Incidence of pulmonary embolism in total knee arthroplasty

The end-tidal carbon dioxide concentration (ETCO2) of 47 patients undergoing prosthetic knee operations was monitored to detect pulmonary embolism during the anthroplasties. The ETCO2 of one patient dropped suddenly following the release of the tourniquet and insertion of the bone cement. Intracardiac aspiration did not reveal any air. At autopsy there was massive pulmonary thromboembolism and the deep veins of the right leg contained old formed thrombi. Patients undergoing such procedures should be investigated to exclude the presence of deep vein thrombosis so that measures to prevent pulmonary thromboembolism must be taken well in advance. As regards the occurrence of air embolism it is believed that insertion of the bone cement is the most important single factor in the prevention of air embolism during knee arthroplasty.