Legal question - Consent letters

[paddled hard]

My wife and I switch, most often it's me on the receiving end and I like it long and hard with various implements. I'm 62 and my wife is concerned that she might be charged with a crime if I should die doing a session or die with marks on my backside. We have discussed doing a blanket consent letter that would absolve her in that situation. I understand her concern and even tho I'm in good health it's not inconceivable. Has anybody done something similar? We've considered having an attorney draw it up. Any attorneys out there have an opinion? Any site owners care to share their consent agreements that spanking models probably have to sign? Should one be done for each session or would a blanket consent cover it just the same?