Noninvasive capnometry monitoring for respiratory status during pediatric seizures

OBJECTIVE: To determine the reliability and clinical value of end-tidal CO2 by oral/nasal capnometry for monitoring pediatric patients presenting post ictal or with active seizures. DESIGN: Clinical, prospective, observational study. SETTING: University affiliated children's hospital. INTERVENTIONS: One hundred sixty-six patients (105 patients with active seizures, 61 post ictal patients) had end-tidal CO2 obtained by oral/nasal sidestream capnometry, and respiratory rates, oxygen saturation, and pulse rates recorded every 5 mins until 60 mins had elapsed. End-tidal CO2 values were compared with a capillary PCO2 and clinical observation. MEASUREMENTS AND MAIN RESULTS: The mean end-tidal CO2 reading was 43.0 +/- 11.8 torr [5.7 +/- 1.6 kPa] and the mean capillary PCO2 reading was 43.4 +/- 11.7 torr [5.7 +/- 1.6 kPa]. The correlation between end-tidal CO2 and capillary PCO2 was significant (r2 = .97; p < .0001). A relative average bias of 0.33 torr (0.04 kPa) with end-tidal CO2 lower than capillary PCO2 was established with 95% limits of agreement +/-4.2 torr (+/-0.6 kPa). Variability of difference scores was not related to range of mean scores (r2 = .00003), age (r2 = .0004), or respiratory rates (r2 = .0009). End-tidal CO2 (r2 = .22; p < .001) correlated better with respiratory rate changes when compared with oxygen saturation (r2 = .02; p = .01). CONCLUSIONS: Dependable end-tidal CO2 values can be obtained in pediatric seizure patients using an oral/nasal cannula capnometry circuit. Continuous end-tidal CO2 monitoring provides the clinician with a reliable assessment of pulmonary status that can assist with decisions to provide ventilatory support.