1. An Audit of Sub-Tenons block for Squint Surgery in Children Dr Steve Gilbert Queen Margaret Hospital Dunfermline

2. Introduction An audit of the post operative recovery from squint surgery, with and without sub-tenons block was carried out over four years. Three surgeons operated on children, one of whom used sub-tenons laevobupivacaine at the end of the procedure (SS) and two who didn’t (AB & AB)

3. methods Children received a standardised analgesic regime during anaesthesia Fentanyl 1μg/kg at induction Diclofenac 2mg/kg PR at the end of surgery Paracetamol 20mg/kg as a loading dose, post op, followed by 15mg/kg 4 hourly Ibuprofen 10mg/kg 6h post op if reqd Oramorph 0.3mg/kg if reqd After repair of the conjunctiva one of the surgeons injected 1ml 0.5% laevobupivacaine to the sub tenons space (ST) while the others didn’t (N).

4. Data collection Nurses scored the children’s pain and nausea at hourly intervals 0 – none 1 – mild 2 – moderate 3 – severe

5. Other data collected were; Operation Premed quality of induction (happy-0, calm-1, scared-2, crying-3 or hysterical-4) analgesic and antiemetic drugs given in theatre and in the ward post op times of first drink, food and home readiness.

6. Results Between December 2004 and November 2007 88 children between the ages of 1 and 17 60 had a sub tenons block (68%) and 28 didn’t (32%) Average age was 6.6 (N) and 5.2 (ST). Mean quality of induction, graded 0 (happy) to 4 (hysterical) was 0.68 (N) and 0.72 (ST). Average length of data collection 5.5h ST & 5.2h (N)

7. Operations Bilateral medial rectus in 28% (N) and 82% (ST) Single eye in 43% (N) and 0.8% (ST) Re-operation in 7% (N) and 1.5% (ST) Inferior oblique disinsertion in 11% (N) and 5% (ST)

8. Pain Scores The maximum pain scores were 3 in 2%, 2 in 22% of the ST group and 1 in 40%, while 38% had no pain. In the N group maximum pain scores were 3 in 11%, 2 in 41% and 1 in 33%. Only 3 children had a score of 0 (11%). Average pain scores were 0.62 (N) and 0.29 (ST).

9. Maximum Pain Scores

10. Paracetamol & other analgesics

11. PONV & anti-emetics

12. Time to oral intake & home readiness

13. Summary The simple technique of sub-tenons block at the end of paediatric squint surgery leads to significantly less postoperative pain. Only one child in the sub-tenons group complained of blurred vision. There were no complications of the block. There was more nausea & vomiting in the Sub-tenons group. ? Significance – follow up needed

14. Discussion Previous studies have used topical retrobulbar or subconjunctival LA 1 1,2 No difference in outcome Pilot study showed significant effect at 2 hours with lignocaine 2%, but follow up RCT only found benefit at 1h. 1. Yeşim A, Necmettin Ü, Handan C, Necile E, Postoperative analgesia in children using preemptive retrobulbar block and local anesthetic infiltration in strabismus surgery. Regional Anesthesia and Pain Medicine;23, p 569- 574, 1998 2. Carden, S M Adjunctive intra-operative local anaesthesia in paediatric strabismus surgery: a randomized controlled trial. Australian & New Zealand Journal of Ophthalmology. 26(4):289-97, 1998 Nov 3. Sheard R, Mehta J, Barry J et al, Subtenons Lidocaine Injection for Postoperative Pain Relief After Strabismus Surgery in Children: A Prospective Randomized Controlled Trial Journal of American Association for Pediatric Ophthalmology and Strabismus;8(4):p 314-17. 2004

15. Conclusion Sub-tenons block is an effective technique More research needed – multicentre? stephen.gilbert@nhs.net

16. Finally This paper is dedicated to Andy Barr He didn’t do sub- tenons & was always interested in the result