Advances in Intracranial Pressure Monitoring and Its Significance in Managing Traumatic Brain Injury

Abstract

Intracranial pressure (ICP) measurements are essential in evaluation and treatment of neurological disorders such as subarachnoid and intracerebral hemorrhage, ischemic stroke, hydrocephalus, meningitis/encephalitis, and traumatic brain injury (TBI). The techniques of ICP monitoring have evolved from invasive to non-invasive-with both limitations and advantages. Some limitations of the invasive methods include short-term monitoring, risk of infection, restricted mobility of the subject, etc. The invasiveness of a method limits the frequency of ICP evaluation in neurological conditions like hydrocephalus, thus hampering the long-term care of patients with compromised ICP. Thus, there has been substantial interest in developing noninvasive techniques for assessment of ICP. Several approaches were reported, although none seem to provide a complete solution due to inaccuracy. ICP measurements are fundamental for immediate care of TBI patients in the acute stages of severe TBI injury. In severe TBI, elevated ICP is associated with mortality or poor clinical outcome. ICP monitoring in conjunction with other neurological monitoring can aid in understanding the pathophysiology of brain damage. This review article presents: (a) the significance of ICP monitoring; (b) ICP monitoring methods (invasive and non-invasive); and (c) the role of ICP monitoring in the management of brain damage, especially TBI.

Keywords: intracranial pressure; invasive methods; non-invasive methods; telemetry; traumatic brain injury; waveform analysis.

Figure 1

A pressure–volume curve representing the relation between cranial volume and ICP. The three sections on this curve show the regions of good (I), poor (II), and failed (III) compensatory mechanisms which are involved in autoregulation of cerebrovascular reactivity (modified from [3]).

Figure 2

A single ICP pulse showing the components of ICP waveform. P1, percussion wave; P2, tidal wave; P3, dicrotic wave; and the beginning of P3 which aligns with the position of dicrotic notch on the arterial pulse.