摘要目的:探讨大面积烧伤患者住院期间血红蛋白最低值与预后的关系，从而探寻大面积烧伤患者输血的血红蛋白预警阈值。方法:该研究为回顾性观察性研究。2012年10月—2022年10月，陆军军医大学（第三军医大学）第一附属医院收治288例符合入选标准的大面积烧伤患者，其中男243例、女45例，年龄18~65岁。根据患者最终预后，将患者分为死亡组（54例）和存活组（234例），比较2组患者的性别、年龄、体重指数、烧伤总面积、Ⅲ度烧伤面积、伤后第1次手术时间、第1次手术术前凝血酶原时间（PT）与活化部分凝血活酶时间（APTT）及血红蛋白水平、合并吸入性损伤情况、手术次数、总手术面积、总手术时间、总住院时间、住院期间降钙素原最高值和血小板计数最低值及血红蛋白最低值与脓毒症发生情况等临床资料。根据住院期间血红蛋白最低值，将患者分为<65 g/L组、≥65 g/L且<75 g/L组、≥75 g/L且<85 g/L组、≥85 g/L组，比较4组患者的总住院时间、住院期间病死率与脓毒症发生率、伤后90 d内病死率。利用限制性立方样条模型，在调整协变量前、后，分析大面积烧伤患者住院期间血红蛋白最低值与死亡风险的关系。将住院期间血红蛋白最低值分别作为连续性变量和分类变量，采用logistic回归模型分析调整协变量后大面积烧伤患者住院期间血红蛋白最低值与死亡风险的关系。结果:与存活组比较，死亡组患者的烧伤总面积、Ⅲ度烧伤面积和总手术面积均显著增大，第1次手术术前APTT显著延长，手术次数显著减少，总住院时间显著缩短，住院期间降钙素原最高值显著升高，住院期间血小板计数最低值和血红蛋白最低值显著降低，住院期间脓毒症发生比例显著升高（ Z值分别为-6.72、-5.40、-2.15、-2.99、-2.21、-7.84、-6.23、-7.03、-3.43， χ2=161.95， P值均<0.05）；2组患者其余临床资料比较，差异均无统计学意义（ P>0.05）。按住院期间血红蛋白最低值分组的4组患者的住院期间病死率与脓毒症发生率、伤后90 d内病死率比较，差异均有统计学意义（ χ2值分别为12.12、15.93、10.62， P<0.05）；总住院时间比较，差异无统计学意义（ P>0.05）。限制性立方样条模型分析显示，在调整协变量前、后，大面积烧伤患者住院期间血红蛋白最低值与死亡风险均呈近似线性关系（ χ2值分别为0.81、0.75， P>0.05）。调整协变量后，logistic回归模型分析显示，当将住院期间血红蛋白最低值作为连续性变量分析时，大面积烧伤患者死亡风险随着血红蛋白的降低而升高（比值比为0.96，95%置信区间为0.92~0.99， P<0.05）；当将住院期间的血红蛋白最低值以中位值75.5 g/L为分界值分类时，血红蛋白<75.5 g/L的患者与血红蛋白≥75.5 g/L的患者的死亡风险比较，差异无统计学意义（ P>0.05）；当同前将患者按住院期间血红蛋白最低值分为4组时，以≥85 g/L组为参考，仅<65 g/L组患者的死亡风险显著升高（比值比为5.37，95%置信区间为1.57~18.29， P<0.05）。 结论:大面积烧伤患者住院期间血红蛋白最低值与死亡风险呈近似线性相关，当血红蛋白水平下降至65 g/L或更低时，患者的死亡风险显著增加，提示可将65 g/L的血红蛋白水平作为大面积烧伤患者输血的预警阈值。

abstractsObjective:To investigate the relationship between the lowest hemoglobin value during hospitalization and the prognosis in patients with extensive burns, in order to explore the hemoglobin warning threshold for blood transfusion in patients with extensive burns.Methods:The research was a retrospective observational study. From October 2012 to October 2022, 288 patients with extensive burns who met the inclusion criteria were admitted to the First Affiliated Hospital of Army Medical University (the Third Military Medical University), including 243 males and 45 females, aged 18 to 65 years. These patients were assigned to the death group ( n=54) and the survival group ( n=234) based on their final prognosis. The clinical data including gender, age, body mass index, total burn area, full-thickness burn area, time of first operation after injury, preoperative prothrombin time (PT) and activated partial thromboplastin time (APTT) and hemoglobin level of the first surgery, complication of inhalation injury, number of surgeries, total surgical area, total surgical time, total length of hospital stay, and highest procalcitonin value, lowest platelet count and hemoglobin values, and occurrence of sepsis during hospitalization were compared between the two groups of patients. According to the lowest hemoglobin value during hospitalization, the patients were assigned to <65 g/L group, ≥65 g/L and <75 g/L group, ≥75 g/L and <85 g/L group, and ≥85 g/L group. The total length of hospital stay, mortality and incidence of sepsis during hospitalization, and mortality within 90 days after injury were compared among the four groups of patients. The relationship between the lowest hemoglobin value during hospitalization and the mortality risk of patients with extensive burns was analyzed using a restricted cubic spline model before and after adjusting covariates. A logistic regression model was adopted to analyze the relationship between the lowest hemoglobin value during hospitalization and the mortality risk of patients with extensive burns after adjusting covariates, with the lowest hemoglobin value during hospitalization as a continuous variable and a categorical variable, separately. Results:Compared with those in survival group, the total burn area, full-thickness burn area, and total surgical area of patients in death group were significantly increased, the preoperative APTT of the first surgery was significantly prolonged, the number of surgeries was significantly reduced, the total length of hospital stay was significantly shortened, the highest procalcitonin value during hospitalization was significantly increased, the lowest platelet count and hemoglobin values during hospitalization were significantly decreased, and the incidence proportion of sepsis during hospitalization was significantly increased (with Z values of -6.72, -5.40, -2.15, -2.99, -2.21, -7.84, -6.23, -7.03, and -3.43, respectively, χ2=161.95, P values all <0.05). There were no statistically significant differences in the other clinical data of patients between the two groups ( P>0.05). There were statistically significant differences in mortality and incidence of sepsis during hospitalization, and mortality within 90 days after injury of patients among the four groups divided according to the lowest hemoglobin value during hospitalization (with χ2 values of 12.12, 15.93, and 10.62, respectively, P<0.05). There was no statistically significant difference in the total length of hospital stay of patients among the four groups ( P>0.05). The restricted cubic spline model analysis revealed an approximately linear relationship between the lowest hemoglobin value during hospitalization and the mortality risk of patients with extensive burns before and after adjusting covariates (with χ2 values of 0.81 and 0.75, respectively, P>0.05). After adjusting covariates, the logistic regression model analysis showed that the mortality risk of patients with extensive burns increased with decreasing hemoglobin when the lowest hemoglobin value during hospitalization was analyzed as a continuous variable (with odds ratio of 0.96, with 95% confidence interval of 0.92 to 0.99, P<0.05). When using the median value of 75.5 g/L as the cut-off value for categorizing the lowest hemoglobin value during hospitalization, there was no statistically significant difference in the mortality risk between patients with hemoglobin <75.5 g/L and those with hemoglobin ≥75.5 g/L ( P>0.05). When the patients were divided into four groups based on the lowest hemoglobin value during hospitalization as above, using ≥85 g/L group as a reference, only patients in <65 g/L group had a significantly increased mortality risk (with odds ratio of 5.37, with 95% confidence interval of 1.57 to 18.29, P<0.05). Conclusions:There is an approximately linear correlation between the lowest hemoglobin value during hospitalization and the mortality risk of patients with extensive burns. When the hemoglobin level drops to 65 g/L or lower, the mortality risk of patients increases significantly, suggesting that a hemoglobin level of 65 g/L could serve as a warning threshold for blood transfusion in patients with extensive burns.