Juan Manuel Correa, the American driver injured in a Formula Two crash which claimed the life of Anthoine Hubert at the Belgian GP last weekend, has been placed in an induced coma at a London hospital.
The 20-year-old Correa is in a critical but stable condition after being diagnosed with Acute Respiratory Distress Syndrome.
A statement released by Correa's family reads: "As time has progressed, new complications have surfaced as a consequence of the massive impact he (Correa) suffered in Belgium."
Correa, who was born in Ecuador, broke both legs and injured his spinal cord in the estimated 160 mph (257 kph) accident and was transported to hospital in London this week following an operation in Liege.
His family adds: "We are confident that our son will surprise us like he always does with his tremendous fighting will and strength and will recover completely."
The incident at the Spa-Francorchamps track happened when Hubert appeared to lose control of his car on the exit of a corner before slamming into the far-side barrier. His car flew off the tire wall and slid across the circuit before he was hit by Correa's car.
There are various tributes to Hubert by Formula One drivers at the Italian Grand Prix.
Charles Leclerc has "RIP TONIO" on his helmet, while Lewis Hamilton has the message "Racing for Anthoine" on his Mercedes.
Leclerc won the Belgian GP and dedicated what was his first victory in F1 to Hubert, his friend and former rival.
Hamilton posted a message to Instagram on Friday in memory of the French driver.
He wrote: "Still thinking of Anthoine. It feels like the world has just moved on already but you are very much still in my thoughts."