Technicians from firewall vendor Check Point are examining Queensland Health's systems to try to uncover why some clinical staff have been denied access to the integrated electronic medical record (ieMR) at five hospitals this week.

eHealth Queensland CEO Richard Ashby said the problem became noticeable on Monday night and saw up to 10 per cent of requests for access to the ieMR denied. Wards at Princess Alexandra Hospital in Brisbane have reverted to paper to ease the load, but the emergency department and ICU were still using electronic systems, he said.