As a new medical director, I thought to myself, “What is the worst that could happen at our rural, 12-bed ED?” The scenarios we all know came to mind: pericardiocentesis, thoracotomy, lateral canthotomy, resuscitative endovascular balloon occlusion of the aorta, and skull trephination (burr hole). At our monthly departmental meetings, we reviewed all of these procedures so we would be ready. I ordered the necessary kits so we would have the tools on-site. Our hospital had never even had a skull trephination kit before. The one I ordered arrived the day before a 2-year-old patient arrived at triage.

The Case

A 2-year-old male was brought to the emergency department by his mother after falling out of a shopping cart seat and striking his head. He initially appeared well and was running around the triage room. After a period of observation, he became increasingly somnolent, and on repeat exam, his pupils were slightly unequal. A head CT revealed a large epidural hematoma with midline shift. His pupils quickly became significantly worse at 6 mm and 2 mm, and he became unresponsive. I intubated him and called the nearest pediatric trauma center (one hour away) to begin arranging for helicopter transport. During the conversation with the trauma surgeon at the major academic center, I told him I was planning on doing an emergent burr hole. He said, “I’ve never done one of those—it’s up to you.”

I had seen one of these in residency and went to the supply room to find the newly arrived burr hole kit, took a deep breath, then started to prepare for the procedure by reviewing the CT.

I performed the burr hole with the technique described below and evacuated 150 mL of blood. The pupils improved. We placed a sterile dressing on the wound, and the helicopter team transported the patient to the pediatric trauma center.

One month later, the mother brought the boy back to the emergency department. The patient was running around the emergency department with no deficits and gave me a hug.

Location to Drill

Emergency department skull trephinations are done in the temporal location 2 cm anterior and 2 cm superior to the tragus.¹

Technique

1. Measure the skull thickness on CT to set stopper depth (see Figure 1).
2. Shave the hair with clippers; sterile prep and drape.
3. Inject local anesthetic and then make a 4-cm vertical skin incision down to the periosteum at a point 2 cm superior and 2 cm anterior to the tragus.
4. Use a periosteal elevator to expose the skull.
5. Have an assistant hold the patient’s head firmly prior to drilling.
6. Apply the trephine with gentle, steady pressure until the skull is penetrated. The two nonautomated choices for trephine are the Integra hand crank model with stopper (see Figure 1) and the Galt trephine (see Figure 2). The bone fragment may come out in the device or may need to be removed with forceps. Place the bone fragment in a sterile cup with saline.
7. Once the bone fragment is removed, the clot may not immediately extrude. Use a small sterile pediatric suction catheter to facilitate hematoma drainage.
8. If identified, the bleeding artery (usually the middle meningeal) may be ligated/clamped.¹

Complications

• Emergency department skull trephinations should only be performed in the temporal region to avoid venous sinus injury and complications of air embolism or hemorrhage.
• Avoid plunging by using the stopper on the hand crank and by measuring skull thickness on the CT image.
• Infection is a possibility.

Historical Perspective

Trephinations of the skull have been found in human skulls older than 10,000 years of age. Skulls from virtually every major civilization show evidence of successful trephinations. There are three common methods for performing trephinations:²

1. Scraping bone (see Figure 3)
2. Drilling a series of small holes and connecting them
3. Making crosshatch cuts in the bone and connecting them to remove a rectangular piece of bone¹

Discussion

The medical literature supports skull trephination by emergency physicians in emergency departments without immediate neurosurgery capability for the talk-and-deteriorate patient with anisocoria, Glasgow Coma Scale (GCS) score <9, and CT-proven epidural hematoma (EDH). The available studies are retrospective and small.^1,3,4 A small (n=5) retrospective chart review by Smith et al examined all known cases of skull trephination done by emergency physicians at non-neurosurgical institutions before transfer to a neurosurgical institution.¹ The mean time saved to decompression by emergency department intervention was two hours without complications. The Galt trephinator was used. This small study of talk-and-deteriorate EDH patients resulted in uniformly good outcomes without complications.

A second study by Poon et al reported rapidly deteriorating patients with EDH who presented to a neurosurgical institution had a mean time to EDH evacuation of 0.7 ± 1.0 hours, with nine of 11 patients having good outcomes. For 12 patients with EDH presenting to hospitals without neurosurgery and no ED trephination, the time to evacuation, once transferred to a neurosurgical institution was 3.2 ± 0.5 hours, with mortality of 67 percent (eight of 12 patients).³

Cohen et al found that EDHs not drained within 70 minutes of onset of anisocoria are associated with poor outcome.⁵ Taking these critical time windows into account, it makes sense that talk-and-deteriorate patients have the potential to greatly benefit from emergency department skull trephination in institutions without neurosurgical capabilities. Nelson studied 11 patients with local non-neurosurgeon drainage of epidural hematoma prior to transfer to neurosurgical centers, and the data showed consistently favorable outcomes.⁴

In 2016, the Brain Trauma Foundation and the Congress of Neurological Surgeons stated, “It is strongly recommended that patients with an acute EDH in coma (GCS<9) with anisocoria undergo surgical evacuation as soon as possible.”⁶ Additionally, the Brain Trauma Foundation states, “There are insufficient data to support one surgical treatment method. However, craniotomy provides a more complete evacuation of the hematoma.”⁶

As emergency physicians, it is our duty to rule out the life threats and be prepared to reverse life-threatening conditions with heroic procedures we often have never performed. If you practice at a hospital without neurosurgery, skull trephination is a tool you can use to save a life one day.

---

Dr. Beffa is an emergency physician with VEP Healthcare and medical director of the emergency department at Sutter Amador Hospital in Jackson, California.

References

1. 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;39(3):377-383.
2. Goodrich JT, Flamm ES. Historical overview of neurosurgery. In: Winn HR, ed. Youmans and Winn Neurological Surgery. 7th ed. Philadelphia: Elsevier; 2017:1, 8-48.
3. Poon WS, Li AK. Comparison of management outcome of primary and secondary referred patients with traumatic extradural hematoma in a neurosurgical unit. Injury. 1991;22(4):323-325.
4. Nelson JA. Local skull trephination before transfer is associated with favorable outcomes in cerebral herniation from epidural hematoma. Acad Emerg Med. 2011;18(1):78-85.
5. Cohen JE, Montero A, Israel ZH. Prognosis and clinical relevance of anisocoria-craniotomy latency for epidural hematoma in comatose patients. J Trauma. 1996;41(1):120-122.
6. Bullock MR, Chesnut R, Ghajar J, et al. Surgical management of acute epidural hematomas. Neurosurgery. 2006;58 (3 Suppl):S7-15.