Clinical studies in severe traumatic brain injury: a controversial issue

Dynamics of brain tissue changes induced by traumatic brain injury assessed with the Marshall, Morris-Marshall, and the Rotterdam classifications and its impact on outcome in a prostacyclin placebo-controlled study

BACKGROUND

The present study evaluates the types and dynamics of intracranial pathological changes in patients with severe traumatic brain injury (sTBI) who participated in a prospective, randomized, double-blinded study of add-on treatment with prostacyclin. Further, the changes of brain CT scan and their correlation to Glasgow Coma Scale score (GCS), maximal intracranial pressure (ICP(max)), minimal cerebral perfusion pressure (CPP(min)), and Glasgow Outcome Score (GOS) at 3, 6, and 12 months were studied.

METHODS

Forty-eight subjects with severe traumatic brain injury were treated according to an ICP-targeted therapy protocol based on the Lund concept with the addition of prostacyclin or placebo. The first available CT scans (CT(i)) and follow-up scans nearest to 24 h (CT(24)) were evaluated using the Marshall, Rotterdam, and Morris-Marshall classifications.

RESULTS

There was a significant correlation of the initial Marshall, Rotterdam, Morris-Marshall classifications and GOS at 3 and 12 months. The CT(24) Marshall classification did not significantly correlate to GOS while the Rotterdam and the Morris-Marshall classification did. The CT(i) Rotterdam classification predicted outcome evaluated as GOS at 3 and 12 months. Prostacyclin treatment did not influence the dynamic of tissue changes.

CONCLUSIONS

The Rotterdam classification seems to be appropriate for describing the evolution of the injuries on the CT scans and contributes in predicting of outcome in patients treated with an ICP-targeted therapy. The Morris-Marshall classification can also be used for prognostication of outcome but it describes only the impact of traumatic subarachnoid hemorrhage (tSAH).

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).

CONCLUSION

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.