Research In The Intensive Care Units

When are patients at risk?

After a severe head injury or rupture of a blood vessel in the brain fluid starts to build up.  Unlike other parts of the body the brain cannot swell because it is contained within the skull.  The result is that pressure builds up and the brain gets tight.  The brain can accommodate small rises in pressure but if the pressure gets too high the heart is unable to pump sufficient blood into the brain and permanent damage can result.  There is not a single cut-off pressure at which this occurs.   It varies from person to person and depends on other clinical factors at the time.

Dr Ian Piper and his colleagues are attempting to develop ways of measuring brain tightness.   A grant from the Neurosciences Foundation has enabled them to explore a new technique that involves using well established methods of measuring blood pressure, pressure within the brain and the velocity of blood in blood vessels in the brain.   The latter involves measuring the doppler shift in an ultrasound beam.  The Doppler principle is also used in astronomy to measure the speed that galaxies are moving and explains the change in pitch in the sound of a siren moving towards us or going away from us.

The special techniques developed by Dr Piper and his colleagues is to compute mathematical indices which tell us about the interplay between these measurements as the patient's condition changes.   One of the most critical decisions in an intensive care unit is when to allow nature to control pressure in the brain.  By gaining experience of the new monitoring method in practice Dr Piper hopes that doctors will be better able to make this decision.   In addition, knowledge of the exact nature of the change could help to determine the cause of the pressure rise and hence the best way to treat it.

This research is not confined to the Institute.  Dr Piper now co-ordinates a multi-centre network of neuro-intensive care researchers with a specific interest in assessing new forms of intensive care monitoring
(see http://www.brainit.gla.ac.uk/brainit).

	"The Institute of Neurological Sciences has a first rate intensive care unit which is well equipped and has expert staff.  Extra resources are needed, however, to enable us to improve what intense care units can do, both here and elsewhere in the world.  The support of the Neuroscinences Foundation has helped us to obtain the additional equipment which was needed for this work." Dr Ian Piper