OK. I don't know what you have already done, but :
When ever you talk to anyone at the hospital about this, make sure you get their name and position, and make it very clear to them that you are recording that information. I find it helpful to ask people to spell their names, even if it is Smith, --it's a good, and respectful, signal that you are calling them to account. Also ask for a receipt number if you speak to anyone on the phone and ask that a transcription of the conversation is emailed to you. Another respectful 'wind up skirt' exercise
The patient liaison person/ people, will have to formally report the incident if you tell them about it. It then needs to be investigated. (Ask for a copy of their investigation process policy--they will shit themselves. All policy documents are governance issues and have to be available to the public)
From there you need to talk to the person who is responsible for their investigative process and ask for a copy of the report into the incident. DO NOT GET FOBBED OFF. Sorry for yelling, but they will not want to give it to you, however as a participant in the incident you have an interest and eventually they will have to hand it over. Ask on your own behalf to start with, then begin to gently and vaguely introduce the idea of an insurance company. They hate insurance companies.
To be honest, you need to think what precisely you want from them. Do you want a payment, an apology, a change in policy? The thing you have to realize that if they agree to your requests, what ever they are, they are admitting culpability which opens them up to further action down the track. The first sign of a confidentiality/ no disclosure agreement will signal that you are entitled to compensation (which is obvious ) and they are offering you about 20% of what they may have to pay.
I know it is tempting to go to a no-win-no-fee lawyer, but you will get shit all out of it and the lawyer will do very nicely. Try to go it alone to start with and if you do get a legal rep, be very careful about what is, or isn't, in their contract. Marg xxx