Differences of cerebral oxygen saturation in dialysis patients: a comparison of three principals of near infrared spectroscopy

Regional cerebral oxygen saturation during initial mobilization of critically ill patients is associated with clinical outcomes: a prospective observational study

BACKGROUND

Vital signs help determine the safety of early mobilization in critically ill patients in intensive care units. However, none of these variables directly assess cerebral circulation. Therefore, we aimed to investigate the relationship of regional cerebral oxygen saturation (rSO2) and vital signs with in-hospital death in critically ill patients.

METHODS

This prospective study included critically ill patients admitted to the Uonuma Kikan Hospital Emergency Center who received physical therapy between June 2020 and December 2022. We continuously measured rSO2 during the initial mobilization using a wearable brain near-infrared spectroscopy device. With in-hospital death as the primary endpoint, the association between rSO2 and in-hospital death was assessed in Analysis 1 to determine the rSO2 cut-off value that predicts in-hospital death. In Analysis 2, patients were categorised into survival and non-survival groups to examine the temporal changes in vital signs and rSO2 associated with postural changes during mobilization.

RESULTS

Of the 132 eligible patients, 98 were included in Analysis 1, and 70 were included in Analysis 2. Analysis 1 demonstrated that lower premobilization rSO2 was independently associated with in-hospital death (odds ratio 0.835, 95% confidence interval 0.724-0.961, p = 0.012). Receiver operating characteristic curve analysis identified an optimal rSO2 cut-off value of 57% for predicting in-hospital death (area under the curve 0.818, sensitivity 73%, specificity 83%). Analysis 2 showed that rSO2 changes during mobilization were unrelated to changes in vital signs, suggesting rSO2 as an independent prognostic marker.

CONCLUSIONS

The results suggest that rSO2 measured during initial mobilization is associated with in-hospital death in critically ill patients.

Cerebral oxygenation saturation in childhood: difference by age and comparison of two cerebral oximetry algorithms

Few reports are available on the monitoring of regional cerebral oxygen saturation (rSO2) in pediatric patients undergoing non-cardiac surgical procedures. In addition, no study has examined the rSO2 levels in children of a broad age range. In this study, we aimed to assess and compare rSO2 levels in pediatric patients of different age groups undergoing non-cardiac surgery. We used two oximeters, tNIRS-1, which uses time-resolved spectroscopy, and conventional INVOS 5100C. Seventy-eight children-26 infants, 26 toddlers, and 26 schoolchildren-undergoing non-cardiac surgery were included. We investigated the differences in the rSO2 levels among the age groups and the correlation between the models and physiological factors influencing the rSO2 values. rSO2 measured by INVOS 5100C was significantly lower in infants than those in other patients. rSO2 measured by tNIRS-1 was higher in the toddler group than those in the other groups. The rSO2 values of tNIRS-1 and INVOS 5100C were moderately correlated (r = 0.41); however, those of INVOS 5100C were approximately 20% higher, and a ceiling effect was observed. The values in INVOS 5100C and tNIRS-1 were affected by blood pressure and the minimum alveolar concentration of sevoflurane, respectively. In pediatric patients undergoing non-cardiac surgery, rSO2 values differed across the three age groups, and the pattern of these differences varied between the two oximeters employing different algorithms. Further research must be conducted to clarify cerebral oxygenation in children.