Intracranial pressure and its surrogates

Excerpt

Intracranial hypertension [intracranial pressure (ICP) >20 mmHg] is a life-threatening complication seen in a significant proportion of patients following severe traumatic and nontraumatic brain insults [1‐3]. Sustained elevations in ICP generally signal secondary injury processes such as cerebral edema, hemorrhage, hydrocephalus and ischemia, and as a consequence the management of ICP has become a keystone in neurocritical care. Especially in unresponsive patients when the diagnostic yield of physical examination is limited, temporal trends in ICP can help identify critical changes in intracranial compliance and responses to therapy. Many studies indicate an independent association between the magnitude and duration of ICP elevation and unfavorable outcomes following severe brain injury [2‐4]. The difference of ICP and mean arterial pressure, cerebral perfusion pressure (CPP), is widely used to infer relationships between systemic circulatory function and cerebral blood flow. Many interventions in brain resuscitation, such as hyperosmolar therapy, sedation, controlled ventilation, and use of vasopressor or inotropic agents, are targeted to ICP and CPP goals. Current guidelines recommend ICP monitoring in patients with severe traumatic brain injury (TBI) who are comatose after resuscitation and who either have abnormalities on cranial computed tomography (CT) scan or meet at least two of the following three criteria: age >40 years; systolic blood pressure <90 mmHg; or motor posturing [5]. …