We read with great interest the article by Levit et al 1 comparing trigger finger release using wide-awake local anesthesia without tourniquet (WALANT) and local anesthesia with tourniquet (LAWT). The findings resulted in a statistically nonsignificant reduction in pain during injection (mean difference [MD] −1.69; 95% CI −4.14 to 0.76; P = .18). This suggests that WALANT may not have clinical benefits over LAWT.
A trial sequential analysis (TSA) should be conducted to get the required information size (RIS) or the number of patients necessary to ascertain conclusive results and assess whether additional trials could potentially alter the reported nonsignificant findings. 2 Based on the TSA graph, if the z-curve crosses the trial sequential monitoring boundary or RIS, sufficient evidence for the anticipated effect may have been obtained, and no further trials are needed.
To address this gap, we used raw data from the original meta-analysis to perform a TSA with TSA version 0.9.5.10 Beta (The Copenhagen Trial Unit, Center for Clinical Intervention Research, The Capital Region, Copenhagen University Hospital) software, focusing on pain on injection. We defined a type 1 error rate of 5% and aimed to achieve 80% statistical power. TSA showed that the Z-curve did not cross the monitoring boundary or RIS. The calculated RIS for this outcome was 659, while the included trials only comprised 151 patients. These findings suggest a lack of power to confidently exclude the possibility of a type 2 error. Further large, high-quality, randomized trials are needed to evaluate the efficacy of WALANT.
Footnotes
Author’s Note: All authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation.
Ethical Approval: Ethical approval is not applicable to this article.
Statement of Human and Animal Rights: This article does not contain any studies with human or animal subjects.
Statement of Informed Consent: This article does not contain any studies with human or animal subjects.
Data Availability: Data availability is not applicable to this article as no new data were created or analyzed in this study.
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding: The author(s) received no financial support for the research, authorship, and/or publication of this article.
ORCID iD: Pedro Romeiro 
https://orcid.org/0000-0003-2286-4582
References
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