Noninvasive and sensitive optical assessment of brain death

Abstract

Brain death is an irreversible loss of all brain functions, and the assessment is crucial for organ supply for transplantation. The noninvasive, sensitive, universally available and timely ancillary method to assess brain death has not been established. Here, we attempted to explore a noninvasive way in brain death assessment. Eighteen brain‐dead patients and 20 healthy subjects were measured by near‐infrared spectroscopy (NIRS), with a multiple‐phase protocol at varied fraction of inspired O2 (FIO2). We found that the concentration changes ratios of oxyhemoglobin to deoxyhemoglobin (Δ[HbO2]/Δ[Hb]) in the cerebral cortex of brain‐dead patients were significantly higher than those of healthy subjects. And, the Δ[HbO2]/Δ[Hb] in low‐to‐high FIO2 phase was most sensitive to distinguish brain‐dead patients from healthy subjects, with a recommended threshold ranged in 1.40~1.50. The innovative incorporation of NIRS and a varied FIO2 protocol was shown to be a noninvasive and reliable way in assessing brain death. This successful attempt of NIRS application is a help for fast and accurate evaluation of brain death, promptly offering quality‐assured donor organs and indicate us a protocol‐aided way to expand the use of NIRS.

Task and Non-task Brain Activation Differences for Assessment of Depression and Anxiety by fNIRS

“…Functional near-infrared spectroscopy (fNIRS) is a noninvasive, functional neuroimaging technique that could assess brain function by quantifying cerebral oxygenation at the microvasculature level (6)(7)(8). After more than 40 years of development, this technology has been used for evaluation of cerebral function (9)(10)(11) and extended to the clinical field of psychiatry, as one of the objective modalities for probing psychoses (12). fNIRS is sensitive to external stimulation or events; it allows for longitudinal monitoring of the changes in brain metabolism.…”

Monte Carlo modeling of photon migration in realistic human thoracic tissues for noninvasive monitoring of cardiac hemodynamics

“…Much progress of NIRS and DOT research in human head has been achieved. Accurate modeling of tissue increased the utility of photon migration for a broader range of applications including: cerebral metabolism , cerebral edema , traumatic brain injury , functional neuroimaging . However, the study on photon migration in human heart has not been thoroughly researched yet.…”

Reorganization of prefrontal network in stroke patients with dyskinesias: evidence from resting‐state functional near‐infrared spectroscopy

“…FNIRS has also wide application in other clinical diseases. For example, fNIRS has been used in assessing brain death [54], monitoring patients with shock [55], and studying spinal cord injury [56]. With the development of fNIRS technology and excavation of new indicators, it will certainly give a boost to fNIRS use in clinical applications.…”

“…FNIRS has been an effective tool in clinical research [29,30] and has a wide range of applications in stroke research. Yang et al demonstrated that fNIRS was an effective tool for the monitoring, treatment and research of stroke, and was expected to be used in the prevention of stroke by combining with other techniques [31].…”