Table 3. PICOS table summarizing study rationale.

PICOS: population, intervention, control, outcome, study design, CRPS: complex regional pain syndrome, ICU: intensive care unit, NRS: numeric rating scale, VAS: visual analog scale, PPR: percentage pain relief, WMD: weighted mean difference

PICOS	Inclusion Criteria
Population	Patients of all adult ag groups over the age of 18. Patient suffering from CRPS I and CRPS II. Human studies including both males and females.
Intervention	Any intervention that included interventional techniques, neuromodulation or unconventional therapies.
Control Group	Any control group or absence of control group.
Outcome	Change in patient’s pain levels as measured by numeric rating scale (NRS), visual analog Scale (VAS), percentage pain relief (PPR), McGill pain questionnaire and weighted mean difference for pain (WMD). Adverse effects of interventions, persistence of therapeutic effect at follow up, improvement in autonomic, sensory, motor changes, psychological improvement and quality of life improvement.
Study Design	Case reports and case series, Observational studies including retrospective and prospective, Randomized control trials, Meta-analysis and systematic reviews.