DOS 2016

192

· DOS Abstracts

Efficacy of ultrasound-guided Saphenous and

Obturator Nerve Blocks after primary Knee

Arthroplasty. A double-blind, randomized clinical

study

Jens Bagger, Mette Hornsleth, Katja Lenz, Pia Therese Jaeger, Katrine Tanggaard,

Jens Børglum, Kenneth Jensen

Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg;

Departement og Anestesiology, Copenhagen University Hospital Bispebjerg; Department

of Anestesiology HOC, Copenhagen University Hospital Rigshospitalet; Department of

Anestiosiology, Zeeland University Hospital, Roskilde; Department of Anestiosiology,

Zeeland University Hospital, Roskilde; Departement og Anestesiology, Copenhagen

University Hospital Bispebjerg

Background:

Pain treatment following TKA often combines systemic analgesic with pe-

ripheral nerve Blocks and local infiltration analgesia (LIA).

Purpose / Aim of Study:

Wee hypothezed that a single-shot, low-volumen saphenous

nerve block would improve pain and ambulation scores and reduce opioid consumption

compared with placebo Blocks without LIA, and that addition of an obturator (posterior

branch) nerve block would potentially confer additional benefits

Materials and Methods:

75 patients were randomized in a 1:1:1 ratio to either an

ultrasound-guided saphenous nerve block (S Group), a combined saphenous/obturator

nerve block (SO Group), or placebo Blocks using isotonic saline (P Group).The primary

outcome was pain at 45 degree passive flexion of the knee joint in the first 24 hours

after surgery. Secondary autcomes included pain at rest, morphine demand, nausea and

vomiting, ambulation scores, length of stay. The nerve Blocks was add-ons to a regimen

consisting of naproxem, gabapentin, zolpidem and morphine iv PCA.

Findings / Results:

74 patients were included. The S Group had less pain on movement

(p<0.001) compared to placebo. This was replicated in the SO Group (p<0.05). Pain at

rest and morphine demand was significantly reduced in the S Group in the first 6 hours,

but the SO Group was similar to the placebo Group. Althoug nonsignificant, patients were

discharged earlier in the active Groups (p=0.019 and p=0.154). There were no differ-

ence in ambulation between Groups. 28 patients had in- hospital complications, 9 of

which were severe (Pneumonia, opioid intox, GI bleeding)

Conclusions:

The addition of a low-volumen saphenous nerve block significantly re-

duced pain on movement, pain at rest and opioid demand after primary TKA, but failed to

offer benefits for ambulation and length of stay. The value of adding an obtorator block

remains questionable

No conflicts of interest reported

143.