The computer systems at the Royal Melbourne Hospital will "hopefully" be restored by the end of the day after a computer virus wreaked havoc.
Melbourne Health, which manages the hospital, is still working to control a virus that has affected the hospital's core computer systems and personal computers since Friday afternoon.
The virus moved through the hospital's systems over the weekend, and IT staff and security consultants have been working around the clock to isolate the problem.
The virus has stopped hospital staff from accessing patient pathology results, with lab staff forced to do a "manual work around" the problem.
"This has slowed down the process and we have reverted to old-fashioned methods with paper-based records and phoning through and faxing results," Professor Chris MacIsaac told 3AW on Tuesday.
Dr MacIsaac, who heads the intensive care unit, said any "time-critical results" have been prioritised by the laboratory and are still getting through in a "timely fashion".
The hospital said the security of patient medical records has not been compromised, and elective surgeries and outpatient appointments are continuing as normal.
"Patient safety has always been our highest priority and has been maintained," the hospital said in a statement.
"We are working to fix this issue as quickly as possible. As soon as the virus has been removed, we will investigate how it came to infect Melbourne Health."
The Australian healthcare sector is increasingly technology reliant, with former Health Minister Peter Dutton having previously described Australia's AU$1 billion Personally Controlled E-Health Record project as a "struggling" system that failed to attract doctors to participate.
Since 2011, the former Labor government, in conjunction with the states, has invested over AU$1 billion in the e-health program aimed at improving patient care through making it easier for healthcare providers to access and share information about a patient throughout the medical system.
However, unlike the problems affecting the US government's healthcare website, Australia's e-health system has had very little interest from the public and doctors in signing up.
The healthcare industry has also been seen as an area of opportunity by vendors, such as IBM and Apple that announced their partnerships last April, to form a unit that would analyse and profit from healthcare data gathered from mobile devices.