Effects of stellate ganglion block on vasomotor symptoms

Abstract

Objective Uncontrolled intervention studies, including studies involving breast cancer survivors, have demonstrated improvements in vasomotor symptoms (VMS) following stellate ganglion blockade (SGB) with local anesthetic. This study presents the first randomized, sham-controlled trial of SGB for the treatment of VMS. Methods Participants included 40 postmenopausal women aged 30 to 70 years with moderate-to-severe VMS. The design was a randomized, sham-controlled trial comparing the effect of SGB versus sham injection on the frequency of total and moderate-to-severe VMS as measured by daily diaries. Image-guided SGB was performed with 0.5% bupivacaine 5 mL. Sham injection of saline was performed in the subcutaneous tissue in the neck. VMS were recorded at baseline and for six months thereafter. Objective VMS were recorded using ambulatory sternal skin conductance monitoring over a 24-hour period at baseline and 3-month follow-up. Results There were no significant group differences in overall VMS frequency, but the frequency of moderate-to-very severe VMS was reduced more in the active compared to sham treatment group, RR 0.50, CI 0.35–0.71, p<0.001. The frequency of objective VMS was also reduced to a greater degree in the SGB group compared to the sham group (RR 0.71, CI 0.64–0.99, p<0.05). There were no study-related serious adverse events. Conclusions SGB may provide an effective treatment for VMS in women who seek non-hormonal therapies due to safety concerns and personal preference. The finding that SGB significantly reduces objectively measured VMS provides further evidence of efficacy. A larger trial is warranted to confirm these findings.

Stellate ganglion blockade and verbal memory in midlife women: Evidence from a randomized trial

“…The mean subjective detection of physiologic VMS was 55%. As in the parent trial[5], the frequency of physiologic VMS was significantly reduced from baseline to the 3-month assessment in the SGB group ( p =0.03) but not in the sham-control group ( p =0.31), for a significant group by time interaction ( p =0.02). There was no significant difference between treatment groups in reported VMS from baseline to 3-months post-injection ( p =0.69 for the Group × Time interaction), due to a 34% placebo effect in the sham group.…”

“…Participants underwent an informed consent process before completing any study procedure and were compensated for time and effort. Four of the 40 women in the parent study [5] were ineligible for the cognitive evaluation; one had a history of multiple sclerosis, two had a previous brain aneurysm, and one had a history of coma following a motor vehicle accident (See Figure 1). The trial study was registered on www.clinicaltrials.gov (NCT00992914).…”

“…Using fluoroscopic guidance, 0.5% bupivacaine (5 mL) was injected into the anterolateral portion of the C6 vertebra[5]. For sham control, the same positioning, monitoring, sterile preparation and technique were used, except the needle was placed in the superficial tissues overlying the C6 tubercle.…”

“…Four uncontrolled open-label studies showed that SGB reduced vasomotor symptoms (hot flashes and night sweats; VMS)[1-4]. Our pilot randomized, sham-controlled clinical trial compared active SGB with bupivacaine to a sham procedure involving subcutaneous saline injection on VMS in 40 women over 6 months of follow-up [5]. Compared to the sham-control group, the SGB group showed a significantly greater decrease in the frequency of moderate-to-severe patient-reported VMS, the intensity of VMS, and the frequency of physiologic VMS measured with ambulatory skin conductance monitors.…”

Management of Menopausal Symptoms

“…However, the frequency of moderate-to-severe hot flushes as well as that of objectively measured symptoms was reduced significantly more by the active than by the sham treatment. 69 A larger, sham-controlled RCT of this modality would be appropriate.…”