The Democrat-dominated Senate on Tuesday unanimously approved the first six members of President Obama's Cabinet just hours after he was sworn in, but the day was marred by a seizure that struck Sen. Edward M. Kennedy, Massachusetts Democrat, at the traditional Capitol Hill luncheon honoring the new president.
And a key Republican senator's skepticism Tuesday about approving Hillary Rodham Clinton as secretary of state meant she had to wait at least another day to formally join Mr. Obama's administration.
In a welcoming present for the new Democratic chief executive, Senate leaders agreed to waive votes and confirm unanimously six of Mr. Obama's Cabinet choices: physicist Steven Chu as energy secretary; Arne Duncan as secretary of education; Arizona Gov. Janet Napolitano as head of the Department of Homeland Security; former Colorado Sen. Ken Salazar as interior secretary; retired Army Gen. Eric K. Shinseki as head of the Department of Veterans Affairs; former Iowa Gov. Tom Vilsack as agriculture secretary. It also approved Congressional Budget Office chief Peter R. Orszag to run the Office of Management and Budget.
Lawmakers emerging from the luncheon said Mr. Kennedy, who has brain cancer, suffered a seizure and had to be taken out of the room in a wheelchair. Several lawmakers said he appeared to be doing better when he was taken to Washington Hospital Center.
"I'm not a doctor, but he looked better, like he was going to be OK," said Sen. Orrin G. Hatch, Utah Republican.
Those at the luncheon said Sen. Robert C. Byrd, West Virginia Democrat, had also been taken out of the luncheon before Mr. Kennedy was stricken. However, the condition of the 91-year-old Mr. Byrd was not thought to be serious.
Regarding Mrs. Clinton's nomination, Sen. John Cornyn, Texas Republican, said the Senate needed more information about how former President Bill Clinton's international foundation could affect his wife's role as the country's top diplomat.
Mr. Cornyn is one of several Republicans who have raised questions about the business and charitable dealings of Mr. Clinton and his foundation.
"Transparency transcends partisan politics, and the American people deserve to know more," said Mr. Cornyn.
Mrs. Clinton was endorsed last week by the Senate Foreign Relations Committee in a 16-1 vote, and her ultimate confirmation is still considered highly likely. She released a five-page disclosure program to Mr. Obama upon accepting the nomination and has insisted her husband's business and charitable links will not affect her job.
Senate Majority Leader Harry Reid, Nevada Democrat, and Senate Minority Leader Mitch McConnell, Kentucky Republican, agreed on Tuesday to a three-hour floor debate Wednesday followed by a vote on Mrs. Clinton's nomination in the afternoon.
For a brief moment Tuesday, Defense Secretary Robert M. Gates, held over from the Bush administration, was the only official member of the new Democratic president's Cabinet before the seven appointees were approved.
In one of his very first official acts as president, Mr. Obama signed the official nominating papers for his Cabinet selections inside the Capitol shortly after being sworn in, joking as he signed that he was left-handed and people should "get used to it."
Just an hour later, lawmakers and staffers said Mr. Kennedy had what looked to be a "lengthy seizure."
Sen. Christopher J. Dodd, Connecticut Democrat, said Mr. Kennedy was talking and aware after the seizure, although still in discomfort as he boarded the ambulance. Mr. Kennedy's wife, Vicki, was with him.
"He looked better when they put him in the ambulance," Mr. Dodd said.
Mr. Reid said on the Senate floor that Mr. Kennedy's seizure was a sad blot on the happy day of Mr. Obama's inauguration. Mr. Kennedy, 76, underwent surgery after being diagnosed with brain cancer in May. He has been able to return for his senatorial duties only intermittently since then.
"I would ask all within the sound of my voice to pause briefly and offer our thoughts and prayers for Senator Kennedy and his lovely wife," Mr. Reid said.
Sen. John D. Rockefeller IV, West Virginia Democrat, told reporters that Mr. Obama noticed when Mr. Kennedy became ill, and rushed over to his table, the Associated Press reported.
"There was a call for silence throughout the room," he said. "The president went over immediately. The lights went down, just to reduce the heat, I think."
In his remarks, Mr. Obama said his prayers were with the stricken senator, his family and wife.
"He was there when the Voting Rights Act passed, along with [Rep.] John Lewis, [Georgia Democrat], who was a warrior for justice," the newly inaugurated president said. "And so I would be lying to you if I did not say that, right now, a part of me is with him."
Two other key Cabinet picks have not even had a Senate floor vote scheduled.
While Mr. Obama's Cabinet picks are expected to secure relatively quick approval, there have also been some personnel hiccups that have marred the new president's generally well-reviewed transition.
Mr. Obama has yet to name a replacement for New Mexico Gov. Bill Richardson as secretary of commerce. The governor, who also briefly vied for the Democratic presidential nomination against Mr. Obama, withdrew from consideration earlier this month to deal with a grand-jury investigation into corruption in his home state.
Timothy F. Geithner, the New York Federal Reserve Bank president tapped to be Treasury secretary, had his confirmation hearing before the Senate Finance Committee delayed last week after reports surfaced of irregularities in the nominee's tax records over several years. The hearing will be held Wednesday, and Mr. Geithner is expected to eventually be confirmed, assuming no new embarrassing revelations come to light.
Former Sen. Tom Daschle, South Dakota Democrat, is also expected to be easily confirmed as secretary of health and human services. However, having appeared before the Senate Health, Education, Labor and Pensions Committee, Mr. Daschle still must go before the Senate Finance Committee before he will be officially confirmed.
The committee also meets Wednesday to approve the nomination of Rep. Hilda L. Solis, California Democrat, as labor secretary, although some committee Republicans have grumbled about the vagueness of Mrs. Solis' answers during her hearing.
Despite the praise for Mr. Obama's transition effort and the backing of a Democratic-dominated Senate, the confirmation process is not proving noticeably faster than past administrations.
According to a survey by Congressional Quarterly, President Reagan had 12 of his 14 Cabinet picks approved two days after he took office, and President Clinton had 13 of the 15 main posts within a day of his inauguration. President Bush saw seven of his nominees approved by the Senate the day he was sworn in and his entire Cabinet in place 11 days later.
• Sean Lengell contributed to this article.