The life in every breath

The new technology centers on capnographs, devices that gauge how much carbon dioxide patients exhale.

Years ago, doctors, and especially surgeons, began using capnographs to differentiate between the tracheas and esophagi of patients who require breathing tubes.

The trachea, the airway to the lungs where breathing tubes are inserted, releases carbon dioxide; the esophagus, which leads to the stomach, does not.

Oridion has developed an advanced capnograph that identifies carbon dioxide and gives doctors information the company says is specific enough for medical diagnoses, especially when a patient is in critical condition. Carbon dioxide levels can indicate conditions ranging from slow blood circulation to metabolic shutdown.

“It’s very useful in cardiac arrest,’’ said Baruch Krauss, an anesthesiologist at Children’s Hospital Boston who also works as an Oridion adviser. “It tells you how effectively your blood is flowing and how well your heart is pumping. Then it tells you how your lungs function.’’

Exhaled carbon dioxide often provides doctors with more information about patients than oxygen in the bloodstream, because oxygen can linger even while lethal carbon dioxide accumulates in the body, said Krauss. “When you hold your breath, you still have oxygen in your blood, but you’re not breathing, are you?’’ he said. “There is no CO2 coming out.’’

During a medical procedure, that dynamic can cause trouble. If doctors track only the oxygen levels in an anesthetized patient on an operating table, for example, minutes can pass before they know the patient has really stopped breathing, said Krauss. Capnographs such as those developed by Oridion could serve as an early-warning system for clinicians monitoring respiration, he said.

“Let’s say you’re getting a colonoscopy, and you stop breathing,’’ asked Krauss. “Would you want to know two minutes later or one second after you stop exhaling CO2?’’