Triggering modalities to synchronise non-invasive respiratory support in preterm infants: a systematic review and meta-analysis.

Increasing evidence suggests that synchronised nasal intermittent positive pressure ventilation (sNIPPV) may be the optimal mode of non-invasive respiratory support. However, no comprehensive review of sNIPPV modes is available. This review aims to describe different synchronisation methods for sNIPPV and compare their effectiveness in clinical, physiological and technical outcomes with other modes of non-invasive respiratory support. This review identified all clinical studies in preterm infants that compared sNIPPV to other non-invasive respiratory support modes or compared different trigger modalities between 1990 and 2026. A search was carried out in MEDLINE, Embase and the Cochrane Library. Main outcomes were categorised as clinical (eg, extubation failure (EF)), physiological (eg, breathing effort) and technical (eg, synchronisation rate). 49 studies (2864 infants) were included, with a low to moderate risk of bias. Meta-analysis showed a reduction in EF (risk ratio=0.38; 95% CI 0.17 to 0.85; p=0.03) in favour of sNIPPV compared with nasal continuous positive airway pressure (nCPAP). Physiological outcomes were significantly improved during sNIPPV compared with nCPAP and nasal intermittent positive pressure ventilation (NIPPV), especially breathing effort. When reviewing technical outcomes, non-invasive neurally adjusted ventilatory assist showed lower patient-ventilator asynchrony (PVA) (index ranging from 7% to 50%), a higher synchronisation rate (80%-99%) and a shorter trigger delay (35 ms) compared with other sNIPPV modes. This review shows that synchronising NIPPV results in consistent physiological (reduced patient effort) and technical benefits (reduced PVA). However, evidence on positive effects on (long-term) major clinical outcomes remains limited and requires further studies. CRD420251022479.