Functional Near Infrared Spectroscopy to Detect Pain in Young Children Under General Anesthesia
Condition: Pain
Study type: Observational

Summary: 
      This is a three-phase pilot prospective study to develop a devise capable of detecting
      changes in cortical blood volume and oxygenation due to noxious stimuli. The hypothesis of
      the study is that optical signal changes corresponding to blood volume and oxygenation will
      be detected with functional near infrared spectroscopy in the prefrontal cortex of children
      under general anesthesia in response to peripheral noxious stimuli produced from the
      neurophysiological monitoring (SSEP).
    

Detailed description: 
      Pain is a subjective feeling, and an objective measure of pain is needed to obtain improved
      clinical management and safe outcomes of pain treatment. At present, there is a lack of
      specific physiological markers of acute pain that can guide analgesic treatment both during
      and after surgery. The anesthesiologist typically relies on hemodynamic variables to guide
      administration of opioids for surgical pain, but those parameters are not always either
      specific or sensitive. On the other hand, uncontrolled pain during surgery can lead to
      emotional distress and enhancement of the systemic inflammatory response (1).

      Current evidence (2-4) shows that the prefrontal cortex plays an important role in pain
      perception and emotional elaboration. Functional neuroimaging (functional magnetic resonance
      imaging functional magnetic resonance imaging (fMRI) functional near infrared spectroscopy
      fNIRS) has been recently utilized to investigate cerebral pain-related activity (5, 6).

      The investigators propose to detect the optical signal changes over the prefrontal cortex
      using fNIRS and diffuse optical imaging (DOI) in response to noxious electrical stimulation.
      This electrical stimulation will be applied over the ulnar nerve at the wrist in children
      undergoing neurosurgery with SSEP monitoring. This noxious electrical stimulation is the
      standard stimulus used to establish baseline somatosensory evoked potentials in this patient
      population for this surgery. DOI is a mathematical methodology used to generate an image from
      the optical signals analogous to the mathematical methodology of generating a MRI from
      nuclear magnetic spectroscopy signals.

      The investigators will evaluate the magnitude of change of fNIRS-DOI signals after two
      different intensities of noxious electrical stimulation and following intravenous
      administration of fentanyl (2 mcg/kg). The investigators will also analyze the temporal
      correlation of the prefrontal cortex fNIRS-DOI changes with the SSEPs. The results will lead
      to the identification of an objective specific biomarker for acute pain in children. Our
      long-term goal is to develop a portable and readily accessible device to improve management
      of intraoperative nociception and to evaluate acute pain in awake non-verbal children.
    

Intervention name(s): fNIRS
Intervention type(s): Device
Intervention description(s): Near infrared spectroscopy (NIRS) is a non-invasive, portable, relatively inexpensive optical technology similar to pulse oximetry except that it measures total hemoglobin, oxy-hemoglobin, and deoxyhemoglobin in brain tissue (capillaries) rather than arteries.
Other intervention name(s): Functional Near Infrared Spectroscopy
Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        The patients who are presenting to CCHMC for tethered spinal cord release , posterior fossa
        decompression, or spine surgery; the anesthetic plan includes endotracheal intubation and
        neuromonitoring.
      
Keywords: Acute pain measurement in children