The daughters of another patient who died while critical care nurse Charles Cullen was employed by St. Luke's Hospital filed notice Thursday of their intent to file a wrongful death lawsuit.

Loretta Keller, 66, of Nazareth died at Easton Hospital on Feb. 2, 2002, three days after her heart stopped following treatment for non-Hodgkin's lymphoma at St. Luke's Hospital in Fountain Hill, where Cullen worked.

The civil summons was filed Thursday by the Palmer Township law firm of Cohen & Feeley, which represents several other families that have gone to court with concerns that loved ones may have been Cullen victims.

Attorney Martin Cohen said Keller's death occurred under unusual circumstances during Cullen's employment, but that the firm has not completed enough research to make a detailed case.

''We are trying to dissect anybody who calls here, looking at exactly what has gone on with their care and treatment to see if there are any inconsistencies,'' Cohen said. ''Some people clearly identify Mr. Cullen and some people are not sure. In this particular case we have a sudden death and a woman who seemed to be all right.''

Cohen said the two-year statute of limitations for medical malpractice lawsuits has forced his firm to file civil summonses, which preserve his clients' rights to file a wrongful death lawsuit, before knowing all the details of their cases.

In the Keller case, the filing deadline would have been today.

The summons names St. Luke's Hospital, Liberty Nursing Center, Cullen, Easton Hospital, Two Rivers Hospital Corp. (Easton Hospital's former owners), the defunct Healthforce nursing employment agency that hired Cullen at Easton Hospital, and related entities as defendants.

Cullen has been charged in Somerset County, N.J., with murder and attempted murder for allegedly killing one patient and allegedly trying to kill another in 2003 with overdoses of the heart drug digoxin at Somerset Medical Center in Somerville.

Cullen has told prosecutors that he has killed up to 40 patients in his 16-year nursing career, and the ongoing investigations into Cullen's past in seven counties in New Jersey and Pennsylvania have made collecting all the facts on many of his clients' cases nearly impossible, Cohen said.

The law firm said Keller had outpatient chemotherapy treatment during the day on Jan. 30, 2002, and fell over during dinner. She was taken to Easton Hospital in Wilson, where doctors told the family her heart had stopped.

She died there three days later.

According to Keller's obituary, she worked for the Nazareth Area School District as an administrative assistant for 20 years before retiring in 1999, volunteered at Nazareth Moravian Hall Square and had two daughters and two grandsons.

Cohen said he has contacted the administrations of both St. Luke's and Easton hospitals to discuss an agreement that would suspend the deadline to file detailed civil lawsuits until the criminal investigation into Cullen is complete.

To date, six civil summonses have been filed involving deaths that may be tied to Cullen. Four of the potential lawsuits are being handled by Cohen & Feeley, which has solicited victims' families with newspaper and television advertisements.

''We are trying to work something out with the hospitals that these matters be held up once the statute is protected, until the criminal investigation is complete,'' Cohen said.

Donald Auten, attorney for Two Rivers Hospital Corp., which owned Easton Hospital during Cullen's four-month employment there, said Cohen has raised the issue but not presented a formal proposal.

St. Luke's spokeswoman Susan Schantz did not immediately return two calls to her pager seeking comment Thursday. Another hospital spokeswoman said she could not answer questions on the suit and that Schantz would not be able to return calls until Monday.