Sub-Tenon's Block: A National United Kingdom Survey

BACKGROUND AND OBJECTIVE: A survey was undertaken to ascertain current practices in ophthalmic regional anesthesia with an emphasis on sub-Tenon's block. Despite its increasing use, there are currently no guidelines for its explicit management. PATIENTS AND METHODS: An anonymized postal questionnaire survey was sent to 173 consultant anesthesiologist members of the British Ophthalmic Anaesthesia Society. RESULTS: Sub-Tenon's blocks were regularly performed by 87.8% of respondents. The majority used a blunt metal cannula via the inferonasal quadrant. Local anesthetic was placed post-equatorially by 58% of respondents and deep posteriorly by 16.7%; 18% used vasopressors. There was no agreement for aseptic precautions, international normalized ratio, platelet levels, or venous access. Complications included vascular and muscular injuries, a case of fainting, and several cases of dysrhythmias. Current United Kingdom guidelines for monitoring patients were not being followed. CONCLUSION: These results show a need for robust national guidelines, especially in view of increasing use, indications, and potential risks of sub-Tenon's block.