Medical manual of chemical warfare, 1943 / War Office.

  • Great Britain. War Office.
Date:
1943
Catalogue details

Licence: Public Domain Mark

Credit: Medical manual of chemical warfare, 1943 / War Office. Source: Wellcome Collection.

    42/100 (page 42)
    partly converted by the liver into bile pigments which are formed in excessive amounts and give rise to jaundice. Hzeemolysis may continue for several days after exposure to the gas and anemia is therefore progressive. While hemolysis is taking place a simple estimation of the hemoglobin percentage in the whole blood will give an erroneous idea of the extent of red cell destruction since much of the hemoglobin may be in solution in the plasma and not in the corpuscles. A red cell count will make the situation clear. In the absence of a centrifuge, hemolysis may be recognized by making equal dilutions of the patient’s blood and of normal blood and comparing the supernatant fluids after sedimentation. The following technique is con- venient :— Prick the finger of the patient and allow three drops of his blood to fall into twelve drops of 3-8 per cent. sodium citrate solution in a watch glass oer small tube. Mix well and draw up the mixture into a glass tube of length 20 cm. and internal bore 2-3 mm., the end of which has been slightly tapered, as for a pipette. Close the lower end of the tube with a short length of narrow rubber tubing that has been stoppered with a piece of glass rod or clipped. Prepare a precisely similar tube with the blood of a normal person to serve as a control. Stand both tubes vertical for half an hour or longer so that the corpuscles may sediment. If there is any hemolysis in the suspected blood it will be shown by the tint of the supernatant fluid when compared with that of the control. Even in the early stages of poisoning there is evidence of increasing damage of the kidneys, liver and spleen, and these organs are intensely congested. This is soon followed by tubular degeneration in the kidneys, with excretion of blood casts and toxic degeneration and necrosis of the liver. With incipient recovery the excretion of blood pigments ceases, though albuminuria may continue for a considerable time; the blood count reaches a minimum value which may be well below 2 million red cells per cubic millimetre ; blood regeneration is manifested by poikilocytosis and anisocytosis as well as by the appearance of nucleated red corpuscles and reticulocytes; and the damage to the kidney and liver is slowly repaired. When hemoglobinuria is very severe there is some risk that actual blood clots may form in the bladder. Death in the most severe cases may take place within 48 hours of exposure and may be preceded by complete anuria. Although it has been suggested that such anuria is caused by blockage of the capillaries of the kidney by the debris of red cells, and of the tubules by cellular debris and casts, it is more probably attributable to acute arsenical poisoning of the kidney, coupled with a failing circulation, and rapid death must be attributed as much to the poison- ous effects of arsenic on the organs of the body as to the results of acute blood destruction. 53. Treatment. (1) Blood transfusion is indicated whenever severe anemia is shown either clinically, by percentage of hemoglobin, or by the number of red cells, and certainly if the haemoglobin falls to 60 per cent. or the red cells to 4,000,000 perc.mm. The risk of hemolysis of the transfused blood by the gas is appar- ently slight after an interval of two to three hours aiter exposure. Trans- fusion may need to be repeated since hemolysis may continue for several days. For a single transfusion 500 c.cm. is an advisable quantity. Owing to the general toxic effect of the gas the destruction of red cells which it causes cannot be regarded in the same light as the loss of an equal quantity of blood by a simple hemorrhage, and transfusion should, therefore, be done slowly, careful observation being kept on the general circulation and the blood pressure, lest over-filling of the circulation should damage a heart already poisoned.