Transcutaneous Carbon Dioxide Monitoring During Weaning From Mechanical Ventilation in Children: The WeanCO2 Study.

INTRODUCTION

Spontaneous breathing trial (SBT) is recommended during weaning from mechanical ventilation (MV), but objective and easy tools lack to identify pediatric weaning failure. We aimed to assess whether changes in estimated arterial CO₂ (PaCO₂) derived from transcutaneous measurements (PTCCO₂) were associated with pediatric weaning failure.

METHODS

Children (age 72 h -18 years) with MV > 12 h were continuously monitored using a transcutaneous sensor to estimate PaCO₂ from skin CO₂ tension (PTCCO₂). Values were recorded during SBT (30 min on positive end-expiratory pressure (PEEP) +5 cmH2O, with pressure support of +5 cmH2O for endotracheal tubes with internal diameter ≤ 3.5 mm), then up to 6 h after extubation. Mean PTCCO2 and PTCCO2 changes during SBT, and after extubation, were retrospectively collected to evaluate their association with SBT failure and extubation failure (reintubation within 48 h).

RESULTS

Eighty children (median [IQR] age 1.1 [0.3; 8.7] years) were included, with 89 SBT (14 failures, 75 successes). Sixty-four patients were extubated following their first SBT, with 10 (16%) extubation failures. PTCCO2 changes were not associated with SBT and extubation failures. Patients who failed extubation had a higher mean PTCCO2 value after extubation as compared to those who were successfully extubated (mean PTCCO2 of 51.8 [46.2; 55.4] vs. 42.3 [37.5; 47.2] mmHg, p = 0.02). The difference between the maximal PTCCO2 value within the 2 h following extubation and the value at extubation were higher in patients who failed extubation (ΔPTCCO2 of 20 [9.1; 26] vs. 6.8 [2.9; 9.7] mmHg, p < 10-2).

CONCLUSION

Early post-extubation increase in estimated PaCO₂ was associated with extubation failure, whereas PTCCO₂ changes during SBT were not.