Opto-electronic plethysmographic study of the chest wall after lung transplantation

Opto‐eletronic plethysmographic study of the chest wall after lung transplantation Background: Lung transplantation is the established surgical therapy for pulmonary end‐stage disease. Aims: Even though the pulmonary function after lung transplantation is well studied, the chest volume changes remain uninvestigated. The aim of the present study was to examine such changes by the optoelectronic plethysmography (OEP), a non invasive technology. Methods: Seven patients with end‐stage pulmonary disease were studied before and after lung transplantation by OEP during quiet and forced breathing. Standard pulmonary function tests were also obtained. Three patients with pulmonary fibrosis had single lung transplantation and four patients with cystic fibrosis had bilateral. Result: The functional tests demonstrated increasing in pulmonary function (e.g. FEV1 % from 44 ± 15 to 83 ± 6). After bilateral transplantation, the OEP revealed a volume rearrangement: a decrease was noted in functional residual capacity (FRC: ‐2.14 ± 1.3L), in vital capacity (‐ 1.1 ± 1.1L), in total lung capacity (– 2.59 ± 1.6L). The chest wall volume reduction was different in the upper thorax, lower thorax and abdominal compartment (e.g. FRC: ‐0.68L, ‐0.13L ‐ 1.59L respectively). After single lung transplantation the pattern was similar but less evident. Conclusions: This first, preliminary, study of the chest wall volume changes reveals a rearrangement of such volumes after single or double lung transplantation. Facing the dramatic improvement in spirometric value, OEP recorded a decrease in volume parameters; such decreases were inhomogeneous through the body compartments privileging the abdomen. Further studies are needed to better understand the value of these findings and their clinical impact.