The delta index – the difference between end tidalcarbon dioxide concentration in rightand left lateral decubitus position– could predict pulmonary embolism –preliminary results

Aim: To determine the presence and the importance of a difference in end tidal carbon dioxide between lateral decubitus positions for pulmonary embolism prediction. Material and methods: There were 32 patients aged 65.7±14.4 (16M, 16F) with pulmonary embolism and 15 patients aged 56.7±20.3 (10M, 5F) with excluded pulmonary embolism Capnography was performed in supine, left and right lateral decubitus position. The absolute value of the difference in end tidal carbon dioxide concentration between left and right decubitus position was called the delta index. Demographics and clinical data were collected. Results: The delta index was significantly higher in patients with pulmonary embolism vs those with excluded pulmonary embolism: 4 (3-5.5) mmHg vs 1 (1-2) mmHg p<0.001. Area under curve for the delta index was 0.92; 95% CI 0.83-1.0 p 3 mmHg to predict PE the sensitivity and specificity was 66% and 100%, respectively. Conclusions: The patients with pulmonary embolism had increased variability of end tidal carbon dioxide concentration while changing their position.