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Radiation Emergency Medical Management (REMM)

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Time Phases of Acute Radiation Syndrome - Dose Range 1-2 Gy
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Dose Range in gray (Gy)
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Data adapted from:
Diagnosis and Treatment of Radiation Injuries
(PDF - 202 KB)
(IAEA Safety Reports Series No. 2, Vienna 1998)
            Timeline: 1-2 Gy
Acute Radiation Syndrome time phases resulting from 1-2 Gy radiation expoure Next

ARS time phases and approximate whole body dose from exposure: 1-2 Gy
Predominant Manifest Illness Subsyndromes Phases
Prodromal Latent Manifest Illness (Critical Phase) Recovery or Death
bar chart of subsyndrome severity of hematopoietic, gastrointestinal, and neurovascular subsyndromes
bar chart legend
  • Onset: 2 hours after exposure or later
  • Percent of victims who vomit at this dose: ~10-50%
  • None
  • Slight
Level of consciousness
  • Unaffected
Body temperature
  • Normal
Medical response
  • Outpatient observation
  • Hospitalization generally not necessary unless victim has underlying immunocompromise, trauma, chronic illness, etc., that predispose to a worse outcome.
  • From end of prodrome through day 21-35
  • None
Medical response
  • Hospitalization generally not necessary.
  • Post-event monitoring may be assisted by laboratory tests that estimate dose, e.g., sequential CBCs and dicentric chromosomes.
  • > 30 days after prodrome
  • Depends on dose and underlying host factors
Possible clinical effects
  • Fatigue
  • Weakness
  • None likely from radiation alone
Medical response
  • As needed for signs/symptoms
  • Counseling and long-term effects monitoring may be helpful
  • Expected unless complicated by trauma or chronic illness
  • Counseling and long-term effects monitoring may be helpful and is critical for pregnant victims.
  • Psychological support helpful