Electroacupuncture

Electroacupuncture is a form of acupuncture where a small electric current is passed between pairs of acupuncture needles. 
According to some acupuncturists, this practice augments the use of regular acupuncture, can restore health and well-being, and is particularly good for treating pain. There is evidence for some efficacy (when used in addition to antiemetics) in treating moderate post-chemotherapy vomiting, but not for acute vomiting or delayed nausea severity. 
Use by acupuncturists.
According to "Acupuncture Today", a trade journal for acupuncturists:
That article adds:
Electroacupuncture is also variously termed EA, electro-acupuncture or incorporated under the generic term electrotherapy.
"Electroacupuncture according to Voll" (EAV) claims to measure "energy" in acupuncture points and to diagnose ailments. Some devices are registered in FDA as galvanic skin response measuring devices; they may not be used in diagnosis and treatment. Units reportedly sell for around $15,000 and are promoted for diagnosis of conditions including "parasites, food and environmental sensitivities, candida, nutritional deficiencies and much more." It is promoted for diagnosis of allergies.
Scientific research.
The Cochrane Collaboration, a group of evidence-based medicine (EBM) reviewers, reviewed eleven randomized controlled trials on the use of electroacupuncture at the P6 acupuncture point to control chemotherapy-induced nausea or vomiting. The reviewers found that electroacupuncture applied along with anti-vomiting drugs reduced first-day vomiting after chemotherapy more effectively than anti-vomiting drugs alone. However, the drugs given were not the most modern drugs available, so the reviewers stated that further research with state-of-the-art drugs was needed to determine clinical relevance. The reviewers concluded:
The Cochrane Collaboration also reviewed acupuncture and electroacupuncture for the treatment of rheumatoid arthritis. Because of the small number and poor quality of studies, they found no evidence to recommend its use for this condition. The reviewers concluded:
A 2016 systematic review and meta-analysis found inconclusive evidence that electroacupuncture was effective for nausea and vomiting and hyperemesis gravidarum during pregnancy.
Regarding EAV devices, "results are not reproducible when subject to rigorous testing and do not correlate with clinical evidence of allergy". There is no credible evidence of diagnostic capability. The American Cancer Society has concluded that the evidence does not support the use of EAV "as a method that can diagnose, cure, or otherwise help people with cancer" or "as a reliable aid in diagnosis or treatment of .. other illness" In double-blind trials, "A wide variability of the measurements was found in most patients irrespective of their allergy status and of the substance tested. Allergic patients showed more negative skin electrical response at the second trial, compared to normal controls, independent of the tested substance. No significant difference in skin electrical response between allergens and negative controls could be detected."
Safety.
Researchers at the U.S. Food and Drug Administration (FDA) Center for Devices and Radiological Health (Rockville, Maryland) evaluated three representative devices intended for electrostimulation of acupuncture needles. The abstract at PubMed summarizes their findings: