WASHINGTON – The decision by the pope’s doctors to perform a tracheotomy – an incision in the neck directly into the trachea, or windpipe – is a strong indication that John Paul II’s condition is quite serious, medical specialists said Thursday.

“It’s a major development,” said Martin Blaser, chairman of medicine at New York University Medical Center in Manhattan and president-elect of the Infectious Diseases Society of America. “This is not a good sign.”

The operation allows a patient to breathe through that new opening instead of through the nose and mouth. Although it is commonly used to provide an alternative airway for patients with a breathing obstruction, its use in the pope is almost certainly not for that but for any of three other common reasons, doctors said.

Suction: At a minimum, a tracheostomy allows easy access to the trachea so doctors and nurses can periodically suction from the airway the fluids that accumulate as a result of pneumonia – an infection in the lungs, which the pope appears to have.

Preventing reinfection: The elderly and the frail often develop pneumonia as a result of aspirating bacteria from their mouth or nasal passages into their lungs. That’s especially true of patients with Parkinson’s disease, the progressive neurological disorder that has long afflicted the pope. Such patients lose control over their epiglottis, the fleshy barrier that separates their food-carrying esophagus from the trachea, which when healthy should remain sterile. By bypassing the upper respiratory tract, a tracheostomy offers a cleaner air supply. And its need suggests that the pope has been suffering not from influenza or a cold but from repeated aspiration pneumonias, perhaps the most common cause of death for Parkinson’s patients.

Emergency airway access: If the pope should stop breathing on his own and it becomes necessary to place him on a mechanical ventilator, a tracheostomy will make the procedure easier. Otherwise it is necessary to perform an emergency intubation through the mouth, which can be difficult and traumatic in a patient as frail as the pope.