords from the government ... but if the government is really interested in your passwords, they have other approaches they can use (cue the XKCD about a $5 wrench.)