An Audit ofAn Audit ofSub-Tenons block for Sub-Tenons block for

Squint Surgery in Squint Surgery in Children Children

Dr Steve GilbertDr Steve GilbertQueen Margaret HospitalQueen Margaret Hospital

DunfermlineDunfermline

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)

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).

Data collection

• Nurses scored the children’s pain and nausea at hourly intervals

• 0 – none• 1 – mild• 2 – moderate • 3 – severe

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.

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)

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)

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).

Maximum Pain Scores

pain max pain ave 1h 2h 3h 4h 5h0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

ST N

Paracetamol & other analgesics

0

2040

6080

100

%

P x 1 P x 2 I O

P (paracetamol) I (ibuprofen) O (oramorph)

ST

N

PONV & anti-emetics

ST N0

5

10

15

20

25

30

35

40

nauseavomitingpost op anti emetic

Time to oral intake & home readiness

00.5

11.5

22.5

33.5

44.5

5

oral home

ST

N

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

Discussion

• Previous studies have used topical retrobulbar or subconjunctival LA

11,2

• 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

Conclusion

•Sub-tenons block is an effective technique

•More research needed – multicentre?

•stephen.gilbert@nhs.net

Finally

This paper is dedicated to Andy BarrHe didn’t do sub-tenons & was always interested in the result