Volume-assured pressure support versus bilevel positive airway pressure in non-invasive ventilation: A systematic review of clinical effectiveness.

BACKGROUND: Volume-assured pressure support (VAPS) modes automatically adjust inspiratory pressure to maintain target ventilation, theoretically improving upon traditional bilevel positive airway pressure (BiPAP). However, their comparative effectiveness across different clinical contexts remains incompletely characterized. METHODS: dynamics. PRIMARY ENDPOINTS: ). Secondary endpoints included clinical success rates, patient comfort, adherence, and mortality. RESULTS: correction in two studies (0.18 kPa/h faster, p < 0.001; 83.3% vs 66.6% normalization at 30 min, p = 0.015); four showed equivalent response. Intubation rates favored VAPS in hypercapnic failure (6.4% vs 15.2%) but a single study (n = 89) suggested potential harm in hypoxemic failure (60% vs 42%, p > 0.05). In chronic settings, both modes achieved equivalent gas exchange (six of seven studies). Patient adherence predicted survival better than mode selection (HR 0.34, 95% CI: 0.18-0.64). CONCLUSIONS: These hypothesis-generating findings show VAPS provides faster early stabilization in acute hypercapnic respiratory failure and equivalent outcomes in chronic stable conditions. However, substantial within-strata heterogeneity limits granular guidance, particularly in chronic settings combining mechanistically distinct diseases (Chronic obstructive pulmonary disease, Obesity hypoventilation syndrome, neuromuscular disorders). The intubation difference in hypoxemic failure (single study, n = 89) requires replication. Disease-specific randomized trials are needed before definitive recommendations.