Distal nerve blocks at the elbow for traumatic fingertip semi-amputation repair – A case report

Abstract

Regional anesthesia has been proven useful in hand surgery after trauma, most commonly via brachial plexus blocks (BPB), with widely established benefits. Distal nerve blocks at the elbow are used much less frequently. A 15-year-old boy was admitted because of traumatic amputation of the 4^th digit on his right hand. Difficult intubation was suspected. History was indicative of obstructive sleep apnea, and nil per os status was confirmed, with no apparent risk factors for regurgitation. Ultrasound-guided blocks of the median, radial, and ulnar nerves at the elbow were performed with 2% Lidocaine and 0.5% Levobupivacaine. Sedation was maintained with Propofol 3–4 mg/kg/h, with oxygen support via nasal cannula at 3 L/min. Basic monitoring of vital functions was applied. Throughout the procedure, the patient maintained perfect hemodynamic and respiratory stability. Postoperative analgesia was adequate, with no nonsteroidal anti-inflammatory drugs administered in the first 12 h postoperatively. Distal nerve blocks at the elbow may present a safe and effective anesthetic technique when managing traumatic injuries of the fingers, presenting a simpler and less risky technique than BPB and requiring less provider expertise. Previous studies have demonstrated the use of these blocks in acute pain management following fractures, but to our knowledge, no inquiry has been made into the use of these blocks for surgical anesthesia in amputation management. One needs to keep in mind the dermatomal distribution of innervation as other digits may not require covering all three nerves as the 4^th digit does. Caution must be taken to account for any possibility of increased risk of regurgitation, as well as the use of an upper arm pneumatic tourniquet.

Introduction

Regional anesthesia (RA) in the form of peripheral nerve blocks (PNBs) has been proven useful in hand surgery after trauma.[1,2] Most commonly, brachial plexus blocks (BPBs) are utilized,[3,4] with the axillary approach often being most suitable. Distal blocks of the median, radial, and ulnar nerves are used as well but much less frequently.[2] The benefits of RA under procedural sedation are apparent as well, circumventing any complications related to general anesthesia (GA), difficult intubation and/or extubation, or invasive airway instrumentation.

Case Presentation

A 15-year-old boy, weighing 115 kg, was urgently admitted to the University Children’s Hospital in Belgrade because of traumatic semi-amputation of the 4^th digit on his right hand. Stigmata of a potentially difficult intubation were apparent, namely, increased neck circumference, a shortened thyromental distance, and shortened inter-incisory distance. History was indicative of obstructive sleep apnea (OSA), which had not been confirmed with polysomnography. Nil per os (NPO) status was confirmed, with no apparent risk factors for regurgitation. Anesthetic management included procedural sedation with spontaneous breathing, and ultrasound-guided blocks of the median [Figure 1], radial [Figure 2], and ulnar [Figure 3] nerves at the elbow.

Figure 1.

(a) - Ultrasound anatomy. (b) - Median nerve (yellow), brachial artery (red)

Figure 2.

(a) - Ultrasound anatomy. (b) - Radial nerve (yellow), brachioradialis muscle (green), brachialis muscle (orange), humerus (blue)

Figure 3.

(a) - Ultrasound anatomy. (b) - Ulnar nerve (yellow), triceps brachii muscle (green), humerus (blue)

On induction, the patient received 100 mcg of Fentanyl intravenously. For the blocks, the patient received 1,5 ml of 2% Lidocaine and 3 ml of 0,5% Levobupivacaine per nerve. Sedation was maintained with Propofol 3–4 mg/kg/h, with oxygen support via nasal cannula at 3 L/min. Basic monitoring of vital functions was applied. Throughout the procedure, the patient maintained perfect hemodynamic and respiratory stability, with no significant elevations of heart rate and blood pressure, or drops in oxygen saturation. Sedation was halted 8 min prior to end of surgery, and awakening was uneventful. Postoperative analgesia was adequate, with no nonsteroidal anti-inflammatory drugs (NSAIDs) administered in the first 12 h postoperatively.

Discussion

Previous studies by Mori et al.[5], as well as Frenkel et al.,[6] have demonstrated the use of these blocks in acute pain management following fractures in children. Their sole use of highly diluted lidocaine (0,1–0,2%), although adequate for acute pain management, in our experience would not be suitable for surgery due to much more painful stimulation and potentially prolonged surgery. Additionally, adequate postoperative pain control mandates the use of a long-acting local anesthetic, in our case levobupivacaine. To our knowledge, no inquiry has been made into the use of these blocks for surgical anesthesia in amputation management prior to our case report. BPBs have not been shown to positively affect vascular anastomosis in digit reimplantation compared to GA or infiltration with local anesthetic, as demonstrated by Mahmutoglu et al.[7]. However, the same study demonstrated a larger drop of hemoglobin levels in patients receiving a BPB, compared to patients who did not. The potential effect of nerve blocks at the elbow on vascular anastomosis and bleeding propensity is still undetermined, requiring further research. One also needs to keep in mind the dermatomal distribution of innervation as other digits usually do not require covering all three nerves as the 4^th digit does.[8] Finally, talking to your surgeon prior to the intervention is key, so as to determine whether an upper arm tourniquet will be used. The role of the intercostobrachial nerve (ICBN) in modulating tourniquet pain has been studied regarding BPBs. Le-Wendling et al.[9] examined the effect of ICBN block under supraclavicular BPB, showing that tourniquet pain was minimal with an adequately performed BPB and manageable with minimal doses of intraoperative opioids. When it comes to a more distal approach, for example, under axillary BPB as shown by Seyed Siamdoust et al.[10], ICBN block was necessary and effective for covering tourniquet pain as axillary BPB alone was not sufficient. Therefore, in the case of distal nerve blocks at the elbow, tourniquet placement on the upper arm would require an additional ICBN block.

Distal nerve blocks at the elbow may present a safe and effective anesthetic technique when managing traumatic injuries of the fingers, presenting a simpler and less risky technique than BPB and requiring less provider expertise. Additionally, no motor block of the upper arm is observed, in contrast to BPB. As surgical anesthesia of the digit is achievable, spontaneous breathing without invasive airway instrumentation presents itself as a solution for high-risk patients. Certainly, in case of an upper arm pneumatic tourniquet, a BPB would be more suitable as tourniquet pain would not be covered by the nerve blocks at the elbow. Alternatively, an ICBN block could be added. Caution must be taken to account for any possibility of increased risk of regurgitation and/or aspiration (e.g., NPO, gastroesophageal reflux disease, vomiting, drugs). Further research is needed to evaluate the differences of these blocks compared to BPBs regarding postoperative analgesia and analgesic consumption.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.