Small change in capnography led to the detection of an intravascular thrombus.

This report highlights the importance of accurate interpretation of even small intraoperative capnography changes. In this case, an otherwise unexplained sudden small decrease in end-expiratory carbon dioxide tension (P(ET)CO2) led to the detection of a deep venous thrombus. During the surgery of a 34-year-old woman with a known carcinoma of the corpus uteri, who was scheduled for paraaortal lymphadenectomy, a sudden decrease in carbon dioxide tension occurred. In careful exploration of the surgical field to rule out a thromboembolic event, the surgeons noticed an induration of the right iliac vein. A consulting vascular surgeon exposed a right-sided, irregular, double-lumen, common iliac vein with a thrombus the tip of which floated in the inferior vena cava. Following complete thrombectomy, the procedure was accomplished without further adverse events.