Abstract: Objective To observe the effect of one lung ventilation (OLV) preconditioning on perioperative oxygenation during
pediatric video-assisted thoracoscopic surgeries (VATS). Methods A total of 171 children aged 5 days to 11 years underwent
VATS for empyema dissection and abscess excisions (n=55), mediastinal tumor resection (n=34), repair of the diaphragmatic
hernia or diaphragmatic plication (n=21), pulmonary lobectomy or biopsy (n=43), or esophageal disease (n=18). Of these
patients, 127 were younger than 3 years of age. A 5-Fr pediatric endobronchial blocker was used for OLV with a delivered
inspired oxygen fraction (FiO2) of 1.0. After lateral decubitus, a sequential protocol of a 5- to 8-min OLV preconditioning and a
5-min two lung ventilation (TLV) was performed followed by OLV again before incision for VATS. In cases of a SpO2<95%
without malposition of the blocker during OLV, a 5 cm H2O positive end expiratory pressure was applied; TLV was maintained
for a SpO2<90%. Results OLV provided good surgical conditions in 160 cases. Acceptable saturations were achieved in 166
cases during OLV. In 2 cases in empyema group and 3 in esophageal disease group, the ventilation protocol was converted to
intermittent TLV during the operation due to hypoxemia. In esophageal disease group, the procedure and OLV duration,
postoperative ventilation time and length of stay (LOS) were the longest among the groups, and the number of cases
developing postoperative atelectasis was greater than that in diaphragmatic hernia and pulmonary disease groups. In
empyema and esophageal disease groups, the oxygenation index (PaO2/FiO2) after total collapse of the lung in OLV and after
extubation were lower than that in mediastinal tumor group (P<0.05 or 0.01). Conclusion OLV preconditioning can maintain
an acceptable oxygenation during pediatric OLV. A longer procedure and OLV duration is associated with a prolonged
postoperative length of ventilation and LOS.