Bovis ISSN 2398-2993

Peterson block

Synonym(s): Local anesthesia

Contributor(s): Daisy Norgate, Tristan Merlin , Adam Auckburally

RVC logo

Introduction

Uses

  • Nerve supply to the eye and surrounding structures is complex and this technique requires skill and anatomical knowledge.
  • This block involves local anesthesia of the cranial nerves supplying sensory and motor function to the eye and some of its surrounding structures.
  • This block produces anesthesia of the eye and orbit, with immobilization of the globe and produces almost complete anesthesia of the lateral aspect of the head except for the eyelids.
  • The Peterson block is usually combined with the auriculopalpebral block Auriculopalpebral block (motor only) to provide complete paralysis of the eyelids to facilitate surgery.

Uses

  • Desensitization of the eye and orbit for eye surgery such as enucleation and foreign body removal.
  • With additional modification, such as the addition of an auriculopalpebral block to abolish motor activity, surgery of the eyelids is possible (e.g. mass removal).
  • The Peterson technique may also be necessary for some horn procedures in adult bovids.

Advantages

  • Safer than the Retrobulbar block Retrobulbar block as there is less risk of globe penetration and hemorrhage.
  • Additionally, potential catastrophic injection of the meninges surrounding the optic nerve is minimized using this technique.
  • More effective than alternative techniques if performed correctly.
  • Less edema and inflammation with this block than with infiltration of local anesthetics into the eyelids and orbit.
Note re nerves blocked:
  • The nerves blocked include the ophthalmic and maxillary branches of the trigeminal nerve.
    • The mandibular division should not be affected as this branches off before the other two divisions of the trigeminal nerve exit via the foramen orbitorotundum.
  • If enough local anesthetic is deposited in the pterygopalatine fossa, it is also possible to block the optic nerve.
    • This is also dependent upon the final positioning of the needle and proximity of local anesthetic deposition to the optic foramen.
    • The optic nerve should not be affected if this technique is correctly performed.  

Disadvantages

  • Technically more challenging to perform than other blocks anesthetizing the same or similar area.

Requirements

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Preparation

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Procedure

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Aftercare

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed Papers

  • Recent references from PubMed and VetMedResource.
  • Edmondson M A (2016) Local, regional, and spinal anesthesia in ruminants. Vet Clin of Nor Amer: Food Anim Prac 32, 535-552 PubMed.
  • Grimm K A, Lamont L A, Tranquilli W J et al (2015) Veterinary anesthesia and analgesia: Lumb and Jones. 5th edn. Wiley and Blackwell. Iowa.


ADDED