Abstract
As the number of patients who are dying during the treatment in the intensive care unit (ICU) and coronary care unit (CCU) is increasing nowadays, definite criteria of the post-mortem examination should be established. This is particularly urgent for pulmonary changes. The patients who died in the ICU and CCU cannot be regarded as identical with those who succumbed to shock, since the main cause of death and clinical course are quite variable. Although uniformity of lung change cannot be expected in those who died in the ICU and CCU unlike in the case of shock, the author made critical evaluation of the histopathological features of the lung change in comparison with those in shock.
Careful investigation of the lung of those who died in the ICU and CCU, most of whom were suffering from myocardial infarction, various other heart diseases or cerebrovascular accidents, revealed hyperemia and luminal dilatation in the pulmonary arterial trees, which are morphological evidence of the angioparesis type in the lung circulation. The most striking or acute cases revealed diffuse stasis which involved the pulmonary arterial, venous and capillary trees in their entirety. In protracted cases, however, the change was mostly in the pulmonary arterial and venous trees. Another outstanding feature was hemolysis in the vascular lumen, which was found in most of the patients. Microthrombi and increased intra-vascular coagulation were also discernible. In those who died during early stages of treatment, no definite change was observed in the intra-alveolar space. In protracted cases, however, in addition to the intra-vascular alteration, intra-alveolar changes such as hemorrhage, perivascular edema and desquamation of alveolar cells were observable. The hyline membrane disease which is considered to be the most fatal complication of the lung was observed in 12% of the patients, indicating that this is also the most important complication in the ICU and CCU. Pulmonary edema and bronchopneumonia were frequently observed in the majority of the cases, but the changes appeared not to have been fatal. This suggests that medical care and monitoring in the ICU and CCU were quite appropreate. Pulmonary fibrosis which results from protracted shock lung was not frequently observed. Only three patients revealed this change in the present study. Edema in the peribronchial space and in the interstitial space of the lung also remained less important. Even in those who had such changes, no significant edematous involvement was observed in the alveolar wall. These findings also testify that appropreateness of medical care and monitoring in the ICU and CCU exerted favorable effects for the survival of the patients from the severe lung complication.
