Carbon dioxide embolism during transoral robotic thyroidectomy under ultra-low-pressure insufflation: a report of two cases

Transoral robotic thyroidectomy (TORT) offers excellent cosmetic outcomes but requires carbon dioxide (CO 2 ) insufflation, which carries the rare risk of CO 2 embolism.We report two cases of suspected CO 2 embolism during TORT performed at the ultra-low insufflation pressure of 3 mmHg.In both patients, sudden decreases in end-tidal CO 2 (EtCO 2 ) and oxygen saturation occurred during subplatysmal flap dissection, while the hemodynamic parameters remained stable.Arterial blood gas analysis revealed arterial hypercapnia with a concomitant decrease in EtCO 2 , resulting in a widened arterial EtCO 2 gradient, supporting the diagnosis.Immediate cessation of CO 2 insufflation, administration of 100% oxygen, and surgical compression of the suspected venous entry sites led to rapid normalization of EtCO 2 and oxygenation.Both procedures were performed without any complications.These cases demonstrate that CO 2 embolism can occur even under ultra-low-pressure insufflation and emphasize the importance of vigilant capnographic monitoring and prompt anesthetic-surgical coordination during TORT.