Pediatric emergency medicine trisk 1982 1982
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FIGURE 90.12 Effect of whole-body radiation on lymphocytes in the first 2 days after
exposure.
Estimating the whole-body radiation dose may be difficult, especially when
complicated by injuries that are not due to radiation. The signs and symptoms
during the prodromal period are quite nonspecific except for a rapidly decreasing
lymphocyte count. Nausea and vomiting are sensitive but nonspecific symptoms.
Patients who do not have nausea and vomiting are unlikely to have been exposed
to a radiation dose that is large enough to cause acute radiation syndrome.
However, individuals may have nausea and vomiting for reasons other than
exposure to radiation. The whole-body radiation dose from radiation accidents is
rarely uniform. The nonuniform nature of the radiation dose makes it more
difficult to predict the biologic effects from the exposure. Chromosome analysis
(cytogenetic dosimetry) may be helpful in estimating the radiation dose, but the
results may not be available for about 1 week.
The second type of radiation exposure that can occur is local exposure, which
involves a radiation dose to a small part of the body. Large doses can be tolerated
if only a small part of the body is exposed. Local radiation injuries may cause
bone marrow depression if accompanied by a significant whole-body radiation
