Introduction This study aimed to investigate whether low-volume local anesthetic with intravenous dexamethasone can reduce the incidence of diaphragmatic paresis while maintaining the analgesic duration compared with conventional volume of local anesthetic without intravenous dexamethasone when performing ultrasound-guided superior trunk block in patients undergoing arthroscopic shoulder surgery.
Methods Eighty-four adult patients undergoing arthroscopic shoulder surgery under general anesthesia were randomly assigned to receive ultrasound-guided superior trunk block using 7 mL of 0.5% ropivacaine with 0.15 mg/kg of intravenous dexamethasone (treatment group), or 15 mL of 0.5% ropivacaine with intravenous normal saline (control group). The co-primary outcomes were (1) the duration of analgesia (time between block completion and onset of surgical pain with a Numeric Rating Scale pain score of 4 or higher), which was compared against a non-inferiority margin of 3 hours, and (2) the incidence of diaphragmatic paresis evaluated using M-mode ultrasonography in the post-anesthesia care unit.
Results The mean duration of analgesia was 12.4 (6.8) and 11.2 (4.6) hours in the treatment and control groups, respectively (mean difference: −1.2 hours; 95% CI −3.8 to 1.3]; p for non-inferiority<0.001), meeting the non-inferiority criteria. The incidence of diaphragmatic paresis was 45.2% and 85.4% in the treatment and control groups, respectively (relative risk: 0.53; 97.5% CI 0.35 to 0.80; p<0.001).
Conclusions Superior trunk block using low-volume local anesthetic with intravenous dexamethasone can reduce the incidence of diaphragmatic paresis while providing non-inferior analgesic duration compared with the conventional volume of local anesthetic in patients undergoing arthroscopic shoulder surgery.
Trial registration number Clinical Research Information Service of Republic of Korea Registry (KCT0005998).
- Nerve Block
- Pain Management
- Brachial Plexus
- Upper Extremity
- Acute Pain
Data availability statement
The data supporting the findings of this study are available from the corresponding author upon reasonable request.
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Presented at The results from this study were presented in the 16th Asian Australasian Congress of Anesthesiologists, Seoul, Korea on November 10–November 13, 2022.
Contributors YK contributed to data acquisition, data analysis, and manuscript preparation. SY contributed to the study conception and design, data analysis, and revision of the manuscript. SHK contributed to the data collection and revision of the manuscript. HK contributed to data analysis and manuscript preparation. JB contributed to data analysis and revision of the manuscript. S-KP contributed to data collection and revision of the manuscript. J-TK contributed to the study design, data collection, and revision of the manuscript. Y-JL contributed to the study design, data interpretation, and revision of the manuscript. All authors read and approved the final version of the manuscript. SY is responsible for the overall content as a guarantor.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.