A recent medical-error tragedy in Seattle provides yet another example of why the nation needs passage of that federal patient safety bill that languished in conference committee after passing both chambers of Congress this year.

On Nov. 4, a woman undergoing an aneurysm procedure at Virginia Mason Medical Center was injected with a highly toxic antiseptic solution, rather than a harmless dye needed for follow-up X-rays. She died after 19 days of extreme measures, including amputation.

But unlike many such cases of preventable mistakes, the hospital has been apologetic and forthright in its admission of culpability. It even posted a staff memo on its Web site urging improved patient safety. The Seattle Times obtained an internal memo that shows that the hospital is taking immediate steps to reform its procedures.

Sadly, many hospitals won’t take such post-tragedy steps for fear that it would encourage or help malpractice litigation. And that’s where the proposed federal law comes in.

Modeled after a successful safety program in the airline industry, the law would establish patient safety organizations that would serve as clearinghouses of information on harmful medical errors. The key is that the information sent to PSOs would remain shielded from lawyers looking for malpractice fodder.

The idea is to build a database of information that researchers can draw on to establish improved safety guidelines for specific procedures. PSOs can also inform health-care professionals of mistakes that they may be apt to make, too.

Five years ago, the Institutes of Medicine issued a stunning report that medical errors account for more deaths per year than auto accidents, breast cancer or AIDS. Two of the chief reasons for these mistakes are the lack of consistent safety guidelines for medical procedures and the lack of information sharing when things go wrong.

In a recent article on the fifth-year anniversary of the IOM study, Dr. Lucian Leape, who helped write the report, said, “We’ve made a little bit of progress, but it has not been striking.”

Dr. Robert Wachter, a national advocate for patient safety, cited a 2000 study in which pilots and surgeons were asked their attitudes about being challenged by subordinates who thought something was askew. The pilots were nearly unanimous in wanting that information. Half the surgeons said they didn’t want to hear it.

What makes the post-tragedy actions of the Virginia Mason Medical Center all the more extraordinary is that they defy the legal environment that rewards secrecy and punishes candor.

All of the major medical associations support the congressional bill on patient safety. Congress should take advantage of that encouraging sign and help the medical profession heal itself.