ACUTE RADIATION EFFECTS ON MAN
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Recently, Thoma & Wald (1959) have tried to make a broader com-
parison of the blood counts in persons accidentally exposed to radiation.
They attempted to reduce various parameters, such as the white cell count,
platelet count, haematocrit, etc., to a common denominator by assigning
“score values” to deviations from the normal. In this way, they arrived at
“profiles of injury”, on the basis of which five groups at different exposure
levels (less than 150, 240-365, 400-600, 640-1350, and 9200 rad) could be
differentiated quite well within 6 days after exposure. Even if only the
cumulative scores for total white count are plotted, by day 6 patients who
received more than 400 rad can be reasonably well distinguished from those
who received less.
Treatment of the Haemopoietic Syndrome
The treatment of a patient with the haemopoietic syndrome after
exposure to ionizing radiation presents the same problems as the management of any other patient with pancytopenia. However, the irradiated
patient presents the additional challenge that the aplastic state of the bone
marrow may be reversible.
Thus, if the patient can be carried through the
critical period, he will recover, in contrast to many cases of idiopathic or
drug-induced bone marrow aplasia.
Sorensen et al. (1960) have studied the efficacy of a flexible and individually adjusted conventional replacement therapy in dogs subjected to wholebody irradiation. Twenty mongrel dogs ranging in weight from 23 lb. to
59 lb. were used. The animals had been dewormed, vaccinated against
canine distemper and infectious canine hepatitis, and held for observation
for at least six weeks before irradiation. Animals were divided into pairs
on the basis of similarity in size, weight, age and breed. Of each pair, one
dog was placed in the control group and one in the therapy group and both
were irradiated on the same day, using a 250 kVp X-ray therapy unit.
The
dose rate was approximately 27 r per minute and the total dose for each
animal was 400 r, measured asthe dosein air at the proximal skin surface in
the centre of the field. Phantom measurements showed that the midline
tissue dose was about 75 % ofthe air dose at the proximal skin surface. All
animals were given a physical examination daily and blood counts were done
at regular intervals.
Therapy in the treatment group consisted of anti-
biotics, transfusions and fluids.
Antibiotic therapy with oxytetracycline was initiated as soon as an
animal developed fever, and was continued after the fever had subsided.
When in spite of this treatment the temperature again went up, usually
3-5 days later, the animals were put on penicillin and streptomycin. When
this was no longereffective in controlling the infection, the dogs were switched
to tetracycline. Erythromycin wasalso used occasionally. The doses were
significantly higher than ordinarily used in clinical medicine.