J Neurotrauma. 2023 Apr 26. doi: 10.1089/neu.2022.0419. Online ahead of print.
ABSTRACT
Hyperventilation (HV) therapy uses vasoconstriction to reduce intracranial pressure (ICP) by reducing cerebral blood volume. However, as HV also lowers cerebral blood flow (CBF), it may provoke misery perfusion (MP) where the decrease in CBF is coupled with increased oxygen extraction fraction (OEF). MP may rapidly lead to the exhaustion of brain energy metabolites, making it vulnerable to ischemia. MP is difficult to detect at the bedside, which is where transcranial hybrid, near-infrared spectroscopies are promising since they noninvasively measure OEF and CBF. We have tested this technology during HV (∼30 minutes) with bilateral, frontal lobe monitoring to assess MP in twenty-seven sessions in eighteen patients with traumatic brain injury. In this study, HV did not lead to MP at a group level (p>0.05). However, a statistical approach yielded eighty-nine events with a high probability of MP in nineteen sessions. We have characterized each statistically significant event in detail and their possible relation with clinical and radiological status (decompressive craniectomy and presence of a cerebral lesion), without detecting any statistically significant difference (p>0.05). However, MP detection stresses the need for personalized, real-time assessment in future clinical trials with HV, in order to provide an optimal evaluation of the risk-benefit balance of HV. Our study provides pilot data demonstrating that bedside transcranial hybrid near-infrared spectroscopies could be utilized to assess potential MP.
PMID:37125452 | DOI:10.1089/neu.2022.0419
