The clinical application of transcutaneous carbon dioxide monitoring during rigid bronchoscopy or microlaryngeal surgery in children

Study objective During rigid bronchoscopies and microlaryngeal surgery (MLS) in children, there is currently no reliable method for managing ventilation strategies based on carbon dioxide (CO2) levels. This study aimed to investigate the effects of the clinical implementation of transcutaneous CO2 (tcPCO(2)) monitoring during rigid bronchoscopies or MLS. Design Prospective observational study. Setting Operating theatre of a tertiary pediatric hospital, from January 2019 to March 2021. Patients Children with an age < 18 years, undergoing rigid bronchoscopy or MLS, were eligible for inclusion. Children with tracheostomy and/or skin conditions limiting tcPCO(2) monitoring were excluded. Interventions TcPCO2 monitoring was performed in two groups; blinded before clinical implementation (control group) and visible for ventilation management after clinical implementation (tcPCO(2) group). Measurements The total tcPCO(2) load outside of the normal range (35-48 mm Hg) was calculated as the area under the curve (AUC) and compared between the groups. Anesthesiologists in the tcPCO(2) group received a questionnaire after each procedure. Main results A total of 120 patients were included. No significant differences were found between the two groups in the AUC during the procedure (19,202 (7,863-44,944) vs 17,737 (9,800-47,566) mm Hg <middle dot> s, P = 0.84) or between different ventilation strategies. The maximal tcPCO(2) level was 69.2 (62.1-81.2) mm Hg in the control group and 71.1 (62.8-80.8) mm Hg, (P = 0.85) in the tcPCO(2) group. Spontaneous breathing was associated with lower tcPCO(2) levels. The general satisfaction score of tcPCO(2) monitoring rated by the anesthesiologist was 8.19 (0.96). Conclusions TcPCO2 levels reached approximately twice the upper limit of the normal range during rigid bronchoscopy and MLS. Availability of tcPCO(2) monitoring did not affect these high levels, despite adjustments in strategy. However, tcPCO(2) monitoring provides valuable insight in CO2 load and applied ventilation strategies.