#EMConf: Acute Radiation Syndrome

Measurement of radiation: Grays (1 Gy = 100 rad)

must be ionizing radiation at large dose (> 70 rad) affecting significant portion of the body exposed over a short period of time

Acute radiation syndrome progresses over 4 stages:

  • Prodromal Phase: nausea, vomiting; the faster the onset of GI symptoms, the worse the prognosis
  • Latent Phase: relative recovery (hours to weeks depending on dose)
  • Manifest Illness Stage: 
    • clinical syndromes of hematopoietic, GI, CNS, cardiovascular 
    • Hematopoietic:
      • lymphocytes deplete first
      • hemorrhage, pancytopenia, infection
      • if 48-hour lymphocyte count > 1200: likley insignifcant radiation dose, good prognosis
      • if 48-hour lymphocyte count < 500, significant radiation dose, poor prognosis
    • GI: nausea, vomiting, abdominal pain, diarrhea, bleeding, fluid loss/ shock
    • CNS: altered mental status, ataxia, seizure, cerebral edema
    • Cardiovascular: damage to blood vessels, shock unresponsive to treatment
  • Recoveryr or Death: typically determined by dose of radiation received; lethal dose 350-450 rad


  • supportive
  • decontamination
  • treat injuries/ burns
  • serial CBC, Chem7


Tintinalli, Judith, et al. “Radiation Injuries.” Tintinalli’s Emergency Medicine, 8th ed., McGrath-Hill, 2016, pp 51 – 57.