Sub-tenon's block: a national United Kingdom survey

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.

An anonymized postal questionnaire survey was sent to 173 consultant anesthesiologist members of the British Ophthalmic Anaesthesia Society.

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.

These results show a need for robust national guidelines, especially in view of increasing use, indications, and potential risks of sub-Tenon's block.