The new neural pressure support (NPS) mode and the helmet: did we find the dynamic duo?

Background: Noninvasive ventilation (NIV) is commonly used in clinical practice to reduce intubation times and enhance patient comfort. However, patient-ventilator interaction (PVI) during NIV, particularly with helmet interfaces, can be challenging due to factors such as dead space and compliance. Neurally adjusted ventilatory assist (NAVA) has shown promise in improving PVI during helmet NIV, but limitations remain. A new mode, neural pressure support (NPS), aims to address these limitations by providing synchronized and steep pressurization. This study aims to assess whether NPS per se improves PVI during helmet NIV compared to standard pressure support ventilation (PSV). Methods: The study included adult patients requiring NIV with a helmet. Patients were randomized into two arms: one starting with NPS and the other with PSV; the initial ventilatory parameters were always set as established by the clinician on duty. Physiological parameters and arterial blood gas analysis were collected during ventilation trials. Expert adjustments to initial ventilator settings were recorded to investigate the impact of the expertise of the clinician as confounding variable. Primary aim was the synchrony time (Time_sync), i.e., the time during which both the ventilator and the patient (based on the neural signal) are on the inspiratory phase. As secondary aim neural-ventilatory time index (NVT_I) was also calculated as Time_sync divided to the total neural inspiratory time, i.e., the ratio of the neural inspiratory time occupied by Time_sync. Results: Twenty-four patients were enrolled, with no study interruptions due to safety concerns. NPS demonstrated significantly longer Time_sync (0.64 ± 0.03 s vs. 0.37 ± 0.03 s, p < 0.001) and shorter inspiratory delay (0.15 ± 0.01 s vs. 0.35 ± 0.01 s, p < 0.001) compared to PSV. NPS also showed better NVT_I (78 ± 2% vs. 45 ± 2%, p < 0.001). Ventilator parameters were not significantly different between NPS and PSV, except for minor adjustments by the expert clinician. Conclusions: NPS improves PVI during helmet NIV, as evidenced by longer Time_sync and better coupling compared to PSV. Expert adjustments to ventilator settings had minimal impact on PVI. These findings support the use of NPS in enhancing patient-ventilator synchronization and warrant further investigation into its clinical outcomes and applicability across different patient populations and interfaces. Trial registration: This study was registered on www.clinicaltrials.gov NCT06004206 Registry URL: https://clinicaltrials.gov/study/NCT06004206 on September 08, 2023.