A Randomized Comparison between 4, 6 and 8 mL of Local Anesthetic for Ultrasound-Guided Stellate Ganglion Block

Abstract

Background: Because it affords greater accuracy than landmark-based techniques, ultrasound guidance may reduce the volume of local anesthetic required for sympathetic blockade of the upper extremity. We hypothesized that 4 mL would provide a similar clinical effect when compared to larger volumes. Methods: One hundred and two patients with chronic neuropathic pain of the upper extremity or face were randomly assigned to receive an ultrasound-guided (USG) stellate ganglion block (SGB) with either 4 mL (group A), 6 mL (group B) or 8 mL (group C) mL of 1.0% lidocaine. Skin temperatures of the face, hand, and axillary fold were measured bilaterally at baseline, 10, 20, and 30 min after the block. Our primary outcome was the relative increase in hand temperature on the blocked side at 30 min and our non-inferiority margin was −0.6 °C. Secondary outcomes included success rate (as defined by a relative temperature increase of ≥1.5 °C), pain relief, degree of ptosis and side-effects. Results: The 95% confidence intervals for the difference of the means exceeded our non-inferiority margin (A versus B: −0.76 to 0.24; A versus C: −0.89 to 0.11) for temperature changes in the hand; however, success rates were similar (44, 45 and 55% for A, B and C respectively, p = 0.651). No intergroup differences were found in temperature-related outcomes for the other measurement sites (face, axilla). The incidence of minor side-effects was significantly higher in group C and no block-related complications were noted. Conclusions: We were unable to establish the non-inferiority of a 4 mL volume for sympathetic blockade of the hand. The clinical significance of these findings is unclear as success rates were similar between the different groups. In contrast, the 6- and 8 mL volumes were not associated with greater temperature changes in the face and axilla.

<p>Ultrasound-Guided Thoracic Paravertebral Block as a Sympathetic Blockade for Upper Extremity Neuropathic Pain: A Prospective Pilot Study</p>

“…In our study, after US-TPVB using 10 mL of local anesthetics, only seven participants (58.3%) showed an increase ≥1.5°C on their ipsilateral hands compared to the contralateral hands, which was considered as a meaningful increase after sympathetic blockade in previous studies. 5 , 16 , 22 Presumably, 10 mL of local anesthetics would not be enough to reach the target sympathetic ganglia in some cases. Therefore, future studies could be conducted to investigate the adequate volume of injectates enough to soothe thoracic sympathetic ganglia during the US-TPVB because higher volumes of local anesthetics are commonly used during the US-guided procedure in the thoracic paravertebral areas.…”

“…3,4 Empirically, the stellate ganglion block (SGB) is one of the most popular sympathetic blockades to manage facial pain or pain in the upper extremities. 5,6 SGB, however, may not always guarantee a successful outcome to control the sympathetic outflow of the upper extremity because an anatomic variant like Kuntz bypass exists, 7 and the procedure usually targets the middle sympathetic ganglion at the C6 spinal level in practice rather than the stellate ganglion. 5 Therefore, the thoracic sympathetic ganglion block (TSGB) at the T2 or T3 spinal levels could be a confirmatory technique for managing pain in the upper extremities.…”

“… 5 , 6 SGB, however, may not always guarantee a successful outcome to control the sympathetic outflow of the upper extremity because an anatomic variant like Kuntz bypass exists, 7 and the procedure usually targets the middle sympathetic ganglion at the C6 spinal level in practice rather than the stellate ganglion. 5 Therefore, the thoracic sympathetic ganglion block (TSGB) at the T2 or T3 spinal levels could be a confirmatory technique for managing pain in the upper extremities. Compared to the SGB, the TSGB involves a complicated procedure as the needle tip should be advanced profoundly into the anterior paravertebral space.…”

Prolonged blockade of the cervical sympathetic nerve by stellate ganglion block accelerates therapeutic efficacy in trigeminal neuropathy

“…Previous reports have indicated that facial blood fl ow (FBF) [7,18], perfusion index (PI) [19][20][21], and facial skin temperature (FST) [13,14,22] increase during sympathetic block by SGB and could be regarded as indicators of sympathetic blockade symptoms. Therefore, FBF, FST, and PI were recorded before SGB (baseline) and at 10, 20, 60, 120, and 180 minutes after SGB.…”

“…Because its sympatholytic effects increase blood flow and partial oxygen pressure in the head, neck, and upper extremities [7], SGB is commonly used in the diagnosis and management of sympathetically maintained pain in the orofacial region [8], post-herpetic neuralgia [9], facial nerve palsy [10], and traumatic trigeminal neuropathy [11]. Previous studies have investigated whether the duration of Horner's syndrome [12] or the degree of skin temperature rise [13] can help determine the appropriate local anesthetic to administer for SGB, as well as the difference in sympathetic blockade based on skin temperature rise at the C6 or C7 blocking sites [14]. These studies revealed that the effect of SGB on sympathetic blockade was proportional to the duration of increased blood flow.…”