Hospital officials continued to question staff yesterday at Anne Arundel Medical Center, where three infants in the critical-care nursery were found with opiates in their blood this week.
"We've identified people who were certainly around [the newborns]," Beth Evins, director of administrative and customer relations at the Annapolis hospital, said yesterday. She also said that "every piece of fact we get puts us closer to the truth."
The three babies remained in stable condition in the hospital's year-old critical-care nursery, which provides services to premature infants and those with serious health problems. No other babies in the unit have had similar problems.
Hospital officials are investigating whether someone tried to harm the infants and whether the hospital's medical supplies, equipment, cleaning or medicine distribution systems could have been the source of the opiates.
Since Tuesday, when the infants developed breathing problems, administrators have interviewed more than 30 part-time and full-time employees who may have encountered the children, Ms. Evins said.
They included nurses, patient-care technicians and neonatologists in the Perinatal Services Department, which includes the 15-bed critical-care nursery.
Tomorrow, hospital officials plan to continue their internal investigation, including interviewing more clinical employees and secretaries who work in the nursery.
"The goal of Monday is to get through the remainder of the clinical staff," Ms. Evins said. "We'll broaden our discussions from there. We're sort of doing a ripple effect."
Hospital authorities conducting the interviews include Sharon M. Rossi, clinical director of perinatal services; Dr. Jon B. Lowe, senior vice president of medical staff affairs; and two nurses specializing in the neonatal field.
No employees have been fired or disciplined in any fashion, officials said.
The investigation unfolded early last week after a toxicologic test found traces of unidentified opiates in the blood of the newborns. Officials ruled out the possibility that the opiates may have been transmitted to the children during pregnancy.
Hospital officials say they expect to learn the identity of the drugs early next week through a number of laboratory tests.
The Maryland Medical Laboratory in Baltimore is testing samples of various solutions and medications being used by the children. In addition, blood samples are being examined by the hospital and by another independent laboratory.
Officials have not ruled out the possibility that the previous tests may have been mistaken.
No parents have withdrawn their children from the nursery, officials said, and police have not been contacted yet because criminal activity is not suspected.
Officials said they have tried to reassure parents about the safety and security of the critical-care unit. The hospital has installed a locking system that will admit only the staff to the nursery and has replaced all medical supplies stored in the unit.
"We've informed them at every step of the way," Ms. Evins said. "We've been as factual with them as with anyone else."
After the incidents, all of the infants in the critical-care unit were transferred for about 24 hours to an adult coronary care unit while the nursery was examined.