- Design
- Single-centre randomised clinical trial
- Population
- 180 adults having posterior lumbar interbody fusion
- Primary outcome
- Chronic postsurgical pain at 3 months
- Effect
- 19.1% vs 34.8%, RR 0.6 (0.3-0.9); 6 months RR 0.8 (0.4-1.5)
A single-centre randomised trial (Anesthesia & Analgesia, 7 October 2026) assigned 180 patients having posterior lumbar interbody fusion to deep or moderate neuromuscular block; 178 were analysed.
Chronic postsurgical pain at three months, the primary outcome, was less common with deep block (19.1% vs 34.8%; RR 0.6, 95% CI 0.3-0.9). By six months the difference was smaller and not significant (14.6% vs 19.1%; RR 0.8, 0.4-1.5). Deep block was also associated with lower early pain scores, less opioid use, lower muscle injury markers on day one and better-preserved paraspinal muscle on MRI at six months.
The plausible mechanism is less forceful retraction against relaxed paraspinal muscle. This is one centre and the benefit faded by six months, so it is a reason to consider deep block for this operation rather than a new standard. Deep block requires quantitative monitoring and a reliable reversal plan.
- Consider deep neuromuscular block for posterior lumbar fusion where retraction is extensive
- Use quantitative neuromuscular monitoring whenever deep block is maintained
- Plan reversal and confirm a train-of-four ratio of at least 0.9 before extubation
- Track chronic pain at three and six months in your own spine service
Why it matters
It suggests an intraoperative choice the anaesthetist controls may influence pain months later.
Don't overread it
Single-centre, with the benefit no longer significant at six months.
The statistics, in plain English
A risk ratio of 0.6 at three months means about 40% fewer patients had chronic pain, with an interval (0.3-0.9) that excludes no effect. At six months the interval (0.4-1.5) crosses 1.0, so the longer-term benefit is uncertain. The biomarker and MRI findings are secondary and support, rather than prove, the mechanism.
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