Pediatric emergency medicine trisk 1980 1980
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TABLE 90.13
DOSE–EFFECT RELATIONSHIP AFTER ACUTE WHOLE-BODY
RADIATION EXPOSURE
Whole-body
absorbed dose
(Gy)
Comments
0.1
Asymptomatic (minimal detectable dose using
cytogenetics)
Asymptomatic (minor depression of white blood cell and
platelets)
Nausea and vomiting in approximately 15% of patients
within 2 days of exposure
0.5
1
2
4
6
Nausea and vomiting in most patients
Nausea, vomiting, and diarrhea within 48 hrs; severe
hematologic depression; 50% mortality without medical
treatment
100% mortality within 30 days without medical treatment;
50% mortality with medical treatment
7
Gastrointestinal syndrome; survival unlikely; death in 2–3
wks
50
Cardiovascular/Neurovascular syndrome; death in 24–72
hrs
With doses of 2 to 4 Gy, the primary effect of whole-body radiation is to
depress the bone marrow. Although the absolute lymphocyte count ( Fig. 90.12 )
decreases rapidly within the first 24 hours, there is no need for specific medical
treatment. The patient will be at greatest risk 3 to 4 weeks after the radiation
exposure when the total white blood cell, neutrophil, and platelet counts reach a
nadir ( Fig. 90.13 ). At this time, the patient is vulnerable to death from infection
and bleeding. If the patient can be supported during this period of vulnerability
and if the bone marrow is not irreversibly damaged, a recovery phase ensues.
The gastrointestinal syndrome occurs from absorbed doses of more than
approximately 7 Gy. During the prodromal phase there is prompt onset of severe
nausea, vomiting, and diarrhea. There is a latent period of approximately 1 week
and then recurrence of GI symptoms, sepsis, electrolyte imbalance, and likely
