Aspiration of massive free air from a large bore intravenous catheter sheath: A case report

We firstly experienced a rare case demonstrating that massive volume of free air was aspirated from a large bore intravenous catheter sheath of the pulmonary arterial catheter during placement. A 44-year-old male patient underwent the emergency induction of anesthesia for transplantation of liver donated by the brain death subject. After the induction, the central venous and pulmonary artery catheter placement was conducted. The aspiration of venous blood confirmed the intravascular insertion, but massive free air was aspirated when we advanced the sheath proximally. A perforation of subclavian vein and subsequent pneumothorax was strongly suspected. The emergency computed tomography revealed no sign of pneumothorax, pneumomediastinum nor extravasation. The operation was undergone with intensive monitoring and no further adverse complication was observed. The postoperative medical inquiry concluded that the massive free air was not aspirated from extravascular space, for example, thorax or mediastinum through the tip of the sheath, but from the proximal main port of the sheath. When the tip of sheath is occluded by the migration into small vessels, the large negative pressure through side port might easily aspirate the air through the 1-way valve of the main proximal port. Physicians should keep in mind of the structure of the catheter sheath.