Increased ICP and Its Cerebral Haemodynamic Sequelae
Joseph Donnelly , Marek Czosnyka , Spencer Harland , Georgios V Varsos , Danilo Cardim , Chiara Robba , X. Liu , Philip N. Ainslie , Peter Smielewski
AbstractObjectives: Increased intracranial pressure (ICP) is a pathological feature of many neurological diseases; however, the local and systemic sequelae of raised ICP are incompletely understood. Using an experimental paradigm, we aimed to describe the cerebrovascular consequences of acute increases in ICP. Materials and methods: We assessed cerebral haemodynamics [mean arterial blood pressure (MAP), ICP, laser Doppler flowmetry (LDF), basilar artery Doppler flow velocity (Fv) and estimated vascular wall tension (WT)] in 27 basilar artery-dependent rabbits during experimental (artificial lumbar CSF infusion) intracranial hypertension. WT was estimated as the difference between critical closing pressure and ICP. Results: From baseline (~9 mmHg) to moderate increases in ICP (~41 mmHg), cortical LDF decreased (from 100 to 39.1%, p < 0.001), while mean global Fv was unchanged (from 47 to 45 cm/s, p = 0.38). In addition, MAP increased (from 88.8 to 94.2 mmHg, p < 0.01 and WT decreased (from 19.3 to 9.8 mmHg, p < 0.001). From moderate to high ICP (~75 mmHg), both global Fv and cortical LDF decreased (Fv, from 45 to 31.3 cm/s, p < 0.001; LDF, from 39.1 to 13.3%, p < 0.001) while MAP increased further (94.2 to 114.5 mmHg, p < 0.001) and estimated WT was unchanged (from 9.7 to 9.6 mmHg, p = 0.35). Conclusion: In this analysis, we demonstrate a cortical vulnerability to increases in ICP and two ICP-dependent cerebro-protective mechanisms: with moderate increases in ICP, WT decreases and MAP increases to buffer cerebral perfusion, while with severe increases of ICP, an increased MAP predominates.
|Publication size in sheets||0.5|
|Book||Heldt Thomas (eds.): Intracranial Pressure & Neuromonitoring XVI, Acta Neurochirurgica, Supplement, vol. 126, 2018, Springer International Publishing, ISBN 978-3-319-65797-4, [978-3-319-65798-1], DOI:10.1007/978-3-319-65798-1|
|Keywords in English||Intracranial pressure; Cerebral haemodynamics; Autoregulation; Cerebral perfusion pressure|
|Score||= 5.0, 20-10-2019, MonographChapterAuthor|
|Publication indicators||= 0; : 2017 = 0.44|
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