Clinical Trial Details
— Status: Recruiting
Administrative data
| NCT number |
NCT04174001 |
| Other study ID # |
P00031784 |
| Secondary ID |
|
| Status |
Recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
February 11, 2020 |
| Est. completion date |
December 2024 |
Study information
| Verified date |
February 2024 |
| Source |
Boston Children's Hospital |
| Contact |
Craig McClain, MD |
| Phone |
617-355-7737 |
| Email |
Craig.McClain[@]childrens.harvard.edu |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
One of the challenges in pediatric anesthesiology is to ensure adequate cerebral perfusion
pressure to prevent cerebral ischemia or hyperemia from pressure-passive perfusion. However,
there is no optimal tool for longitudinally monitoring cerebral perfusion under general
anesthesia (GA). In addition, the safe limits of blood pressure that maintains adequate
cerebral perfusion in infants and children are not clear. Furthermore, patients with
neurological impairments may have impaired cerebral auto-regulation (CA) function which may
associated with functional outcomes. To address the critical public health issues associated
with the safe use of general anesthesia in during neurosurgery, monitoring cerebral perfusion
and oxygenation continuously during the peri-operative period.
The investigators have pioneered a novel technology, diffuse correlation spectroscopy (DCS),
to optically measure cerebral blood flow (CBF) non-invasively and demonstrated that it is
safe and practical as a bedside CBF monitor in the NICU. Blood flow is distinct from blood
oxygenation, but both are important for brain health. Clinical near infrared spectroscopy
(NIRS) devices are available to monitor oxygenation by light absorption, but CBF must be
monitored by light scattering, which is only available with research DCS devices. While the
physical principles of the methods are different, the sensors for both techniques are very
similar. The investigators have therefore combined DCS with advanced frequency-domain NIRS
(FDNIRS) in a single device to simultaneously monitor cerebral tissue oxygen saturation
(cStO2), blood volume (CBV), CBF and oxygen metabolism (CMRO2), which cannot be monitored
with existing clinical devices. The investigators have previously shown that these measures
are far more sensitive than cStO2 alone in several infant brain pathologies. In this study,
the investigators aim to test the feasibility of integrating the FDNIRS-DCS technology into
perioperative monitoring to study cerebral hemodynamics and oxygen metabolism continuously in
children during general anesthesia and surgery. Additionally, the investigators will
determine how anesthesia-related events affect cerebral hemodynamic instability and how
anesthetic level correlates with CA functions in children.
Description:
Cerebral autoregulation (CA) is a mechanism that maintains cerebral flood flow (CBF) despite
the fluctuations in the arterial blood pressure. This process protects the brain from
ischemic or hemorrhagic insults during events of hypo- or hyperperfusion, respectively.
Children under general anesthesia (GA) are particularly vulnerable to these events because
anesthetic agents profoundly impact cerebral metabolic supply and demand. At the same time,
to varying degrees, anesthetic agents can compromise respiration, produce hypotension, and
even inhibit cerebral autoregulation function. General anesthesia-induced cerebral
hypoperfusion can occur during routine GA and is associated with deleterious neurological
outcomes in children. Thus, primary goals in managing GA are therefore to maintain adequate
hemodynamics and cerebral perfusion under intact CA.
A recent large retrospective study demonstrated that blood pressure ranges in anesthetized
children are significantly lower than in awake, healthy children. However, the safe limits of
blood pressure that maintains adequate cerebral perfusion in infants and children are not
clear and my vary depending on the age and disease severity. Currently, bedside CBF
monitoring had been impractical. Transcranial Doppler ultrasound (TCD) is the only clinically
available tool to measure cerebral blood flow velocity in larger arteries. Although TCD has
been used for obtaining cerebral hemodynamics including autoregulation for clinical use, it
is not practical for long-term monitoring due to the difficulty to secure the probe on the
patient's head. Furthermore, the accuracy of the TCD measurement is highly operator-dependent
which impedes its general use.
Cerebral oximeters, based on near-infrared spectroscopy (NIRS) have become popular means of
assessing cerebral hemoglobin oxygen saturation (cStO2) during GA, but its use has not become
routine. Clinically relevant desaturation (generally below 50-60 percent) implies a mismatch
between brain oxygen supply and demand. When presenting persistently, they can serve as an
intraoperative warning sign of hemodynamic and metabolic comprise. A recent study with 453
healthy infants undergoing general anesthesia for non-cardiac surgery found the episodes of
desaturation is rare (2%) despite that critically low blood pressure (MAP <35 mmHg) was
observed in almost 40% of subjects. Because desaturation events are relatively rare, they are
unlikely to be responsible for adverse outcomes in non-cardiac surgery. However, the
magnitude of the change in cStO2 from the awake to anesthetized state was associated with the
range of MAP experienced during GA, suggesting systematic changes in cerebral perfusion may
be more important than desaturation events for assessing hemodynamic risk.
To address the critical public health issues associated with the safe use of anesthesia in
children, the investigators propose to develop new beside tools to monitor cerebral
hemodynamics and perfusion continuously during anesthesia. The investigators aim to quantify
cStO2, CBF, CMRO2, and its coupling relationship in children with and without neurologic
impairments while awake and during different phases of GA (aim1). With continuous measures of
arterial blood pressure, the investigators will further determine CA functions by studying
the relationship between CBF and ABP simultaneously with anesthesia-related physiological
events, including hypercapnia (aim2). Ultimately, the investigators aim to integrate our
technology into perioperative monitoring to enable age-appropriate, goal-directed cerebral
hemodynamic management to spare infant brains from the potentially deleterious effects of
anesthesia.
