Approach and Troubleshooting to Scalp, Facial, and Airway Blocks

Head and neck area has a rich nerve supply from the branches of the fifth cranial nerve and the cervical spinal nerves. The use of regional anaesthesia has been commonplace for ophthalmic, dental, and certain maxillofacial procedures and was commonly practiced by surgeons since many years. Blocks of the head and neck are usually performed by anaesthesiologists as an adjunct to provide perioperative pain relief. However, certain neurosurgical procedures require an awake patient for intraoperative neurological monitoring and hence are performed under scalp block or cervical plexus block as sole anaesthetic technique. The trigeminal nerve supplies majority of the scalp and face and branches out and emerges extracranially through various foramina. While the upper cervical nerves form a plexus and can be blocked easily with a single injection, the nerves of the face and scalp are widespread and need to be blocked individually at multiple sites. Besides blocking surgical areas certain regional blocks are exclusively performed as a part of establishing airway access in an awake patient. The unique submucosal course of nerves allows for transmucosal blocks in the upper airway. Apart from the sensory and motor blockade the contribution of autonomic nerves and their implication in chronic pain has increased the scope of head and neck blocks. Head and neck blocks present are not devoid of complications and respiratory compromise is a serious limitation in few blocks due to the blockade of nerves lying in close proximity. Additionally due to the proximity of the cervical nerves with the major vessels supplying the brain, intravascular injection can lead to catastrophic complications.