What type of anesthesia is required for trephination?

Trephination Procedure and Anesthesia Requirements

Trephination should be performed under local anesthesia with proper infiltration of the site, and a digital nerve block is not required for this procedure. 1

What is Trephination?

Trephination (also called trephination or burr hole creation) is a surgical procedure involving drilling a small hole through tissue to relieve pressure or drain fluid. In medical contexts, this typically refers to:

• Creating a small hole through the skull for neurosurgical purposes 2, 3
• Creating a small opening through a nail or tooth for drainage in dental emergencies 4

Anesthesia Requirements for Trephination

Local Anesthesia Technique

• Infiltrate the skin at the marked site using a small gauge needle (27G or smaller) to raise a dermal bleb 1
• Proceed with deeper infiltration into the subcutaneous tissue, intercostal muscles (if applicable), periosteum, and parietal tissues 1
• Use 0.25% bupivacaine with a maximum dose of 2 mg/kg for longer-lasting anesthesia 1
• For dental/nail trephination, local infiltration around the site is sufficient 4

Digital Block Not Required

• A digital nerve block is not necessary for trephination procedures 1
• Local infiltration at the site provides adequate anesthesia for the procedure 1

Procedural Considerations

Pre-Procedure Assessment

• Ensure appropriate imaging has been performed to guide the procedure location 1
• Ultrasound guidance is recommended when applicable (especially for pleural or thoracic trephination) 1
• Routine coagulation studies are only necessary in patients with known risk factors 1

Equipment

• Use the appropriate drill size based on the procedure type:
  • For skull trephination: 2.35mm round dental drill with serrated edges ("Rosenbohrer") 3
  • For dental trephination: appropriate dental bur 4

Monitoring Requirements

• Standard monitoring should be used during the procedure (pulse oximetry, blood pressure) 1
• An assistant should be present to monitor the patient's vital signs 1

Special Considerations

Pain Management

• Preemptive analgesia should be employed before the painful stimulus 1
• Consider multimodal analgesia combining local anesthesia with systemic administration of analgesics for more complex cases 1
• For post-procedure pain management, NSAIDs and/or paracetamol are typically sufficient 1

Emergency Setting Considerations

• In emergency settings (such as expanding epidural hematoma), the procedure may need to be performed rapidly 5, 6
• Even in emergencies, proper local anesthesia should still be administered 6
• The benefits of immediate trephination in life-threatening situations outweigh the risks 5, 6

Conclusion

Trephination is a procedure that can be safely performed under local anesthesia with proper infiltration of the site. A digital nerve block is not required, as targeted local anesthesia provides sufficient pain control for this procedure. The technique should be performed by practitioners with appropriate training, particularly in emergency settings where it may be life-saving.