Transcutaneous carbon dioxide monitoring in children undergoing rigid bronchoscopy: a prospective blinded observational study.

Abstract

Anesthetic management during rigid bronchoscopy in children can be challenging, and continuous end-tidal carbon dioxide (EtCO2) monitoring is often unachievable. Transcutaneous carbon dioxide (TcCO2) monitoring is strongly correlated with the partial pressure of carbon dioxide (PaCO2) and EtCO2. We aimed to investigate the incidence of hypercapnia in children undergoing rigid bronchoscopy. We enrolled patients aged < 18yr scheduled for rigid bronchoscopy in a prospective observational study. We recorded TcCO2 values from anesthesia induction to the postanesthesia care unit (PACU) stay. We ended monitoring when TcCO2 reached values ≤ 50mm Hg. The operating room (OR) team was blinded to the TcCO2. The outcome of primary interest was the incidence of hypercapnia (TcCO2 > 50mm Hg) in the OR. Other outcomes were the incidences of hypercapnia in the PACU and severe hypercapnia (TcCO2 > 90mm Hg), factors possibly related to hypercapnia (patient, surgery, or anesthesia factors), and the incidence of perioperative adverse events. A total of 30 patients were enrolled. The median [interquartile range (IQR)] age was 3.5 [1.5-8.0] yr. The incidence of hypercapnia was 100% in the OR and 60% in the PACU. Five cases (17%) presented with severe hypercapnia in the OR. The highest median [IQR] TcCO2 was 69 [61-79] mm Hg. The most common adverse event was oxygen desaturation (57%, 17/30). Patients with severe hypercapnia had long stays in the PACU. Hypercapnia was a frequent event in children undergoing rigid bronchoscopy and severe hypercapnia was associated with a long PACU stay. Further studies are needed to assess the utility of TcCO2 monitoring in guiding ventilatory interventions during these cases.