Capnography is widely used in anesthesia and critical care medicine, typically for monitoring patients with an endotracheal tube or laryngeal mask airway (LMA). Capnography has also been used for non-intubated patients to detect apnea or respiratory insufﬁciency. In non-intubated children for cardiac catheterization side-stream capnography demonstrated good correlation between exhaled CO2 and arterial, central venous, and capillary PCO2. However, stable monitoring of CO2, using a conventional side stream system, can be challenging. The CO2 sampling tube is prone to obstruction from moisture, and high-ﬂow oxygen administration, either via oxygen mask or nasal cannula, will alter the CO2 readings. Mainstream capnography systems measure CO2 at the site of exhaled gas and may be less affected by administered oxygen as compared to side-stream systems
Nihon Kohden has developed an extremely small mainstream CO2 sensor (cap-ONE) that can accurately measure oral as well as nasal exhaled CO2 in non-intubated patients. After further development and evolution, the cap-ONE is now available as the world’s smallest mainstream CO2 sensor weighing only 4 g with an original open-face oxygen mask (cap-ONE mask). cap-ONE mask is easily used for pediatric patients, who are receiving supplemental oxygen, and the cap-ONE CO2 sensor reliably detects respiratory depression, including apnea and hypoventilation while oxygen is supplied.
It is recommended that oxygen flow should be more than 6 L/min, when using a conventional oxygen mask in order to prevent the patient from rebreathing exhaled gas, which is retained in the mask. cap-ONE mask has a wide opening in the front to let oral and nasal exhaled gas out of the mask. This design prevents exhaled gas from remaining in the mask even when oxygen flow is low. Also, well dispersed oxygen is supplied from the sides of cap-ONE mask, so oxygen concentration inside the mask remains consistent and stable.