title: Emergency Medical Services in the State of Maryland. Echelons of trauma care.
mesh_terms: D004632:Emergency Medical Services / Q000592:standards*; D006801:Humans; D009316:National Institutes of Health (U.S.); D012769:Shock / Q000628:therapy; D014187:Transportation of Patients; D014193:Trauma Centers / Q000592:standards*; D014481:United States