Accuracy of capnography with a 30 foot nasal cannula for monitoring respiratory rate and end-tidal CO2 in children

We tested the accuracy of a low flow (50 cc/min) sidestream capnography sys tem equipped with an experimental 30-foot nasal cannula to monitor ventilat ory status in children. End-tidal CO2 and respiratory rate, both at room ai r and in the presence of supplemental oxygen, were recorded simultaneously from the experimental 30-foot nasal cannula and the standard, FDA approved, 10-foot nasal cannula. The 30-foot nasal cannula was as accurate as the 10 -foot nasal cannula in measuring respiratory rate and end-tidal CO2 in chil dren. When supplemental oxygen was delivered by facemask, there was no dilu tional effect on the respiratory rate or end-tidal CO2 recorded with either the 10-foot or 30-foot nasal cannulas in place.