Dr. David C. Arndt posed an immediate threat to health, safety and welfare when he allegedly left a patient at Mount Auburn Hospital in Cambridge to go to a bank in Harvard Square, the state Board of Registration in Medicine ruled Wednesday. He returned about 35 minutes later and completed the operation.
"I've never seen anything quite like this," said Nancy Achin Sullivan, executive director of the board.
The hospital, which suspended Arndt last month, issued a statement saying the patient was not harmed and the hospital reported the incident to the board. Arndt's patients have been transferred to other surgeons.
"Mount Auburn Hospital is dedicated to excellent patient care and maintains high standards of care," the statement said. "Those standards were breached in this incident."
Arndt and his lawyer, Claudia Hunter, did not immediately return phone calls requesting comment Thursday.
According to the board's investigator, who interviewed the operating room staff and other hospital employees, the patient was anesthetized for spinal fusion surgery at around 9:20 a.m. The first incision was made around 11 a.m.
During the surgery Arndt asked a nurse several times to call his office in Wellesley to see if his paycheck had arrived.
Around 5:30 p.m., with the surgery about three-quarters completed, another surgeon stepped into the operating room and handed Arndt an envelope containing his check. Arndt asked him to wait there for five minutes while he took a break. The other surgeon told the board he assumed Arndt was going to the bathroom.
The second surgeon was not credentialed to perform spinal fusion surgery, and was not scrubbed in, the board said.
While he was gone, Arndt failed to answer several pages.
Arndt later explained he had thought the surgery would be over before the bank closed at 7 p.m, but the operation took longer than he expected. He also told the board he left his outside page number at the hospital desk.
He explained that he had to get to the bank before it closed because he was in "a financial crisis," and had to pay overdue bills. He told the board's investigator that he regretted his actions, and had "exercised remarkably horrible judgment."
In suspending Arndt's license, the board called him "an immediate and serious threat to the health, safety and welfare of the public."
A 1992 graduate of Harvard Medical School, Arndt also has operating privileges at Brigham and Women's, Beth Israel Deaconess and New England Baptist hospitals in Boston, and Newton-Wellesley Hospital. He also is licensed to practice medicine in Louisiana.
He has practiced at Mount Auburn since 1998, and had no prior record of discipline there, according to a hospital spokeswoman.
Arndt may not practice in Massachusetts until further order of the board. He can appeal the board's decision.