Single Injection Digital Block: Is a Transthecal Injection Necessary?

Abstract

Three different methods of injection to obtain digital block anaesthesia were performed on 15 healthy volunteers to evaluate the success and extent of anaesthesia. We found that the traditional transthecal injection technique was inaccurate and the injected agent mainly flowed into the subcutaneous space, and did not remain within the sheath. The deep transthecal single injection kept the anaesthetic agent within the flexor tendon sheath, as intended. The duration of anaesthesia and the area anaesthetised by the subcutaneous injection and the traditional transthecal injection was similar and satisfactory. However, the anaesthetic area after the deep transthecal injection was significantly smaller than that of the other two techniques (P<0.01). A transthecal digital block offers no advantage over a simple subcutaneous digital block.

Digital nerve blocks: A systematic review and meta‐analysis

“…Fifteen studies included a dorsal approach in at least 1 of their injection groups: 2 studies used the DRB, 8 , 9 12 studies included the TDB, 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 1 study included the TDB+, 22 and 1 study included the MCB technique 10 . Eight studies used volar approaches to the digital nerve block: 6 included the TTB, 12 , 13 , 21 , 23 , 24 , 25 and 4 included the MTTB. 3 , 24 , 25 , 26 Thirteen studies included a single subcutaneous injection: 2 included the SIMPLE, 15 , 17 9 included the SCB, 16 , 18 , 19 , 20 , 24 , 25 , 27 , 28 , 29 and 1 included the SCB‐A1‐pulley.…”

“…Eight studies used volar approaches to the digital nerve block: 6 included the TTB, 12 , 13 , 21 , 23 , 24 , 25 and 4 included the MTTB. 3 , 24 , 25 , 26 Thirteen studies included a single subcutaneous injection: 2 included the SIMPLE, 15 , 17 9 included the SCB, 16 , 18 , 19 , 20 , 24 , 25 , 27 , 28 , 29 and 1 included the SCB‐A1‐pulley. 23 Nine studies focused on only 1 digital nerve block technique, 3 , 8 , 9 , 11 , 22 , 26 , 27 , 28 , 29 12 studies compared 2 techniques, 10 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 23 and 2 studies compared 3 techniques.…”

“… 23 Nine studies focused on only 1 digital nerve block technique, 3 , 8 , 9 , 11 , 22 , 26 , 27 , 28 , 29 12 studies compared 2 techniques, 10 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 23 and 2 studies compared 3 techniques. 24 , 25 …”

Subcutaneous Single Injection Digital Block with Epinephrine

“…The extent of anesthesia was recorded by the authors. Each middle finger was divided into 6 zones; the palmar and dorsal areas of the distal segment, middle segment, and proximal segment corresponding to the two surfaces and the three phalangeal segments of the finger [8]. …”

“…This technique requires at least two injections. Various protocols for single injection digital block have been reported since 1990 [5–8]. In particular, a subcutaneous single injection digital block is simple procedure [8].…”