Efficacy and safety of stellate ganglion block with different volumes of ropivacaine to improve sleep quality in patients with insomnia: a comparative study.

The aim of this study was to compare the efficacy and safety of ultrasound-guided stellate ganglion block (SGB) with different volumes of 0.375% ropivacaine on sleep quality in patients with insomnia.A total of 80 patients who were selected to undergo SGB for the treatment of insomnia were enrolled. The patients were divided into saline control group, and low-volume (4 mL), medium-volume (6 mL), and high-volume (8 mL) ropivacaine injection groups according to the random table method. The treatment included 7 blocks with once every three days. The left and right stellate ganglions are alternately blocked. The onset and maintenance time of Horner syndrome, the degree of carotid artery dilation and blood flow velocity before and 20 minutes after the first block, the occurrence of complications such as drug crossing of the midline of the artery and hoarse throat were recorded, and the improvement of sleep disorders was evaluated with the Pittsburgh Sleep Quality Index Scale.Horner syndrome occurred in 100% of all volumes of ropivacaine block. The ipsilateral internal carotid artery was dilated and was accompanied by increased blood flow. The degree of dilation and increase in blood flow were not affected by the volumes of drug injection. There were no serious complications in any group, but the incidences of hoarseness and dysphagia were higher in the medium- and high-volume groups than those in the low-volume group (all p < 0.05). Compared with the low- and medium-volume groups, the high-volume group had a faster onset of action, longer maintenance time, and the highest chance of the drug crossing the artery (all p < 0.05). Compared to those before the pre-block and in the control groups, insomnia was improved in all volume groups after the block with nonsignificant intergroup differences.4 mL of 0.375% ropivacaine for ultrasound-guided SGB is sufficient to improve the sleep quality of insomnia patients, whose overall risk is lower than block with 6 mL or 8 mL of ropivacaine.