[The role of haptoglobin in asphyxia mechanism (II)--Acute drowning and hanging].

We examined changes in plasma during drowning and hanging to determine the mechanism of acute asphyxia. Rabbits were used for the acute drowning and hanging experiments (using artificial sea water or fresh water for the former and complete or incomplete hanging for the latter). The plasma was examined for changes in haptoglobin and total protein contents. For acute drowning, the haptoglobin level reduced dramatically after one minute of inhalation of artificial sea and fresh water by about 46.0% and about 61.0%, respectively. Total protein content showed the same pattern of reduction. Afterward, haptoglobin remained generally unchanged but the total protein content returned to the original level 3 minutes after inhalation. For the handing, the haptoglobin level reduced within 1 minute. When respiratory arrest was near, both haptoglobin and total protein contents rose gradually. The changes in the haptoglobin level caused by hanging were similar to those that occur in acute asphxia when the air passage is completely obstructed and in subacute asphxia when the air passage is strangulated. Totally different and unique patterns were seen in association with drowning in comparison with obstructive asphyxia. These results suggested that the pathological physiology of acute drowning is different from that of fatal neck compression or other types of acute asphyxia.