Burr hole


  • Expanding intracranial hematoma is rapidly fatal and requires early therapeutic intervention. Morbidity/mortality significantly increases if treatment delayed more than 1.9 hours.[1] Other studies have indicated poor prognosis if treatment delayed beyond 70 minutes.[2]
  • This procedure is rarely performed by emergency physicians, and every effort should be made to discuss the patient and plan for procedure with a neurosurgeon prior to intervention.


  • Epidural or subdural hematoma with midline shift on imaging and unequal pupils on exam.[3]
  • GCS <8
  • Anticipated extended time to assessment/treatment by neurosurgeon.


  • GCS >8
  • Neurosurgery available in reasonable timeframe
  • Lack of imaging-confirmed epidural or subdural hematoma
    • In absence of imaging (e.g. in rural/wilderness area at facility without CT availability), very high clinical suspicion may be enough.[3]
      • e.g. evidence of severe head trauma and unequal pupils, patient presents awake and talking but rapidly deteriorates in setting of head trauma and unequal pupils, etc.


  • Unilateral transtentorial herniation (more common) usually causes ipsilateral fixed and dilated pupil if it localizes
  • Bilateral transtentorial herniation (less common) due to extensive mass effect or severe trauma

Equipment Needed

  • Cranial access kit
    • Razor
    • Scalpel
    • Self-retaining retractors
    • Drill (manual or air/electric powered)
      • Should have both sharp (penetrator) and dull drill bits or a drill bit with appropriate "clutch" mechanism (preferred)
    • Blunt and sharp hooks
    • Hemostats and forceps
  • Sterile PPE
  • Chlorhexidine or betadine
  • Sterile saline
  • Electrocautery (Bovie), if available


Burr hole.JPG
  • Place patient supine
  • Select optimal site based on location of hemorrhage on CT (if unsure, use temporal site)
    • Temporal - 2 finger-breadths above and 2 finger-breadths forward of the auditory canal
    • Parietal - over parietal eminence
    • Frontal - 10 cm above eye in mid-pupillary line (about 3 cm from sagittal suture)
  • Shave scalp widely over selected site
  • Cleanse skin with chlorhexadine or betadine and drape in sterile fashion
  • Set drill depth based on thickness of skull (as measured on CT)
  • Make ~3cm incision and dissect down to bone with scalpel (control bleeding with direct pressure or electrocautery)
  • Dissect periosteum off bone with scalpel
  • Apply retractors to maintain field
  • Apply drill perpendicular to skull and begin drilling while applying firm pressure
    • Have assistant apply gentle saline wash to drilling site
  • Continue drilling until loss of resistance felt or drill bit stops spinning (when using "clutch"-type drill bit)
  • Use hooks to remove any remaining bone fragments
    • Preserve skull fragments in container of sterile saline
  • If subdural hematoma, elevate dura with sharp hook and make careful incision with scalpel
  • Allow blood to drain freely (gentle suction may be used, but DO NOT suction brain tissue)
  • Once blood flow slows/stops, apply loose dressing (DO NOT tamponade bleeding)


  • Provide ceftriaxone IV for antibiotic prophylaxis after procedure
  • Transfer immediately to facility with appropriate ICU and neurosurgical capability


  • Bleeding
  • Infection
  • Damage to brain parenchyma

See Also

External Links




  1. Mendelow AD, Karmi MZ, Paul KS, Fuller GA, Gillingham FJ. Extradural haematoma: effect of delayed treatment. British Medical Journal. 1979;1(6173):1240-1242.
  2. Smith SW, Clark M, Nelson J, et al. Emergency department skull trephination for epidural hematoma in patients who are awake but deteriorate rapidly. J Emerg Med. 2010 Sep;39(3):377-83.
  3. 3.0 3.1 3.2 Wilson MH, Wise D, Davies G, Lockey D. Emergency burr holes: “How to do it.” Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. 2012;20:24. doi:10.1186/1757-7241-20-24.
  4. Hacking C and Elgendy A. Uncal herniation. Radiopaedia. http://radiopaedia.org/articles/uncal-herniation-1.
  5. MacLellan, K. The occasional burr hole. CJRM 1998;3(4):223-2