The Melbourne Magistrates' Court today heard Esmaili is withdrawing from a drug dependence and has psychiatric illnesses.
He was remanded until August 24.
Pritzwald-Stegmann, a cardiac and thoracic surgeon, remains in the Alfred Hospital in a critical condition.
The Royal Australasian College of Surgeons branded the alleged attack "obscene".
Pritzwald-Stegmann, a father in his 40s who moved to Australia after completing his studies in New Zealand, was treated at Box Hill Hospital and then taken to The Alfred, where he was last night in a critical condition in its Intensive Care Unit after emergency surgery. His family were at his bedside.
Shocked colleagues and friends of the German-born doctor, whose lifesaving work has included placements in Europe, were "praying for a miracle".
One wrote: "This absolutely breaks my heart."
Another man and a woman, who were also captured on CCTV, may be witnesses who could have information that would assist police.
Medical groups last night called for zero-tolerance of violence against hospital staff.
OUTDOOR SMOKING 'OFF THE MENU' IN VICTORIA
Royal Australasian College of Surgeons trauma chairman Dr John Crozier said the alleged attack was obscene.
"The brain is a delicate organ, and the human, ultimately, a fragile creature," Dr Crozier said. "Such criminal violence is unacceptable."
AMA Victoria president Dr Lorraine Baker said violence against healthcare workers was a "common and regular occurrence".
"Healthcare workers are entitled to work in a safe environment. You should be able to turn up to work and not be abused, threatened or assaulted," Dr Baker said.
"But it is a terrible reality, and sometimes a regular occurrence for those who work in hospital emergency departments and on the wards."
