Increased Intracranial Pressure

1. Increased Intracranial Pressure Mary Ann Reilly BSN, MS, CRRN Santa Clara Valley Medical Center, Rehab Nurse Manager

2. In 2004 the SJ Mercury wrote: "As he was giving his speech he stumbled slightly and then he started to perspire a bit. I thought almost immediately that something is not right.“ • His repeated vomiting prompted paramedics to treat him with oxygen and monitor his heart for half an hour -- routine care for a sudden food-borne illness

4. The initial suspicion that Mayor Ron Gonzales had food poisoning Wednesday night shows just how difficult some strokes are to detect -- and experts say it offers a warning to people who might find themselves with similar symptoms.

5. Gonzales' type of stroke is called an intraventricular hemorrhage. • This means that a blood vessel had broken and was leaking into the ventricle, which carries spinal fluid.

6. So what’s the big deal? • Skull

7. Components of Cranial Vault • Meninges • Dura • Arachnoid • Pia • Brain • Brain tissue 80-88% • Blood • Blood 2-11% • CSF • CSF 9-10%

9. http://learntech.uwe.ac.uk/neuroanatomy/neuro4_1.htm

10. Blood • 15-20 of the cardiac output • 20-25% of all oxygen inspired • 750cc/min • 80% from carotid arteries • 20% from vertebral • Circle of Willis is collateral circulation • No sugar/fat/oxygen storage

11. Autoregulation • When intra-cranial pressure begins to rise, the body’s own compensatory mechanisms include decreasing the production of CSF and restricting the blood flow to the brain(by vasoconstriction).

12. Autoregulation • Self Regulated • PCO2 (carbon dioxide) vasodilator • For every 1mmHg change in PCO2 there is a 1-2cc change in blood flow per 100 GMs of brain • (1300-1400Gms avg. wt.) =s [750 +65] or [750 + 130] • Diameter of vessels • Hypercapnia: Increases CBF • Hypocapnia: Decreases CBF

13. Intercrainial Pressure Regulation • When BP increases, cerebral arterioles constrict to keep blood entering brain at steady rate. • When BP falls, cerebral arterioles dilate to increase blood flow to brain

14. Intercrainial Pressure Regulation • Metabolic regulation—changes in O2 and CO2: Low O2 and increased CO2 cause vasodilation CSF regulation—decreased production or increased reabsorption decreases ICP.

15. Factors Affecting CBF • Viscosity of the blood • Seizures • Anemia • Drugs

16. CSF • 125-150 cc clear fluid • 500cc produced per day • 20cc per hour • Replaced 4-7 times per day • Function • Protection, cushions • Waster disposal • Nutritional support (2/3 bodies BS)

17. CSF Pressure • Norm • 1-15 mmHg or <200mm H2O • Low pressure • Dehydration • Increased pressure • Val Salva,Tumor, Subdural Hematoma, Subarachnoid Hemorrhage, Infections, Hydrocephalus

18. Symptoms of Increasing ICP • Headache • Visual changes • Nausea • Vomiting • Behavior changes • Changes in LOC • Seizures

19. Symptoms • Aniscoria • Hemiparesis • Vital sign changes • Cushing Triad

20. http://learntech.uwe.ac.uk/neuroanatomy/neuro4_4.htm

21. Cushing’s Triad • Vital Sign Changes in ICP— • Systolic pressure increases (widened pulse pressure results). • Slowing of heart occurs—bradycardia (occurs as result of reflexive slowing in response to increased systolic pressure) • Respiration changes—becomes slowed

22. Could it be? • Difficulty speaking • Blurred vision • Hypertension • Shallow rapid breathing • Visual disturbances • Paresthesia • Hypoglycemia

23. OR? - Confusion • Lethargy • Nausea & Vomiting • Coma • Seizures • Syndrome of Inappropriate ADH

24. OR? • Changes in LOC • Nausea & Vomiting • Irritability • Disorientation • Personality changes • Seizures • Fluid Overload

25. OR? • Street drug • Alcohol withdrawal • Over dose • Diabetic ketoacidosis • Hypervitiaminosis A • Drug • www.merck.com/mrkshared/mmanual/section1/chapter3/3c.jsp

26. Diagnosis of Increased Intracranial Pressure • Overt symptoms • Papilledema • Nuchal rigidity • Lumbar Puncture***

27. Lumbar Puncture • Contraindicated • Focal signs • Intracranial mass • Papilledema • Cardiorespiratory compromise • Infection of skin

28. Rational for Contraindication • A simple analogy Performing a LP in the presence of I-ICP, may result in herniation

29. Herniation • Tentorium • Midbrain and diencephalon through the tentorium • Uncal • Tonsillar • Cerebellar tonsils through the foramen magnum

30. Diencephalic Stage • Confused and drowsy • Constricted pupils • Gaze palsies

31. Mesencephalic Stage: • Unconscious • Decerebrate posturing • Dilated pupils • Hyperventilation

32. Pontine Stage • Unconscious • Decerebrate posturing • Constricted pupils • Irregular breathing

33. Decorticate posture • Indicated by rigidity, flexion of the arms, clenched fists, and extended legs. The arms are bent inward toward the body with the wrists and fingers bent and held on the chest. Presence of this type of posturing implies severe damage to the brain with immediate need for medical attention.

34. Decerebrate Posturing • Internal rotation and extension of the arms & lower limb extension • Due to midbrain compression as the brainstem is further compressed

35. Medullary Stage • Unconscious • Flaccid • Loss of homeostatic control: • Increase heart rate • Decrease blood pressure • Hyperthermia • Cheyne-Stokes breathing

36. Cheyne-Stokes • Breathing describes a waxing and waning ventilation, sometimes with periods of apnea, that occur in cycles. • It is due to a delay in the medullary chemoreceptor response to blood gas changes

37. 1893 http://thediagram.com/3_6/

40. Common Causes of I-ICP • Vascular abnormalities • AV malformations, aneurisms, stroke • Diffuse cerebral ischemia • Closed head trauma, shaken baby, vasospasm • CNS infections • Tumors • Trauma • Obstruction of CSF flow

41. Hydrochepalus

43. Intra Cerebral Hemorrhage

44. AV Malformation

45. Crainal Defect

46. Crainial defect with midline shift

47. The Monroe-Kelle Hypothesis states that an increase in the volume of one component (blood, brain tissue, CSF) must be accompanied by a decrease in another component if intracranial pressure is to remain constant. The CSF and blood volume are the compartments that most easily change to accommodate changes in pressure.  Interventions to prevent secondary brain injury follows these principles and focuses primarily on cerebral blood flow and drainage. 

48. Management / Trauma • Rapid transportation • Early intubation • Aggressive resuscitation • Immediate CT • ICP monitoring

49. CAT Scans • Sensitivity for visualizing blood approximately 96% • Visualizes • Fractures • Hematomas

50. Operative Management • Burr holes • Intra-operative ultra sound • Surgical evacuation of mass lesion • Craniotomy • Craniectomy • Ventricular drainage http://www.trauma.org/neuro/neuromonitor.html