Onset, Duration, and Pain Score Obtained Using Lidocaine Mixed With Epinephrine and Bicarbonate in Plastic Surgery

The aim of this study was to systematically review the effects of lidocaine mixed with epinephrine and bicarbonate in plastic surgery in terms of onset, duration, and the pain score.In PubMed, Embase, Web of Science, and the Cochrane Library, the terms "epinephrine" AND "lidocaine" AND "plastic surgery" were searched, resulting in 210 titles. Among them, 25 full papers were reviewed, 11 were excluded, and 5 mined papers were added. Therefore, 19 papers were analyzed.The mean time for the onset of maximum vasoconstriction caused by lidocaine with epinephrine (LE) ranged from 1.3 minutes (1:50,000 epinephrine) to 25.9 minutes (1:100,000 epinephrine). The mean duration of vasoconstriction caused by LE ranged from 40 minutes (1:100,000 epinephrine) to 136.7 minutes (1:50,000 epinephrine) on the forearm, and 60 minutes (1:100,000 and 1:200,000 epinephrine) on the face. The mean duration of local anesthesia ranged from 112.0 minutes (1:1,600,000 epinephrine) to 480 minutes (1:80,000 epinephrine). Before sodium bicarbonate (SB) was mixed with 1% lidocaine and 1:100,000 epinephrine, the mean pH ranged from 4.05 to 4.24. After mixing SB with 1% lidocaine and 1:100,000 epinephrine, the solution became alkalized, and the mean pH ranged from 7.05 to 7.66. For alkalization, the ratio of LE to SB was 9:1 to 10:1. Before alkalization of LE, the mean pain score ranged from 2.35 to 7.6. In contrast, after alkalizing the mixture by adding 8.4% SB, the mean pain score ranged from 0.64 to 4.3.The results of this study may be helpful for using lidocaine in plastic surgery.