TY - JOUR
T1 - Effect of controlled blood pressure increase on cerebral blood flow velocity and oxygenation in patients with subarachnoid haemorrhage
AU - Olsen, Markus Harboe
AU - Capion, Tenna
AU - Riberholt, Christian Gunge
AU - Bache, Søren
AU - Ebdrup, Søren Røddik
AU - Rasmussen, Rune
AU - Mathiesen, Tiit
AU - Berg, Ronan M G
AU - Møller, Kirsten
N1 - © 2023 The Authors. Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.
PY - 2023/9
Y1 - 2023/9
N2 - BACKGROUND: Patients with aneurysmal subarachnoid haemorrhage (SAH) might have impaired cerebral autoregulation, that is, CBF - and thereby oxygen delivery - passively increase with an increase in CPP. This physiological study aimed to investigate the cerebral haemodynamic effects of controlled blood pressure increase in the early phase after SAH before any signs of delayed cerebral ischaemia (DCI) occurred.METHODS: The study was carried out within 5 days after ictus. Data were recorded at baseline and after 20 min of noradrenaline infusion to increase mean arterial blood pressure (MAP) by a maximum of 30 mmHg and to an absolute level of no more than 130 mmHg. The primary outcome was the difference in middle cerebral artery blood flow velocity (MCAv) measured by transcranial Doppler (TCD), while differences in intracranial pressure (ICP), brain tissue oxygen tension (PbtO2 ), and microdialysis markers of cerebral oxidative metabolism and cell injury were assessed as exploratory outcomes. Data were analysed using Wilcoxon signed-rank test with correction for multiplicity for the exploratory outcomes using the Benjamini-Hochberg correction.RESULTS: Thirty-six participants underwent the intervention 4 (median, IQR: 3-4.75) days after ictus. MAP was increased from 82 (IQR: 76-85) to 95 (IQR: 88-98) mmHg (p-value: <.001). MCAv remained stable (baseline, median 57, IQR: 46-70 cm/s; controlled blood pressure increase, median: 55, IQR: 48-71 cm/s; p-value: .054), whereas PbtO2 increased significantly (baseline, median: 24, 95%CI: 19-31 mmHg; controlled blood pressure increase, median: 27, 95%CI: 24-33 mmHg; p-value <.001). The remaining exploratory outcomes were unchanged.CONCLUSION: In this study of patients with SAH, MCAv was not significantly affected by a brief course of controlled blood pressure increase; despite this, PbtO2 increased. This suggests that autoregulation might not be impaired in these patients or other mechanisms could mediate the increase in brain oxygenation. Alternatively, a CBF increase did occur that, in turn, increased cerebral oxygenation, but was not detected by TCD.TRIAL REGISTRATION: clinicaltrials.gov (NCT03987139; 14 June 2019).
AB - BACKGROUND: Patients with aneurysmal subarachnoid haemorrhage (SAH) might have impaired cerebral autoregulation, that is, CBF - and thereby oxygen delivery - passively increase with an increase in CPP. This physiological study aimed to investigate the cerebral haemodynamic effects of controlled blood pressure increase in the early phase after SAH before any signs of delayed cerebral ischaemia (DCI) occurred.METHODS: The study was carried out within 5 days after ictus. Data were recorded at baseline and after 20 min of noradrenaline infusion to increase mean arterial blood pressure (MAP) by a maximum of 30 mmHg and to an absolute level of no more than 130 mmHg. The primary outcome was the difference in middle cerebral artery blood flow velocity (MCAv) measured by transcranial Doppler (TCD), while differences in intracranial pressure (ICP), brain tissue oxygen tension (PbtO2 ), and microdialysis markers of cerebral oxidative metabolism and cell injury were assessed as exploratory outcomes. Data were analysed using Wilcoxon signed-rank test with correction for multiplicity for the exploratory outcomes using the Benjamini-Hochberg correction.RESULTS: Thirty-six participants underwent the intervention 4 (median, IQR: 3-4.75) days after ictus. MAP was increased from 82 (IQR: 76-85) to 95 (IQR: 88-98) mmHg (p-value: <.001). MCAv remained stable (baseline, median 57, IQR: 46-70 cm/s; controlled blood pressure increase, median: 55, IQR: 48-71 cm/s; p-value: .054), whereas PbtO2 increased significantly (baseline, median: 24, 95%CI: 19-31 mmHg; controlled blood pressure increase, median: 27, 95%CI: 24-33 mmHg; p-value <.001). The remaining exploratory outcomes were unchanged.CONCLUSION: In this study of patients with SAH, MCAv was not significantly affected by a brief course of controlled blood pressure increase; despite this, PbtO2 increased. This suggests that autoregulation might not be impaired in these patients or other mechanisms could mediate the increase in brain oxygenation. Alternatively, a CBF increase did occur that, in turn, increased cerebral oxygenation, but was not detected by TCD.TRIAL REGISTRATION: clinicaltrials.gov (NCT03987139; 14 June 2019).
KW - Blood Pressure
KW - Brain Ischemia
KW - Cerebrovascular Circulation/physiology
KW - Humans
KW - Intracranial Pressure
KW - Oxygen/metabolism
KW - Stroke
KW - Subarachnoid Hemorrhage/complications
KW - Ultrasonography, Doppler, Transcranial
KW - blood pressure
KW - brain tissue oxygenation
KW - cerebral blood flow
KW - subarachnoid haemorrhage
UR - http://www.scopus.com/inward/record.url?scp=85159366820&partnerID=8YFLogxK
U2 - 10.1111/aas.14277
DO - 10.1111/aas.14277
M3 - Journal article
C2 - 37192754
VL - 67
SP - 1054
EP - 1060
JO - Acta Anaesthesiologica Scandinavica
JF - Acta Anaesthesiologica Scandinavica
SN - 0001-5172
IS - 8
ER -