A Lateral Percutaneous Technique for Stellate Ganglion Blockade in Rats

Abstract

In the present study, we describe and show the efficacy of a lateral approach to stellate ganglion block (SGB) in rats. Twenty-one rats were randomized into three groups: the posterior technique group (n = 7), the lateral technique group (n = 7), and the control group (n = 7). Thiopental was administered intraperitonally as 5 mg per 100 g of each rat's weight for sedation during the procedure. In the posterior technique group, SGB was performed by a posterior percutaneous approach as described previously. In the lateral technique and control groups, the cervical vertebrae was fixed between the left first and third fingers of the physician's left hand while palpating the C7 process with the second finger. The study drug was 0.2 mL 0.25% plain bupivacaine for the two percutaneous treatment groups, and 0.2 mL saline in the controls. Two animals in the posterior technique group died immediately after local anesthetic injection (P < 0.01). There were no deaths in the new technique group or in the controls. Ptosis appeared at 300 +/- 120 s in the posterior group, whereas it was seen almost immediately after withdrawing the needle in the lateral technique group (6 +/- 4 s) (P < 0.001). Ptosis did not occur in the control group. There was no statistically significant difference in heart rate among groups (P > 0.069). The lateral approach to SGB does not require the induction of general anesthesia. The approach is associated with early development of ptosis and may be associated with a lower mortality rate compared to the conventional posterior approach.