Objective: To clarify the clinical characteristics of influenza pneumonia in the elderly patients and the relationship between D-dimer and the severity of influenza pneumonia.
Methods: In the study, 52 hospitalized patients older than 65 years with confirmed influenza pneumonia diagnosed in Peking University People's Hospital on 5 consecutive influenza seasons from 2014 were retrospectively analyzed. General information, clinical symptoms, laboratory data, treatment methods and prognosis of the patients were collected. The relationship between D-dimer and pneumonia severity was analyzed, and receiver operating characteristic (ROC) curve was used to evaluate the predictive value of D-dimer.
Results: Among the 52 patients, 31 were male (31/52, 59.6%), the average age was (77.1±7.4) years, and 19 of them (36.5%) were diagnosed with severe pneumonia. About 70% patients presenting with fever. In the severe group, the patients were more likely to complain of dyspnea than in the non-severe group (14/19, 73.7% vs. 10/33, 30.3%, P=0.004), severe pneumonia group had higher level of CURB-65 (confusion, urea, respiratory rate, blood pressure, and age>65), pneumonia severity index (PSI), C-reactive protein, urea nitrogen, lactate dehydrogenase, fasting glucose, and D-dimer (P value was 0.004, < 0.001, < 0.001, 0.003, 0.038, 0.018, and < 0.001, respectively), albumin was lower than that in the non-severe group [(35.8±5.6) g/L vs. (38.9±3.5) g/L, t=-2.348, P=0.018]. There was a significant positive correlation between the D-dimer at the first admission and PSI score (r=0.540, 95%CI: 0.302 to 0.714, P < 0.001), while a significant negative correlation with PaO2/FiO2 (r=-0.559, 95%CI: -0.726 to -0.330, P < 0.001). Area under the curve of D-dimer was 0.765 (95%CI: 0.627 to 0.872). Area under the curve of PSI was 0.843 (95%CI: 0.716 to 0.929). There was no statistically significant difference in test efficacy between the two (Z=2.360, P=0.174). D-dimer level over 1 225 μg/L had a positive predict value for influenza pneumonia in hospital death with a sensitivity of 76.92% and a specificity of 74.36%.
Conclusion: Influenza pneumonia in the elderly always has atypical symptoms, dyspnea is a prominent feature in severe cases, D-dimer level is associated with the severity of influenza pneumonia, and greater than 1 200 μg/L has a good predictive value for in-hospital death in the elderly.
目的: 研究老年流感肺炎的临床特征以及D-二聚体与流感肺炎严重程度的相关性，以期提高临床医生对此类肺炎的甄别和管理。
方法: 回顾性收集2014年起连续5个流感季(当年10月1日至次年3月31日)于北京大学人民医院诊断为流感肺炎的住院患者，年龄>65岁，收集患者的一般资料、临床症状、实验室检查、治疗方式及预后，比较重症和非重症肺炎的临床特点，分析D-二聚体与肺炎严重程度的关系，并应用受试者工作特征(receiver operating characteristic, ROC)曲线评估其预测流感肺炎死亡的效能。
结果: 共纳入实验室确诊的老年流感肺炎住院患者52例，男性31例(59.6%)，平均年龄(77.1±7.4)岁，符合重症肺炎诊断标准者19例(36.5%)，约70%病例出现不同程度发热，重症肺炎组与非重症肺炎组相比，呼吸困难的发生率差异有统计学意义(14/19例，73.7% vs. 10/33例，30.3%，P=0.004)，重症肺炎组的CURB-65(confusion, urea, respiratory rate, blood pressure, and age>65)评分、肺炎严重度指数(pneumonia severity index, PSI)评分、C反应蛋白、乳酸脱氢酶、尿素氮、空腹血糖、D-二聚体均高于非重症肺炎组，两组间差异有统计学意义(P值分别为0.004、< 0.001、< 0.001、0.003、0.038、0.018、< 0.001)，重症肺炎组的白蛋白则低于非重症肺炎组[(35.8±5.6) g/L vs. (38.9±3.5) g/L, t=-2.348，P=0.018]。入院首次检测的D-二聚体与PSI评分呈显著正相关(r=0.540, 95%CI: 0.302~0.714，P < 0.001)，与氧合指数呈显著负相关(r=-0.559, 95%CI: -0.726~-0.330，P < 0.001)。以患者是否住院期间死亡绘制ROC曲线，D-二聚体曲线下面积为0.765(95%CI: 0.627~0.872)，PSI曲线下面积为0.843(95%CI: 0.716~0.929)，二者相比，检验效能差异无统计学意义(Z=2.360，P=0.174)。D-二聚体>1 225 μg/L预测流感肺炎住院期间死亡的敏感性为76.92%，特异性为74.36%。
结论: 高龄老年流感肺炎患者的发热症状不典型，呼吸困难是重症肺炎的突出表现，D-二聚体升高与老年流感肺炎严重程度相关，D-二聚体>1 200 μg/L对于老年重症流感肺炎住院期间死亡具有较好的预测价值。
Keywords: Aged; D-dimer; Influenza, human; Pneumonia.