Most methods of sedation will bring on respiratory depression as a side effect. It's the reason you need to be on a ventilator when you're having anesthesia.
Needless to say, a patient who wants survive what the OP describes shouldn't risk additional respiratory depression.
Disclaimer: I'm no medical expert. I may be talking out of my ass.
Sedation should always be preferred to restraints, but for various reasons it is not possible to sedate someone 100% of the time in the ICU. The use of restraints described in the article is disturbing, but more context would be needed to understand whether they were appropriate or not.
Needless to say, a patient who wants survive what the OP describes shouldn't risk additional respiratory depression.
Disclaimer: I'm no medical expert. I may be talking out of my ass.