目的　探讨婴幼儿重症百日咳死亡相关因素。方法　回顾分析2015年1月1日至2019年10月31日收治的 婴幼儿百日咳25例病死病例（死亡组）及80例同期收治的重症存活病例（存活组）的临床资料。结果　死亡组男性5例 （20.0%），中位发病日龄77天，20例（80.0%）未接种百日咳疫苗；存活组男性47例（58.8%），中位发病日龄83天，63例（78.8%） 未接种疫苗。与存活组相比，死亡组男性少、痉挛性咳嗽发生率低、肺实变（或肺不张）发生率高、外周血白细胞（WBC）增 多更显著、肺动脉高压发生率高、使用丙种球蛋白比例低，差异均有统计学意义（P<0.05）。 多元logistic回归分析发现，男 性、使用丙种球蛋白（OR=0.03、0.03）为重症百日咳死亡的保护因素，WBC最高值高、肺动脉高压（OR=1.10、13.31）为 死亡的危险因素，有痉挛性咳嗽患儿死亡概率更小（OR=0.02）。 预测死亡的WBC最高值的最佳临界值为55.37×109/L， AUC=0.83（95%CI：0.73~0.93） P<0.001。结论　未接种疫苗、高WBC血症、肺动脉高压明显增加婴幼儿重症百日咳的 病死率，使用丙种球蛋白、早期换血减轻高WBC血症可能改善其预后，慎用激素。

Objective　To explore the risk factors of death in severe pertussis in infants. Methods　The clinical data of pertussis in infants including 25 dead cases (death group) and 80 severe cases (survival group) admitted from January 1, 2015 to October 31, 2019 were analyzed retrospectively. Results　In the death group, there were 5 males (20%), median onset age was 77 days and 20 patients (80%) had not received pertussis vaccine. The survival group had 47 males (58.8%, median onset age was 83 days and 63 patients (78.8%) had not been vaccinated. Compared with the survival group, the death group had fewer males, lower incidence of spasmodic cough, higher incidence of pulmonary consolidation (or atelectasis), more significantly increased peripheral white blood cell count (WBC), higher incidence of pulmonary hypertension, and lower proportion of gamma globulin usage, and the differences were statistically significant (P<0.05). Multivariate logistic regression analysis found that males and gamma globulin usage were the protective factors for the death in severe pertussis (OR=0.03, 0.03), the highest WBC and pulmonary hypertension were the risk factors for death (OR= 1.10, 13.31), and the death rate of children with spastic cough was lower (OR= 0.02). The optimal cut-off value of the highest WBC for predicting death is 55.37 × 109/L, and the area under curve (AUC) was 0.83 (95% CI: 0.73~0.93, P<0.001). Conclusions　Unvaccinated, hyperleucaemia and pulmonary hypertension significantly increased the mortality of severe pertussis in infants. The use of gamma globulin and early blood exchange may improve the prognosis of hyperleukaemia. Use hormones with caution.