A sharply divided Georgia Supreme Court on Monday upheld a key part of a sweeping 2005 law that made it more difficult for patients to win medical malpractice cases involving emergency health care providers.

The court’s 4-3 ruling was a blow to plaintiff’s attorneys and other critics of the legislation who argued the higher standard of proof required by the law made it almost impossible for patients injured by emergency room workers to win malpractice claims.

Critics of the law took another hit Monday when the court released a separate ruling, this one by a 5-2 vote, that upheld a provision that allowed one side in a lawsuit to pay the other side’s legal fees in some cases. They had argued the practice could discourage many victims from bringing legitimate claims to court.

The court will likely issue a third ruling this month on a lawsuit that challenges the law’s $350,000 limit on jury awards for malpractice victims’ pain and suffering damages.

The lawsuit involving the emergency room provision was brought by Carol Gliemmo, who said an emergency room doctor at a Columbus hospital failed to detect a debilitating illness in April 2007 when she came in complaining of sudden pain behind her eyes.

She was released from the hospital when her blood pressure went down. But two days later her family practitioner ordered a CT scan, which revealed a brain hemorrhage that left her paralyzed. Her family then filed a lawsuit claiming the doctor was negligent in failing to order a test that would have detected the brain aneurysm.

But the legislation requires the Gliemmos to prove emergency room doctors acted with “gross negligence,” a standard that forces attorneys to prove they knowingly mistreated their patients. The family claimed the requirement was unconstitutional, saying it’s a nearly insurmountable hurdle.

The court’s majority opinion, penned by Justice George Carley, found that it was “entirely logical” for lawmakers to approve the legislation in hopes of stemming the rising cost of medical malpractice insurance. He was joined by Justices P. Harris Hines, Harold Melton and David Nahmias.

A dissent written by Justice Robert Benham criticized the new legislation for leaving patients with a “lower standard of care and a higher burden of proof.” He was joined by Chief Justice Carol Hunstein and Justice Hugh P. Thompson.

The second ruling, which centered on a case involving a former Atlanta Falcons player, upheld a part of the law designed to discourage frivolous lawsuits with new incentives for patients to settle out of court.

The “offer of settlement” provision required some plaintiffs to pay the other side’s attorney’s fees if they lose their case or if they win only a portion of a settlement offer.