An adjustment of fraction of inspired oxygen using the oxygen reserve index during one-lung ventilation in pediatric patients: a prospective, randomized controlled trial.

Background: One-lung ventilation (OLV) during thoracic surgery frequently requires approximately 100% oxygen, imposing the risk of hyperoxemia. This study aimed to assess whether oxygen reserve index (ORI)-guided fraction of inspired oxygen (FiO2) adjustment can reduce the incidence of hyperoxemia in children undergoing lung resection.

Methods: This prospective, randomized controlled trial enrolled children aged < 7 years scheduled for thoracoscopic lung resection. The participants were randomly assigned to either a conventional group (FiO2 adjusted based on arterial blood gas analysis [ABGA]) or an ORI group (FiO2 titrated to maintain an ORI target of 0.15). ABGA was performed 10 and 30 min after the start of OLV (T1 and T2). The primary outcome was the incidence of hyperoxemia 30 min after OLV (T2).

Results: Data from 64 children (31 conventional, 33 ORI groups) were analyzed. The incidence rate of hyperoxemia at T2 was similar between the conventional and ORI groups (54.8% vs. 60.6%; P = 0.801). However, partial pressure of arterial oxygen at T1 was significantly lower in the ORI group than in the conventional group (214.61 ± 65.52 mmHg vs. 268.84 ± 92.71 mmHg; P = 0.014). The ORI group demonstrated a lower time-weighted average FiO2 during OLV (0.79 ± 0.12 vs. 0.87 ± 0.09; P = 0.004). The ORI group required more rescue interventions than the conventional group and experienced fewer episodes of hypoxia.

Conclusions: ORI-guided FiO2 adjustment does not significantly reduce the incidence of hyperoxemia in children undergoing OLV but reduces time-weighted FiO2 and hypoxic events.