Canadian-born Cordero had been admitted to the hospital for what initially appeared to be pneumonia, Kloots wrote on Instagram on April 1.
After an initial test came up negative, a subsequent test ultimately turned up positive for COVID-19.
In an emotional Instagram post last week, Kloots wrote, "My whole world has stopped. Please pray for my husband. Prayer warriors, prayer circles, whatever you've got.
"Energy, meditation, positive thinking. He is fighting for his life right now. Elvis and I need you Nick Cordero. It's time to fight daddy."
Late Saturday night, Kloots shared the details in an Instagram Story.
Cordero, 41, had a new infection in his lung that caused his fever to spike, his blood pressure to drop and his heart to beat irregularly.
"He lost consciousness, he lost his pulse and they had to resuscitate him... They had a very hard time getting him back. (Then) I got a phone call at 2:30 in the morning, they needed my consent to put him on dialysis to assist with his kidneys.
"This afternoon, we got a phone call that things were really moving in the right direction and that his life was being saved, which was huge. And we all kind of celebrated for a minute until ... they had to go into immediate surgery to save the blood flow to his leg," she said in the video.
"He is struggling. Just every minute counts right now. Please keep praying," a choking Kloots said.
On Sunday, she shared an update, asking people to pray that Cordero would wake up from sedation.
Later in the day, Kloots said she FaceTimed with Cordero and his blood pressure improved after he heard Elvis Presley's "Got A Lot O' Livin' To Do".
The couple have a son, Elvis.
Cordero received a Tony nomination in 2014 for his role as Cheech in "Bullets Over Broadway". RDSRDS