Can apneic oxygen insufflation become a novel lung protective ventilation strategy? A randomized, controlled,...

The aim of this study was to determine whether a AOI strategy on non-ventilated lung could reduce the regional and systemic proinflammatory cytokine and oxidative stress response associated with esophagectomy, and to evaluate whether AOI can be used as a novel lung protective ventilation strategy. Its impact on oxygenation after OLV, surfactant protein A, B, C (SP-A, B, C), postoperative hospital stay and postoperative pulmonary complications (PPCs) was also evaluated.

Fifty-four adults (ASA II-III) undergoing esophagectomy with OLV were enrolled in the study. Patients were randomly assigned into 2 groups: control group (group C) and treated group (group T). Group C was treated with traditional OLV mode,while group T was given AOI of 5 L/min oxygen on the non-ventilated lung immediately at the beginning of OLV. Arterial blood gas was analyzed before and after OLV. A bronchoalveolar lavage(BAL) was performed after OLV on the non-ventilated lung. Proinflammatory cytokine, oxidative stress markers(TNF-α, NF-κB,sICAM-1,IL-6,IL-10,SOD,MDA) and SP-A, B, C were analyzed in serum and BALF as the primary endpoint.The clinical outcome determined by PPCs was assessed as the secondary endpoint.

Patients with AOI had better oxygenation in the recovery period, oxygenation index(OI) (394[367-426] and 478[440-497]mmHg, respectively) of group T at T₂ and T₃ were significantly higher than those (332[206-434] and 437[331-512]mmHg, respectively) of group C. OLV resulted in an increase in the measured inflammatory markers in both groups, however, the increase of inflammatory markers upon OLV in the group C was significantly higher than those of group T. OLV resulted in an increase in the measured SP-A, B, C in serum of both groups. However, the levels of SP-A, B, C of group T were lower than those of group C in serum after OLV, and the results in BALF were the opposite. The BALF levels of SOD(23.88[14.70-33.93]U/ml) of group T were higher than those(15.99[10.33-24.16] U/ml) of group C, while the levels of MDA in both serum and BALF of group T(8.60[4.14-9.85] and 1.88[1.33-3.08]nmol/ml, respectively) were all lower than those of group C (11.10[6.57-13.75] and 1.280[1.01-1.83]nmol/ml) after OLV. There was no statistical difference between the two groups in terms of postoperative hospital stay and the incidence of PPCs.

AOI on non-ventilated lung during OLV can improve the oxygenation function after OLV, relieve the inflammatory and oxidative stress response in the systemic and non-ventilated lung after OLV associated with esophagectomy.

ChiCTR-IOR-17011037 . Registered on 31 March 2017.