摘要糖尿病酮症酸中毒（diabetic ketoacidosis，DKA）是糖尿病严重的急性并发症之一，以高血糖、酮症、酸中毒为主要表现，是胰岛素不足和拮抗胰岛素激素增加所致的代谢紊乱综合征。2型糖尿病并发酮症酸中毒相对少见，而在糖尿病酮症酸中毒中继发纵隔气肿则非常罕见。肺泡破裂后到达肺门的气体可沿不同的路径形成前纵隔、中纵隔、后纵隔的气肿，甚至形成颅内硬膜外积气。纵隔气肿的诊断主要依靠胸部电子计算机断层扫描。在纠正DKA后，纵隔气肿一般在5~10 d自行吸收，预后良好。四川省甘孜藏族自治州德格县人民医院收治的1例DKA患者出现Kussmaul呼吸后，肺泡内压力增大、肺泡内外压力差增大、肺泡壁蛋白质被分解，这些因素促使肺泡破裂形成纵隔气肿；经过快速补液、胰岛素控制血糖、维持酸碱平衡等治疗后，纵隔气肿自行吸收，根据排他性诊断，可明确DKA继发纵隔气肿。通过对该病例临床资料的分析，旨在提高临床医师对纵隔气肿与DKA之间的内在的认识，避免过度检查、过度治疗，为正确的诊治提供策略。

abstractsDiabetic ketoacidosis (DKA), a serious acute complication of diabetes mellitus, mainly manifests as hyperglycemia, ketosis, and acidosis. It is a metabolic syndrome resulting from insulin deficiency and increased insulin-antagonistic hormone levels. While type 2 diabetes mellitus complicated by DKA is relatively uncommon, secondary pneumomediastinum in DKA is extremely rare. Following alveolar rupture, air can travel through various routes to reach the hilum, causing anterior, middle, or posterior pneumomediastinum or even leading to intracranial epidural pneumatosis. The diagnosis of pneumomediastinum is mainly dependent on chest computed tomography findings. After the successful treatment of DKA, pneumomediastinum usually resolves spontaneously within 5-10 days with a good prognosis. One DKA patient admitted to Dege County People's Hospital developed Kussmaul respirations, followed by an increase in intra-alveolar pressure, an elevation in intra and extra-alveolar pressure difference, and protein decomposition in the alveolus wall, which promoted alveolar rupture and induced mediastinal emphysema. After rapid fluid replacement, blood glucose control with insulin, and maintenance of acid-base balance (correction DKA), the mediastinal emphysema was spontaneously absorbed. Through the analysis of the clinical data of this case, the purpose is to improve the clinicians' internal understanding of the relationship between mediastinal emphysema and DKA, avoid over-examination and over-treatment, and provide strategies for correct diagnosis and treatment.