Pulmonary volume-feedback and ventilatory pattern after bilateral lung transplantation using neurally adjusted ventilatory assist ventilation.Grasselli, G., et al.
British Journal of Anaesthesia 2021 [record in progress].
This study aimed to investigate whether Neurally Adjusted Ventilatory Assist (NAVA) Ventilation, driven by diaphragm electrical activity (EAdi), would reveal if vagally mediated pulmonary volume feedback is preserved during the early phases following bilateral lung transplantation.
Patients were randomised to two positive-end expiratory pressure (PEEP) levels: 6 and 12 cm H2O. Patients were then randomised again to three NAVA levels: baseline NAVA, 50% of baseline NAVA level, and 150% of baseline NAVA level.
19 bilateral lung transplant recipients.
Effect of varying NAVA levels on ventilatory parameters, and effect of varying PEEP on ventilatory parameters.
This is an interesting and complex study of Neurally Adjusted Ventilator Assistance (NAVA) following bilateral lung transplant. Nineteen patients over the age of 18 years were randomised, although the method of randomisation is not clear from the methods presented. There are two levels of randomisation, initially to 2 PEEP levels, which have 4 levels of ventilatory assistance, then another randomisation to 3 levels of NAVA. This design makes the results of the study incredibly difficult to interpret. A large proportion (11/30) did not have a stable signal from the diaphragmatic monitor (EADi) that was contained within a specialised nasogastric tube. This meant that they were excluded from the study. Due to the small number of patients and the nature of the data collected, the study was unlikely to show significant improvements in key parameters and there is no indication it was powered for a specific outcome. Whilst the study is novel, having applied this new technique to lung transplant recipients soon after surgery, it does not show significant benefits as there was no control arm. The claim that the technique is feasible is true, however it was not possible in over a third of patients. More work is needed to assess this protocol.
ClinicalTrials.gov - NCT03367221