Читать книгу Complications in Equine Surgery - Группа авторов - Страница 260

Inadvertent puncture of the dural optic nerve sheath and injection of the local anesthetic into the subarachnoid space causes migration to the brain, resulting in anesthesia of the brainstem.

In humans, the incidence of central nervous system complications presumed to be caused by spread of the local anesthetic to the brainstem was estimated at 0.27% [98]. In horses, there are no case reports of this complication in the literature, but in a cadaveric study of ultrasound‐guided retrobulbar blocks inserting the needle into the orbital fossa dorsal and caudal to the eye, injection of contrast media into the optic nerve sheath could be confirmed in 1 in 40 cases [99]. The authors of this paper acknowledge that ultrasound visualization of the optic nerve in this case was not possible. In other animal species, brainstem anesthesia was suspected following a retrobulbar block in a cat under general anesthesia [100].