The medical team said the 69-year-old had been making continuous progress following Thursday's surgery and his organs were working well.
"Already 24 hours after surgery, Lauda could be extubated, was spontaneously breathing and had full consciousness," the hospital said in a statement.
The Austrian would stay at the hospital until he had made a full recovery, which could mean spending a while there.
The former F1 driver-turned-businessman had to cut short his vacation on the Spanish island of Ibiza to travel to Vienna as he became unwell.
According to Austrian daily ?sterreich, Lauda travelled to Vienna when his condition deteriorated after contracting the flu.
In 1976, the former Ferrari driver was involved in a serious accident at the German circuit of N?rburgring, sustaining severe burns.
He underwent kidney transplants in 1997 and 2005.
Lauda was crowned F1 champion three times: in 1975, 1977 and 1984.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
