Ignaz Semmelweis - Discovery of Cadaverous Poisoning

Discovery of Cadaverous Poisoning

Semmelweis was appointed assistant to Professor Johann Klein in the First Obstetrical Clinic of the Vienna General Hospital on July 1, 1846. A comparable position today in a US hospital would be "chief resident." His duties were to examine patients each morning in preparation for the professor's rounds, supervise difficult deliveries, teach students of obstetrics and be 'clerk' of records.

Maternity institutions were set up all over Europe to address problems of infanticide of illegitimate children. They were set up as gratis institutions and offered to care for the infants, which made them attractive to underprivileged women, including prostitutes. In return for the free services, the women would be subjects for the training of doctors and midwives. There were two maternity clinics at the Viennese hospital. The First Clinic had an average maternal mortality rate due to puerperal fever of about 10% (actual rates fluctuated wildly). The Second Clinic's rate was considerably lower, averaging less than 4%. This fact was known outside the hospital. The two clinics admitted on alternate days but women begged to be admitted to the Second Clinic, due to the bad reputation of the First Clinic. Semmelweis described desperate women begging on their knees not to be admitted to the First Clinic. Some women even preferred to give birth in the streets, pretending to have given sudden birth en route to the hospital (a practice known as street births), which meant they would still qualify for the child care benefits without having been admitted to the clinic. Semmelweis was puzzled that puerperal fever was rare among women giving street births. "To me, it appeared logical that patients who experienced street births would become ill at least as frequently as those who delivered in the clinic. What protected those who delivered outside the clinic from these destructive unknown endemic influences?"

Semmelweis was severely troubled that his First Clinic had a much higher mortality rate due to puerperal fever than the Second Clinic. It "made me so miserable that life seemed worthless". The two clinics used almost the same techniques, and Semmelweis started a meticulous process of eliminating all possible differences, including even religious practices. The only major difference was the individuals who worked there. The First Clinic was the teaching service for medical students, while the Second Clinic had been selected in 1841 for the instruction of midwives only.

He excluded "overcrowding" as a cause, since the Second Clinic was always more crowded and yet the mortality was lower. He eliminated climate as a cause because the climate was the same. The breakthrough occurred in 1847, following the death of his good friend Jakob Kolletschka, who had been accidentally poked with a student's scalpel while performing a postmortem examination. Kolletschka's own autopsy showed a pathology similar to that of the women who were dying from puerperal fever. Semmelweis immediately proposed a connection between cadaveric contamination and puerperal fever.

He concluded that he and the medical students carried "cadaverous particles" on their hands from the autopsy room to the patients they examined in the First Obstetrical Clinic. This explained why the student midwives in the Second Clinic, who were not engaged in autopsies and had no contact with corpses, saw a much lower mortality rate.

The germ theory of disease had not yet been developed. Thus, Semmelweis concluded some unknown "cadaverous material" caused childbed fever. He instituted a policy of using a solution of chlorinated lime (modern calcium hypochlorite, the compound used in today's common household chlorine bleach solution) for washing hands between autopsy work and the examination of patients. He did this because he found that this chlorinated solution worked best to remove the putrid smell of infected autopsy tissue, and thus perhaps destroying the causal "poisonous" or contaminating "cadaveric" agent hypothetically being transmitted by this material.

The result was that the mortality rate in the First Clinic dropped 90%, and was then comparable to that in the Second Clinic. The mortality rate in April 1847 was 18.3%. After hand washing was instituted in mid-May, the rates in June were 2.2%, July 1.2%, August 1.9% and, for the first time since the introduction of anatomical orientation, the death rate was zero in two months in the year following this discovery.