Over a 10-year period, 118 severe burn patients with inhalation injury from the Department of Burns and Plastic Surgery, West China Hospital of Sichuan University, evaluated retrospectively. The study indicates that a high respiratory system SOFA score and large-area TBSA are risk factors impacting patient survival, with both having high predictive values. The combined evaluation level of the two factors reaches the diagnostic value of the rBaux score.
In this survival study's Kaplan–Meier analysis, the inpatient survival time of elderly patients over 60 years was considerably less than that of other patients. The exact cause might be related to thinner skin, diminished feeling, mental changes, pre-existing comorbidities, or a variety of other circumstances [16, 17]. Although the Cox multivariate analysis outcomes do not include the element of age, we cannot entirely rule out this risk factor from the revised Baux score for burns. In our study, older age had a nearly significant p value of 0.05 (p = 0.085), indicating a substantial link with death. According to logistic regression analysis, Henry et al. also reported that older age is not a mortality predictor of burn injury due to the small sample population of elderly patients . Inhalation injury frequently aggravates the disease, requiring some patients to be moved to the ICU ward for respiratory support therapy, reducing their hospital survival time. However, ICU hospitalization variables, on the other hand, are not predictors of patient survival. Severe burns can impede skin function substantially, produce significant fluid loss, harm the interior environment, and raise the risk of infection [19,20,21]. Extensive TBSA burns are still an important risk factor for patients in our research, which is consistent with the majority of prior investigations.
Some studies suggest that when evaluating the application of the oxygenation index score in burn patients with inhalation injury, the PF ratio cannot indicate the severity of inhalation injury, and mechanical ventilation should be considered a risk factor for mortality [22, 23]. Furthermore, when evaluating patients with inhalation injury, adding 17 points to the Baux score might easily lead to clinicians underestimating the impact of inhalation damage on patients' survival chances, and the rBaux score lacks the clinical indicators of dynamic evaluation. inhalation injury. These patients are frequently accompanied with a certain degree of secondary pneumonia in the early stages of burns, and have a greater mortality and comorbidities than patients without inhalation injury . Many studies have also created other scoring systems for predicting the prognosis of burn patients; however, when utilized therapeutically for patients with inhalation injury, these scoring systems fail to take into account pathophysiological changes in pneumonia, carbon monoxide levels, and oxygenation levels [25,26,27,28]. The acute respiratory distress syndrome (ARDS) is the major cause of mortality in individuals with inhalation injury [29,30,31]. There are also various standards for detecting ARDS, such as the systemic inflammatory response syndrome (SIRS) and Berlin standards . However, reliable evaluation of the independent respiratory system in severe burn patients with inhalation injury remains a challenge.
According to the revised Sepsis-3 (2016) consensus guideline, the SOFA scores predict the outcome of critically sick patients better than SIRS that characterizes sepsis. Although quickly SOFA (qSOFA), a relatively simple and affordable bedside clinical score, is thought to have a lesser predictive value than the revised Baux score, the usefulness of SOFA in assessing multiple systems functions in critically sick patients cannot be overstated. However, the SOFA score is especially useful for complete dynamic grading. Based on the patient's baseline risk level, it is currently believed that a SOFA score of 2 or higher indicates increasing by 2 to 25 times in the risk of death when compared to patients with a SOFA score of less than 2 [33, 34]. Moreover, the respiratory SOFA scores of 3–4 includes mechanical ventilation components. As a result, we divided the study population into three groups based on the above-mentioned SOFA score reasons. The results showed that the respiratory SOFA scores can be a risk factor for survival in individuals with severe burns and inhalation injuries. A 12-year retrospective research undertaken by Swanson and their colleagues found that lung damage is the second most prevalent cause of mortality in the first week following burns (84%), after only burn shock (62%) . Our findings are consistent with this result. It was discovered that the median survival period of patients with a respiratory system SOFA score more than 2 was only 5 days, and the survival rate was only 79%, showing that the more serious the inhalation injury, the higher the patient's likelihood of dying. Further investigation revealed that the respiratory SOFA score has a comparable predictive value to the TBSA (AUROC: 0.857 and 0897). When the two clinical indicators are combined to assess the prognosis of patients, they have similar value to the rBaux score and can dynamically assess and monitor patient prognosis.
There are some limitations to this study that must be addressed. First, the study was designed using data from a small sample size obtained from a single center, which did not fully account for all potential influencing factors; second, because this was a retrospective review, there may have been some selection biases and errors in record entry; thus, prospective studies with a large sample size from multiple institutions are required; and third, severe burn with inhalation injury in the pediatric population was not included in this study.