The clinical effects of cerebral NIRS monitoring versus no monitoring in children and adults: a systematic review with meta-analysis and trial sequential analysis

Hypoxic-ischemic brain injury due to cerebral hypoxia/ischemia is seen in patients within multiple clinical settings across all age groups. Despite uncertainty regarding benefits and harms, cerebral NIRS monitoring is increasingly used as a monitoring tool to guide treatment, in settings where the patients are at risk of cerebral hypoxia/ischemia. It is especially used during aortic and cardiac surgery, but also in the intensive care units, including neonatal, pediatric and adult intensive care. As the rates of hypoxic-ischemic brain injury are typically low in many of these settings, it is difficult for randomised clinical trials to obtain a sufficiently large number of events to evaluate the clinical effect, when conducted in individual clinical settings. This is also seen in the available systematic reviews with meta-analysis including trials within specific clinical settings – numbers are too low and larger/more trials are needed.
The purpose of cerebral NIRS monitoring is the same within the individual clinical settings; to prevent hypoxic/ischemic brain injury. If all trials irrespectively of participant age or clinical setting were pooled in one meta-analysis, we might reach a sufficient information size (evaluated by Trial Sequential Analysis) to evaluate the beneficial and harmful effects of cerebral NIRS monitoring. Thus, we intend to conduct a systematic review with meta-analysis and Trial Sequential Analysis, to evaluate the effects of clinical care with access to cerebral NIRS monitoring versus clinical care without access to cerebral NIRS monitoring, in children and adults across all clinical settings (pooling of trials within surgery, and neonatal-, pediatric-, and adult intensive care). 
We are aware that the heterogeneity between the included trials might impair our possibility to interpret the results to specific clinical settings. If the analysis reveals that NIRS has a beneficial effect on any of our predefined outcomes, it will rather be an encouragement to continue the conduct of randomised clinical trials within each clinical setting, in order to reach the sufficient information size (evaluated by a sequential analysis method).
The protocol for the systematic review with meta-analysis has been published in Systematic Reviews Journal. The publication can be found here
As per the 9th of May, the literature search and data collection is on-going.