Increased Intracranial Pressure in TBI
OVERVIEW
- normal ICP 7-15mmHg
- sustained increases > 20mmHg is associated with ischaemic brain injury
MONRO-KELLIE DOCTRINE
- cranium can be thought of a fixed box such that any changes in volume of its contents leads to an increase in pressure
- contents: blood, CSF, brain tissue
CAUSES
- artefact
- coughing/valsalva
- intracranial blood: haematoma (epidural, subdural, SAH, intraparenchymal)
- CSF: hydrocephalus
- parenchyma: oedema, tumour, abscess
- other: tension pneumocephalus
MANAGEMENT
- exclude artefact/measurement errors
- ensure adequate oxygen delivery
— PaO2
— treat clinically significant anaemia - maintain cerebral perfusion pressure to > 60mmHg (CPP = MAP – ICP)
– fluids (avoid albumin–SAFE TBI)
— inotropes, vasopressors - optimise venous return from brain:
— head up positioning, no venous obstruction (remove hard collar), low PEEP - avoid cerebral vasoconstriction
— PaCO2 35-40mmHg - decrease cerebral metabolic rate:
— sedation, analgesia
— paralysis
— avoid hyperthermia
— treat seizures
— barbiturate coma - osmotherapies:
—mannitol 0.25 to 1 g/kg, target Osm 300-320 mOsm/kg
— hypertonic saline, target Na+ 145-155 - Repeat CT scan to exclude a new mass lesion
- Consider hypothermia (decrease cerebral metabolism, possible neuroprotection)
— Adverse outcome in paediatric TBI RCT from CCCTG
— McIntyre MA suggesting titrated to ICP and prolonged duration maybe beneficial
— Ongoing trials including POLAR in ANZ - Consider surgical techniques (to reduce volume in the ‘box’, or to ‘open the box’):
— EVD (if already present, ensure patent and draining)
— haematoma evacuation
— decompressive craniectomy (controversial)
Decompressive craniotomy is contentious
- DECRA showed decreased ICP and reduced ICU length of stay but no mortality benefit and a greater number of patients with an unfavourable neurological outcome in those who received decompressive craniectomy
- Patients with mass lesions(unless too small to require surgery) were excluded
- Only a single surgical intervention was used
References and Links
CCC Neurocritical Care Series
Emergencies: Brain Herniation, Eclampsia, Elevated ICP, Status Epilepticus, Status Epilepticus in Paeds
DDx: Acute Non-Traumatic Weakness, Bulbar Dysfunction, Coma, Coma-like Syndromes, Delayed Awakening, Hearing Loss in ICU, ICU acquired Weakness, Post-Op Confusion, Pseudocoma, Pupillary Abnormalities
Neurology: Anti-NMDA Encephalitis, Basilar Artery Occlusion, Central Diabetes Insipidus, Cerebral Oedema, Cerebral Venous Sinus Thrombosis, Cervical (Carotid / Vertebral) Artery Dissections, Delirium, GBS vs CIP, GBS vs MG vs MND, Guillain-Barre Syndrome, Horner’s Syndrome, Hypoxic Brain Injury, Intracerebral Haemorrhage (ICH), Myasthenia Gravis, Non-convulsive Status Epilepticus, Post-Hypoxic Myoclonus, PRES, Stroke Thrombolysis, Transverse Myelitis, Watershed Infarcts, Wernicke’s Encephalopathy
Neurosurgery: Cerebral Salt Wasting, Decompressive Craniectomy, Decompressive Craniectomy for Malignant MCA Syndrome, Intracerebral Haemorrhage (ICH)
— SCI: Anatomy and Syndromes, Acute Traumatic Spinal Cord Injury, C-Spine Assessment, C-Spine Fractures, Spinal Cord Infarction, Syndomes,
— SAH: Acute management, Coiling vs Clipping, Complications, Grading Systems, Literature Summaries, ICU Management, Monitoring, Overview, Prognostication, Vasospasm
— TBI: Assessment, Base of skull fracture, Brain Impact Apnoea, Cerebral Perfusion Pressure (CPP), DI in TBI, Elevated ICP, Limitations of CT, Lund Concept, Management, Moderate Head Injury, Monitoring, Overview, Paediatric TBI, Polyuria incl. CSW, Prognosis, Seizures, Temperature
ID in NeuroCrit. Care: Aseptic Meningitis, Bacterial Meningitis, Botulism, Cryptococcosis, Encephalitis, HSV Encephalitis, Meningococcaemia, Spinal Epidural Abscess
Equipment/Investigations: BIS Monitoring, Codman ICP Monitor, Continuous EEG, CSF Analysis, CT Head, CT Head Interpretation, EEG, Extradural ICP Monitors, External Ventricular Drain (EVD), Evoked Potentials, Jugular Bulb Oxygen Saturation, MRI Head, MRI and the Critically Ill, Train of Four (TOF), Transcranial Doppler
Pharmacology: Desmopressin, Hypertonic Saline, Levetiracetam (Keppra), Mannitol, Midazolam, Sedation in ICU, Thiopentone
MISC: Brainstem Rules of 4, Cognitive Impairment in Critically Ill, Eye Movements in Coma, Examination of the Unconscious Patient, Glasgow Coma Scale (GCS), Hiccoughs, Myopathy vs Neuropathy, Neurology Literature Summaries, NSx Literature Summaries, Occulocephalic and occulovestibular reflexes, Prognosis after Cardiac Arrest, SIADH vs Cerebral Salt Wasting, Sleep in ICU
LITFL
- ECG Library — Raised Intracranial Pressure
- Eponymictionary – Monro-Kellie doctrine
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC
