ICP Monitoring & Head Trauma
wisey at nyc.pipeline.com
Mon May 22 12:36:33 EST 1995
In article <3pi8qc$dk5 at ixnews2.ix.netcom.com>, Charles Hokanson writes:
>It is estimated that there are approximately 400,000 cases of severe
>head trauma each year in the US. Of these, approximately 100,000 cases
>utilize ICP monitoring. I am interested to know:
>1. Why are the other 300,000 cases not monitored for ICP?
>2. Under what circumstances is ICP monitroing contra-indicated?
>3. What other technologies are available besides ICP monitoring as an
>accurate predictor of patient prognosis? (ie temperature, PC02, Po2,..)
>4. What are the limitations of present ICP monitoring systems?
>5. Does anyone have any recommendations for improvement?
>6. General commnets concerning treatment of severe head trauma.
There are probably less than 100,000 cases of "severe" head injuries in the
United States, i.e. Glasgow Coma Score of less than 8. The remainder of
the 400,000 are probably moderate and mild head injuries. A substantial
proportion of severe head injuries do not get intracranial pressure
monitoring. The reasons can be as varied as lack of equipment and
facilities for monitoring, the tendency to be non-invasive in patients
perceived to be hopelessly injured, and controversy about the usefulness of
intracranial monitoring in all cases. A number of published studies have
suggested that blood flow measurements may be useful (but only during the
very early phase after injury). A huge variety of flow measurement systems
have been used, ranging from Xenon clearance, transcranial doppler, and
tracer monitoring in the blood stream to functional MRI. There are a few
studies suggesting that the levels of certain intracellular enzymes, such
as LDH, in cerebrospinal spinal fluids may be prognostic. Evoked
potentials (somatosensory, visual, auditory, and motor evoked responses)
are frequently used to assess unconscious patients. If the patient is
awake or moving, the neurological examination is exquisitely sensitive to
rising intracranial pressure. The Glasgow Coma Score is still one of the
best documented predictors of recovery and mortality in severe head injury.
Finally, a number of clinical trials are going on right now. Two recently
completed clinical trials did not show significant positive effects due to
PEG-SOD (superoxide dysmutase from Sterling) or tirilazad mesylate (an
antioxidant steroid from Upjohn). Ongoing trials are looking at glutamate
receptor blockers (CIBA-Geigy and others). There are some reports that
certain glycolysis substrates may be useful. There is controversy about
hyperbaric therapy and manipulation of blood gases. Of course, almost all
patients are now treated with mannitol and furosemide (Lasix) to reduce
brain swelling. Older studies suggest that amphetamine-like drugs may
hasten and improve the extent of recovery. Several groups (one at
University of Texas and another at Nihon University in Tokyo) are looking
at hypothermia with some promising initial results. These are just quick
thoughts off the top of my head. If you are interested, the annual
Neurotrauma Symposium held the two days before the Society of Neuroscience
meeting in San Diego this November will gather most of the experts in the
field and there will be a review of ongoing and completed clinical trials
in brain and spinal cord injury. Email me for more information.
Wise Young, Ph.D., M.D.
Department of Neurosurgery
NYU Medical Center
550 First Avenue
New York, NY 10016
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