Lethal air embolism during arthroscopy. A case report.

We report a case of lethal air embolism during diagnostic arthroscopy using air to distend an acutely injured knee. Air had escaped from the joint through an intra-articular fracture and entered the venous system. During arthroscopy, pressure within the joint may be 5 to 10 times higher than venous pressure, so any medium may escape. We advise that the use of air, especially in freshly injured joints, should be abandoned in favour of saline or carbon dioxide.