Roles of neurally adjusted ventilatory assist in improving gas exchange in a severe acute respiratory distress syndrome patient after weaning from extracorporeal membrane oxygenation: a case report.

Yuya Goto,Yuya Miyazaki,Shinshu Katayama,Makoto Ozaki,Yoko Sato,Yosuke Mori,Toru Kotani,Atsuko Shono

doi:10.1186/s40560-016-0153-4

Abstract

BackgroundPatient-ventilator asynchrony is a major cause of difficult weaning from mechanical ventilation. Neurally adjusted ventilatory assist (NAVA) is reported useful to improve the synchrony in patients with sustained low lung compliance. However, the role of NAVA has not been fully investigated.Case presentationThe patient was a 63-year-old Japanese man with acute respiratory distress syndrome secondary to respiratory infection. He was treated with extracorporeal membrane oxygenation for 7 days and survived. Dynamic compliance at withdrawal of extracorporeal membrane oxygenation decreased to 20 ml/cmH2O or less, but gas exchange was maintained by full support with assist/control mode. However, weaning from mechanical ventilation using a flow trigger failed repeatedly because of patient-ventilator asynchrony with hypercapnic acidosis during partial ventilator support despite using different types of ventilators and different trigger levels. Weaning using NAVA restored the regular respiration and stable and normal acid-base balance. Electromyographic analysis of the diaphragm clearly showed improved triggering of both the start and the end of spontaneous inspiration. Regional ventilation monitoring using electrical impedance tomography showed an increase in tidal volume and a ventilation shift to the dorsal regions during NAVA, indicating that NAVA could deliver gas flow to the dorsal regions to adjust for the magnitude of diaphragmatic excursion. NAVA was applied for 31 days, followed by partial ventilatory support with a conventional flow trigger. The patient was discharged from the intensive care unit on day 110 and has recovered enough to be able to live without a ventilatory support for 5 h per day.ConclusionOur experience showed that NAVA improved not only patient-ventilator synchrony but also regional ventilation distribution in an acute respiratory distress patient with sustained low lung compliance.

Highlights

Patient-ventilator asynchrony is a major cause of difficult weaning from mechanical ventilation
Our experience showed that Neurally adjusted ventilatory assist (NAVA) improved patient-ventilator synchrony and regional ventilation distribution in an acute respiratory distress patient with sustained low lung compliance
Asynchrony is more obvious and often a problem when the patient is converted to partial ventilatory support for the weaning from mechanical ventilation and gas exchange is insufficiently maintained, it is observed during full ventilatory support

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Consent Written informed consent was obtained from the patient's kin for publication of this case report. Competing interests The authors declare that they have no competing interests. Authors’ contributions YG and SK carried out the chart review and data collection and were responsible for patient care. AS analyzed the data from electrical impedance tomography. YoM, YiM, and YS were responsible for patient care. TK coordinated the study, was responsible for patient care, and supported the data analysis. All authors contributed to interpretation of the data and provided comments on the report at various stages of development. All authors read and approved the final manuscript. Author details 1Department of Anesthesiology and Intensive Care Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan. Author details 1Department of Anesthesiology and Intensive Care Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan. 2Department of Anesthesiology, Shimane University, Shimane 693-8501, Japan

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