CURRENT Essentials of Critical Care.pdf

Chapter 1 Monitoring & Support 13■■Intracranial Pressure MonitoringEssential Concepts• Intracranial compartment in adults has fixed volume due to rigidskull; contains brain, cerebrospinal fluid (CSF), cerebral bloodvolume; increase in size of any one of these can lead to elevationof intracranial pressure (ICP)• ICP measurements can estimate cerebral perfusion pressure(CPP): CPP MAP ICP where MAP is mean arterial pressure;CPP at or above 70 mm Hg by increasing MAP or decreasingICP may improve survival• ICP monitoring techniques used in management of severe headinjury, subarachnoid hemorrhage, Reye syndrome, hepatic encephalopathy,other disorders causing intracranial hypertension• Controlling ICP in 20 mm Hg range associated with improvedoutcome• Increased morbidity and mortality associated with ICP 20 mmHg that persists for more than 10 to 15 minutes, particularly inpatients with severe closed head injuriesEssentials of Management• Several monitoring systems available: catheters, hollow screwor bolt, fiberoptic transducer tipped catheters• Devices can be placed into several locations: lateral ventricle,intraparenchymal, subdural or subarachnoid space, epiduralspace• Intraventricular catheters remain gold standard in most caseswith added benefit of CSF drainage to help control elevatedpressures• Complications include hemorrhage, hematoma formation, infection,cortical damage■ PearlMisinterpretation of the data obtained from an ICP monitoring systemmay result in improper choice of therapeutic intervention.ReferenceDoyle DJ et al: Analysis of intracranial pressure. J Clin Monit 1992;8:81.[PMID: 1538258]