THE THERAPEUTIC VALUE OF BLOODLETTING IN A CHILD SUFFERING FROM SEVERE COMPLICATIONS OF POSTSCARLATINA GLOMERULONEPHRITIS IN 1897: THE FALLACY OF POST HOC, ERGO PROPTER HOC REASONING

Abstract

Bloodletting until as late as the end of the 19th century was falsely considered by many physicians to have a curative effect on poststreptococcal glomerulonephritis in children because few, if any, i9th century physicians were aware that this form of acute glomerulonephritis has a very favorable prognosis, irrespective of its initial severity. An excellent example of the fallacy of post hoc, ergo propter hoc reasoning is the following case history, published in 1897. A boy, 8 years old, well developed, was affected with a mild form of scarlatina. The disease had about abated when a grave nephritis supervened. The eyelids were edematous; the urine contained about 1 per cent albumin and showed, microscopically, white and red blood-cells, renal epithelia and numerous granular casts. The heart was normal, the pulse 96 per minute; the general condition, which was fair at the onset, became worse. Without somnolence or other distinct premonitory symptoms uremia supervened suddenly, with four rapidly succeeding convulsive attacks, one of which lasted about half an hour and affected particularly the right half of the body. Chloroform inhalations caused momentary relief but did not prevent repetition of the convulsive attacks, which ensued with greater frequency and intensity. The child was apparently moribund. As the pulse was still strong, however, venesection was resorted to, though very little hope was held out for recovery. About 100 cc. of blood were withdrawn from the right median cephalic vein. The result was more striking than any the observer had ever noticed following therapeutic intervention.