MANILA, Philippines -- (UPDATE 2) Former president Joseph Estrada, who promised to join the interfaith rally in Makati City against Charter change on Friday, had to skip the protest to rush to the side of his 103-year-old mother after learning she was in critical condition following a medical emergency.

"The doctors said that Doña Mary had flatlined, as in she was no longer responding," Estrada?s spokesperson, Margaux Salcedo said. "But they were able to revive her, and she's now undergoing blood transfusion."

"He was devastated. Even if this event [anti-Charter change rally] was so important to him, he really had to go to her," Salcedo said.

"What she underwent was severe hypotension. Her blood pressure went down to 60 and she had extreme difficulty in breathing," Salcedo said, quoting Dr. Ernesto Acosta, the Ejercito matriarch?s attending physician.

"Considering her age, this is a really critical condition...that she could go anytime. Even up to now, it's wait and see," Salcedo said.

The doctors resuscitated Doña Mary by putting her on blood suppressors and adjusting her respirator, but she remains under observation.

"Right now she's undergoing blood transfusion," Salcedo said in a phone interview.

She said Estrada was "very depressed. He's doing his best to monitor her situation. He can't leave her side."

Initially, Salcedo, quoting Estrada, said the matriarch had "flatlined," meaning her vital organs had stopped functioning, but Dr. Acosta later clarified that it was not a flatline since a "very, very, very faint" pulse remained.

Estrada's media liaison officer, Angel Gonong, said the former president was already at the house of Makati Mayor Jejomar Binay, president of the United Opposition, along with other friends and supporters, when he got a call from Dr. Pilarica Ejercito, his eldest sister, who was attending to their mother.

Salcedo said that, as far as she knew, Estrada was joined by all of his living brothers and sisters.

His children, however, were not able to join him.

Estrada?s son, Senator Jose ?Jinggoy? Estrada filled in for him at the Ayala rally, where he announced to the crowd why Estrada could not make it, Salcedo said.