No abstract

Dogs were submitted to one of three hemorrhagic shock procedures: normovolemic shock, oligemic hypotension or posthemorrhagic hypotension. 13 animals fulfilled well-defined criteria of irreversible hemorrhagic shock, based on mortality, take-up volume and metabolic changes. Lung function was measured at regular intervals. Lungs were fixed by infusion fixation. The macroscopical aspect of the lungs was not different from that of six control dogs which were anesthetized for the same period. Minor microscopical changes were found, but the only histological parameter which was significantly different from the controls was accumulation of granulocytes. Gas exchange remained normal, ventilation was increased with an enlarged dead space and veno-arterial shunting was reduced. Pulmonary vascular resistance was not different from the control group.

During the immediate postoperative course after upper abdominal surgery, pulmonary complications often occur, caused, inter alia, by reduced regional ventilation and by atelectases as a result of: (1) narrowing of the small peripheral bronchi, and (2) impaired respiratory function. Based on these pathophysiological mechanisms, an instrument (Bartlett-Edwards Incentive Spirometer) has been devised, which aims at giving the patient an opportunity of sustained maximal inspiration under standardized and controlled conditions. The use of this instrument has been followed by reports of a considerable reduction in postoperative pulmonary complications. In a controlled clinical investigation of the pre- and postoperative condition of the lungs, we were unable to show any beneficial effect of the instrument. In general, we have a low frequency of severe postoperative pulmonary complications, as compared with the results reported in the literature. We ascribe this to our very effective pre- and postoperative respiratory therapy.

No abstract