The 92-year-old veteran leader, who has been hospitalised since December 10, was put on ventilator Monday.
"His (Karunakaran) fever has come down, but his condition continues to be a cause of concern," a doctor said.
The doctors treating him at the private hospital here are in constant touch with the doctors at the CMC Hospital Vellore, where he was admitted after developing complications in 2008.
His son K Muraleedharan and daughter Padmaja Venugopal are at the hospital, besides a large number of supporters.
All eyes are on the Congress executive meeting here on Tuesday. The meeting is expected to take a decision on taking back Muraleedharan into the party.
"If the meeting decides to give a green signal, it could well be an emotional decision for the ailing Karunakaran who for long has been wanting to see the party take back his son. All those who are at the helm of affairs in the party today were groomed by Karunakaran," a senior Congress leader said.
Thiruvananthapuram: The condition of former Kerala chief minister K Karunakaran has improved slightly but he continues to be critical, doctors attending on him said on Tuesday.
First Published: Tuesday, December 14, 2010, 11:44