Ultrasonographic evaluation of the diaphragm during NHF versus NIV use in respiratory failure

Introduction: NHF is a new ventilation support device with impact on respiratory muscle parameters. The efficiency compared to NIV and standard oxygen remains unclear. Methods: We measured ultrasound data from diaphragmatic movements in 35 patients with respiratory insufficiency. In a cross-over design NIV (IPAP 14 mbar, EPAP 6 mbar) or NHF (35 l/min) was used in a randomized order. The following parameters were measured or calculated: Tdi,ee, Tdi,ei, Tex rest, Tex max insp, Tex sniff, TFdi, dTdi and Tdi,ee. Results: Compared to baseline Tdi,ee (endexpiratory diaphragm thickness), Tdi,ei (endinspiratory diaphragm thickness), Tex rest (diaphragm excursion during rest) and Tex max insp (diaphragmatic excursion during maximal inspiration) were significantly changed. Between NHF and NIV there were no significant differences. Discussion: NHF supports the respiratory muscles compared to oxygen and shows no differences to NIV. Therefore the terminus “oxygen therapy“ should not use in constant touch with the NHF device. NHF is able to prevent and treat respiratory muscle weakness.