"All the appropriate treatment is being given to him, but he is still critically ill. His recovery will require a lot of supplements," said Dr Naresh Trehan, who is attending to Mr Shukla.
Mr Shukla was operated upon yesterday and is on dialysis, doctors said.
The 84-year-old Congress leader sustained three bullet wounds after he was caught in an ambush by suspected Maoists on a Congress convoy. (Timeline: How it happened) Hospital sources said the bullets has injured his large intestine and grazed past liver and a lung. He also has a bullet injury in his leg, sources said adding that Mr Shukla has lost a lot of blood and there is a possibility of infection. (Read: How Naxals ambushed the Congress convoy)
Doctors are closely monitoring Mr Shukla in the intensive care unit of the hospital. They are concerned about his age.
Twenty four people, including state party president Nand Kumar Patel, were massacred by suspected Maoists in that attack. (NIA team to visit Raipur today)
Mr Shukla was first taken from the site of the ambush in Jagdalpur to Chhattisgarh capital Raipur, before being flown in an air ambulance to Delhi.
Delhi Chief Minister Shiela Dikshit and veteran BJP leader LK Advani visited Mr Shukla in hospital yesterday.
Mr Shukla belongs to an old Congress family, one of the famous Shukla brothers. His father was Ravi Shankar Shukla was the first Chief Minister of reorganised Madhya Pradesh.