As a medical specialist, I would offer assistance if required / requested without any expectation in return. Having said that a "Thank You" from the patient / relative would be sufficient; however, I think the airline could show some
appreciation (as the medical assistance may have avoided a very expensive diversion) for my inconvenience, especially if assitance is prolonged such as a bottle of nice champagne, upgrade on return journey or similar. I don't think money needs / should be exchanged either with the airline or the patient.
If airlines constantly don't show apprecaition (and doctors are human after all!

), it is unlikely they will be stampeded with offers of help the next time it is sought.