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.