Sudden herniation through the foramen magnum (back of the skull) is fatal (Kennedy, 2001).
Increased ICP is defined as a sustained elevation in pressure above 20mm of Hg/cm of H20. The craniospinal cavity may be considered as a balloon. During slow increase in volume in a continuous mode, the ICP raises to a plateau level at which the increase level of CSF absorption keeps pace with the increase in volume. Intermittent expansion causes only a transient rise in ICP at first. When sufficient CSF has been absorbed to accommodate the volume the ICP returns to normal. Expansion to a critical volume does however cause persistent raise in ICP, which thereafter increases logarithmically with increasing volume. The ICP finally rises to the level of arterial pressure, which it self begins to increase (Thamburaj, 2004).
Raised ICP causes arterial hypertension, bradycardia (Cushing's response) and respiratory changes. It is traditionally accepted that hypertension and bradycardia are due to ischaemia or pressure on the brainstem. There is also a suggestion that they could be due to removal of supratentorial inhibition of brainstem vasopressor centers due to cerebral ischaemia and that bradycardia is independent of the rise in blood pressure. The respiratory changes depend on the level of brainstem involved. The midbrain involvement results in Chyne-Stokes respiration. When midbrain and pons are involved, there is sustained hyperventilation. There is rapid and shallow respiration when upper medulla involvement with ataxic breathing in the final stages. Pulmonary edema seems to be due to increased sympathetic activity as a result of the effects of raised ICP on the hypothalamus, medulla or cervical spinal cord (Thamburaj, 2004).
There are observable signs that point out that Joyce is indeed suffering from increased intracranial pressure. The most significant of which was the dilation of the left eye.
It was revealed in the assessment data that Joyce's pupil in the left eye is greater than her right eye. This only shows that there is malfunctioning in her internal head part or within the brain, particularly in the right side of her brain. it should be noted that dilation of the eyes must be equal on both sides as a result of normal functioning inside the brain. And because the left eye's pupil is dilated more than the right eye, it can only be assumed that there is a very strong pressure inside the brain, forcing the left eye's pupil to be dilated heavily.
Another significant data that shows that the patient is suffering from raised intracranial pressure is her abnormal blood pressure, body temperature and intracranial pressure rates. All of these three aspects are beyond and/or under the normal limit of an average person. Joyce's blood pressure is very low (the normal blood pressure is 110/70 - 120/80). This could only mean that there is something wrong in her blood circulation which can be affected by the electrolytes and or malfunctioning of some of her body organs, nerves and systems. Her body temperature is beyond the normal limit which is 37 degree Celsius to 37.5 degree Celsius (Dunn, 2002).
Abnormal blood pressure also shows that her blood circulation and body organs are not working properly thereby affecting the production of body heat. Joyce's intracranial pressure is also high and over the limit of the normal rate. This reflects that there is an increased intracr