Objective:To investigate the application value of metagenomics next-generation sequencing（mNGS）in the detection of pathogens and antimicrobial resistance genes in bronchoalveolar lavage fluid（BALF）of patients with severe pneumonia.Methods:Clinical data of 93 patients with severe pneumonia who underwent both BALF traditional microbial culture and mNGS testing from May 2020 to September 2021 in the intensive care unit of the Second Affiliated Hospital of Shandong First Medical University were retrospectively collected. Using traditional cultivation methods as the gold standard，analyze the sensitivity，specificity，bacterial resistance phenotype，and resistance genes of mNGS in detecting bacteria and fungi. SPSS 22.0 software was used to analyze the data.Results:The positive rate of mNGS was 84.9%（79/93），and the positive rate of traditional culture was 49.5%（46/93），and the difference was statistically significant（ χ2=26.56， P<0.01）. mNGS mixed infection detection rate was 60.2%（56/93），which was significantly higher than that of traditional culture 16.1%（15/93）（ χ2=38.29， P<0.01）. Using traditional cultivation methods as the gold standard，the sensitivity of mNGS for detecting bacteria and fungi was 97.8%（45/46），specificity was 31.0%（13/42），positive predictive value was 60.8%（45/74），and negative predictive value was 92.9%（13/14）. The consistency of the detection results between the two methods was 65.9%（58/88）. mNGS detected a total of 26 cases（28.0%）harboring resistance genes based on the mNGS results，the treatment regimen was adjusted in 50（53.8%）patients. Conclusion:The mNGS can improve the detection rate of pathogens in BALF of patients with severe pneumonia and can obtain antimicrobial drug resistance genes，which can provide the basis for clinical realization of precise antimicrobial drug-targeted therapy.

Objective:To investigate the application value of metagenomics next-generation sequencing（mNGS）in the detection of pathogens and antimicrobial resistance genes in bronchoalveolar lavage fluid（BALF）of patients with severe pneumonia.Methods:Clinical data of 93 patients with severe pneumonia who underwent both BALF traditional microbial culture and mNGS testing from May 2020 to September 2021 in the intensive care unit of the Second Affiliated Hospital of Shandong First Medical University were retrospectively collected. Using traditional cultivation methods as the gold standard，analyze the sensitivity，specificity，bacterial resistance phenotype，and resistance genes of mNGS in detecting bacteria and fungi. SPSS 22.0 software was used to analyze the data.Results:The positive rate of mNGS was 84.9%（79/93），and the positive rate of traditional culture was 49.5%（46/93），and the difference was statistically significant（ χ2=26.56， P<0.01）. mNGS mixed infection detection rate was 60.2%（56/93），which was significantly higher than that of traditional culture 16.1%（15/93）（ χ2=38.29， P<0.01）. Using traditional cultivation methods as the gold standard，the sensitivity of mNGS for detecting bacteria and fungi was 97.8%（45/46），specificity was 31.0%（13/42），positive predictive value was 60.8%（45/74），and negative predictive value was 92.9%（13/14）. The consistency of the detection results between the two methods was 65.9%（58/88）. mNGS detected a total of 26 cases（28.0%）harboring resistance genes based on the mNGS results，the treatment regimen was adjusted in 50（53.8%）patients. Conclusion:The mNGS can improve the detection rate of pathogens in BALF of patients with severe pneumonia and can obtain antimicrobial drug resistance genes，which can provide the basis for clinical realization of precise antimicrobial drug-targeted therapy.

Objective:To retrospect the blood transfusion status of patients with extensive burns in multiple centers and analyze its influencing factors.Methods:A retrospective case series study was conducted. Clinical data of 455 patients with extensive burns who met the inclusion criteria and were admitted to the burn centers of 3 hospitals from January 2016 to June 2022 were collected, including 202 patients from the First Affiliated Hospital of Nanchang University, 179 patients from the Second Affiliated Hospital of Zhejiang University School of Medicine, and 74 patients from the First Affiliated Hospital of Anhui Medical University. The following data were collected from patients during their hospitalization, including infusion of red blood cells, plasma, and platelets during hospitalization; age, gender, body mass index, combined underlying diseases, cause of injury, time of admission after injury, type of admission, total burn area, full-thickness burn area, combination of inhalation injury, combination of other trauma, and combination of pulmonary edema; the blood lactic acid, serum creatinine, total bilirubin, and albumin values within 24 h of admission; combination of bloodstream, wound, lung, and urinary tract infection, and combination of sepsis; the number of escharectomy or tangential excision and skin grafting surgery (hereinafter referred to as surgery) and total surgical blood loss volume; occurrence of hemoglobin<70 g/L, admission to intensive care unit (ICU), conduction of mechanical ventilation and continuous renal replacement therapy (CRRT), length of hospital stay, and prognosis were recorded. In 602 surgeries of patients within 14 days after injury, data including area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and surgical blood loss volume per surgery, operation site, and use of tourniquet and wound graft were collected. Data were statistically analyzed with Mann-Whitney U test, Kruskal-Wallis H test, and Spearman correlation analysis. Combined with the results of single factor analysis and clinical significance, multiple linear regression analysis was performed to screen the independent influencing factors of red blood cell infusion volume and plasma infusion volume, as well as blood loss volume per surgery. Results:During the whole hospitalization period, 437 (96.0%) patients received blood transfusion therapy, including 435 (95.6%) patients, 410 (90.1%) patients, and 73 (16.0%) patients who received transfusion of plasma, red blood cells, and platelets, respectively. The patients were mainly male, aged 18 to 92 years. There were statistically significant differences in the plasma infusion volume among patients with different combination of underlying disease, combination of inhalation injury, combination of other trauma, combination of pulmonary edema, combination of bloodstream infection, combination of wound infection, combination of lung infection, combination of urinary tract infection, combination of sepsis, occurrence of hemoglobin value <70 g/L, admission to ICU, conduction of mechanical ventilation, and conduction of CRRT (with Z values of -2.06, -4.67, -2.11, -6.13, -9.56, -4.93, -8.08, -4.78, -9.12, -6.55, -9.37, -11.46, and -7.17, respectively, P<0.05). The total burn area, full-thickness burn area, blood lactic acid value within 24 h of admission, serum creatinine value within 24 h of admission, albumin value within 24 h of admission, number of surgeries, and total surgical blood loss volume were correlated with the plasma infusion volume of patients (with r values of 0.39, 0.51, 0.14, 0.28, -0.13, 0.47, and 0.56, respectively, P<0.05).There were statistically significant differences in the red blood cell infusion volume among patients with different gender, combination of inhalation injury, combination of other trauma, combination of pulmonary edema, combination of bloodstream infection, combination of wound infection, combination of lung infection, combination of urinary tract infection, combination of sepsis, occurrence of hemoglobin value <70 g/L, admission to ICU, conduction of mechanical ventilation, and conduction of CRRT (with Z values of -2.00, -4.34, -3.10, -4.22, -8.24, -7.66, -8.62, -4.75, -7.42, -9.36, -6.12, and -8.31, -6.64, respectively, P<0.05). The age, total burn area, full-thickness burn area, blood lactic acid value within 24 h of admission, serum creatinine value within 24 h of admission, total bilirubin value within 24 h of admission, number of surgeries, and total surgical blood loss volume were correlated with the red blood cell infusion volume of patients (with r values of 0.12, 0.22, 0.49, 0.09, 0.18, 0.13, -0.15, 0.69, and 0.77, respectively, P<0.05). Combined underlying diseases, full-thickness burn area, combined pulmonary edema, serum creatinine value within 24 h of admission, combined sepsis, conduction of CRRT, number of surgeries, and total surgical blood loss volume were the independent influencing factors for plasma infusion volume during hospitalization in patients with extensive burns (with standardized regression coefficients of 0.09, 0.16, 0.12, 0.07, 0.11, 0.15, 0.31, and 0.26, respectively, P<0.05). Female, full-thickness burn area, serum creatinine value within 24 h of admission, combined sepsis, occurrence of hemoglobin value <70 g/L, conduction of CRRT, and total surgical blood loss volume were the independent influencing factors for red blood cell infusion volume during hospitalization in patients with extensive burns (with standardized regression coefficients of 0.10, 0.12, 0.10, 0.11, 0.05, 0.19, and 0.54, respectively, P<0.05). There were statistically significant differences in blood loss volume per surgery of patients with different surgical site and wound graft (with Z values of -2.54 and -2.27, respectively, P<0.05). The area of escharectomy or tangential excision and skin graft harvesting and duration of operation were correlated with the blood loss volume per surgery of patients (with r values of 0.40 and 0.21, respectively, P<0.05). The area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and active wound grafts were the independent influencing factors for blood loss volume per surgery of patients with extensive burns (with standardized regression coefficients of 0.41, 0.16, and 0.12, respectively, P<0.05). Conclusions:The major factors influencing blood transfusion status in patients with extensive burns are female, combined underlying diseases, full-thickness burn area, serum creatinine value within 24 h of admission, combined pulmonary edema, occurrence of hemoglobin value <70 g/L, combined sepsis, conduction of CRRT, number of surgery, and total surgical blood loss volume. In addition, the area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and active wound grafts indirectly affect the patient's blood transfusion status by affecting the blood loss volume per surgery.