[Brainstem anesthesia after extraconal retrobulbar block: can it be avoided? Case report]

The CEROF-HC is a public hospital specialized in ophthalmology. Anesthetic blocks for ophthalmic surgeries are common and effective. But the technique is not devoid of risks, and there is the possibility of meningeal perforation and injection of the local anesthetic (LA) in the central nervous system (CNS). The objective of this study was to report a case of brainstem anesthesia as a complication of the ophthalmologic regional anesthesia, stress the importance of preventing this accident, and discuss the treatment.

A female patient, 60 years old, ASA II, with a diagnosis of grade II cataract, was scheduled for a facectomy and implantation of intraocular lens in the right eye. The patient had a past medical history of hypertension and vitrectomy. Physical exam, laboratory and cardiologic exams were normal. An extraconal retrobulbar block was performed with local anesthetic (lidocaine and bupivacaine) and hyaluronidase (total volume of 5 mL). Immediately after, the patient developed apnea and loss of consciousness. She was treated with tracheal intubation and mechanical ventilation, remaining stable. The surgery was performed as planned. Thirty minutes after the intubation, the patient began to move, recovering completely, without deficits.

Although safe, ophthalmic block is not devoid of risks. The main risk factor is improper anesthetic technique. In the ophthalmic block, the local anesthetic (LA) can reach the CNS by inadvertently puncturing the ophthalmic artery or the meninges that surround the optic nerve, with dispersion to the subarachnoid space. Although rare, it can lead to a severe complication with respiratory arrest that can be fatal if it is not diagnosed promptly. Here we present the possibilities of such a complication, and discuss the nomenclature of anesthetic blocks used in ophthalmology. The importance of the knowledge of this and other complications by the surgical team is paramount, as well as the preparation and adequate monitoring to diagnose and treat immediately this complication to minimize the risks to the patient.