Intracranial Pressure (ICP) Megan McClintock, MS, RN Megan McClintock, MS, RN11/4/11

Normal Values ICP 5-15 mm Hg ICP 5-15 mm Hg CPP mm Hg (< 50 is bad) CPP mm Hg (< 50 is bad) CSF20-30 mL/hr CSF20-30 mL/hr

Factors Affecting ICP Arterial & venous pressure (high or low) Arterial & venous pressure (high or low) Intrabdominal/intrathoracic pressure Intrabdominal/intrathoracic pressure Posture Posture Temperature Temperature Blood gases (acidosis, hypoxia, high CO2) Blood gases (acidosis, hypoxia, high CO2) All are potent vasodilators All are potent vasodilators

Compensation Change in CSF volume Change in CSF volume Absorption/production Absorption/production Movement of CSF to the spinal subarachnoid space Movement of CSF to the spinal subarachnoid space Change in intracranial blood volume Change in intracranial blood volume Collapse of cerebral veins/dural sinuses Collapse of cerebral veins/dural sinuses Cerebral vasoconstriction/dilation Cerebral vasoconstriction/dilation Change in venous outflow Change in venous outflow Change in brain tissue volume Change in brain tissue volume Distension of dura Distension of dura Compression of brain tissue Compression of brain tissue

Symptoms of  ICP Change in LOC Change in LOC Most sensitive & reliable indicator of neuro status Most sensitive & reliable indicator of neuro status Change in VS Change in VS Cushing’s triad Cushing’s triad Change in pupils Change in pupils Response to light, blurred vision, diplopia, eye movements, papilledema Response to light, blurred vision, diplopia, eye movements, papilledema Change in motor function Change in motor function Hemiparesis/hemiplegia, decorticate or decerebrate posturing Hemiparesis/hemiplegia, decorticate or decerebrate posturing Headache Headache Vomiting Vomiting

Diagnostic Testing CT CT MRI MRI Angiography Angiography Transcranial Doppler Transcranial Doppler EEG, Evoked Potentials EEG, Evoked Potentials PET PET NO LP!!!!!!!! NO LP!!!!!!!!

ICP Monitoring

LICOX

Assessment Glasgow Coma Scale Glasgow Coma Scale Pupils Pupils Cranial Nerves Cranial Nerves Eye movement Eye movement Motor strength Motor strength Vital signs (including respiratory pattern - pg 1435) Vital signs (including respiratory pattern - pg 1435)

Treatment CSF drain, ICP monitoring CSF drain, ICP monitoring ET tube/trach to keep PaO2 at 100, PaCO ET tube/trach to keep PaO2 at 100, PaCO Surgical removal of mass Surgical removal of mass Hemicraniectomy Hemicraniectomy Only light sedation (ie. Versed, Ativan) Only light sedation (ie. Versed, Ativan) Be careful with drugs that alter the neuro state Be careful with drugs that alter the neuro state Rapid-acting opioids (Morphine, Fentanyl) are best Rapid-acting opioids (Morphine, Fentanyl) are best Propofol is good (rapid-acting, short half-life) Propofol is good (rapid-acting, short half-life) Avoid benzodiazepines Avoid benzodiazepines

Drugs Mannitol Mannitol Osmotic diuretic given intravenously Osmotic diuretic given intravenously Decreases ICP by plasma expansion and osmotic effect Decreases ICP by plasma expansion and osmotic effect Hypertonic saline (3%) Hypertonic saline (3%) Can be as effective as mannitol or used concurrently Can be as effective as mannitol or used concurrently Raises the osmolality of the ECF in the brain Raises the osmolality of the ECF in the brain Corticosteroids Corticosteroids Used for vasogenic edema around tumors and abscesses but not for head-injured patients Used for vasogenic edema around tumors and abscesses but not for head-injured patients Barbiturates Barbiturates Reduce metabolic rate decreasing CBF and ICP Reduce metabolic rate decreasing CBF and ICP

Interventions No fever or shivering (or agitation, pain, seizures) No fever or shivering (or agitation, pain, seizures) No Valsalva, coughing, sneezing No Valsalva, coughing, sneezing Avoid restraints Avoid restraints Family member at bedside Family member at bedside Seizure precautions Seizure precautions Quiet, non-stimulating environment Quiet, non-stimulating environment Light touch and talk even if in a coma Light touch and talk even if in a coma

Interventions Respiratory Respiratory Patent airway Patent airway Watch breathing patterns Watch breathing patterns Side-lying Side-lying Watch for snoring Watch for snoring Careful use of suctioning Careful use of suctioning HOB  30 degrees HOB  30 degrees Prevent abdominal distension (NG tube – depends on injury) Prevent abdominal distension (NG tube – depends on injury) Monitor ABGs Monitor ABGs Nutrition Nutrition

Interventions Fluid & Electrolytes Fluid & Electrolytes Monitor closely (esp. Na, Gl, K, Mg, osmo) Monitor closely (esp. Na, Gl, K, Mg, osmo) Watch for diabetes insipidus & SIADH (pg 1437) Watch for diabetes insipidus & SIADH (pg 1437) Body position Body position HOB  30 degrees HOB  30 degrees No neck flexion No neck flexion Turn gently and slowly Turn gently and slowly Avoid extreme hip flexion Avoid extreme hip flexion Prevent pain Prevent pain