Question

Whether a child died after a normal birth or died before birth can be confirmed
(a) The weight of the child
(b) The dead space air
(c) The tidal volume of air
(d) Residual volume of air

Answer 1

Hint: If the child died after birth, respiration must have occurred even for a short period but if the child died before birth, there will be no shreds of evidence of respiration.

Complete answer:
There is a test known as the hydrostatic or floatation test in which the concept of residual volume is used to determine if a child has breathed or inhaled air or not. This determination is useful in finding if a child has died before birth or after birth because if the child died after birth, respiration must have occurred even for a short period but if a child died before birth, there will be no pieces of evidence of respiration. In this test, the lungs of the dead child are placed in water after closing the orifices by ligatures. If the lungs float in water, this means that the residual volume of air is present in the lungs and this implies that the lungs have undergone respiration. Based on this fact, it is determined that the child has breathed and thus died after a normal birth.
So, the correct answer is ‘Residual volume of air’.

Note: The hydrostatic test is used in forensic investigations in the cases of suspected infant deaths. The test uses the concept of residual volume because this is the volume of air that is present in the lungs even after a full exhalation and it causes the buoyancy of lungs in the water.