Comparison of the SenSmart™ and the INVOS™ neonatal cerebral near-infrared spectrometry devices

Objectives: To determine the correlation and agreement between the SenSmart™ and the INVOS™ devices of neonatal cerebral regional oxygen saturation (CrSO₂) measurements using neonatal sensors. The secondary objective was to develop a regression model that predicts CrSO₂-INVOS values using CrSO₂-SenSmart indices and determine whether the values between the devices are interchangeable. Methods: A prospective, cross-sectional study was conducted in infants during the first 4 weeks of life. Simultaneous, bilateral CrSO₂ was measured using the SenSmart™X100 (CrSO₂-SenSmart) or INVOS™ 5100C (CrSO₂-INVOS) device in each frontoparietal area for 2 h. Five-minute CrSO₂ values were extracted for analysis. Results: Thirty infants were recruited with 720 pairwise measurements and 26 (84%) were evaluated in the first week of life. Mean gestational age of the preterm and term infants was [30.9 ± 2.8 (n = 14) and 38.8 ± 1.1 (n = 16)] weeks, respectively. Overall CrSO₂- was 77.08 ± 9.70% and 71.45 ± 12.74% for the SenSmart and INVOS, respectively (p < 0.001). The correlation coefficient (r) between the CrSO₂-SenSmart and INVOS was 0.20 (p < 0.001). The mean difference between the CrSO₂-SenSmart and INVOS was 5.63 ± 13.87% with -21.6% to 32.8% limits of agreement. The r and mean difference was 0.39 (p < 0.001) and 8.87 ± 12.58% in preterm infants, and 0.06 (p = 0.27) and 2.79 ± 14.34 in term infants. Conclusion: The CrSO₂-SenSmart tended to read higher than the CrSO₂-INVOS device. There was no correlation between the CrSO₂-SenSmart and the CrSO₂-INVOS in term infants and it was weak in preterms. Due to imprecise agreement, the CrSO₂-SenSmart values are not interchangeable with those of the CrSO₂-INVOS.