[Diaphragmatic fatigue in respiratory distress syndrome in dogs]

Diaphragmatic fatigue (DF) in respiratory distress syndrome (RDS) induced by injection of fat were studied in 7 dogs. After injection of fat, all dogs developed respiratory distress and tachypnea, PaO2 fell to the level lower than 8 kPa. Transdiaphragmatic pressure (Pdi) decreased progressively (P less than 0.05-0.001), Pdi-stimulation frequency (Pdi-F) curve shifted to the right, central frequency (Fc), median frequency (Fm) and high/low frequency ratio (H/L) significantly decreased (P less than 0.05-0.001). It is concluded that the contractile force of the diaphragm progressively decreased after RDS was induced, which suggested the occurrence of DF.