Doctors removed Rep. Gabrielle Giffords from a respirator on Saturday, a week after she and 18 other people were shot in Tucson, but she underwent surgery to insert a tracheotomy tube in her windpipe.
A statement from University Medical Center said the tube would protect her airway and free her from a ventilator. The statement said a feeding tube also was inserted, and that both procedures "are not uncommon among brain-injured patients in the Intensive Care Unit."
Doctors said she remains in critical condition, but is recovering well. Her husband, astronaut Mark Kelly, has remained by her bedside.
Six people were killed in the attack last Saturday.
The Safeway grocery store where the shooting occurred reopened at 7 a.m. local time. Business was brisk.
"Our employees have been through so much but they are here, they're working and kind of anxious to reconnect with their customers and the community. We're doing OK," store spokeswoman Cathy Kloos said.
Jared Loughner, 22, was targeting Giffords at her "Congress on Your Corner" event at the supermarket, authorities said. He took a cab to the grocery store and went inside to get change for the fare before the rampage, authorities have said.
Across town, thousands of shoppers browsed for guns at a trade show, despite new questions about permissive gun laws in the United States.
"People see it as either guns are going to get banned, or I'm going to get shot," said stall holder Randall Record, 27, explaining the mood at the Crossroads of the West Gun Show on the outskirts of the city. "Either way, it drives sales."
Also Saturday, paramedics recalled what happened when they were dispatched to the supermarket a week earlier.
Firefighter paramedic Tony Compagno said after his fire engine arrived on the scene, he jumped out and began triage on the victims that lay on the walkway outside the grocery store.
At least four people were already dead.
Compagno, a 13-year veteran paramedic, said Giffords and the youngest victim of the mass shooting, 9-year-old Christina Taylor Green, needed the most immediate attention. Green was among those who died.
"It was a lot of chaos and a lot of blood," said Kyle Canty, 39, who responded along with Compagno. "It's like snapshots in my head."
As the city of Tucson continued to try to heal, a video shot by the suspected gunman showed the former community college student touring campus at night and at times rambling about free speech and the Constitution.
Loughner shot and narrated the video tour of the Pima Community College campus that illustrated his deep anger toward it, at one point saying "I'm gonna be homeless because of this school."
College officials confirmed that the video, discovered on YouTube, was the last straw in their decision to suspend Loughner from school Sept. 29.
In the video, he calls Pima "a genocide school." Panning an empty concourse, he says: "We're examining the torture of students."
The Los Angeles Times received a copy of the video under an open records request.
Also Saturday, authorities revealed details about the suspect's final hours. Loughner posed for photos with a gun, dressed only in a bright red G-string, and had the film developed on the eve of the rampage, according to a law enforcement official who spoke on condition of anonymity because he was not authorized to do so.
The detailed timeline of Loughner's busy 11 hours before the shooting also had Loughner checking into a motel, posting "Goodbye friends" on the Internet and buying bullets from a Walmart.
As those details came to light, at least a half-dozen lawmakers around the country met with constituents at gatherings similar to the "Congress on Your Corner" meeting where Giffords was shot. The events, they said, sent a message that violence would not keep them from meeting face-to-face with constituents at supermarkets, hardware stores or anywhere else.
The events, however, were held amid tight security.