Comparing near-infrared spectroscopy-measured cerebral oxygen saturation and corresponding venous oxygen saturations in children with congenital heart disease: a systematic review and meta-analysis

Background: Near-infrared spectroscopy ( NIRS) is a non-invasive approach that measures cerebral regional oxygen saturation (rScO(2)). In this study, we evaluated the evidence on the validity of NIRS and the interchangeability between NIRS and common invasive approaches by exploring the correlation and consistency and comparing the mean and standard deviation between the NIRS rScO(2) and jugular bulb venous oxygen saturation (SjvO(2)) as well as central venous oxygen saturation (ScvO(2)) in the perioperative period of children with congenital heart disease (CHD). Methods: We searched electronic bibliographic databases (PubMed, The Cochrane Library and Embase) and screened the studies that met the inclusion criteria. We included cross-sectional studies of CHD pediatric patients in the perioperative period receiving both tests for NIRS rScO(2) and SjvO(2) or NIRS rScO(2) and ScvO(2). Methodological quality assessment and heterogeneity analyses were performed. We qualitatively summarized the results of Bland-Altman's analysis. Meta-regression, subgroup analyses, and sensitivity analyses were carried out to explore the causes of heterogeneity. Results: There was no significant difference in Cohen's d between rScO(2) and ScvO(2) or between rScO(2) and SjvO(2) (Cohen's d =0.06, 95% CI: -0.16 to 0.28; Cohen's d =0.03, 95% CI: -0.25 to 0.31, respectively) and notable heterogeneity existed (I-2=76.0%, P<0.001; I2=73.6%, P<0.001, respectively). A positive linear correlation was present between rScO2 and ScvO(2) or between rScO(2) and SjvO(2) (r=0.58, 95% CI: 0.54 to 0.63; r=0.60, 95% CI: 0.54 to 0.66, respectively) and the heterogeneity was not significant (I-2=36.7%, P=0.065; I2=12.7%, P=0.328, respectively). In most studies, the 95% limits of agreements of Bland-Altman's analysis were large. No evidence of publication bias was observed. Conclusions: The rScO(2) measured by NIRS reflected the SjvO2 and ScvO(2) monitored by invasive measurements in the perioperative period of children with CHD to some extent. However, wide limits of agreements between rScO(2) and SjvO(2) as well as ScvO(2) indicated that NIRS and SjvO2 as well as ScvO(2) are not interchangeable. Whether NIRS plays a prominent role in monitoring cerebral oxygen saturation in children with CHD needs further research.