Ver el código de «Elevated intracranial pressure»

==Background==
*Monroe-Kellie hypothesis
**Volume of intracranial space is constant
**3 components
***Brain Tissue (80%)
***Blood (10% or 150mL)
***CSF (10% or 150 mL)
**Increase in one of the components → reduction of other two →must maintain a fixed total intracranial volume.
*CSF is created at a rate of 20mL/hr or 500mL/day. 
*Neuronal injury occurs secondary to vascular compromise to brain cells either by a reduction in cerebral blood flow or direct ischemia. This is an ''' emergency'''  and requires emergent intervention if sustained > 5-10 minutes

==Clinical Features==
*[[Headache]] (from increased pressure on heavily innervated meninges)
**Characteristically worse in the morning
*[[Nausea/vomiting]]
**Vomiting due to increased ICP typically occurs in the morning, often effortless
*[[Seizure]]
*[[Lethargy]]
*[[Cranial nerve palsies]]
**[[abducens nerve palsy|CN 6 palsy]] (false localizing sign)
*[[Papilledema]] (bilaterally blurred optic disc margins)
*[[ECG]] with [[QT prolongation]] and T-wave inversions
*Dilated optic nerve on [[ocular ultrasound]]
**Measure optic nerve 3mm posterior to the globe, from inner wall to inner wall
**Normal is <5mm<ref>Blaivas M, Theodoro D, Sierzenski PR. Elevated intracranial pressure detected  by bedside emergency ultrasonography of the optic nerve sheath. Acad Emerg Med. 2003 Apr;10(4):376-81.</ref>

==Differential Diagnosis==
{{Intracranial mass DDX}}

==Evaluation==
''Increased ICP is due to an increase in any one of the 3 components of the intracranial space''
#Increased brain tissue
#*[[brain tumor|Neoplasms]]
#*[[brain abscess|Cerebral abscess]]
#Increased CSF volume
#*Decreased reabsorption
#**Obstructive [[hydrocephalus]]
#**Non-obstructive/communicating hydrocephalus
#**[[Ventriculoperitoneal shunt problems|Ventriculoperitoneal shunt problem]]
#Increased blood volume
#*[[ICH|Intracranial haemorrhage]]
#*Cerebral [[venous sinus thrombosis]]
#*Failed cerebral autoregulation (causing increases CBF or CBV)

==ED Management==
{{Increased ICP treatment}}

==Neuro ICU Management==
*Ensure data accurate
**Observe for accurate waveforms in arterial and ICP monitors 
***EVD zeroed at ear, changes with coughing/positioning
***Arterial line zeroed at ear (for accurate CPP measurement; although typically level at heart reasonably accurate
*Assess ABC (as increased ICP often causes decline in mental status)
**If need to intubate - ensure measures to avoid coughing/bucking (increases ICP)
***[[Lidocaine]] 1% 1ml/kg 1x IV bolus as premedication

===Goals===
*Keep CPP 60-110mmHg
**If <110 utilize pressors (norepinephrine [preferred] or neosynephrine)
**Levophed: start at 4 mcg/min; maximum 20 mcg/min.
**Phenylephrine: start at 0.4 mcg/kg/min; maximum 9 mcg/kg/min.
*Keep ICP < 20mmHg (nonsustained temporary elevations <5 minutes ok)

===Take Stepwise approach to treatment===
====1st (conservative)====
*Elevate Head of bed to 30-45 deg to increase CSF outflow and keep head midline
**May "sandbag" head of those in c-collar to promote venous drainage(c-collar can restrict venous outflow)
*Control agitation/pain
**[[Opioids]], [[benzodiazepines]], sedative hypnotics
***Favor short acting medications to allow neuro exam checks
***[[Midazolam]], [[fentanyl]] and [[propofol]] are often appropriate.
*Maintain normocapnia (pCO2 35-40)
*Maintain normothermia
**Treat shivering
***Bair hugger (warms skin temperature)
***APAP 650 q6h PRN for temperature >38.5°F 
*Maintain euvolemia
*Maintain euglycemia

====2nd (Intervention-short term)====
*Hyperventilate to pCO2 30-35mmHg
*Oxygen saturation >95%
**This is short term as patient will equilibrate; is only meant as a temporizing measure. Attempt to wean to normocapnia as soon as able. Further do not over-ventilate past 25mmHg as may exacerbate damage via cerebral hypoxia (CO2 is primarily involved in autoregulation of cerebral vasculature).
*Hypertonic fluids
**[[Mannitol]] 20% 1-1.5g/kg rapid IV bolus (no need for central line) as an osmotic diuretic to lower ICP '''OR'''
**23% Na 30mL over 15 minutes (Needs central line)
*Consult Neurosurgery (urgent) for possible evacuation or ventricular drainage
**This is especially relevant for mass lesions causing mass effect, hydrocephalus and intracranial bleeds

====3rd (Intervention- long term)====
*Hypertonic fluid maintenance
**Iatrogenic hypernatremia. Use [[hypertonic saline|3% NaCl]] to maintain na >145 with q6hr serum Na cks. 
***3%NS at 1mL/kg/hr appropriate (typically start at 50mL/hr).
***May continue to push Na > 145, then >150 then >155 prn to manage ICP
****Eventually osmotic pressures will equilibrate over days. requiring higher Na values (rationale behind pushing Na slowly upward as needed rather than pushing hypernatremia to maximum). 
**Iatrogenic hyperosmolar maintenance 
***[[Mannitol]] 20% 0.5g/kg q4hrs with serum Osm checks q6hrs. (Target osm of 300-320 mOsm/L)

====4th (Intervention - Refractory elevation)====
*[[Pentobarbital]] coma
**loading dose: 5-20mg/kg bolus then 4mg;kg/hr titrated to burst supression on EEG.
*Induced [[hypothermia]] (32-34°F)
**Cooling System (ie. Arctic Sunt, Stryker Medi-Therm)
***Must perform surveillance cultures (routine blood culture, UA, CXR) every 48 hours since artificially supressing fever.
**Shivering protocol
***[[Vecuronium]] or pancuronium <ref>Angela Logan et al Optimal Management of Shivering During Therapeutic [[Hypothermia]]After Cardiac Arrest Crit Care Nurse 2011;31:e18-e30 http://ccn.aacnjournals.org/content/31/6/e18.full.pdf</ref>
*Paralytics
**Risk of ICU myopathy/neuropathy with long term use.

==See Also==
*[[Intracranial hemorrhage (main)]]
*[[Head Trauma (Main)]]
*[[Glasgow Coma Scale (GCS)]]
*[[Cerebral edema in brain cancer]]

==References==
<references/>

[[Category:Neurology]]
[[Category:Critical Care]]