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

Abstract

Background: To investigate if the correlation between left and right cerebral tissue oxygen saturation (SctO₂) 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 SctO₂ were collected during anesthesia. The primary outcome was the correlation between left and right SctO₂ at 30 min after OLV which was analysed by Pearson correlation and linear regression model. Secondary outcomes included the trend of left-right SctO₂ change over the first 30 min after OLV, correlation of left-right SctO₂ during OLV for each patient; maximal difference between left-right SctO₂ and its relationship with postoperative delirium.

Results: Left-right SctO₂ 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 SctO₂ 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 SctO₂ 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 SctO₂ 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 SctO₂ 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 SctO₂ was affected by one-lung ventilation in patients undergoing lung cancer surgery. This result indicates the requirement of bilateral SctO₂ 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).

Keywords: Cerebral tissue saturation; Correlation; Lung cancer; One-lung ventilation.