To investigate the accuracy and usefulness of combined transcutaneous carbon dioxide (PtcCO₂) and oxygen (PtcO₂) measurement compared with arterial blood gas analysis (PaCO₂ and PaO₂), 10 patients undergoing laryngomicrosurgery under total intravenous anesthesia were studied. The PtcCO₂ values revealed a high degree of correlation with PaCO₂ during anesthesia (r=0.96) and after anesthesia (r=0.93). The PaO₂ values revealed a generally good correlation with PaO₂ during anesthesia (r=0.81), but not after anesthesia (r=0.23). Capnography values are invalid after anesthesia, and an arterial catheter is not always indicated and feasible in microlaryngoscopy. Transcutaneous devices provide an effective method for the non-invasive monitoring of PCO₂ during and after anesthesia, in situations whereas continuous, precise control of CO₂ levels is desired such as laryngomicrosurgery.