Intracranial pressure: more than a number.
Many doctors involved in the critical care of head-injured patients understand intracranial pressure (ICP) as a number, characterizing the state of the brain pressure-volume relationships. However, the dynamics of ICP, its waveform, and secondarily derived indices portray useful information about brain homeostasis. There is circumstantial evidence that this information can be used to modify and optimize patients' treatment. Secondary variables, such as pulse amplitude and the magnitude of slow waves, index of compensatory reserve, and pressure-reactivity index (PRx), look promising in clinical practice. The optimal cerebral perfusion pressure (CPP) derived using the PRx is a new concept that may help to avoid excessive use of vasopressors in CPP-oriented therapy. However, the use of secondary ICP indices remains to be confirmed in clinical trials.
Czosnyka
Marek
M
Academic Neurosurgical Unit, University of Cambridge Clinical School, Cambridge, United Kingdom. MC141@medschl.cam.ac.uk <MC141@medschl.cam.ac.uk>
Smielewski
Peter
P
Timofeev
Ivan
I
Lavinio
Andrea
A
Guazzo
Eric
E
Hutchinson
Peter
P
Pickard
John D
JD
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology; D001930:Brain Injuries / Q000175:diagnosis* / Q000503:physiopathology* / Q000628:therapy; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted