Cerebrovascular assessment of patients undergoing shoulder surgery in beach chair position using a multiparameter transcranial Doppler approach.
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Publication Date
2019-08Journal Title
Journal of clinical monitoring and computing
ISSN
1387-1307
Publisher
Springer Nature
Volume
33
Issue
4
Pages
615-625
Language
eng
Type
Article
Physical Medium
Print-Electronic
Metadata
Show full item recordAbstract
Abstract
Purpose. Although the beach-chair position (BCP) is widely used during shoulder surgery it has been reported to associate with reduction in cerebral blood flow, oxygenation and risk of brain ischaemia. We assessed cerebral haemodynamics using a multiparameter transcranial Doppler-derived approach in patients undergoing shoulder surgery.
Methods. 23 anaesthetised patients (propofol (2 mg/kg)) without history of neurologic pathology undergoing elective shoulder surgery were included. Arterial blood pressure (ABP, monitored with a finger-cuff plethysmograph calibrated at the auditory meatus level) and cerebral blood flow velocity (FV, monitored in the in the middle cerebral artery) were recorded in supine and BCP. All subjects underwent interscalene block ipsilateral to the side of FV measurement. We evaluated non-invasive intracranial pressure (nICP) and cerebral perfusion pressure (nCPP) calculated with a black-box mathematical model; critical closing pressure (CrCP); diastolic closing margin (DCM - pressure reserve available to avoid diastolic flow cessation); cerebral autoregulation index (Mxa); pulsatility index (PI).
Results. Significant changes occured for DCM (mean decrease of 6.43 mmHg (p=0.01) and PI (mean increase of 0.11 (p=0.05)). ABP, FV, nICP, nCPP and CrCP showed a decreasing trend. Cerebral autoregulation was dysfunctional (Mxa >0.3) and PI deviated from normal ranges (PI>0.8) in both phases. ABP and nCPP values were low (<60 mmHg) in both phases. Changes between phases did not result in CrCP reaching diastolic ABP, therefore DCM did not reach critical values (≤0 mmHg).
Conclusions. BCP resulted in significant cerebral haemodynamics changes. If left untreated, reduction in cerebral blood flow may result in brain ischaemia and postoperative neurologic deficit.
Key words: Beach chair postion; transcranial Doppler; non-invasive intracranial pressure; cerebral autoregulation.
Keywords
Shoulder, Brain, Humans, Brain Ischemia, Oxygen, Propofol, Ultrasonography, Doppler, Transcranial, Ultrasonography, Doppler, Blood Flow Velocity, Monitoring, Physiologic, Anesthesia, Risk, Cerebrovascular Circulation, Adolescent, Adult, Aged, Aged, 80 and over, Middle Aged, Female, Male, Hemodynamics, Young Adult, Patient Positioning, Arterial Pressure, Sitting Position
Sponsorship
ICM+ software is licensed by the University of Cambridge, Cambridge Enterprise Ltd. MC and PS have a financial interest in a part of its licensing fee. The procedure of non-invasive ICP assessment is distributed as a plug-in for ICM+ monitoring software. BS and MC have financial interest in its licensing fee. The remaining authors declare no conflict of interest.
Cambridge Commonwealth, European & International Trust Scholarship, University of Cambridge provided financial support in the form of Scholarship funding for DC. Woolf Fisher Trust provided financial support in the form of Scholarship funding for JD. NIHR Brain Injury Healthcare Technology Co-operative, Cambridge, UK, provided financial support in the form of equipment funding for DC and MC. The sponsors had no role in the design or conduct of this manuscript.
Identifiers
External DOI: https://doi.org/10.1007/s10877-018-0211-7
This record's URL: https://www.repository.cam.ac.uk/handle/1810/285830
Except where otherwise noted, this item's licence is described as Attribution 4.0 International