Non-invasive cerebral oximetry for the emergent resuscitation of comatose cardiac arrest patients: Is there still some light in the dark?

摘要

Identification of early outcome predictors of prolonged cardiac arrest (CA) is a crucial and still unsolved issue. In this issue of the journal, Ito and colleagues from the Japan-Prediction of neurological Outcomes in patients Post cardiac arrest Q-POP) study provides novel data on the potential utility of near-infrared spec-troscopy (NIRS)-derived regional cerebral oxygen saturation (rSO2) as an early prognosticator in comatose patients with prolonged CA.1 NIRS is based on spectroscopy technology that utilizes the near-infrared region of the electromagnetic spectrum to explore superficial tissue.2 Using the difference of absorption between oxy-and deoxy-haemoglobin, the NIRS technique allows continuous non-invasive monitoring of cerebral oxygenation in the frontal cortex (rSC>2). In the Japanese prospective multicentre study NIRS was used in 672 patients who were resuscitated from out-of-hospital CA. The NIRS device was placed within 3 min from hospital arrival and rSC>2 values, although they were available to clinicians, did not influence therapy. The main finding is that rSC>2 was superior to arterial blood lactate and base excess (i.e. immediately available, straightforward, prognostic biomarkers) in predicting 90-day neurological outcome. Using a cut-off value of 42%, the sensitivity of rSC>2 was 79% for good outcome prediction, with a specificity of 95%.