Holmberg A, Sauter AR, Klaastad Ø et al.
Anaesthesia 2017; 72: 967-977. DOI: 10.1111/anae.13939
Aims of the study
To evaluate whether pre-emptive analgesia with a preoperative ultrasound-guided infraclavicular brachial plexus block resulted in better analgesia than an identical block performed postoperatively.
Design & location
Prospective, double blind, randomised clinical trial at Oslo University Hospital.
Methodology
52 patients undergoing fixation of a fractured radius were randomly allocated into 2 groups of 26 each. A preoperative group and a postoperative group with 0.5 ml.kg-1 ropivacaine 0.75%. All patients received general anaesthesia with remifentanil and propofol, paracetamol plus opioids for breakthrough pain.
Primary outcome
Time until first rescue opioid analgesia after emergence from anaesthesia.
Secondary outcomes
Postoperative pain scores and analgesic requirement at 30 min, 60 min, 2 h, 4h, 8h, 24h, 7 days and 6 months after surgery.
Statistics
Data analysed using IBM SPSS, version 22.0 software.
Independent samples t-test, Mann-Whitney U test, Chi-squared test and Fisher’s exact test.
Results
Mean time to first rescue analgesic after emergence from general anaesthetics was 544 min in the preoperative group compared with 343 min in the postoperative block group (p=0.015). There were statistically significant pain scores and requirement for analgesics between the 2 groups until 4h after surgery.
Conclusions
Preoperative block provides longer and better acute postoperative analgesia compared to an identical postoperative block with no significant differences in chronic pain.
Limitations
Did not classify fracture and the severity of soft tissue injury.
5 different surgeons operated.
Discussion From Journal Club Meeting
- Value of study: It is known that pre-emptive analgesia is better when used before a stimulus is applied, but there are some contradicting studies to this.
- Remifentanil is known to cause hyperalgesia so they could have (?should have) used other opioids.
- In order for pre-emptive analgesia to be successful, duration of analgesia must include both surgical and post-surgical period.
Summary by Dr S Eswarappa. Journal Club 07 September 2017.
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