J Neurosurg. 2020 Jan 10;1-10. doi: 10.3171/2019.11.JNS192759. Epub 2020 Jan 10.

CBF changes and cerebral energy metabolism during hypervolemia, hemodilution, and hypertension therapy in patients with poor-grade subarachnoid hemorrhage.

Journal of neurosurgery

Henrik Engquist, Anders Lewén, Lars Hillered, Elisabeth Ronne-Engström, Pelle Nilsson, Per Enblad, Elham Rostami

PMID: 31923897 DOI: 10.3171/2019.11.JNS192759

Abstract

OBJECTIVE: Despite the multifactorial pathogenesis of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH), augmentation of cerebral blood flow (CBF) is still considered essential in the clinical management of DCI. The aim of this prospective observational study was to investigate cerebral metabolic changes in relation to CBF during therapeutic hypervolemia, hemodilution, and hypertension (HHH) therapy in poor-grade SAH patients with DCI.

METHODS: CBF was assessed by bedside xenon-enhanced CT at days 0-3, 4-7, and 8-12, and the cerebral metabolic state by cerebral microdialysis (CMD), analyzing glucose, lactate, pyruvate, and glutamate hourly. At clinical suspicion of DCI, HHH therapy was instituted for 5 days. CBF measurements and CMD data at baseline and during HHH therapy were required for study inclusion. Non-DCI patients with measurements in corresponding time windows were included as a reference group.

RESULTS: In DCI patients receiving HHH therapy (n = 12), global cortical CBF increased from 30.4 ml/100 g/min (IQR 25.1-33.8 ml/100 g/min) to 38.4 ml/100 g/min (IQR 34.2-46.1 ml/100 g/min; p = 0.006). The energy metabolic CMD parameters stayed statistically unchanged with a lactate/pyruvate (L/P) ratio of 26.9 (IQR 22.9-48.5) at baseline and 31.6 (IQR 22.4-35.7) during HHH. Categorized by energy metabolic patterns during HHH, no patient had severe ischemia, 8 showed derangement corresponding to mitochondrial dysfunction, and 4 were normal. The reference group of non-DCI patients (n = 11) had higher CBF and lower L/P ratios at baseline with no change over time, and the metabolic pattern was normal in all these patients.

CONCLUSIONS: Global and regional CBF improved and the cerebral energy metabolic CMD parameters stayed statistically unchanged during HHH therapy in DCI patients. None of the patients developed metabolic signs of severe ischemia, but a disturbed energy metabolic pattern was a common occurrence, possibly explained by mitochondrial dysfunction despite improved microcirculation.

Keywords: ACA = anterior cerebral artery; CBF = cerebral blood flow; CMD = cerebral microdialysis; CPP = cerebral perfusion pressure; DCI = delayed cerebral ischemia; GCS = Glasgow Coma Scale; HHH = hypervolemia, hemodilution, and hypertension; ICP = intracranial pressure; L/P = lactate/pyruvate; MAP = mean arterial pressure; MCA = middle cerebral artery; NIC = neurosurgical intensive care; PCA = posterior cerebral artery; ROI = region of interest; SAH = subarachnoid hemorrhage; SBP = systolic blood pressure; TBI = traumatic brain injury; XeCT = xenon-enhanced CT; and hemodilution therapy; cerebral blood flow; cerebral microdialysis; delayed cerebral ischemia; hypertension; hypervolemia; rCBF = regional CBF; subarachnoid hemorrhage; triple-H; vascular disorders; xenon CT

Publication Types

• Journal Article