Objective:To investigate the clinical characteristics and risk factors of critical burn patients complicated with invasive fungal infection.Methods:A retrospective case series study was conducted. From January 2017 to December 2022, 88 critical burn patients combined with invasive fungal infection who met the inclusion criteria were admitted to Zhengzhou First People's Hospital, including 61 males and 27 females, aged 26-74 years. Data on invasive fungal infection sites and the detection of pathogens in patients were recorded. According to the survival outcome within 28 days after admission, the patients were divided into survival group (63 cases) and death group (25 cases). The following data of patients were compared between the two groups, including the basic data and injuries of patients at admission such as age, sex, body weight, total burn area, combination of inhalation injury, combination of hypertension and diabetes, acute physiology and chronic health status evaluation Ⅱ (APACHE Ⅱ) score, and admission time after burns, the levels of blood biochemical indexes within 24 h after admission such as white blood cell count, platelet count, red blood cell count, monocyte count, neutrophil count, lymphocyte count, alanine transaminase, aspartate transaminase, glucose, creatinine, urea nitrogen, D-dimer, galactomannan (GM), 1,3-β-D glucan, and creatine kinase, the application of invasive procedures and vasoactive drugs during the treatment such as continuous renal replacement therapy, ventilator-assisted breathing, tracheotomy, deep vein catheterization, skin grafting >2 times, the levels of infection indicators on post admission day (PAD) 1, 3, 7, and 14 including C-reactive protein (CRP), procalcitonin, lactic acid, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), and the detection of pathogens in the process of treatment. Data were statistically analyzed with independent sample t test, analysis of variance for repeated measurement, chi-square test, Mann-Whitney U test, and Bonferroni correction. Multivariate logistic regression analysis was performed to screen the independent risk factors that affected death of critical burn patients complicated with invasive fungal infection. Results:The main sites of invasive fungal infection were the wounds (67 cases) and blood stream (46 cases), with Candida fungi (58 strains) as the main strain for fungi infection, and there were a total of 30 cases of infection with mixed pathogenic bacteria. Compared with those in survival group, the APACHE Ⅱ score, proportions of combination with inhalation injury and hypertension of patients in death group were significantly increased ( t=2.11, with χ2 values of 6.26 and 9.48, respectively, P<0.05), while the other basic data and injury condition had no significant changes ( P>0.05). Compared with those in survival group, the levels of D-dimer, GM, and 1,3-β-D glucan of patients in death group were significantly increased within 24 h after admission (with t values of 2.42, 2.05, and 2.21, respectively, P<0.05), while the other blood biochemical indexes within 24 h after admission, as well as the proportions of applying invasive procedures and application of vasoactive drugs during the treatment process were not significantly changed ( P>0.05). The levels of infection indicators of patients on PAD 1 and 3 were similar between the two groups ( P>0.05). The procalcitonin level on PAD 7 and the levels of CRP, procalcitonin, lactic acid, IL-6, and TNF-α on PAD 14, as well as the proportion of infection with mixed pathogenic bacteria of patients in death group were significantly higher than those in survival group (with t values of 4.69, 3.89, 6.70, 6.14, 4.65, and 3.26, respectively, χ2=12.67, P<0.05). Multivariate logistic regression analysis showed that combination with inhalation injury, combination with hypertension, and infection with mixed pathogenic bacteria were independent risk factors for death of critical burn patients complicated with invasive fungal infection (with odds ratios of 5.98, 4.67, and 6.19, respectively, 95% confidence intervals of 1.42-15.39, 1.41-25.28, and 1.86-20.58, respectively, P<0.05). Conclusions:The main sites of infection in critical burn patients complicated with invasive fungal infection are the wounds and blood stream, with Candida fungi as the main strain for fungi infection, and a large proportion of infection with mixed pathogenic bacteria. The combined inhalation injury, combined hypertension, and infection with mixed pathogenic bacteria are the independent risk factors for the death of those patients.