Radiation injury after a nuclear detonation: medical consequences and the need for scarce resources allocation

Abstract

A 10-kiloton (kT) nuclear detonation within a US city could expose hundreds of thousands of people to radiation. The Scarce Resources for a Nuclear Detonation Project was undertaken to guide community planning and response in the aftermath of a nuclear detonation, when demand will greatly exceed available resources. This article reviews the pertinent literature on radiation injuries from human exposures and animal models to provide a foundation for the triage and management approaches outlined in this special issue. Whole-body doses >2 Gy can produce clinically significant acute radiation syndrome (ARS), which classically involves the hematologic, gastrointestinal, cutaneous, and cardiovascular/central nervous systems. The severity and presentation of ARS are affected by several factors, including radiation dose and dose rate, interindividual variability in radiation response, type of radiation (eg, gamma alone, gamma plus neutrons), partial-body shielding, and possibly age, sex, and certain preexisting medical conditions. The combination of radiation with trauma, burns, or both (ie, combined injury) confers a worse prognosis than the same dose of radiation alone. Supportive care measures, including fluid support, antibiotics, and possibly myeloid cytokines (eg, granulocyte colony-stimulating factor), can improve the prognosis for some irradiated casualties. Finally, expert guidance and surge capacity for casualties with ARS are available from the Radiation Emergency Medical Management Web site and the Radiation Injury Treatment Network.

FIGURE 1

Approximate prompt radiation and fallout pattern from a 10-kT nuclear detonation Prompt radiation extends approximately 1 mile from the epicenter, while the shape of the fallout zone is determined by upper-level winds. (Buddemeier 2009.)

FIGURE 2

Hypothetical representation of resource availability (left y-axis) after a nuclear detonation based on location and type of site The operative standard of care (right y-axis) follows the definitions outlined by the Institute of Medicine. Centers close to the site would be immediately impacted and require crisis standards of care. RTR1 (Radiation TReatment, TRiage, and TRansport) sites will be established close to the epicenter shortly after the event and may be disbanded after a few days, as salvageable victims are evacuated. Distance from the detonation will be the primary determinant of timing and severity of resource shortages at regional medical centers (MC). Even referral centers in other regions may experience abrupt resource shortages due to patient transfers or depletion of nationwide supplies.

FIGURE 3

Simplified time courses for hematologic, gastrointestinal (GI) and central nervous system (CNS) symptoms at different whole-body dose exposures The relative severity of signs and symptoms is on an arbitrary scale. (Modified from Waselenko).

FIGURE 4

Leukocyte counts based on exposure dose in patients exposed to radiation in Chernobyl Note that doses less than 5 Gy are associated with an early abortive rise (transient increase) in leukocytes, which are primarily composed of granulocytes. The onset of neutropenia may not occur for weeks, especially with lower exposures, and the duration of neutropenia may be prolonged. (Modified from Vorobiev 1997.)

FIGURE 5

C3H/H3N female mice were exposed to radiation alone or radiation in addition to a non-lethal wound (combined injury) The combination increased mortality at all doses, but mortality was reduced by applying topical gentamicin or silvadene. (Modified from Ledney.)