Acidosis as one of the delivering factors of alveolar macrophages during suffocation.

When death by suffocation occurs, the histological appearance of the lungs depends on the length of time between the beginning of suffocation and death. In cases of acute asphyxia the histological appearance is restricted to congestion of the capillaries and veins, dispersed scattered foci of bleeding into the alveoli and, occasionally, foci of oedema. In cases of protracted suffocation, because of the longer time-interval between the beginning of suffocation and death, the congestion of capillaries and veins is greater, more haemorrhages in the alveoli are found and more oedema is produced.