Water loss by evaporation from the abdominal cavity during surgery.

During abdominal surgery of different degrees of severity the evaporative water loss from wounds and exteriorized bowels was measured by recording the rate of vapour concentration increase in a closed measuring chamber placed over the exposed abdominal cavity. In an animal experiment on 4 rabbits the excessive evaporation of water from exteriorized bowels (15 g/h) gradually decreased and stabilized at approximately 50% of the initial value after 20 min of exposure. In surgical patients the loss by evaporation from a minor incision with only slightly exposed viscera was only 2.1 +/- 0.5 g/h, while moderate incisions with partly exposed but non-exteriorized intestines showed a loss of 8.0 +/- 1.0 g/h. During major exposure with exteriorized bowels a profuse evaporation of 32.2 +/-2.9 g/h was recorded. This evaporation constitutes an additional water loss of a magnitude exceeding the total cutaneous perspiration of healthy adults at rest. Simultaneously the surface temperature of exposed bowels fell by 3.5 degrees C. The evaporative water loss from abdominal exposures is of clinical importance only in time-consuming procedures comprising exposure and exteriorization of the intestines.