Discuss the determinants of intracranial pressure (80% of marks). Outline how it can
be measured (20% of marks).
It was expected answers would include an explanation of the Monro-Kellie Doctrine. Many candidates gave insufficient details of compensatory mechanisms especially regarding decreased total cerebral blood volume (primarily venous) in response to increased intracranial pressure. Most candidates had all the information but had difficulty synthesising the information to write a cohesive answer. Factors affecting ICP could be divided into factors affecting CBV, factors affecting CSF and factors affecting brain tissue. Under factors affecting CBV the effect of blood gases, autoregulation, temperature, metabolism, drugs and venous obstruction could have been detailed.
"Most candidates had all the information but had difficulty synthesising the information to write a
cohesive answer", the examiners complained, implying that they were specifically looking for a particular structure or format which they did not mention in the question stem. This is a great example of an exam question designed to generate poor performance even in candidates who are armed with all the relevant knowledge. To prevent the occurrence of any further such comments from the examiners, a structures approach is taken here, focusing on arranging the information rather than the information itself.
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