Marcus said his experience with Obiora "makes you wonder" about temp nurses. "Have they made errors elsewhere? Who is monitoring them?"
Some temp firms indicated that they don't use a nurse again if they feel at all uneasy. "We just don't want to take the risk," said Jim Essey, who runs a New York-based temp agency and is a former chairman of the American Staffing Assn., an industry trade group.
Other agencies say most rejections stem from picayune problems, such as tardiness and personality clashes.
But data provided by public hospitals show this isn't necessarily so.
According to Riverside County Regional Medical Center, for example, more than 60% of the 339 temp nurses rejected since 2003 failed to demonstrate basic nursing skills on the job. Arrowhead Regional Medical Center, San Bernardino County's public hospital, reported that it had rejected 61 temp nurses since 2005 -- more than half for performance problems.
Hospitals sometimes lose track of which nurses they have already booted. A nurse can be red-flagged by one unit and later sent to another.
At Lakewood Regional Medical Center in March 2008, temp nurse Kelvin Brown was found in a deep sleep at the nurses' station on a ward of patients hooked up to monitors.
He was roused but later fell asleep in a patient's room. Awakened again, he dozed off in the break room. Asked to leave the hospital, he made it as far as the intensive care waiting room before slipping into sleep once more. He left after security called police, according to the nursing board's December 2008 accusation against him.
A supervisor later discovered that Brown had had problems at the hospital before. He had fallen "heavily asleep on every shift and exhibited behavior -- such as talking to and answering himself aloud -- that made staff uncomfortable," the accusation said.
In fact, Brown had been placed on the hospital's "Do Not Return" list while working for another agency for such reasons, the document states.
A spokesman for Tenet Healthcare Corp., Lakewood's parent, confirmed that Brown had worked at the hospital before but disputed the state's account that he'd been previously barred from working there.
Brown could not be located for comment.
In another case, St. Jude Medical Center in Fullerton informed MedStaff Healthcare Solutions in March 2007 that it suspected nurse Donald Paradise of stealing drugs and asked that he never return, a hospital spokesman said. Six months later, Paradise was accused of stealing drugs at a sister hospital, where he also had been sent by MedStaff.
"It's absolutely not acceptable," said Kevin Andrus, a spokesman for St. Joseph Health System, which includes St. Jude.
MedStaff's contract, he said, prohibited it from sending a rejected nurse back to any hospital in the chain, but Andrus conceded that the chain doesn't keep a master list, as some entities do.
A spokesman for MedStaff said that Paradise had passed a drug screening after the St. Jude incident and that the hospital had indicated it was satisfied with that. Andrus says that was not so.
Paradise, who faces a nursing board accusation, could not be reached for comment.
In interviews, several temp nurses who had been in trouble said their employers focused more on keeping slots filled than on who filled them.
That was a lifeline for Obiora.
The agencies "just send and send and send and send," he said.
Lisa Schwartz, director of research at ProPublica, contributed to this report.