The 92-year-old DMK president was readmitted to the Kauvery Hospital in Chennai on Thursday night.

DMK chief M. Karunanidhi, who was admitted to Kauvery Hospital past 11 p.m. on Thursday, spent Friday in hospital under the care of doctors.

A release from the hospital, signed by S. Aravindan, executive director, said he had undergone a tracheostomy procedure to optimise breathing. The procedure was necessitated by the fact that he had breathing difficulty caused by a throat and lung infection.

It may be recalled that he had earlier been admitted to Kauvery Hospital on December 1, a short while after he reportedly developed a drug-induced skin allergy.