Rodriguez 2005.

Study characteristics
Methods	RCT, parallel design
Participants	N= 82 Mean age (no SDs provided): Group 1: 44.1 years Group 2: 46.1 years, Sex: Group 1: 36.6% male Group 2: 46.3% male Upper limb CRPS (type I or type II) with presence of pain mediated by the sympathetic nervous system (defined as a decrease in resting pain by 50% with a stellate ganglion block) Diagnostic criteria: IASP (Merskey 1994; Reinders 2002) Inciting event: 71.4% of CRPS cases were secondary to accidental or violent trauma and 18% occurred following surgical procedures. Mean duration of symptoms (no SDs provided): Group 1: 253.7 days Group 2: 213.4 days Medico‐legal factors: Group 1: 14.6% had a compensation claim Group 2: 24.4% had a compensation claim Previous treatment: participants were excluded if they had previous stellate ganglion blocks; no other previous treatment reported Concomitant treatment: Group 1 also received physical therapy and pharmacological treatment
Interventions	Group 1: SGB, physical therapy and pharmacological treatment Site of block: paratracheal at the height of the cricoid cartilage Number of blocks: 5 Type of substance injected: 10 cc of volume with equal parts of 2% lidocaine and 0.5% bupivacaine Evaluation of technical adequacy: increase in temperature of at least 1° C of the hand and face (affected side) and the presence of Horner's syndrome (ptosis of the upper eye lid and conjunctivitis) Group 2: Physical therapy and pharmacological treatment only(Control group): Received physical therapy and pharmacological treatment
Outcomes	Pain intensity (VAS). Measured at baseline, 1 month and 2 months. Exact follow‐up time appears to be variable among participants (i.e. followed for more than 2 months in some). Therapeuctic efficacy: number of participants with at least 50% reduction in the pain. Measured at 2 months postintervention. Efficacy: (incidence of pain in control group − incidence of pain in the SGB group)/incidence of pain in the control group * 100 Absolute risk reduction (incidence of pain in control group − incidence of pain in the intervention group). Measured at 2 months postintervention. NNTB = 1/ARR (calculated at 2 months postintervention) Relapse (return of pain to less than 50% reduction or return of pain to baseline levels or above); determined at 2 months postintervention
Country of origin	Colombia
Study aim	To determine the analgesic efficacy of the stellate ganglion blockade (SGB) in the alleviation of pain mediated by the sympathetic nervous system in patients with Complex Regional Pain Syndrome
Notes	This is the first published study by Rodriguez. There are 2 other published studies and one IASP abstract that use an identical study design. It is unclear if all the studies represent the same cohort. We attempted to contact the authors 3 times with no success. This study was translated and interpreted by a researcher fluent in Spanish. The study author, TS, worked with the researcher to fully interpret and score. Funded by Colciencias and the Universidad Libre Seccional Cali. No conflict of interest stated. No adverse events reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomized" Comment: method of randomisation unclear
Allocation concealment (selection bias)	Low risk	Opaque envelopes used; randomly given to each participant
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "double blind" Comment: Probably not. Index and control groups are not indistinguishable, and success of blinding was not tested
Blinding of outcome assessment (detection bias) All outcomes	High risk	The investigator was reported to be blinded; however, outcomes were self reported and participants were likely not blinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Participants that dropped out or underwent surgery were excluded from the analysis. The number of excluded participants per group is not reported.
Selective reporting (reporting bias)	High risk	No pain scores were given and time to relapse was unclear
Adequate sample size?	High risk	N = 82 (41 in each group)
Adequate duration of follow‐up?	Low risk	Follow‐up of 2 months
Free of other bias?	Unclear risk	No baseline data given on pain intensity; unsure if groups were similar at baseline