The lung float test, also called the hydrostatic test or docimasia, is a controversial

autopsy An autopsy (also referred to as post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of deat ...

procedure used in determining whether

lung The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...

s have undergone

respiration Respiration may refer to: Biology * Cellular respiration, the process in which nutrients are converted into useful energy in a cell ** Anaerobic respiration, cellular respiration without oxygen ** Maintenance respiration, the amount of cellul ...

. It has historically been employed in cases of suspected

infanticide Infanticide (or infant homicide) is the intentional killing of infants or offspring. Infanticide was a widespread practice throughout human history that was mainly used to dispose of unwanted children, its main purpose being the prevention of re ...

to help determine whether or not an infant was

stillborn Stillbirth is typically defined as fetal death at or after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without signs of life. A stillbirth can often result in the feeling of guilt or grief in the mother. T ...

. In the test, lungs that float in water are thought to have been aerated, while those that sink are presumed to indicate an absence of air. The test is not infallible and many factors can cause the test to give false positive or negative results. Decomposition may result in postmortem gas formation, allowing a non-aerated lung to float. During

labor Labour or labor may refer to: * Childbirth, the delivery of a baby * Labour (human activity), or work ** Manual labour, physical work ** Wage labour, a socioeconomic relationship between a worker and an employer ** Organized labour and the labour ...

, air can be introduced to a deceased infant's lungs while moving through the birth canal. Lungs exposed to air do not always float. Große Ostendorf et al. showed the procedure gave a false result in 2% of cases. In a 1997 paper, J.J. Moar emphasises the risk of misdiagnosing live birth, writing that the "majority of new born infants seen at autopsy show signs of varying degrees of decomposition, as they are often found in garbage, wrapped in newspaper or plastic bags, or lying in an open field. Even microscopic putrefaction can cause unexpanded lungs to float, when gas formation may not be macroscopically apparent. Naturally, any attempts at resuscitation may partially expand the lungs of a new born infant, leading to further difficulty in establishing live birth." The difference between the lungs of a foetus and those of an infant was noted by the Ancient Greek physician

Galen Aelius Galenus or Claudius Galenus (; September 129 – AD), often Anglicization, anglicized as Galen () or Galen of Pergamon, was a Ancient Rome, Roman and Greeks, Greek physician, surgeon, and Philosophy, philosopher. Considered to be one o ...

. The lung float test was described in the 1670s by Hungarian botanist Károly Rayger and first performed in 1681. German physician Johannes Schreyer performed a lung float test in 1690. The application of the lung float test to determine breathing and live birth has many spurious medico-legal considerations. In South Africa a foetus must have breathed to be considered a person under the law. Lung float tests are also used by

forensic pathologists Forensic science combines principles of law and science to investigate criminal activity. Through crime scene investigations and laboratory analysis, forensic scientists are able to link suspects to evidence. An example is determining the time and ...

to determine if a subject drowned.

References

{{reflist Forensic pathology Infanticide Lung Medical aspects of death Stillbirth

See also

References