[Blood gas disorders during one lung ventilation and the efficacy of the monitors]

The incidence and the causes of the abnormal blood gas levels were analysed with 188 patients who had one lung ventilation during general anesthesia, and the monitors to detect such complications were discussed. Abnormal blood gas levels were detected in 47 patients (25%), and 6 of 47 patients had dislocation of endotracheal tube or cuff. There was one patient who suffered from severe blood gas disorder due to the total occlusion of trachea by cuff herniation. Forty one cases (41.8%) had abnormal blood gas levels even though there was no dislocation of endotracheal tube or cuff. In these patients the blood gas abnormalities were mild and transient. These data suggest that mild blood gas disorders were relatively easily detected with pulse oximeters and capnography. However, serious disorders were not detected with these monitors if the anesthesiologists were not familiar with these equipment.