Increased Intracranial Pressure PDF

Increased Intracranial Pressure Acute & Chronic Nursing theory Week 9  Key’s Terms ICP – is the pressure exerted because of the combined total volume of the 3 components within the skull (Norm: 0-10 mm Hg…. 15 mm Hg is upper limit) MAP – Mean arterial pressure (Minimum 65 mmHg to perfuse vi...

Increased Intracranial Pressure Acute & Chronic Nursing theory Week 9  Key’s Terms ICP – is the pressure exerted because of the combined total volume of the 3 components within the skull (Norm: 0-10 mm Hg…. 15 mm Hg is upper limit) MAP – Mean arterial pressure (Minimum 65 mmHg to perfuse vital organs, Norm: 70 – 110) CPP – cerebral perfusion pressure – tells us how well the brain is perfused (Normal 60-100 mmHg) IICP – Increased ICP is life threatening – result of increase in one or all 3 components (ICP>20 is clinically significant & must be treated) Equilibrium The skull is a rigid compartment made up of 3 components with a fixed volume Brain tissue (80%) Arterial and venous blood (10%) Cerebral spinal fluid (10%) Normally, the 3 components are in a balanced state of equilibrium  Under normal conditions, the balance among these components maintains the ICP As the skull is a closed system any increase in one of these components requires a decrease in another or ICP will increase (M-K doctrine) Monro-Kellie Hypothesis Explains the relationships between the compensatory responses of the brain when the ICP increases It defines the relationship between CPP, MAP and ICP as: CPP = MAP - ICP Monro-Kellie Hypothesis ICP relies on the brain's ability to either : 1. Constrict cerebral arterioles = decrease cerebral blood volume or 2. Increase the absorption of CSF = decrease in cerebral CSF The Skull offers little flexibility for changes in the size of the three intracranial components. Any increase in one component necessitates a compensatory decrease in the volume of another, or an increase in ICP will result  Goal is to prevent the critical point where brain swelling increases Intracranial pressure will increase impacting the CPP CPP represents the oxygen, and other key nutrients going to our brain CPP = MAP – ICP Therefore, if ICP increases CPP will decrease resulting in less oxygen, nutrients = ischemia, cell death Key Points: ICP – 5 -15 mmHg (>20 serious and must treat) CPP – 60 – 100 (