Effects of the neurological wake-up test on intracranial pressure and cerebral perfusion pressure in brain-injured patients.
OBJECTIVE
To evaluate the effects of the neurological "wake-up test" (NWT), defined as interruption of continuous propofol sedation and evaluation of the patient's level of consciousness, on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in patients with severe subarachnoid hemorrhage (SAH) or traumatic brain injury (TBI).


METHODS
A total of 127 NWT procedures in 21 severely brain-injured adult patients with either TBI (n = 12) or SAH (n = 9) were evaluated. ICP and CPP levels prior to, during and after the NWT procedure were recorded.


RESULTS
During the NWT, ICP increased from 13.4 +/- 6 mmHg at baseline to 22.7 +/- 12 (P < 0.05) and the CPP increased from 75.6 +/- 11 to 79.1 +/- 21 mmHg (P < 0.05) in TBI patients. Eight patients showed a reduced CPP during the NWT due to increased ICP. In SAH patients, ICP increased from 10.6 +/- 5 to 16.8 +/- 8 mmHg (P < 0.05) and the CPP increased from 76.9 +/- 13 to 84.6 +/- 15 mmHg (P < 0.05).


CONCLUSIONS
When continuous propofol sedation was interrupted and NWT was performed in severely brain-injured patients, the mean ICP and CPP levels were modestly increased. A subset of patients showed more pronounced changes. To date, the role of the NWT in the neurointensive care of TBI and SAH patients is unclear. Although the NWT is safe in the majority of patients and may provide useful clinical information about the patient's level of consciousness, alternate monitoring methods are suggested in patients showing marked ICP and/or CPP changes during NWT.
Skoglund
Karin
K
Department of Neuroscience, Neurosurgery, Uppsala University Hospital, 751 85 Uppsala, Sweden.
Enblad
Per
P
Marklund
Niklas
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000188:drug therapy / Q000503:physiopathology*; D003943:Diagnostic Techniques, Neurological; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D007362:Intensive Care Units; D007427:Intracranial Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D015742:Propofol / Q000627:therapeutic use; D011930:Reaction Time; D012151:Resuscitation / Q000379:methods; D013345:Subarachnoid Hemorrhage / Q000188:drug therapy / Q000503:physiopathology*; D013997:Time Factors; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
D006993:Hypnotics and Sedatives; D015742:Propofol