This is something that I have been considering for quite a while based on a fictional story I had read.
An unconscious individual must undergo emergency surgery in order to stabilise them and prevent the patent's death. This medical intervention is happening without the patent's explicit consent however since a reasonable person can be expected to consent to life saving surgery (absent a living will or some other indication) I don't think anyone would have any ethical concerns about it.
However while the surgery is occurring something that would not cause immediate harm but is highly likely to cause extreme disability in the long term is discovered (for example a tumour). Is it ethical to fix this newly discovered condition at the same time?