严重烧伤病人肺脏损害及其类型探讨

本文观测了57例严重烧伤病人血气及肺功能衰竭死亡病人肺脏的病理形态变化,根据不同的临床情况进行分析比较。结果发现,伤后可很快出现低氧血症,A-aDO_2增大,低碳酸血症和代谢性酸中毒。烧伤面积越大,PaO_2下降幅度越大,合并中、重度吸入性损伤、重度休克和全身性感染的病人,PaO_2下降幅度均大于相应对照病人。肺功能衰竭死亡病人肺部有充血、出血、水肿,小血管内血栓形成,间质炎细胞浸润,血管和支气管周围水肿套形成,细支气管腔内炎性分泌物积聚和出血等改变。本文结果提示,大面积烧伤、吸入性损伤、重度休克和全身性感染是烧伤后肺脏损害的主要发病因素,以吸入性损伤所致肺功能衰竭发生率最高。根据16例肺功能衰竭发生和发展的临床过程,本文提出将其分为3种类型:①早发型(占37.5％),发生于烧伤休克期。重度吸入性损伤对怖的直接损害是其主要原因;②迟发型(占50.0％),类似ARDS,发生于急性感染期。重度休克和早期全身性感染是其主要发病因素;③晚发型(占12.5％),发生于创面修复期和康复期。长时间严重低蛋白血症,营养不良和感染,或长时间卧床致血栓形成引起肺栓塞是其主要原因。这对于在烧伤病程的不同阶段有针对性地防治和减少肺功能衰竭,有重要的临床意义。

Respiratory Insufficiency and Its Classification in Patients with Severe Burns

Blood gases and pathological changes of lung tissues from patients dying of respiratory failure were observed. The results demonstrated that hypoxemia, hypocapnia, enlarging of A-DO2 and metabolic acidosis occurred soon after severe burns. The severity of falling of PaO2 was positively accorded with burn size (TBSA) . In patients complicated with moderate and severe inhalation injury, severe shock and systemic infections, the reduction of PaO2 was much more pronounced than in those without the above mentioned complications. The failed lung tissues showed congestion, hemorrhage, edema and thrombosis. These findings suggested that besides the severity of burns itself, inhalation injury, severe shock and systemic infections were the main etiological factors invoking postburn lung damage, and the inhalation injury ranked the first. Of the 57 patients 16 developed respiratory failure.The postburn respiratory failure could be classified into three patterns: 1 ).Early pattern, 6 cases (37.5%) , occurring during shock stage. Severe inhalation injury was the main cause) 2). Delayed pattern, 8 cases (50.0%) , developing during acute infection stage of the burn course. Clinical course of this pattern simulated to that of ARDS and the main etiological factors included severe shock and early systemic infections; and 3) .Late pattern, 2 cases (12.5%), occurring during wound healing and rehabilitation ages. The reasons chiefly included severe hypoproteinemia, malnutrition, infect and pulmonary embolism due to thrombosis of inferior vena cera or feora vein.