Carbon dioxide rebreathing caused by deformed silicon leaflet in the expiratory unidirectional valve
A five-year-old girl was scheduled for surgical closure of an atrial septal defect under cardiopulmonary bypass. After routine preuse check, anesthesia was induced by inhalation of sevoflurane, using Jackson Rees’ modification of the Ayre's T-piece (JRMATP). Induction and tracheal intubation were uneventful. The lungs were ventilated using a circle breathing system and volume-controlled ventilation (VCV). The capnogram showed an increasing trend of end-tidal carbon dioxide (EtCO2; 45 mmHg) with high inspired carbon dioxide (FiCO2; 12 mmHg). Soda lime in the canister was fresh and did not show any change in color. Increasing the flow of fresh gas had no effect on FiCO2. As the source of the problem could not be identified, the breathing system was changed to JRMATP and anesthesia was continued. Later, the anesthesia machine was replaced and further management of the case was uneventful.