Learning objectives

• Describe the causes of and risk factors for increased intracranial pressure
• Identify increased intracranial pressure
• Manage increased intracranial pressure

Background

• Increased intracranial pressure (ICP) commonly occurs in patients with traumatic brain injury and subarachnoid hemorrhage 
• It is the most frequent cause of morbidity and mortality in these patients
• Brain tumors can also increase ICP
• Increased ICP can impair cerebral perfusion pressure, cerebral blood flow, and cerebral oxygenation, resulting in ischemia, edema, and further increases in ICP
• Can impede surgical access to deep lesions requiring brain retraction
• Can predispose to or exacerbate brain retraction injury
• Can complicate dural closure

Signs

• Before craniotomy:
  • Hypertension
  • Bradycardia
  • Irregular respiratory pattern (Cushing reflex)
• After craniotomy:
  • Tense dura
  • Brain swelling out of the dural opening
  • Difficult brain retraction
• Quantitative measurements:
  • ICP monitoring (External ventricular drain, intraparenchymal pressure monitor)
  • ICP measurement (Pressure transducer slid into the epidural space from a burr hole or at the edge of a craniotomy)

Risk factors

• Subdural ICP >10 mmHg
• Peritumoral edema
• Mean arterial blood pressure >140 mmHg
• Intraoperative hypotension with systolic blood pressure <90 mmHg
• Glioblastoma
• Metastasis

Causes

• Intracranial
  • Tumor
  • Infarct
  • Trauma
  • Hemorrhage
  • Hydrocephalus
  • abscess/infection
  • Parenchymal edema
  • Idiopathic
• Extracranial
  • Airway obstruction
  • Hypoxia/hypercarbia
  • Hypertension exceeding cerebral autoregulatory capacity
  • Hypotension causing cerebral hypoperfusion and reflex vasodilation
  • Venous hypertension from outflow obstruction
  • Volatile anesthetics
  • Nitroglycerin
  • Sodium nitroprusside
  • Vomiting, coughing, pain, shivering, and seizure activity during awake craniotomy

Management

Suggested reading

• Desai VR, Sadrameli SS, Hoppe S, Lee JJ, Jenson A, Steele WJ, et al. Contemporary Management of Increased Intraoperative Intracranial Pressure: Evidence-Based Anesthetic and Surgical Review. World Neurosurgery. 2019;129:120-9.
• Ragland J, Lee K. Critical Care Management and Monitoring of Intracranial Pressure. J Neurocrit Care. 2016;9(2):105-12.
• Tameem A, Krovvidi H. Cerebral physiology. Continuing Education in Anaesthesia Critical Care & Pain. 2013;13(4):113-8.

Clinical updates

Diz et al. (Anesthesia & Analgesia, 2025) report in a meta-analysis of 15 RCTs (>35,000 patients) that balanced crystalloids are associated with higher mortality in traumatic brain injury, likely related to increased cerebral edema and intracranial pressure, whereas non-TBI patients benefited from balanced solutions. These findings support preferential use of normal saline in patients at risk of elevated ICP, reinforcing diagnosis-specific fluid selection in neurocritical care.

• Read more about this study HERE.