Medical Record and The Court

Please help me with this matter.

Let's say a patient is suing a doctor for medical malpractice but the patient does not want his medical record to be used as an evidence. In this case, is the privileged communication absolute? What if the court issued a subpoena duces tecum? Will the patients chart be use even if the client doesn't want to?

Can you please give me references for this scenario. Thank you very much for the help.