Reliability of the NeuroTrend sensor system under hyperbaric conditions

Objective: The goal of this study was to investigate the reliability of the multi-parameter sensor NeuroTrend in a hyperbaric environment for up to 3bar absolute pressure. Measurement of brain tissue oxygenation (ptiO2) under hyperbaric conditions is supposed to elucidate whether hyperbaric oxygenation therapy has the potential to improve ptiO2 to a clinically significant degree in pathological altered brain tissue after traumatic brain injury. Methods: The NeuroTrend sensor hose, filled with equilibrated plasma samples, was stored in a decompression chamber. The plasma samples were equilibrated with three different gas mixtures. After determination of the initial values for temperature, oxygen partial pressure (pO2), carbon dioxide partial pressure (pCO2) and hydrogen ion concentration (pH) in the plasma, the ambient pressure was stepwise increased from 0.1 to 3bar. The same set-up was performed without increasing the ambient pressure. Results: No significant difference in the mean values for all 23 measurement points and for all parameters (pO2, pCO2, pH) of all 10 NeuroTrend sensors was found, under both normobaric and hyperbaric conditions. Conclusion: The study demonstrated that an absolute ambient pressure up to 3bar did not influence the measuring properties and the reliability of the NeuroTrend sensor.