On the distubance of gas exchange in the lung in SIDS.Pathological and ultrastructural observation.

对28例新生儿窒息(2月龄~1岁半)、12例窒息(1日龄~岁)和6例溺水儿(4个月~9岁)进行了组织学观察，所有患儿均表现为肺水肿，部分患儿较窒息、溺水患儿表现更为严重。但是，由于有严重肺水肿的小岛屿发展中国家在医院接受了输血，因此不能得出结论，小岛屿发展中国家的肺水肿严重程度明显高于窒息或溺水的病例。研究了由血小板、纤维蛋白和/或白细胞组成的微栓子的发生情况，认为这是窒息的特征表现。通过观察200倍每30个显微镜视野中微栓子的数量来确定微栓子的出现。在小岛屿发展中国家、窒息和溺水中，平均每30个显微镜视野中的微栓子数目分别为5.67&lt；plus-minus&gt；6.65，5.78&lt；plus-minus&gt；3.42和4.8lt；将患儿分为两组：急性胃内容物或乳汁误吸组和非急性误吸组。急性吸入组平均微栓子数为9.86+7.85。未抽吸组为2.02±1.t，对5例SIDS患者进行超微结构观察，并观察肺泡壁水肿情况。为了测量肺泡壁水肿的严重程度，明确肺泡壁的水肿是否干扰了气体交换，用3例3个月至6个月大的SIDs和1例1例1个月大的颅脑外伤作为对照，测量了肺泡上皮表面组织屏障和内皮细胞表面的组织屏障厚度。小儿麻痹症组组织屏障厚度分别为0.61、0.62、0.65微米，对照组为0.63微米。

Histological observation was performed using 28 cases of SIDS (2 months to one and a half years old) , 12 cases of asphyxia ( 1 day to 64 years old) and 6 cases of drowning (4 months to 9 years old) .All SIDS cases showed pulmonary edema and some SIDS cases showed more severe pulmonary edema, compared with that of cases of asphyxia and drowning. But, because SIDS cases showing severe pulmonary edema had received transfusion in hospitals, it was not concluded that severity of pulmonary edema in SIDS cases was significantly higher than that of asphyxia or drowning. Occurrence of microemboli which were composed of plateletes, fibrin and/or white blood cells, and considered as a characteristic finding in asphyxia, were investigated. Occurrence of microemboli was determined by counting of a number of microemboli per 30 microscopic fields by obseving 200 folds. The average numbers of microemboli per 30 microscopic fields in SIDS, asphyxia and drowning were 5.67<plus-minus>6.65,5.78<plus-minus>3.42 and 4.8<plus-minus>1.77, respectivly. SIDS cases were divided into 2 groups ; cases showing acute aspiration of gastric content or milk into the lung and cases without acute aspiration. The average number of microemboli in the group with acute aspiration was 9.86<plus-minus>7.85. On the other hand, that of the group without aspiration was 2.02<plus-mUltrastructural observation was performed using 5 cases of SIDS.Edema in the alveolar walls was observed in all cases. In order to measure severity of edema in the alveolar walls and make it clear if edema in the alveolar wall disturbs gas exchange, thickness of tissue barrier from the surface of the alveolar epithelium from that of endothelial cells, using 3 SIDS cases (3 months to 6 manths old) showing mild postmortem changes and one case of head trauma (one and 3 months old) as a control. The thickness of tissue barrier in SIDS cases were 0.61,0.62, and 0.65 mum, respectively and in the control case was 0.63mum.