Ultrasound-guided supraclavicular nerve block for implantable port catheters: Does it show a significant difference in pain control?

BACKGROUND: Nerve blocks have been used for decades at head and neck region interventions and recently introduced as an alternative option for subcutaneous port implantation. This study aimed to compare two different local anesthesia techniques used during subcutaneous port implantation.

METHODS: This retrospective study was conducted with 107 patients who were categorized into two groups according to the local anesthesia techniques used during port implantations. Group 1 underwent local infiltration anesthesia and Group 2 received an ultrasound-guided supraclavicular nerve block. In both groups, prilocaine 2% was used for skin anesthesia and no other systemic anesthetic drugs or additional local anesthetics were administered during port implantation. Local anesthetic doses were 400 mg in Group 1 and 200 mg in Group 2. The time required for adequate cutaneous anesthesia, procedure time, complication rate and visual analog scale (VAS) score were recorded for each patient.

RESULTS: Groups 1 and 2 contained 58 and 49 patients respectively. Both groups showed similar demographic distributions of patients ( p  > 0.05). Mean procedure times and the time required for adequate cutaneous anesthesia were longer in Group 2 ( p  < 0.05). Group 2 also showed 12 immediate complications, although they were temporary and recovered without any intervention under surveillance. Mean VAS scores during port implantation were similar in both groups [Group 1: 1.17(±0.60), Group 2: 1.1(±0.62)] ( p  > 0.05).

CONCLUSIONS: The VAS scores did not differ significantly between groups. Although a supraclavicular nerve block may require lower local anesthetic doses for similar cutaneous anesthesia, it is associated with higher immediate complication rates due to unintended blockade of the peripheral nerves. Thus, if the nerve block is preferred over local infiltration anesthesia during port implantation, to prevent life-threatening complications, caution needed especially for the patients with contralateral vocal cord or diaphragm paralysis.