PT  - JOURNAL ARTICLE
AU  - Marianna Laviola
AU  - Caterina Salito
AU  - Andrea Aliverti
TI  - Reproducibility of diaphragm thickness measurements by ultrasonography
DP  - 2011 Sep 01
TA  - European Respiratory Journal
PG  - p2111
VI  - 38
IP  - Suppl 55
4099  - http://erj.ersjournals.com/content/38/Suppl_55/p2111.short
4100  - http://erj.ersjournals.com/content/38/Suppl_55/p2111.full
SO  - Eur Respir J2011 Sep 01; 38
AB  - Although diaphragmatic variations of the length of zone of apposition are readily studied by ultrasonography (US), only preliminary studies have shown the possibility to use US to measure diaphragmatic thickness (TD). In order to determine reference values of TD during various maneuvers and to assess US measurement reproducibility, 8 healthy subjects (4M, 4F) were studied in supine and standing position during spontaneous quiet breathing (QB), slow vital capacity (SVC), maximal inspiratory (MIP) and maximal expiratory (MEP) pressure maneuvers. TD was measured on lateral ribcage using an US linear probe (7.5 MHz). Six subjects were examined by two different operators on two different occasions on a short time period (2-3 days). Three subjects were examined by the same operator on two different occasions on a long time period (6-7 months). TD was determined by a custom-designed software for image processing at end-inspiration (EI) and end-expiration (EE) during QB, at TLC and at maximal pressures during MIP and MEP maneuvers. Overall average values are reported in the following table (values reported as mean±SD).View this table:Diaphragm thickness (TD, mm)ANOVA analysis revealed that no significant differences were present between inter- and intra-observer measures, in both postures, and on both short and long time periods (p>0.05).In conclusion: a) US represent a reliable and reproducible method for TD assessment; b) TD varies of ∼30% and ∼20% in supine and standing position during QB; c) at TLC, TD is about two-fold higher than at FRC; d) during MIP, TD is maximum.