Variations of thoracoabdominal volumes after lung transplantation measured by opto-electronic plethysmography

BACKGROUND: Lung function after lung transplantation (LTx) has been widely studied. On the contrary, the thoracoabdominal volume rearrangement after LTx has yet to be investigated. METHODS: Patients with cystic fibrosis and listed for double LTx at our institution were enrolled for the prospective study to explore the effects of LTx on the rearrangement of respiratory volumes in patients affected by cystic fibrosis, by utilizing the opto-electronic plethysmography (OEP), a noninvasive method to study the volume and motion of the human trunk. Rib cage and abdominal volumes were tested with OEP (OEP system, BTS, Milano, Italy). RESULTS: Eight patients were enrolled (male-to-female ratio: 1:3; mean age 29.3 ± 7.8 years). After LTx the volume changes analyzed with OEP revealed a significant decrease of the total lung capacity (TLC) as well as the functional residual capacity and residual volume when the chest wall volume was considered. Dividing the whole respiratory volume in the three compartments showed different trends. CONCLUSIONS: We consider OEP a particularly useful device in patients with severe respiratory disease, in that it allows a noninvasive estimate of the volume change of the chest wall. This study demonstrates a significant reduction of thoracoabdominal volumes in patients affected by cystic fibrosis treated with bilateral LTx. Abdomen and upper rib cage were congruent with the volume reduction, while the lower rib cage showed an opposite tendency.