Effect of one-lung ventilation on the correlation between left and right cerebral saturation

BACKGROUND: To investigate if the correlation between left and right cerebral tissue oxygen saturation (SctO(2)) was affected by one-lung ventilation (OLV) in patients undergoing lung cancer surgery. METHODS: Patients who underwent surgery for lung cancer were enrolled. Left and right SctO(2) were collected during anesthesia. The primary outcome was the correlation between left and right SctO(2) at 30 min after OLV which was analysed by Pearson correlation and linear regression model. Secondary outcomes included the trend of left–right SctO(2) change over the first 30 min after OLV, correlation of left–right SctO(2) during OLV for each patient; maximal difference between left–right SctO(2) and its relationship with postoperative delirium. RESULTS: Left–right SctO(2) was moderately correlated at baseline (r = 0.690, P < 0.001) and poorly correlated at 30 min after OLV (r = 0.383, P < 0.001) in the Pearson correlation analysis. Linear regression analysis showed a poor correlation between left and right SctO(2) at 30 min after OLV (r = 0.323, P < 0.001) after adjusting for confounders. The linear mixed model showed a change in left–right SctO(2) over the first 30 min after OLV that was statistically significant (coefficient, -0.042; 95% CI, -0.070–-0.014; P = 0.004). For the left–right SctO(2) correlation during OLV in each patient, 62.9% (78/124) patients showed a strong correlation, 19.4% (24/124) a medium correlation, and the rest a poor correlation. The maximal difference between the left and right SctO(2) was 13.5 (9.0, 20.0). Multivariate analysis showed that it was not associated with delirium (odds ratio [OR], 1.023; 95% CI, 0.963–1.087; P = 0.463). CONCLUSIONS: The correlation between left and right SctO(2) was affected by one-lung ventilation in patients undergoing lung cancer surgery. This result indicates the requirement of bilateral SctO(2) monitoring to reflect brain oxygenation. TRIAL REGISTRATION: This study was a secondary analysis of a cohort study approved by the Clinical Research Review Board of Peking University First Hospital (#2017–1378) and was registered in the Chinese Clinical Trial Registry on 10/09/2017 (http://www.chictr.org.cn, ChiCTR-ROC-17012627). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12871-023-02001-7.