A person being treated for carbon monoxide poisoning in a hyperbaric chamber might need to have three visits before seeing results, according to health experts at the Mayo Clinic.

In a hyperbaric chamber, a patient breathes in pure oxygen.

The air pressure in the chamber is increased to three times higher than normal air pressure, according to the Mayo Clinic. This allows a patient’s lungs to take in more oxygen than would be possible breathing at a normal air pressure.

The number of sessions needed ultimately depends on the medical condition of each specific patient, according to the Mayo Clinic. Most patients often benefit from more than one session.

But while carbon monoxide poisoning might be improved after just a few visits, Mayo Clinic experts said, non-healing wounds might require 20 to 40 treatments.

“Hyperbaric oxygen therapy alone can often effectively treat decompression sickness, arterial gas embolism and severe carbon monoxide poisoning,” according to the Mayo Clinic.

Some medical facilities in Connecticut — including Bridgeport Hospital, Greenwich Hospital, Lawrence + Memorial Hospital in New London and Middlesex Health — have the ability to offer hyperbaric oxygen therapy for patients.

But on Tuesday, when accused killer Fotis Dulos was found unresponsive at his Farmington home from an apparent suicide attempt by carbon monoxide poisoning, he was first taken to UConn Health before he was airlifted to Jacobi Medical Center in the Bronx, N.Y.

Initially sources said Dulos — who faces murder charges in connection with his estranged wife’s May 24 disappearance and homicide — was headed to the chamber at Bridgeport Hospital.

But John Cappiello, Bridgeport Hospital’s media coordinator, was quick to clear that up.

Cappiello said the hyperbaric chamber at the city hospital is used strictly “for wound healing, so we don’t expect him here.”

According to Bridgeport Hospital’s website about the hyperbaric chamber, it can accommodate up to six people at once and tend to have advantages compared with single-person chambers.

Bridgeport Hospital’s chamber, the website indicated, is the only “hospital-based multi-place hyperbaric chamber in Fairfield County.”

It was not immediately clear why Dulos wasn’t flown to another Connecticut medical facility that offered hyperbaric oxygen therapy, rather than being flown to the New York City borough — although the trip by LifeStar helicopter wasn’t a long one.

In an individual hyperbaric chamber, a patient will lie down on a table that slides into what looks like a clear plastic tube.

A chamber that accommodates several patients usually looks like a large hospital room and allows patients to sit or lie down. A patient in a multi-person chamber might get oxygen through a mask or a lightweight, clear hood placed over their face.