Efficacy and safety of nasal mask compared to nasal cannula during procedural sedation in gastroscopy: a systematic review, meta-analysis, and trial sequential analysis

BACKGROUND: Hypoxemia is the most common adverse event during propofol-based procedural sedation for gastroscopy. Conventional nasal cannula oxygenation provides low flow rates, permitting room air entrainment and often proving insufficient. Nasal mask oxygenation delivers higher inspired oxygen concentrations, potentially enhancing respiratory safety during sedation. OBJECTIVE: This study compared the efficacy and safety of nasal mask versus nasal cannula oxygen delivery during propofol-based procedural sedation for gastroscopy. METHODS: Electronic databases/registries were systematically searched from inception to January 24, 2026, for randomized controlled trials (RCTs). Inclusion criteria encompassed adult patients undergoing propofol-based sedation for gastroscopy. The primary outcome was the incidence of hypoxemia. Secondary outcomes included severe hypoxemia, minimum oxygen saturation (SpO₂), need for airway or oxygenation interventions, procedure-related adverse events, and postoperative nausea and vomiting (PONV). Random-effects meta-analyses were performed using risk ratios (RRs) or mean differences (MDs) with 95% confidence intervals (CIs). Trial sequential analysis (TSA) assessed the sufficiency of the evidence. Risk of bias was evaluated using RoB 2, and certainty of evidence using GRADE. RESULTS: Five RCTs enrolled 1,267 patients, of whom 1,252 (98.8%) were included in the quantitative synthesis. Nasal mask oxygenation significantly reduced hypoxemia (RR 0.40, 95% CI 0.28 to 0.58, p < 0.0001) and severe hypoxemia (RR 0.39, 95% CI 0.22 to 0.67, p = 0.0007) compared with nasal cannula. Nasal masks also decreased the need for jaw thrust (RR 0.40, 95% CI 0.31 to 0.52) and mask-assisted ventilation (RR 0.16, 95% CI 0.05 to 0.46), while elevating minimum SpO₂ (MD 3.78, 95% CI 1.39 to 6.16). No significant differences emerged in coughing, hiccups, or PONV. CONCLUSIONS: Nasal mask oxygenation is associated with greater respiratory safety compared with nasal cannula oxygenation during propofol-sedated gastroscopy. This advantage manifests as reduced incidence of hypoxemia and fewer airway-related interventions, alongside a comparable overall safety profile. PROSPERO: CRD420261291468.