Impact on analgesia, diaphragmatic function, and recovery between erector spinae plane block versus superior trunk block in arthroscopic shoulder surgery: a randomized controlled trial

Clinical Snapshot

Key Findings

• P Value: p < 0.001 for primary pain outcome

• Effect Size: Large effect size for pain reduction with superior trunk block

• Primary Outcome: Dynamic VAS at 1-hour: superior trunk block 0.1 [0.0, 0.2] vs erector spinae plane block 5.7 [4.0, 7.6]

• Nnt Or Sensitivity: Not calculable from available data

• Confidence Interval: Not provided in abstract

Clinical Application

Both techniques require specialised training and ultrasound guidance, available in most Australian tertiary centres Relevant to Australian anaesthetic practice; both techniques align with ANZCA guidelines for regional anaesthesia in shoulder surgery Patients undergoing arthroscopic shoulder surgery requiring regional anaesthesia

Abstract

BACKGROUND: Effective analgesia and preservation of diaphragmatic function are key considerations in analgesia for shoulder surgery. The superior trunk block provides analgesia with reduced phrenic nerve involvement, while the erector spinae plane block offers minimal impact on diaphragm motion. This randomized controlled trial compared the analgesic efficacy, impact on diaphragmatic motion, and postoperative recovery between the two blocks. METHODS: Sixty patients undergoing arthroscopic shoulder surgery were randomized to receive either erector spinae plane block or superior trunk block. Primary outcomes were postoperative VAS and changes in diaphragmatic excursion. Secondary outcomes included Quality of Recovery-15 (QoR-15) scores, morphine-equivalent consumption, and the handgrip strength motor blockade. RESULTS: The superior trunk block resulted in significantly lower dynamic VAS at 1-h postoperatively (0.1 [0.0, 0.2] vs. 5.7 [4.0, 7.6]; p < 0.001) and reduced 24-h morphine consumption (7.8 [2.5, 15.0] mg vs. 12.7 [7.5, 17.3] mg; p = 0.038) compared to the erector spinae plane block. However, diaphragmatic excursion was better preserved in the erector spinae plane block group (8.37% ± 20.7% vs. -20.09% ± 22.2%; p < 0.001), with a lower incidence of partial hemidiaphragm paresis (3.3% vs. 46.7%; p < 0.001). At 24 h postoperatively, QoR-15 scores were higher in the superior trunk block group (p = 0.047), and no patient in either group developed handgrip motor blockade. CONCLUSIONS: Superior trunk block offers superior early postoperative analgesia and better overall recovery, while erector spinae plane block minimizes diaphragmatic impairment. However, the erector spinae plane block may represent an option only in carefully selected patients at high respiratory risk, acknowledging its significantly poorer early analgesic profile.

References

1. 1.Yang, H. Y., Chang, C. H., Chuang, Y. H., Lee, C. T., Lee, C. W., Chen, C. F., Lin, F. S., & Wu, C. Y. (2026). Impact on analgesia, diaphragmatic function, and recovery between erector spinae plane block versus superior trunk block in arthroscopic shoulder surgery: a randomized controlled trial. Annals of Medicine. https://doi.org/10.1080/07853890.2026.2672843