Optimal cerebral perfusion pressure via transcranial Doppler in TBI: application of robotic technology

Abstract

Individualized cerebral perfusion pressure (CPP) targets may be derived via assessing the minimum of the parabolic relationship between an index of cerebrovascular reactivity and CPP. This minimum is termed the optimal CPP (CPPopt), and literature suggests that the further away CPP is from CPPopt, the worse is clinical outcome in adult traumatic brain injury (TBI). Typically, CPPopt estimation is based on intracranial pressure (ICP)-derived cerebrovascular reactivity indices, given ICP is commonly measured and provides continuous long duration data streams. The goal of this study is to describe for the first time the application of robotic transcranial Doppler (TCD) and the feasibility of determining CPPopt based on TCD autoregulation indices.Electronic supplementary materialThe online version of this article (10.1007/s00701-018-3687-5) contains supplementary material, which is available to authorized users.

Transcranial Doppler Based Cerebrovascular Reactivity Indices in Adult Traumatic Brain Injury: A Scoping Review of Associations With Patient Oriented Outcomes

“…Further investigation of TCD based indices, aside from Mx, should also be done given the evidence of the strength of correlation with outcome Sx has demonstrated. Additionally, ABP based indices are of particular interest given the recent description of entirely non-invasive methods of collecting the requisite physiologic data ( Zeiler et al, 2018b ; Zeiler et al, 2019b ; Zeiler and Smielewski, 2018 ; Gomez et al, 2020 ).…”

“…Finally, advances in TCD technology, such as robotic TCD has allowed for prolonged recording in and above 4 h due to the continuous robotic optimization of probe position. This has already been described as a means of assessing cerebrovascular reactivity for extended periods of time and may extend the percentage of time monitored while in ICU ( Zeiler et al, 2018b ; Zeiler and Smielewski, 2018 ). This may prove to further improve the association of these indices with outcomes following TBI while providing a more complete picture of the post-TBI physiome.…”

“…Table 1 summarizes these indices and their derivation. Notably, those that utilize ABP instead of CPP open the door to the entirely non-invasive measurement of cerebrovascular reactivity ( Zeiler et al, 2018b ; Zeiler et al,2019b ; Zeiler and Smielewski, 2018 ; Gomez et al, 2020 ). This has the potential to expand their application to the neurocritical care of patient populations that do not typically have ICP monitoring as well as to the outpatient setting.…”

Robotic Semi-Automated Transcranial Doppler Assessment of Cerebrovascular Autoregulation in Post-Concussion Syndrome: Methodological Considerations

“…Although TCD is inexpensive and its sensitivity and specificity for monitoring of CBF is excellent, it is typically technically limited to short recording durations as minor movements of carefully placed probes may interrupt data collection. 47 Semi-automated (robotic) TCD has been developed to facilitate extended, uninterrupted recordings using automated correction algorithms and flow velocity sampling methods to maintain optimum probe positioning. 47 Robotic TCD allows more consistent and reproducible assessment of TCD metrics simplifying what was previously a highly operator-dependent intervention.…”

“… 47 Semi-automated (robotic) TCD has been developed to facilitate extended, uninterrupted recordings using automated correction algorithms and flow velocity sampling methods to maintain optimum probe positioning. 47 Robotic TCD allows more consistent and reproducible assessment of TCD metrics simplifying what was previously a highly operator-dependent intervention. As this technology becomes more autonomous and more integrated with plethysmograph and processing software, it may allow non-specialists to carry out the analysis in any outpatient or inpatient setting.…”