Cerebral autoregulation derived blood pressure targets in elective neurosurgery

• Published in: Journal of clinical monitoring and computing Vol. 38; no. 3; pp. 649 - 662
• Main Authors: Beqiri, Erta, García-Orellana, Marta, Politi, Anna, Zeiler, Frederick A., Placek, Michal M., Fàbregas, Neus, Tas, Jeanette, De Sloovere, Veerle, Czosnyka, Marek, Aries, Marcel, Valero, Ricard, de Riva, Nicolás, Smielewski, Peter
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-06-2024; Springer Nature B.V
• Subjects: Aged; Anesthesiology; Arterial Pressure; Automation; Availability; Blood Pressure; Blood Pressure Determination - methods; Brain; Brain Ischemia - physiopathology; Cerebrovascular Circulation; Critical Care Medicine; Elective Surgical Procedures; Female; Health Sciences; Homeostasis; Humans; Intensive; Male; Medicine; Medicine & Public Health; Middle Aged; Monitoring; Monitoring, Intraoperative - methods; Monitoring, Physiologic - methods; Neurosurgery; Neurosurgical Procedures - methods; Original Research; Oxygen Saturation; Retrospective Studies; Statistics for Life Sciences; Telemedicine; Waveforms; Individualised blood pressure; Intraoperative; Neurosurgery; Optimal blood pressure; Lower limit of autoregulation
• ISSN: 1387-1307; 1573-2614; 1573-2614
• DOI: 10.1007/s10877-023-01115-0

Poor postoperative outcomes may be associated with cerebral ischaemia or hyperaemia, caused by episodes of arterial blood pressure (ABP) being outside the range of cerebral autoregulation (CA). Monitoring CA using COx (correlation between slow changes in mean ABP and regional cerebral O
2
saturation—rSO
2
) could allow to individualise the management of ABP to preserve CA. We aimed to explore a continuous automated assessment of ABP
OPT
(ABP where CA is best preserved) and ABP at the lower limit of autoregulation (LLA) in elective neurosurgery patients. Retrospective analysis of prospectively collected data of 85 patients [median age 60 (IQR 51–68)] undergoing elective neurosurgery. ABP
BASELINE
was the mean of 3 pre-operative non-invasive measurements. ABP and rSO
2
waveforms were processed to estimate COx-derived ABP
OPT
and LLA trend-lines. We assessed: availability (number of patients where ABP
OPT
/LLA were available); time required to achieve first values; differences between ABP
OPT
/LLA and ABP. ABP
OPT
and LLA availability was 86 and 89%. Median (IQR) time to achieve the first value was 97 (80–155) and 93 (78–122) min for ABP
OPT
and LLA respectively. Median ABP
OPT
[75 (69–84)] was lower than ABP
BASELINE
[90 (84–95)] (
p
 < 0.001, Mann-U test). Patients spent 72 (56–86) % of recorded time with ABP above or below ABP
OPT
 ± 5 mmHg. ABP
OPT
and ABP time trends and variability were not related to each other within patients. 37.6% of patients had at least 1 hypotensive insult (ABP < LLA) during the monitoring time. It seems possible to assess individualised automated ABP targets during elective neurosurgery.