Intracranial pressure: Invasive and non-invasive monitoring

Abstract

Intracranial pressure (ICP) reflects the relationship between brain volume and intracranial compliance. It is able to affect cerebral functions by altering cerebral perfusion. The primary goal of the clinical management of patients with brain lesions is to prevent secondary ischemic damage by maintaining adequate oxygen and glucose supply to the central nervous system. In this respect, ICP has long been recognized as a vital part in brain monitoring. It can only be estimated by directly measuring it, since clinical or radiological findings are not sensitive and specific enough. Intraventricular catheters and microtransducer-tipped intraparenchymal monitors provide the most reliable measurements at the cost of invasiveness and both are considered the reference standard in clinical practice. In recent years non-invasive approaches based on tympanic membrane displacement, deformation of the temporal bone and changes in cranial diameter pulsation have been proposed as alternatives but they have not proved to be accurate in a clinical scenario. Other non-invasive techniques, however, such as transcranial doppler sonography, the ultrasonographic measurement of the retrobulbar segment of the optic nerve, venous ophtalmodynamometry and ultrasound "Time of Flight" have shown good test performances in predicting raised ICP. This chapter provides an overview of these different approaches focusing on the advantages and limitations of non-invasive methods if compared to the more widely used invasive monitoring devices. © Nova Science Publishers, Inc.