At-home end-tidal carbon dioxide measurement in children with invasive home mechanical ventilation

Background: Carbon dioxide concentration trending is used in chronic management of children with invasive home mechanical ventilation (HMV) in clinical settings, but options for end-tidal carbon dioxide (EtCO₂) monitoring at home are limited. We hypothesized that a palm-sized, portable endotracheal capnograph (PEC) that measures EtCO₂ could be adapted for in-home use in children with HMV. Methods: We evaluated the internal consistency of the PEC by calculating an intraclass correlation coefficient of three back-to-back breaths by children (0–17 years) at baseline health in the clinic. Pearson's correlation was calculated for PEC EtCO₂ values with concurrent mean values of in-clinic EtCO₂ and transcutaneous CO₂ (TCM) capnometers. The Bland–Altman test determined their level of agreement. Qualitative interviews and surveys assessed usability and acceptability by family-caregivers at home. Results: CO₂ values were collected in awake children in varied activity levels and positions (N = 30). The intraclass correlation coefficient for the PEC was 0.95 (p < 0.05). The correlation between the PEC and in-clinic EtCO₂ device was 0.85 with a mean difference of −3.8 mmHg and precision of ±1.1 mmHg. The correlation between the PEC and the clinic TCM device was 0.92 with a mean difference of 0.2 mmHg and precision of ±1.0. Family-caregivers (N = 10) trialed the PEC at home; all were able to obtain measurements at home while children were awake and sometimes asleep. Conclusions: A portable, noninvasive device for measuring EtCO₂ was feasible and acceptable, with values that trend similarly to currently in-practice, outpatient models. These devices may facilitate monitoring of EtCO₂ at home in children with invasive HMV.