RT Journal Article
SR Electronic
T1 Assessment of diaphragm thickness variations by ultrasonography in patients with Duchenne muscular dystrophy (DMD)
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 1390
VO 40
IS Suppl 56
A1 Marianna Laviola
A1 Rita Priori
A1 Marianna Romei
A1 Grazia D'Angelo
A1 Andrea Aliverti
YR 2012
UL http://erj.ersjournals.com/content/40/Suppl_56/1390.abstract
AB Variations of diaphragm thickness (DT) during different respiratory maneuvers can be measured by B-mode ultrasonography (US). In order to verify if this parameter provides useful insights for functional assessment in DMD, we measured DT by a 7.5 MHz US linear probe in the 9th or 10th right intercostal space in 39 DMD patients (age 16.3±4.4 yrs, FVC 53.2±24.8%pred) in supine position at rest (end-expiration during quiet breathing, QB) and maximal inspiratory pressure (MIP) at residual volume. The contribution of the abdominal compartment to tidal volume (Vab%) was assessed by optoelectronic plethysmography during QB and an inspiratory capacity (IC) maneuver.Patients were subdivided into 3 groups according to age (G1: n=11, age<14; G2: n=13, 14<age>18; G3: n= 15, age>18 yrs). MIP was significantly higher in G2 compared to both G1 and G3 (fig., left). The variation of DT during the MIP maneuver, expressed as % change of DT at rest, was significantly greater in G3 compared to G1. Patients belonging to G3 group were also characterized by lower Vab% during IC.In conclusion, in DMD patients>18 yrs MIP decreases and maximal variation of DT increases. These results suggest that diaphragm impairment is expressed as a dissociation between muscle drive and muscle developed force. Measurements of DT by US allow a detailed noninvasive assessment on how alterations in diaphragm function progress in DMD.