Near-infrared Spectroscopy Monitoring During Cardiac Arrest: A Systematic Review and Meta-analysis.

Cournoyer, Alexis; Iseppon, Massimiliano; Chauny, Jean-Marc; Denault, André; Cossette, Sylvie; Notebaert, Éric

BACKGROUND Tissue oximetry using near-infrared spectroscopy (NIRS) is a noninvasive monitor of cerebral oxygenation. This new technology has been used during cardiac arrest (CA) because of its ability to give measures in low-blood-flow situations. The aim of this study was to assess the evidence regarding the association between the types of NIRS measurements (mean, initial, and highest values) and resuscitation outcomes (return of spontaneous circulation [ROSC], survival to discharge, and good neurologic outcome) in patients undergoing cardiopulmonary resuscitation. METHODS This review was registered (Prospero CRD42015017380) and is reported as per the PRISMA guidelines. Medline, Embase, and CENTRAL were searched. All studies, except case reports and case series of fewer than five patients, reporting on adults that had NIRS monitoring during CA were eligible for inclusion. Two reviewers assessed the quality of the included articles and extracted the data. The outcome effect was standardized using standardized mean difference (SMD). RESULTS Twenty nonrandomized observational studies (15 articles and five conference abstracts) were included in this review, for a total of 2,436 patients. We found a stronger association between ROSC and mean NIRS values (SMD = 1.33; 95% confidence interval [CI] = 0.92 to 1.74) than between ROSC and initial NIRS measurements (SMD = 0.51; 95% CI = 0.23 to 0.78). There was too much heterogeneity among the highest NIRS measurements group to perform meta-analysis. Only two of the 75 patients who experienced ROSC had a mean NIRS saturation under 30%. Patients who survived to discharge and who had good neurologic outcome displayed superior combined initial and mean NIRS values than their counterparts (SMD = 1.63; 95% CI = 1.34 to 1.92; and SMD = 2.12; 95% CI = 1.14 to 3.10). CONCLUSIONS Patients with good resuscitation outcomes have significantly higher NIRS saturations during resuscitation than their counterparts. The types of NIRS measurements during resuscitation influenced the association between ROSC and NIRS saturation. Prolonged failure to obtain a NIRS saturation higher than 30% may be included in a multimodal approach to the decision of terminating resuscitation efforts (Class IIb, Level of Evidence C-Limited Data).