Superior Trunk Block Effective Phrenic-Sparing Alternative to Interscalene Block for Shoulder Arthroscopy

Recently published research study reviewed the use of superior trunk block (STB) as an alternative to interscalene block (ISB) for postoperative pain management in patients undergoing shoulder arthroscopy. The study aimed to compare the incidence and degree of hemidiaphragmatic paralysis and the block efficacy of these techniques. The findings were based on a systematic review and meta-analysis of randomized controlled trials (RCTs) that included 359 patients.

Findings and Conclusion of STB versus ISB

The study found that the STB group showed a significantly lower incidence of total hemidiaphragmatic paralysis, subjective dyspnea, and Horner's syndrome compared to the ISB group. Furthermore, the duration of the block and block efficacy showed no significant difference between the groups. The researchers concluded that STB has a better safety profile than ISB, resulting in lower rates of hemidiaphragmatic paralysis and dyspnea while providing a similar block. They suggested that STB could be preferred over ISB, especially in patients susceptible to phrenic nerve paralysis complications.

Significance of Meta-Analysis and Study Outcome

This meta-analysis is the first to pool the results of RCTs comparing STB with ISB in patients undergoing shoulder arthroscopy. The study included 359 patients and found that STB demonstrated equal effectiveness as ISB in providing analgesia while also showing a higher safety profile with lower incidence of hemidiaphragmatic paralysis and minor complications. The study highlighted that STB may offer advantages over ISB, particularly in patients at increased risk of respiratory insufficiency.

Study Limitations and Implications for Clinical Practice

The researchers acknowledged some limitations, such as the relatively small sample size and heterogeneity in some outcomes among the included studies. They also noted that the publication bias analysis suggested some degree of asymmetry in the data, indicating the possibility of small study effects. However, the study's findings have significant implications for clinical practice, and the researchers recommended STB as a preferred alternative to ISB, especially for patients at increased risk of respiratory insufficiency.

In conclusion, this meta-analysis of RCTs comparing STB and ISB in patients undergoing shoulder arthroscopy indicates that STB may be a safer alternative with equivalent analgesic efficacy compared to ISB. The study suggests that STB should be considered as a preferred option, particularly for patients at increased risk of respiratory insufficiency.

Reference –

Amaral S, Arsky Lombardi R, Medeiros H, et al. (November 03, 2023) Superior Trunk Block Is an Effective Phrenic-Sparing Alternative to Interscalene Block for Shoulder Arthroscopy: A Systematic Review and Meta-Analysis. Cureus 15(11): e48217. doi:10.7759/cureus.48217.