Intracranial pressure monitoring in critically ill patients

Abstract

Elevated intracranial pressure (ICP) is a potentially devastating complication of neurologic injury. Elevated ICP may complicate trauma, central nervous system (CNS) tumors, hydrocephalus, hepatic encephalopathy, and impaired CNS venous outflow. Successful management of patients with elevated ICP requires prompt recognition, the judicious use of invasive monitoring, and therapy directed at both reducing ICP and reversing its underlying cause. The rapid recognition of elevated ICP is therefore of obvious and paramount importance so that it can be monitored and so that therapies directed at lowering ICP can be initiated. A raised ICP is measurable both clinically and quantitatively. Continuous ICP monitoring is important both for assessing the efficacy of therapeutic measures and for evaluating the evolution of brain injury. The goal of ICP monitoring is to ensure maintenance of optimal CPP. The ICP also forms a basis for medical or surgical intervention in cases of increased ICP with agents such as 3% sodium chloride (NaCl), mannitol, or diuretics (Lasix), ventriculostomy, cerebrospinal fluid (CSF) diversion, or surgical decompression in cases of intractable ICP elevation that do not respond to conservative management. There are four main anatomical sites used in the clinical measurement of ICP: intraventricular, intraparenchymal, subarachnoid, and epidural .Sometimes subdural and lumbar monitors are also used. Each technique requires a unique monitoring system, and has associated advantages and disadvantages. ICP monitoring may be discontinued when the ICP remains in the normal range within 48-72 hours of withdrawal of ICP therapy or if the patient’s neurological condition improves to the point where he or she is following commands.