Torque 2
I would have thought that the circumstances you decribe were appropriate to call PAN, PAN, PAN on the VHF frequency. That should get everybody's undivided attention, at which point you could explain your needs and get the necessary assistance - even if it turns out to be merely continuing two-way on 121.5. If, after your medical discussion on HF, it turns out that there is no urgency after all, the PAN can always be cancelled with no harm done. Your subsequent diversion indicates that the medical emergency was certainly sufficient to justify such action.
NN