Transthecal Digital Block: An Underutilized Technique In The ED

Abstract

The transthecal digital block is a simple, safe, and effective anesthesia technique that can be used in many digital injuries. It is contraindicated only in cases of infection. The purposes of this article are to (1) discuss the indications for the transthecal digital block, (2) describe the technique, and (3) review the literature. The transthecal technique is used on appropriate patients almost to the exclusion of more traditional digital blocks by many hand surgeons. The advantages of this method are that it requires only a single injection, has a rapid onset of action, and requires only a small amount of anesthetic. It also has virtually no risk of direct mechanical trauma to the neurovascular bundles. This technique has been shown to be exceptionally effective. We encourage emergency physicians to use the transthecal technique when indicated.Comment:This article describes the transthecal digital block as an alternative to the traditional digital block. It is performed by a single injection into the flexor tendon sheath, which could be ideal in the pediatric population (or those adults behaving like kids). The onset of anesthesia is rapid with minimal to no risk of direct mechanical trauma. It could be used for lacerations, nail bed injuries, fingertip injuries, and foreign body removal; however, it is contraindicated in felons, tenosynovitis and any infectious process involving the flexor tendon. The transthecal digital block is most effective for the index, long, ring, and little finger thus providing anesthesia to the volar and dorsal surface. Of important note, volar anesthesia, without dorsal anesthesia, has been reported.The technique is as follows: a 1:1 mixture of marcaine and lidocaine without epinephrine in a syringe with a 25-30 Gauge needle is needed. Insert the needle at 90 degrees angle at the proximal digital crease that has been previously cleaned in usual fashion (seefigure 1).Insert needle midline and away from any neurovascular bundles until the bone of the proximal phalanx is struck. Withdraw the needle about 2-3 mm, and redirect the needle to an angle of 45 degrees along the long axis of the digit (seefigure 2).Inject slowly and no resistance should be felt (about 1.5-3 cc anesthetic). Onset of action is in 2-3 minutes on the average, and lasts about 6-8 hours.Figure 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)This transthecal digital block is worth learning and adding to your armamentarium.Eileen C. Quintana, MD, MPH The transthecal digital block is a simple, safe, and effective anesthesia technique that can be used in many digital injuries. It is contraindicated only in cases of infection. The purposes of this article are to (1) discuss the indications for the transthecal digital block, (2) describe the technique, and (3) review the literature. The transthecal technique is used on appropriate patients almost to the exclusion of more traditional digital blocks by many hand surgeons. The advantages of this method are that it requires only a single injection, has a rapid onset of action, and requires only a small amount of anesthetic. It also has virtually no risk of direct mechanical trauma to the neurovascular bundles. This technique has been shown to be exceptionally effective. We encourage emergency physicians to use the transthecal technique when indicated. Comment:This article describes the transthecal digital block as an alternative to the traditional digital block. It is performed by a single injection into the flexor tendon sheath, which could be ideal in the pediatric population (or those adults behaving like kids). The onset of anesthesia is rapid with minimal to no risk of direct mechanical trauma. It could be used for lacerations, nail bed injuries, fingertip injuries, and foreign body removal; however, it is contraindicated in felons, tenosynovitis and any infectious process involving the flexor tendon. The transthecal digital block is most effective for the index, long, ring, and little finger thus providing anesthesia to the volar and dorsal surface. Of important note, volar anesthesia, without dorsal anesthesia, has been reported. The technique is as follows: a 1:1 mixture of marcaine and lidocaine without epinephrine in a syringe with a 25-30 Gauge needle is needed. Insert the needle at 90 degrees angle at the proximal digital crease that has been previously cleaned in usual fashion (seefigure 1).Insert needle midline and away from any neurovascular bundles until the bone of the proximal phalanx is struck. Withdraw the needle about 2-3 mm, and redirect the needle to an angle of 45 degrees along the long axis of the digit (seefigure 2).Inject slowly and no resistance should be felt (about 1.5-3 cc anesthetic). Onset of action is in 2-3 minutes on the average, and lasts about 6-8 hours. This transthecal digital block is worth learning and adding to your armamentarium. Eileen C. Quintana, MD, MPH