Study of High-velocity nasal Insufflation versus Non-invasive positive pressure ventilation for Emergency type 2 respiratory failure (SHINE): Protocol for a non-inferiority randomized controlled trial (Preprint)

BACKGROUND Type 2 respiratory failure (T2RF) is a common and high-risk presentation in the emergency department (ED). Non-invasive positive pressure ventilation (NIPPV) is a standard first-line therapy for T2RF, particularly in acute exacerbations of chronic obstructive pulmonary disease and cardiogenic pulmonary edema. However, NIPPV has limitations including discomfort, claustrophobia, air leaks, skin injury, and aspiration, which may compromise tolerance and lead to treatment failure or escalation to endotracheal intubation. High-velocity nasal insufflation (HVNI), particularly via a single-prong asymmetric cannula configuration, has been proposed to enhance dead-space washout and improve patient comfort. Despite growing interest, robust evidence evaluating HVNI in heterogeneous, all-cause T2RF populations in the ED remains limited. OBJECTIVE This study aims to determine whether HVNI delivered via a single-prong nasal cannula is non-inferior to standard NIPPV in improving ventilation among adult ED patients with T2RF from any cause. METHODS This is a single-center, open-label, non-inferiority randomized controlled trial conducted in the ED of a tertiary academic center. Adults 21 years and above with T2RF defined as PaCO2 >45 mmHg and pH