The findings came as concerns over energy drinks have intensified following reports last fall of 18 deaths possibly tied to the drinks — including a 14-year-old Maryland girl who died after drinking two large cans of Monster Energy drinks. Monster does not believe its products were responsible for the death.
Two senators are calling for the Food and Drug Administration to investigate safety concerns about energy drinks and their ingredients.
The energy drink industry says its drinks are safe and there is no proof linking its products to the adverse reactions.
Late last year, the FDA asked the U.S. Health and Human Services to update the figures its substance abuse research arm compiles about emergency room visits tied to energy drinks.
The Substance Abuse and Mental Health Services Administration's survey was based on responses it receives from about 230 hospitals each year, a representative sample of about 5 percent of emergency departments nationwide. The agency then uses those responses to estimate the number of energy drink-related emergency department visits nationwide.
The more than 20,000 cases estimated for 2011 represent a small portion of the annual 136 million emergency room visits tracked by Centers for Disease Control and Prevention.
The FDA said it was considering the findings and pressing for more details as it undertakes a broad review of the safety of energy drinks and related ingredients this spring.
"We will examine this additional information ... as a part of our ongoing investigation into potential safety issues surrounding the use of energy-drink products," FDA spokeswoman Shelly Burgess said in a statement.
Beverage manufacturers fired back at the survey, saying the statistics were misleading and taken out of context.
"This report does not share information about the overall health of those who may have consumed energy drinks, or what symptoms brought them to the ER in the first place," the American Beverage Association said in a statement. "There is no basis by which to understand the overall caffeine intake of any of these individuals — from all sources."