Presentations for STAPG Prize

Continuous infusion of local anaesthetic into the extra-articularspace versus placebo for post operative pain control following arthroscopic shoulder surgery

Dr Indra Srikantharajah

Abstract

Arthroscopic shoulder surgery has previously shown a 45% incidence of pain especially in the 48 hours following surgery [1;2].  Contrary to the belief that arthroscopic surgery causes only minor pain, studies have shown that pain in this procedure is often severe especially 24 – 48 hours following surgery [3].

Aim
To investigate the efficacy of a continuous infusion of local anaesthetic (plain Bupivacaine 0.125%) into the extra-articular space for pain relief, against placebo (Sodium Chloride 0.9%) in the 48 hours following arthroscopic shoulder surgery.  The study included the feasibility of discharging patients the same day as surgery with the infusion in situ.

Method         
Forty patients were randomly divided into two groups; group 1 Bupivacaine, group 2 placebo.  Both groups received the infusion via an isometric disposable pump for 48 hours.  Patients and data collectors were blinded to the study.  All patients received intravenous morphine via a Patient Controlled Analgesic pump for 24 hours following surgery and Morphine Sulphate MR tablets with as needed Oramorph to take at home.  Pain scores and amount of morphine used were documented throughout patients’ hospital stay and via telephone at home, after discharge.

Results
Post-operatively, group 2, required significantly higher amounts of morphine during the first 24 hours - (median 27mg, range 1 - 110) to manage their pain than did group 1 (median 10mg, range 0 - 24, Mann-Whitney U = 44.0, P < 0.001).  In the 12-48 hour post operatively period, there were significant differences in the pain scores between the two groups with group 1 reporting significantly lower pain scores than group 2.

Conclusion
Patients undergoing arthroscopic shoulder surgery can safely be discharged on the day of surgery with an extra-articular infusion, delivered via an isometric disposable pump.  Infusions run concurrently with oral analgesia and the line can be removed by the patient after 48 hours.
                  
References

1.  D.Webb, D.Guttmann, P.Cawley and J.H.Lubowitz, Continuous infusion of a local anesthetic versus interscalene block for postoperative pain control after arthroscopic shoulder surgery.  Arthroscopy 23, 1006-1011 (2007).
2.  G.Checcucci, A.Allegra, P.Bigazzi, L.Gianesello, M.Ceruso and G.Gritti, A new technique for regional anesthesia for arthroscopic shoulder surgery based on a suprascapular nerve block and an axillary nerve block: an evaluation of the first results.  Arthroscopy 24, 689-696 (2008).
3.  F.A.Barber and M.A.Herbert, The effectiveness of an anesthetic continuous-infusion device on postoperative pain control.  Arthroscopy 18, 76-81 (2002).