How long to wait after local infiltration anaesthesia: systematic review.

"Disclosure The authors declare no conflict of interest."

"Funding This research was funded in part through National Institutes of Health/National Cancer Institute Cancer Center Support Grant P30 CA008748."

"This systematic review was conducted after protocol registration (PROSPERO CRD42022362414) and reported following the PRISMA statement. Included were all randomized controlled trials and prospective cohort studies investigating the onset of analgesia and/or hypoperfusion after cutaneous injection of lidocaine with epinephrine. Excluded were animal studies, review articles and articles with incomplete descriptions of time, composition or concentration of LIA used. Articles on large nerve blocks and those limited to dental or mucosal LIA were excluded. No restrictions regarding year of publication or language of the article were applied. Studies of non-healthy human subjects were also included. The databases of PubMed (MEDLINE), Scopus and Google Scholar were systematically retrieved. The following keywords were used: ‘local anesthesia’, ‘local infiltration anesthesia’, ‘walant’, ‘walatt’, ‘time’, ‘waiting’, ‘latency’ and ‘onset’, with the Boolean operators ‘AND’, ‘OR’, and their combinations. The search included registries of clinical trials. Additional articles were found through secondary hand searches and through a citation-networking software (ResearchRabbit, Version 2.0, Human Intelligence Technologies, Incorporated). The search was last updated in April 2023. Methods: This systematic review (PROSPERO ID: CRD42022362414) included RCTs and prospective cohort studies. Primary outcomes were (1) onset of analgesia and (2) onset of stable hypoperfusion, assessed directly, or measured indirectly using perfusion imaging. Other data extracted include waiting strategies, means of outcome assessment, anaesthetic concentrations, volume/endpoint of infiltration, and injection sites. Methodological quality was evaluated using the Cochrane risk-of-bias tool for randomized trials. Articles describing waiting strategies were critically appraised by the Joanna Briggs Institute tools."