[Epidemiological characteristics and outcome analysis of inhalation injury patients combined with burn area less than 30% total body surface area in a single center from 2008 to 2016].

To explore the epidemiological characteristics and treatment outcomes of inhalation injury patients combined with burn area less than 30% total body surface area (TBSA) admitted to the First Affiliated Hospital of Naval Medical University. Retrospective observational study with performed on medical records of 266 inhalation injury patients combined with burn area less than 30% TBSA who were admitted to the First Affiliated Hospital of Naval Medical University from January 2008 to September 2016 and met the inclusion criteria. The gender, age, injured site, injurious factors of inhalation injury, degree of inhalation injury, combined total burn area, way of tracheotomy, time of tracheotomy, whether conducted mechanical ventilation or not, whether in intensive care unit (ICU) or not, microbial culture results of bronchoalveolar lavage, total hospitalization days, ICU days, mechanical ventilation days, and whether respiratory infections occurred or not. Single factor and multivariate linear regression analysis was used to screen out the risk factors impacting the total hospitalization days, ICU days, and mechanical ventilation days of patients. Single factor and multivariate logistic regression analysis was used to screen out the risk factors impacting respiratory infections of patients. The 266 patients included 190 males and 76 females, with the majority age of above and equal to 21 and below 65 years (217 patients). Confined space was the major injured site. Hot air was the major factor of inhalation injury. Mild and moderate inhalation injuries were commonly seen in patients. The combined total burn area was 9.00 (3.25, 18.00) %TBSA. In 111 patients who were conducted with tracheotomy, the most were conducted before admitted to the First Affiliated Hospital of Naval Medical University. The total hospitalization days of patients were 27 (10, 55) days. The ICU days of 160 patients were 15.5 (6.0, 40.0) days. The mechanical ventilation days of 109 patients were 6.0 (1.3, 11.5) days. A total of 119 patients were diagnosed with respiratory infections, with 548 strains including 35 types of pathogens were isolated, mainly of Gram-negative bacteria. Single factor linear regression analysis showed age, injurious factors of inhalation injury, combined total burn area, degree of inhalation injury, way of tracheotomy, whether conducted mechanical ventilation or not, and whether respiratory infections occurred or not were the risk factors impacting the total hospitalization days of patients (95% confidence interval (CI)=-0.397－0.001, -0.395－-0.053, 0.015－0.028, 0.009－0.263, 0.008－0.319, -0.419－-0.176, 0.242－0.471, 0.340－0.555, <0.1). Multivariate linear regression analysis showed smoke inhalation, mechanical ventilation, and respiratory infections were the independent risk factors impacting the total hospitalization days of patients (95% CI=-0.384－0.082, 0.022－0.271, 0.261－0.506, <0.05 or <0.01). Single factor linear regression analysis showed injurious factors of inhalation injury, combined total burn area, degree of inhalation injury, way of tracheotomy, whether conducted mechanical ventilation or not, and whether respiratory infections occurred or not were the risk factors impacting the ICU days of patients (95% CI=0.053－0.502, 0.006－0.010, -0.018－0.457, -0.022－0.428, -0.575－-0.241, -0.687－-0.018, 0.132－0.486, 0.369－0.678, <0.1). Multivariate linear regression analysis showed that no tracheotomy and respiratory infections were the independent risk factors impacting the ICU days of patients (95% CI=-0.414－-0.084, 0.278－0.601, <0.01). Single factor linear regression analysis showed injured site, injurious factors of inhalation injury, combined total burn area, degree of inhalation injury, way of tracheotomy, and whether respiratory infections occurred or not were the risk factors impacting mechanical ventilation days of patients (95% CI=-0.565－-0.034, 0.145－0.946, 0.051－1.188, 0.001－0.009, 0.127－0.847, 0.436－1.162, -1.243－-0.229, 0.005－0.605, <0.1). Multivariate linear regression analysis showed open space inhalation, smoke inhalation, severe inhalation injury, no tracheotomy, prophylactic tracheotomy, and respiratory infections were the independent risk factors impacting mechanical ventilation days of patients (95% CI=-0.588－-0.127, 0.138－0.560, 0.143－0.848, -0.909－-0.330, -1.008－-0.015, 0.007－0.519, <0.05 or <0.01). Single factor logistic regression analysis showed age, injured site, degree of inhalation injury, combined total burn area, way of tracheotomy, and whether conducted mechanical ventilation or not were the risk factors impacting respiratory infections of patients (95% CI=0.840－1.362, 0.641－1.044, 1.122－1.526, 1.028－1.661, 1.344－2.405, 1.460－2.612, 0.744－1.320, 0.241－0.424, 2.331－4.090, <0.1). Multivariate logistic regression analysis showed prophylactic tracheotomy, no tracheotomy, and mechanical ventilation were the independent risk factors impacting respiratory infections of patient (95% CI=0.430－0.641, 0.290－0.511, 2.152－8.624, <0.05 or <0.01). The inhalation injury patients combined with burn area less than 30% TBSA are mainly young and middle-aged males. Confined space, smoke inhalation, mechanical ventilation, respiratory infection, and way of tracheotomy are influencing factors of the outcomes in hospital of inhalation injury patients combined with burn area less than 30% TBSA. Additionally, prophylactic tracheotomy shows its potential role in avoiding respiratory infection for patients with moderate or severe degree of inhalation injury.