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 mine 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 P(CO₂) was significant (r² = .97; p < .0001). A relative average bias of 0.33 torr (0.04 kPa) with end-tidal CO₂ lower than capillary P(CO₂) 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.