先天性心脏病体外循环术后昏迷原因的临床病理分析

Autopsy Study on the Causes of Coma in Cases with Congenital Heart Disease Following Cardiac Surgery after Extracorporeal Circulation

目的 了解体外循环术后昏迷的脑部病理损伤基础 ,探讨昏迷的成因。 方法 回顾 2 6例先天性心脏病术后昏迷的临床与尸检资料 ,分析昏迷类型与颅脑病变的关系及其可能的原因。 结果 颅脑病变以脑水肿和颅内出血多见 ,后者包括硬膜外和硬膜下出血各 3例、蛛网膜下腔出血 4例、脑实质出血 1例 ;脑炎脑膜炎 3例、脑软化 1例。结果显示术后不醒的以脑水肿多见 ,而先清醒后昏迷的则以颅内出血多见。由于手术不彻底、手术创伤和术中大出血等引起的低心排血量或低血压 7例 ,是颅脑病变的主要原因。此外 ,气栓 3例、肺炎 3例和肺外感染 2例、肺动脉高压 2例也参与了颅脑病变的形成。余 9例未能查见直接的临床病理原因 ,但其中 6例体外循环时间较长 ,可能与脑损伤有关。 结论 颅内出血和脑水肿是昏迷的主要形态改变 ,但其成因复杂。体外循环不是脑损伤的唯一因素 ,术前选择好适应证 ,术中减少对心脏的创伤和控制术后感染可降低昏迷的发生和早期死亡。

Objective To observe the morphological changes of brain and to analyze the cause of coma after open-heart surgery in cases suffered from congenital heart disease. Methods Twenty six autopsy cases were collected from Jan. 1973 to Sep. 1999 in Fuwai Hospital. Their duration of coma was 1 day to 40 days and all of them died earlier later following cardiac surgery. Their surgical procedure, extracorporeal circulation time, and other clinical records and autopsy findings were reviewed. Results The brain lesions included intracranial hemorrhages (n=11), cerebral edema (n=11), encephalitis and encephalomingitis (n=3), and cerebromalacia (n=1). Intracranial hemorrhages occurred in epidural (n=3), subdural (n=3), subarachoid spaces (n=4), and intracerebral parenchyma (n=1). The causes of coma were deduced as follows: lower cardiac output (n=7), air embolism (n=3), pneumonia (n=3) and other infections (n=2), pulmonary hypertension (n=2), and the unknown causes of coma (n=9). But the 6 out of the last 9 cases showed longer duration (more than 100 min) of extracorporeal circulation. Intracranial hemorrhages occurred more frequently in cases with waking period than those without after cardiac operation, and vice versa the cerebral edema. Conclusion Intracranial hemorrhage and cerebral edema were the main changes of brain in the patients suffered from coma, but its causes were complex and difficult to analyze. These results suggest that further improved heart preservation, shorter time of extracorporeal circulation and effective treatment of infection would be benefit to the prevention of coma.