Monitoring the injured brain: ICP and CBF

• Published in: British journal of anaesthesia : BJA Vol. 97; no. 1; pp. 26 - 38
• Main Authors: Steiner, L.A., Andrews, P.J.D.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-07-2006; Oxford University Press; Oxford Publishing Limited (England)
• Subjects: Anesthesia; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; blood; blood, flow, cerebral; Brain Injuries - physiopathology; cerebral; Cerebrovascular Circulation; Critical Care - methods; flow; Humans; intensive care; Intracranial Pressure; Medical sciences; monitoring; monitoring, intensive care; monitoring, intracranial pressure; Monitoring, Physiologic - methods; monitoring, intensive care; blood, flow, cerebral; monitoring, intracranial pressure; Human; Jugular bulb; Intensive care; Prognosis; Subarachnoid hemorrhage; Vasoconstriction; Cardiovascular disease; Intracranial pressure; blood; Blood flow; Encephalon; cerebral; monitoring; intracranial pressure; monitoring; Clinical management; Ischemia; Anesthesia; Vasospasm; Flow velocity; Application method; Blood pressure; Diagnosis; Monitoring; flow
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/ael110

Raised intracranial pressure (ICP) and low cerebral blood flow (CBF) are associated with ischaemia and poor outcome after brain injury. Therefore, many management protocols target these parameters. This overview summarizes the technical aspects of ICP and CBF monitoring, and their role in the clinical management of brain-injured patients. Furthermore, some applications of these methods in current research are highlighted. ICP is typically measured using probes that are inserted into one of the lateral ventricles or the brain parenchyma. Therapeutic measures used to control ICP have relevant side-effects and continuous monitoring is essential to guide such therapies. ICP is also required to calculate cerebral perfusion pressure which is one of the most important therapeutic targets in brain-injured patients. Several bedside CBF monitoring devices are available. However, most do not measure CBF but rather a parameter that is thought to be proportional to CBF. Frequently used methods include transcranial Doppler which measures blood flow velocity and may be helpful for the diagnosis and monitoring of cerebral vasospasm after subarachnoid haemorrhage or jugular bulb oximetry which gives information on adequacy of CBF in relation to the metabolic demand of the brain. However, there is no clear evidence that incorporating data from CBF monitors into our management strategies improves outcome in brain-injured patients.