Have you heard the saying, “canary in a coal mine”? Well, the saying started because canaries were actually used in coal mines (until 1986!?) to detect dangerous levels of the gas carbon monoxide. With a faster metabolism, canaries show the effects of poisoning by the colorless, odorless gas before the carbon monoxide levels become critical for workers. While many homes and businesses now have electronic carbon monoxide detectors (canaries everywhere rejoice!), inadvertent carbon monoxide exposure and poisoning is still a major issue worldwide.
According to the Centers for Disease Control and Prevention, carbon monoxide poisoning is the most common type of poisoning in many countries, and is responsible for over 20,000 emergency room visits per year in the US. Carbon monoxide gas is produced primarily by motor vehicles and poorly maintained and/or poorly ventilated heating systems, gas stoves, or gas-powered generators. It is particularly dangerous due to its ability to outcompete oxygen for its spot on hemoglobin, the protein in red blood cells that typically carries oxygen from the lungs to the rest of the body. The affinity between hemoglobin and carbon monoxide is approximately 230 times stronger than that between hemoglobin and oxygen.
As a result of exposure to carbon monoxide, an individual may suffer symptoms including headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion. Exposure to high levels of carbon monoxide can cause death in minutes. The standard treatment for carbon monoxide poisoning is to have the patient breathe 100 percent oxygen through a mask. In severe cases, a hyperbaric chamber may be used, which delivers oxygen under higher than normal pressure. However, according to Dr. Malvina Eydelman, director of the Division of Ophthalmic, and Ear, Nose and Throat Devices in the FDA's Center for Devices and Radiological Health, “hyperbaric treatment, which is necessary for severe carbon monoxide poisoning, is less accessible because there are only 60 medical centers with hyperbaric units in the entire US. Moreover, those medical facilities are seldom in rural areas, so treatment in those areas could be delayed considerably due to transport time.”
On March 14th, 2019, the FDA granted marketing authorization of ClearMate to Thornhill Research, Inc. ClearMate, which is intended to be used in an emergency room setting to help treat patients suffering from carbon monoxide poisoning, is designed to quickly remove carbon monoxide from the body by increasing a patient’s respiration rate. The device consists of a gas mixer, valves, meters, breathing circuits, an oxygen reservoir, a mask, and hoses. By delivering both 100 percent oxygen to the patient, as well as a mixture of oxygen and carbon dioxide, the patient breathes faster. More rapid breathing accelerates the rate at which the carbon monoxide leaves the patient’s body, allowing a normal amount of oxygen to attach to hemoglobin and be carried to where it is needed throughout the body. In clinical studies, using ClearMate resulted in faster elimination of carbon monoxide than treatment with 100 percent oxygen alone (although not faster than hyperbaric oxygen therapy).
Per the Thornhill Medical website:
“The compact, 6 Kg, ClearMate™ is totally pneumatic – no electricity, batteries or computers are needed for it to work. ClearMate™ was designed for rescue vehicles, hospital emergency departments, factories, schools, and any other facilities where the earliest possible treatment of CO [carbon monoxide] poisoning will save lives. Whenever carbon monoxide poisoning may have occurred, ClearMate™ can be used on the scene by anyone with minimal training, and with no risk of side effects.”
ClearMate was reviewed under the FDA’s De Novo premarket pathway, the regulatory pathway for low-to-moderate-risk devices of a new type. Approval through the De Novo pathway establishes a new regulatory classification, which means that subsequent devices of the same type with the same intended use may go through the FDA’s 510(k) premarket notification process, whereby devices can obtain marketing authorization by demonstrating substantial equivalence to a predicate device.
So while canaries can let out a sigh of relief, so can patients who might need this device. Previous to the De Novo, ClearMate achieved CE Marking, and was also approved for sale in Canada, Australia, China, Korea and Taiwan. Now that this device is available in the US, Americans who might experience carbon monoxide poisoning have a better chance of survival…and that’s all something we can breathe easier about!