[The need for supplemental blocks in single versus triple injections in infraclavicular brachial plexus blocks with a medial approach: a clinical and anatomic study]

Abstract

Background and objectives: To evaluate the single-injection and triple-injection techniques in infraclavicular blocks with an ultrasound-guided medial approach in terms of block success and the need for supplementary blocks.

Methods: This study comprised 139 patients who were scheduled for elective or emergency upper-limb surgery. Patients who received an infraclavicular blocks with a triple-injection technique were included in Group T (n = 68). Patients who received an infraclavicular blocks with a single-injection technique were included in Group S (n = 71). The number of patients who required supplementary blocks or had complete failure, the recovery time of sensory blocks and early and late complications were noted.

Results: The block success rate was 84.5% in Group S, and 94.1% in Group T without any need for supplementary nerve blocks. The blocks were supplemented with distal peripheral nerve blocks in 8 patients in Group S and in 3 patients in Group T. Following supplementation, the block success rate was 95.8% in Group S and 98.5% in Group T. These results were not statistically significant. A septum preventing the proper distribution of local anesthetic was clearly visualized in 4 patients. The discomfort rate during the block was significantly higher in Group T (p < 0.05).

Conclusion: In ultrasound-guided medial-approach infraclavicular blocks, single-injection and triple-injection techniques did not differ in terms of block success rates. The need for supplementary blocks was higher in single injections than with triple injections. The presence of a fascial layer could be the reason for improper distribution of local anesthetics around the cords.

Keywords: Anestesia; Anestesia regional; Anesthesia; Bloqueio infraclavicular; Bloqueio infraclavicular vertical; Brachial plexus; Cirurgia ortopédica de membro superior; Infraclavicular block; Plexo braquial; Regional anesthesia; Upper‐extremity orthopedic surgery; Vertical infraclavicular block.

Figure 1

Cadaver dissection showing neurovascular bundle. (AA, Axillary Artery; AV, Axillary Vein; Mc, Medial cord; Lc, Lateral cord, Pc, Posterior cord). Cadaver information: Fixation: Thiel fixed, Age: 94, Gender: Female, Cause of death: Natural causes, Body mass index: 24.9. (Kocaeli University Anatomy Laboratory).

Figure 2

Neurovascular pathways are painted for educational purposes. Anatomical structures are marked on the figure. (1) Proximal segment: cords are located close to each other as a group. (2) Distal segment: Cords diverged from each other and located around the artery. Cadaver information: Fixation: Plastinated, Age: 52, Gender: Female, Cause of death: Cerebrovascular accident, Body mass index: 25.1. (Kocaeli University Anatomy Laboratory).

Figure 3

Sonogram showing local anesthetic injection points in infraclavicular block with a triple-injection technique. (AA, Axillary Artery; AV, Axillary Vein).

Figure 4

Left: Septum preventing the proper distribution of the local anesthetic. Following the first injection of 10 mL of local anesthetic, the needle was retracted about 1 cm, and then 5 mL of local anesthetic was given to the lateral site of the artery for the second injection. Right: Hydrodissection of the septum from the artery after a total of 20 mL of local anesthetic injection. (AA, Axillary Artery; PM, M. Pectoralis Major; Pm, M. Pectoralis Minor.

Figure 5

Flow diagram of the study. Supplemental video: USG-guided infraclavicular block: improper distribution of local anesthetic due to a fascial layer.