Severity Of Inhalation Injury Research Articles

Repeat Bronchoscopies Are Poorly Predictive of Outcomes Following Inhalation Injury

Abstract Inhalation injury is an independent predictor of mortality after burn injury. Although bronchoscopy remains the gold standard for diagnosing inhalation injury, there is a paucity of evidence to support repeat bronchoscopies for following inhalation injuries during a patient’s clinical course. This study looks at the ability of serial bronchoscopies to prognosticate outcomes. This was a secondary analysis of a previously reported prospective observational study. Patients diagnosed with inhalation injury had repeat bronchoscopies with blinded investigators assigning severity scores. The study used multivariate regression analysis to investigate whether inhalation injury severity scores of the carinal images were predictive of mortality. Secondary outcomes included diagnosis of acute respiratory distress syndrome or pneumonia during hospitalization. The final analysis included 99 patients. After accounting for age, percent TBSA burn, and injury severity scores, there were no days that were significant for predicting outcomes. All days were poor predictors overall, with the area under the receiver operating curve being <0.8 in all instances. These results do not support the use of serial bronchoscopies for prognostication purposes. Until a larger, randomized clinical trial can evaluate this further, serial bronchoscopies performed for assessment of the progression of inhalation injury may provide more risk than benefit.

Inhalation Injury Severity Score on Admission Predicts Overall Survival in Burn Patients.

Inhalation injury is diagnosed in up to one-third of burn patients and is associated with increased morbidity and mortality. There are multiple scoring systems to grade inhalation injury, but no study has evaluated the ability of these scoring systems to predict outcomes of interest such as overall survival. We conducted a prospective, observational study of 99 intubated burn patients who underwent fiberoptic bronchoscopy within 24 hours of admission and graded inhalation injury using three scoring systems: Abbreviated Injury Score (AIS), Inhalation Injury Severity Score (I-ISS), and Mucosal Score (MS). Agreement between scoring systems was assessed with Krippendorff's Alpha (KA). Multivariable analyses were conducted to determine if variables were associated with overall survival. At admission, median AIS, I-ISS, and MS scores were 2 for all scoring systems. Patients who died had higher overall injury burden than those who survived and had similar median admission AIS and MS scores, but higher I-ISS scores. There was strong correlation between the inhalation injury grade at admission using the three scoring systems (KA=0.85). On regression analysis, the only scoring system independently associated with overall survival was I-ISS (score 3 compared to scores 1-2: OR 13.16, 95% CI 1.65-105.07; p=0.02). Progression of injury after initial assessment may contribute to the poor correlation between admission score and overall survival for injuries graded with AIS and MS. Repeated assessment may more accurately identify patients at increased risk for mortality.

773 Inhalation Injury Severity Score on Admission Predicts Overall Survival in Burn ICU Patients

Abstract Introduction Inhalation injury (II) is identified in about one-third of burn patients and is associated with increased morbidity and mortality. There are multiple scoring systems to grade II; however, no study has compared ability of these scoring systems to predict outcomes of interest such as overall survival. We hypothesized that II grades from each scoring system assessed would correlate strongly and that higher scores (representing higher grade II) would be associated with worse overall survival (OS). Methods This was a prospective, observational study that included intubated burn patients who underwent fiberoptic bronchoscopy within 24 hours of admission. II was graded using three scoring systems: Abbreviated Injury Score (AIS), Inhalation Injury Severity Score (I-ISS), and Mucosal Score (MS). All scoring systems use a Likert-type scale (AIS: 0-4; I-ISS and MS: 0-3) with more severe IIs given higher scores. Agreement between scoring systems was assessed with Krippendorff’s Alpha (KA) >0.80 indicating high reliability. Multivariable analyses were used to determine variables independently associated with OS. Significance was set at p< 0.05. Results 99 patients were included in the analysis. Median percent total body surface area burned and Injury Severity Score (ISS) were 19.5% (interquartile range [IQR] 9-39%) and 25 (13-34), respectively. At admission, median AIS, I-ISS, and MS scores were 2 (1-3) for all scoring systems. Patients who died had higher overall injury burden than those who survived (Table 1). Additionally, patients who died had similar median admission AIS and MS scores, but higher I-ISS scores than those who survived (Table 1). There was strong correlation between the grade of II at admission using the three scoring systems (KA=0.85). On regression analysis, the only II scoring system independently associated with overall survival was I-ISS (score 3 compared to scores 1-2: OR 13.16, 95% CI 1.65-105.07; p=0.02). Conclusions Grade of II on admission correlated well between scoring systems, but only I-ISS on admission was independently associated with OS. Progression of injury after initial assessment may contribute to the poor correlation between admission score and overall survival for IIs graded with AIS and MS. Repeated assessment and re-grading II after initial resuscitation may more accurately identify patients at increased risk for mortality. Applicability of Research to Practice Grading II is common practice in Burn ICUs. This study demonstrates good reliability between the three most common II scoring systems utilized and that I-ISS on admission can be used to predict risk of mortality, which is useful prognostic information for both burn care providers as well as patients and their families.

Inhalation injury in 11 Thoroughbred racehorses: Clinical course on bronchoscopy, treatment and postinjury racing performance

SummaryInhalation injury is a serious and potentially fatal consequence of a fire or explosion. Bronchoscopy is recommended for rapid assessment of inhalation injury in humans; however, descriptions of bronchoscopic observation of inhalation injury in horses are lacking. We describe the clinical course of inhalation injury observed by bronchoscopy, treatment, and racing performance in 26 Thoroughbred racehorses that had been exposed to a fire. On initial bronchoscopy, 11 were diagnosed with inhalation injury (3 of Grade 1 [mild]; 3 of Grade 2 [moderate]; 4 of Grade 3 [severe]; and 1 of Grade 4 [massive]); 11 had no injury (Grade 0); and 4 were found dead. Treatment was based on inhalation injury grade and mainly involved airway lavage via bronchoscopy for soot removal and exudate recovery. Of the 11 horses with inhalation injury, 10 survived and 9 returned to racing. No effects in terms of racing performance (number of starts, finishing position, and earnings) were observed. Prompt and repeated bronchoscopy may be useful for evaluating the severity of inhalation injury, and airway lavage via bronchoscopy may be an effective treatment. If diagnosed and treated early and appropriately, even severe inhalation injury will not necessarily hinder postinjury racing performance in Thoroughbred racehorses.

Survival and analysis of prognostic factors for severe burn patients with inhalation injury: based on the respiratory SOFA score

BackgroundIt is important to determine the severity of inhalation injury in severely burned patients. The oxygenation index PaO2/FiO2(PF) ratio is a key clinical indicator of inhalation injury. Sequential organ failure assessment (SOFA) is developed to assess the acute incidence of critical illness in the population. We hope to provide an assessment of survival or prognostic factor for severely burned patients with inhalation injury based on the respiratory SOFA score.MethodsThis is a retrospective cohort study of all admissions to Department of Burn and Plastic Surgery at West China Hospital of Sichuan University from July 2010 to March 2021. Data was analyzed using Cox regression models to determine significant predictors of mortality. Survival analysis with time to death event was performed using the Kaplan–Meier survival curve with the log-rank test. All potential risk factors were considered independent variables, while survival was considered the risk dependent variable.ResultsOne hundred eighteen severe burn patients with inhalation injury who met the inclusion and exclusion criteria were admitted, including men accounted for 76.3%. The mean age and length of stay were 45.9 (14.8) years and 44.3 (38.4) days. Flame burns are the main etiology of burn (74.6%). Patients with the respiratory SOFA score greater than 2 have undergone mechanical ventilation. Univariate Kaplan–Meier analysis identified age, total body surface area burned (TBSA), ICU admission and the respiratory SOFA score as significant factors on survival. Cox regression analysis showed that TBSA and the respiratory SOFA score were associated with patient survival (p < 0.001). In some patients with severe burns and inhalation damage, the survival probability drops to less than 10% (TBSA greater than 80%: 8.9% and respiratory SOFA score greater than 2: 5.6%). This study statistically found that the TBSA with the respiratory SOFA score model (AUROC: 0.955) and the rBaux score (AUROC: 0.927) had similar predictive value (p = 0.175).ConclusionThe study indicates that a high respiratory system SOFA score was identified as a strong and independent predictor of severely burned patients with inhalation injury during hospitalization. When combined with TBSA, the respiratory SOFA scores can dynamically assess the severity of the patient's lung injury and improve the predictive level.

Development and Application of Multidimensional Lipid Libraries to Investigate Lipidomic Dysregulation Related to Smoke Inhalation Injury Severity.

The implication of lipid dysregulation in diseases, toxic exposure outcomes, and inflammation has brought great interest to lipidomic studies. However, lipids have proven to be analytically challenging due to their highly isomeric nature and vast concentration ranges in biological matrices. Therefore, multidimensional techniques such as those integrating liquid chromatography, ion mobility spectrometry, collision-induced dissociation, and mass spectrometry (LC-IMS-CID-MS) have been implemented to separate lipid isomers as well as provide structural information and increased identification confidence. These data sets are however extremely large and complex, resulting in challenges for data processing and annotation. Here, we have overcome these challenges by developing sample-specific multidimensional lipid libraries using the freely available software Skyline. Specifically, the human plasma library developed for this work contains over 500 unique lipids and is combined with adapted Skyline functions such as indexed retention time (iRT) for retention time prediction and IMS drift time filtering for enhanced selectivity. For comparison with other studies, this database was used to annotate LC-IMS-CID-MS data from a NIST SRM 1950 extract. The same workflow was then utilized to assess plasma and bronchoalveolar lavage fluid (BALF) samples from patients with varying degrees of smoke inhalation injury to identify lipid-based patient prognostic and diagnostic markers.

Hyperbaric Oxygen and Mortality in Burns With Inhalation Injury: A Study of the National Burn Repository.

Mortality in burn injury is primarily influenced by three factors: age, percent burn (%TBSA), and presence of inhalation injury. Numerous modalities have been tried in an attempt to treat those patients with burns and inhalation injury, including the use of hyperbaric oxygen (HBO). The aim of our study was to find the national prevalence of HBO for burns with inhalation injury, and whether HBO influenced mortality in these often severely injured patients. This retrospective study used the National Burn Repository (NBR) to identify hospital admissions of patients with both cutaneous burn and inhalation injuries. After applying exclusion criteria, a total of 13,044 patients were identified. Variables included in the multivariate regression analysis included age, sex, race, payer, mechanism of burn injury, TBSA group, total procedure number, mechanical ventilator days, and treatment with HBO. The main outcome variable was mortality. Of the 13,044 patients, 67 had HBO therapy. The HBO patients were older (mean age 51.7 vs 42.8 years, P < .001), but had smaller burns and thus a similar Baux score (66.6 vs 65.2, P = .661). The HBO patients had a higher mortality (29.9% vs 17.5%, P = .01). On multivariate regression analysis, HBO was an independent predictor of mortality (odds ratio = 2.484, P = .004). Other significant predictors of mortality included age, black race, Medicaid or uninsured patients, and %TBSA. The use of HBO for patients with burns and inhalation injury is uncommon in this database. It is unclear whether that reflects low prevalence or if individual centers do not all impute HBO into the NBR. For those patients in this database, HBO is an independent predictor of mortality. It can be difficult to determine the severity of inhalation injury in the NBR, so those patients receiving HBO could theoretically have more severe inhalation injury.

517 Hyperbaric Oxygen and Mortality in Burns with Inhalation Injury: a Study of the National Burn Repository

Abstract Introduction Mortality in burn injury is primarily influenced by three factors: age, percent burn (%TBSA), and presence of inhalation injury. Numerous modalities have been tried in an attempt to treat those patients with burns and inhalation injury, including the use of hyperbaric oxygen (HBO). The aim of our study was to find the national prevalence of HBO for burns with inhalation injury, and whether HBO influenced mortality in these often severely injured patients. Methods This retrospective study used the National Burn Repository (NBR) to identify hospital admissions of patients with both cutaneous burns and inhalation injuries. After applying exclusion criteria, a total of 13,044 patients were identified. Variables included in the multivariate regression analysis included: age, sex, race, payer, mechanism of burn injury, TBSA group, total procedure number, mechanical ventilator days, and treatment with HBO. The main outcome variable was mortality. Results Of the 13,044 patients, 67 had HBO therapy. The HBO patients were older (mean age 51.7 years vs. 42.8 years, p&amp;lt; 0.001) but had smaller burns and thus a similar Baux score (66.6 vs. 65.2, p=0.661). The HBO patients had a higher mortality (29.9% vs. 17.5%, p= 0.01). On multivariate regression analysis, HBO was an independent predictor of mortality (OR= 2.484, p= 0.004). Other significant predictors of mortality included age, Black race, Medicaid or uninsured patients, and %TBSA. Conclusions The use of HBO for patients with burns and inhalation injury is uncommon in this database. It is unclear whether that reflects low prevalence or if individual centers do not all impute HBO into the NBR. For those patients in this database, HBO is an independent predictor of mortality. It can be difficult to determine the severity of inhalation injury in the NBR, so those patients receiving HBO could theoretically have more severe inhalation injury.

Association of uteroglobin-related protein 1 with smoke inhalation injury severity.

ObjectiveTo evaluate serum uteroglobin-related protein 1 expression early after smoke inhalation injuries and its association with the severity of inhalation injury in burned patients.MethodsSmoke or chemical inhalation injury is associated with morbidity and mortality. The consequences of inhalation result from an inflammatory response. Uteroglobin-related protein 1 is an anti-inflammatory protein and may improve lung inflammation. We hypothesized that uteroglobin-related protein 1 levels could reflect disease severity and predict outcome in patients with inhalation injury. Sixteen patients diagnosed with acute respiratory distress syndrome secondary to smoke inhalation injury were prospectively included in the study. Plasma was collected upon intensive care unit admission and within 24 hours of the inhalation injury. Bronchoscopies were carried out in all patients to assess the severity of inhalation injury within 72 hours. Uteroglobin-related protein 1 plasma levels were determined in duplicate with enzyme-linked immunosorbent assay.ResultsThe mean age was 23 ± 5 years, and the inhalation injury distribution was as follows: three of grade 1, four of grade 2, and nine of grade 3. The level of uteroglobin-related protein 1 was related to inhalation severity (grade 1: 0.389 ± 0.053 arbitrary units versus grade 2: 0.474 ± 0.0423 arbitrary units versus grade 3: 0.580 ± 0.094 arbitrary units; p = 0.007).ConclusionPlasma levels of uteroglobin-related protein 1 are associated with the degree of lung inhalation injury.

Our Experience Treatment Inhalation Injury in Children in Uzbekistan

Thermal inhalation injury is one of the factors aggravating the course of burn disease and resulting in patient’s death. According to literary data, damage to respiratory tract occurs approximately in 30% of cases with severe burn injury. Thermal inhalation injury severity can be determined not so much by airway burns but by toxic inhalation damage to the lungs and whole body with high toxic gaseous and vaporized chemical components of smoke. During a 3 year period 28 children with deep burns of III-IV degree were treated at Burns Department of Republican Scientific Center of Urgent Medical Aid (RSCUMA), Samarkand, Uzbekistan.

Establishment of nomogram predicting model for the death risk of extremely severe burn patients and the predictive value

Objective: To explore the death risk factors of extremely severe burn patients, establish a death risk nomogram predicting model, and investigate the predictive value for death risk of extremely severe burn patients. Methods: The medical records of 231 extremely severe burn patients (190 males and 41 females, aged 18-60 years) who were admitted to the Institute of Burn Research of the First Affiliated Hospital of Army Medical University from January 2010 to October 2018 and met the inclusion criteria were analyzed retrospectively. According to the final outcome, the patients were divided into survival group of 173 patients and death group of 58 patients. The sex, age, severity of inhalation injury, total burn area, full-thickness burn area, burn index, rehydration coefficient and urine volume coefficient of the first and second 24 h after injury, the first base excess, shock index, and hematocrit (HCT) after admission, whether to have pre-hospital fluid infusion, use of ventilator, and use of continuous renal replacement therapy (CRRT), and abbreviated burn severity index (ABSI ) and Baux score on admission of patients in the two groups were recorded or calculated. According to the use of ventilator, the patients were divided into with ventilator group of 131 patients and without ventilator group of 100 patients, and the death, total burn surface area, burn index, incidence and severity of inhalation injury were recorded. According to the use of CRRT, the patients were divided into with CRRT group of 59 patients and without CRRT group of 172 patients, and the death, total burn surface area, and burn index were recorded. Data were statistically analyzed with t test, chi-square test, and Mann-Whitney U test to screen the death related factors of patients. The indexes with statistically significant differences between survival group and death group were included in the multivariate logistic regression analysis to screen the independent death risk factors of patients, and the death risk nomogram predicting model was constructed based on the results.The Bootstrap method was used to validate the death risk nomogram predicting model internally. The predictive value of the nomogram model for predicting death risk of patients was detected by drawing calibration graph and calculating concordance index, and the death risk scores of 231 patients were acquired according to the death risk nomogram model. The receiver's operating characteristic (ROC) curve was drawn, and the optimal threshold and the sensitivity and specificity of optimal threshold in the ROC curve and the area under the curve were calculated. Results: (1) There were statistically significant differences in burn index, ABSI on admission, severity of inhalation injury, total burn area, full-thickness burn area, rehydration coefficient at the first 24 h after injury, use of ventilator, use of CRRT, and Baux score on admission of patients between the two groups (Z=-7.696, -7.031, χ(2)=18.304, 63.065, 23.300, 13.073, 34.240, 59.586, t=-7.536, P<0.01). (2) There were statistically significant differences in death, incidence and severity of inhalation injury, total burn area, and burn index of patients between with ventilator group and without ventilator group (χ(2)=34.240, 17.394, 25.479, Z=-6.557, -7.049, P<0.01). (3) There were statistically significant differences in death, total burn area, and burn index of patients between with CRRT group and without CRRT group (χ(2)=62.982, Z= -47.421, -6.678, P<0.01). (4) The use of ventilator, use of CRRT, and burn index were independent risk factors for the death of extremely severe burn patients (odds ratio=3.277, 5.587, 1.067, 95% confidence interval=1.073-10.008, 2.384-13.093, 1.038-1.096, P<0.05 or P<0.01). (5) The initial concordance index of nomogram predicting model was 0.90 and the corrected concordance index was 0.89. The concordance indexes before and after correction were higher and similar, which showed that the nomogram had good concordance and predictive effect. The optimum threshold of ROC curve was 0.23, the sensitivity and specificity of optimum threshold were 86.0% and 80.0%, respectively, and the area under ROC curve was 0.90 (95% confidence interval=0.86-0.94, P<0.01). Conclusions: Severe burns and damage and/or failure of organ are the main death causes of extremely severe burn patients. The death risk nomogram predicting model established on the basis of use of ventilator, use of CRRT, and burn index have good predictive ability for death of extremely severe burn patients.

Modified abbreviated burn severity index as a predictor of in-hospital mortality in patients with inhalation injury: development and validation using independent cohorts.

The ability to accurately evaluate the severity of inhalation injury can help to optimize patient care. However, there is no accepted severity grading system, especially for inhalation injury. We screened a multicenter burn registry and included adult patients who required oxygen treatment or mechanical ventilation. After the patient data were divided into development and validation cohorts, missing values were replaced with multiple imputation. Twelve potential predictors were analyzed using multivariate logistic regression to identify prognostic variables for in-hospital mortality and scores were assigned to each predictor based on odds ratios to develop the Modified Abbreviated Burn Severity Index, mABSI. The mABSI was validated using c-statistics and calibration curves. We randomly assigned 1377 and 919 patients to the development and validation cohorts, respectively. Age, self-inflicted injury, cutaneous burn area, and mechanical ventilation requirement were identified as independent predictors, and the mABSI (1-17 scale) was, thus, developed. The mABSI has a high discriminatory power (c-statistic = 0.94; 95% CI 0.92-0.97), and both estimated and observed in-hospital mortalities increased from 1% at score ≤ 5 to almost 100% at score ≥ 14 with linear calibration plots. We developed and validated the mABSI which accurately predicts in-hospital mortality.

Increased Ratio of Dead Space to Tidal Volume in Subjects With Inhalation Injury

Inhalation injury increases morbidity and mortality in burn patients. Patients with inhalation injury present with large differences between end-tidal CO2 pressure and [Formula: see text], an indirect measure of dead space. We aimed to investigate the relationships between increased dead space and inhalation injury outcomes. This retrospective study included 51 adult subjects with burns and inhalation injuries. Demographics, size of burns, length of stay, ventilator days, blood gas results, end-tidal CO2 pressure, presence of ventilator-associated pneumonia, and mortality data were collected. Modified Baux scores and ratios of alveolar dead space to alveolar tidal volume ([Formula: see text]/[Formula: see text]) were calculated. Independent t tests were used to compare mean [Formula: see text]/[Formula: see text] of survivors to that of subjects who died and between subjects with and without pneumonia. The relationships between [Formula: see text]/[Formula: see text] and ventilator days or modified Baux score were assessed with bivariate correlation analysis. Our population had a mean age of 52 y and an average burn size of 17.5%. The average length of stay and ventilator days were 12 d and 3.8 d, respectively. The mean modified Baux score was 87. The mean [Formula: see text]/[Formula: see text] was 0.38. Ten subjects died, and 6 subjects had pneumonia. The [Formula: see text]/[Formula: see text] of survivors was significantly smaller for survivors than for subjects who died (0.34 vs 0.52, P = .03). No significant difference was observed between subjects with and without pneumonia (0.36 vs 0.47, P = .26). [Formula: see text]/[Formula: see text] correlated significantly with modified Baux score (r = .524, P < .001). Alveolar dead space ([Formula: see text]/[Formula: see text]) is easily calculated from [Formula: see text] and end-tidal CO2 pressure and may be useful in assessing severity of inhalation injury, the patient's prognosis, and the patient's response to treatment.

Response of routine inflammatory biomarkers and novel Pancreatic Stone Protein to inhalation injury and its interference with sepsis detection in severely burned patients

BackgroundInhalation of thermal and chemical products of combustion evokes an immune response measurable at a systemic level. Inhalation injury related kinetics of currently available inflammatory biomarkers and novel Pancreatic Stone Protein (PSP) as well as their interference with septic events has not been addressed to literature yet. MethodsAnalysis of the influence of inhalation injury and ARDS on biomarker kinetics (PSP, procalcitonin (PCT), C-reactive Protein (CRP), white blood cells (WBC)) in 90 patients admitted to Zurich Burn Center between May 2015 and October 2018 with burns ≥15% total body surface area (TBSA) over 14 days. ResultsTwenty-five (27%) of 90 included patients presented with inhalation injury (median age 52 years [IQR 27], median TBSA 31.5% [IQR 21], mean ABSI-Score 7±3). At admission, only WBC demonstrated significantly higher values in the inhalation injury group (p=0.011). Acute respiratory distress syndrome (ARDS) was present in 32% without association to the severity of inhalation injury (p=0.11). WBC, CRP and PCT failed to delineate inhalation injury related inflammation from septic progression at most time points. PSP was the strongest marker to identify septic patients both by its higher values and steeper increase over time (p<0.001). ConclusionInhalation injury leads to an inflammatory response at a systemic level with alterations of biomarkers. While routine inflammatory markers demonstrated strong interferences between inhalation injury with its associated ARDS and evolving sepsis, PSP reliably identified septic patients in a setting of inflammatory turbulences secondary to inhalation injury.

519 Retrospective Pilot Study to Examine Potential Predictors of a Standardized Scoring System for Smoke Inhalation Injury

Abstract Introduction Smoke inhalation injury is strongly associated with increased morbidity/mortality. Bronchoscopy is used to diagnosis smoke inhalation injury, but its interpretation is subjective. This study sought to assess diagnostic significance of physical exam, history, location, and adjunct studies characteristically performed on patients suspected of smoke inhalation by comparing these findings to outcomes. The primary goal was to examine variables that could be used to create an accurate smoke inhalation injury scoring system in order to develop an objective method that considers the severity of inhalation injury. Methods This retrospective study evaluated demographics, clinical presentation, carboxyhemoglobin level, intubation on arrival, bronchoscopy, comorbidities, hospital course, and outcomes associated with smoke inhalation. Bronchoscopy findings included: red mucosa, carbon particles at carina, and numerical score (1–4). The primary outcome was resuscitation fluid required in the first 24 hours of treatment compared to that predicted by the modified Brooke formula (2cc*weight in kg* Total Burn Surface Area). If the patient received more fluid than predicted, this was considered positive for smoke inhalation. Differences between predictor/outcome variables were determined using Wilcoxon rank sum test for continuous variables and Chi-squared test for categorical. Results A positive bronchoscopy score was defined on the condition of having positive physical exam finding and/or bronchoscopy score 1–4. Physical exam findings consisted of soot or carbon sputum present on the patient along with hoarseness, wheezing, or a red oropharynx on physical exam. If the patient met one of these conditions, we considered this a positive result. Inclusion criteria: age 18–89, admission from 1/1/2004 and 5/31/18, and diagnosis of smoke inhalation injury/burn injury. There was a significant difference in positive bronchoscopy between those positive for our condition of inhalation injury and no injury (p&amp;lt; 0.001; Table 1). Patients with a positive bronchoscopy score were 9 times more likely (OR=9.91, 95% CI = 2.8–35.01) to be diagnosed with inhalation injury as compared to those without a positive bronchoscopy score. Conclusions These results display the importance of bronchoscopy in suspected smoke inhalation injury and reinforce the need for an objective bronchoscopy assessment. Future studies can build upon these results by creating an objective scoring system to guide providers performing bronchoscopy. Applicability of Research to Practice Due to the 9-fold benefit of performing bronchoscopy, it should be the primary tool used to assess potential smoke inhalation injury; other tests may be secondary in nature.

Value of joint prediction model based on the modified systemic inflammatory response syndrome score for predicting mortality risk of patients with large area burns at early stage after admission

Objective: To investigate the predictive value of the joint prediction model based on the modified systemic inflammatory response syndrome (SIRS) score (hereinafter referred to as the joint prediction model) for the mortality risk of patients with large area burns within 24 hours after admission. Methods: The clinical data of 158 patients [111 males, 47 females, aged 40 (28, 50) years] admitted to the Department of Burn Surgery of the First Affiliated Hospital of Naval Medical University from January 2005 to January 2018, conforming to the study criteria, were analyzed retrospectively by the method of case-control study. The age, gender, total burn area, full-thickness burn area, injury cause, with or without inhalation injury, severity of inhalation injury, and tracheotomy condition of patients were recorded, and the modified SIRS score and the modified Baux score of patients were calculated. According to the final outcome, all patients were divided into survival group (n=123) and death group (n=35). The clinical data of patients between two groups, except for modified Baux score, were compared by chi-square test or Mann-Whitney U test to screen the death-related factors of patients. The indexes with statistically significant difference between the two groups were included in the multivariate logistic regression analysis to screen the independent risk factors related to the death of patients, and the prediction model was constructed by combining the modified SIRS score. The receiver's operating characteristic curves of the modified SIRS score, the modified Baux score, and the joint prediction model of 158 patients were drawn to analyze their ability to predict death of patients. The area under curve (AUC) of the receiver's operating characteristic and the sensitivity and specificity of optimal threshold were calculated, and the quality of AUC of the three prediction indexes was compared with Jonckheere-Terpstra test. Results: (1) There were statistically significant differences between the two groups in the modified SIRS score, age, total burn area, full-thickness burn area, severity of inhalation injury, with or without inhalation injury, and tracheotomy condition of patients (Z=-4.356, -3.568, -5.291, -6.052, -4.720, χ(2)=12.967, 19.692, P<0.01). (2) The modified SIRS score, age, full-thickness burn area were the independent risk factors for the death of patients with large area burn (odds ratio=2.699, 1.069, 1.029, 95% confidence interval=1.447-5.033, 1.029-1.109, 1.005-1.054, P<0.05). (3) The AUC of modified SIRS score, the joint prediction model, and the modified Baux score for predicting death of 158 patients within 24 hours after admission were 0.730, 0.879, and 0.895 respectively (95% confidence interval=0.653-0.797, 0.818-0.926, 0.836-0.938, P<0.01). The sensitivities of the three optimal threshold values to death prediction were 54.3%, 91.4%, and 82.9% respectively, while the specificities were 81.3%, 76.4%, and 84.6% respectively. The AUC quality of the joint prediction model was similar to that of the modified Baux score (95% confidence interval=-0.057-0.088, P>0.05), and both of them were significantly better than that of the modified SIRS score (95% confidence interval=0.072-0.259, 0.023-0.276, P<0.05 or P<0.01). Conclusions: Both the joint prediction model and the modified Baux score are considered to be good to predict the death rate of patients with large area burns at early stage after admission. However, the joint prediction model has better clinical practice value due to its advantage of simple scoring and easier access to data acquisition.

Inhalation Injury (A Literature Review)

The analysis of domestic and foreign sources of literature showed that the problem of diagnosis and treatment of inhalation injury still remains relevant as 20-30 years ago. It is known that inhalation injury causes both local and systemic disorders. Existing diagnostic methods do not allow the extent of these disorders to be accurately determined. This, in turn, leads to the absence of clear criteria for the severity of inhalation injury and treatment algorithms.

Dynamic variation trend and prognostic value of bronchial wall thickness in severely burned patients combined with inhalation injury

Objective: To explore the dynamic variation trend of bronchial wall thickness (BWT) in severely burned patients combined with inhalation injury, and to determine the value of BWT to prognosis of patients. Methods: Forty-three severely burned patients with inhalation injury hospitalized in Intensive Burn Department of the Affiliated Hospital of Nankai University (Tianjin No.4 Hospital) from July to November 2016, conforming to the study criteria, were divided into survival group (n=27) and death group (n=16) according to the prognosis of patients within 14 days after admission. All patients underwent fiberoptic bronchoscopy and inhalation injury rating based on abbreviated injury scale at admission. High resolution CT examination was performed in patients of two groups at admission and 24 h post admission, 3, 7, and 14 d post admission to measure the BWT of right superior lobar bronchus trunk opening. Receiver operating characteristic curves of rating of inhalation damage at admission and BWT at admission were drawn to evaluate the predictive value for death of 43 patients. Data were processed with chi-square test, independent sample t test, Wilcoxon rank sum test, analysis of variance for repeated measurement and least-significant difference-t test. Results: (1) The numbers of patients rated as 0, 1, 2, 3, and 4 grade for inhalation injury in survival group and death group were 0, 19, 6, 2, and 0, and 0, 2, 7, 7, and 0, respectively. There were statistically significant differences between the two groups (Z=-3.79, P<0.01). (2) BWT of patients in death group at admission and 24 h post admission, 3, 7, and 14 d post admission was respectively (2.72±0.26), (3.18±0.22), (2.98±0.18), (2.29±0.17), and (1.45±0.21) mm, which was significantly larger than (2.24±0.15), (2.49±0.15), (1.51±0.17), (1.04±0.16), and (1.01±0.13) mm in survival group (t=7.55, 12.14, 27.11, 19.99, 7.11, P<0.01). BWT of patients in survival group and death group at 24 h post admission, 3, 7, and 14 d post admission showed statistically significant difference when compared with that at admission within the corresponding group (t=5.97, 16.63, 28.21, 38.57, 5.34, 3.31, 4.39, 6.48, P<0.01). BWT of patients in survival group and death group on 3, 7, and 14 d post admission was significantly smaller than that at 24 h post admission within the corresponding group (t=22.27, 34.02, 45.03, 2.77, 10.53, 10.59, P<0.01). BWT of patients in survival group and death group on 7 and 14 d post admission was significantly smaller than that on 3 d post admission within the corresponding group (t=10.49, 18.26, 9.57, 11.44, P<0.01). BWT of patients in survival group and death group on 14 d post admission was significantly smaller than that on 7 d post admission within the corresponding group (t=6.97, 6.15, P<0.01). (3) The total areas under ROC curves of inhalation injury rating at admission and BWT at admission for predicting death of 43 patients were 0.880 and 0.956, respectively (with 95% confidence intervals 0.768-0.991, 0.882-1.000, P<0.05). Grade 1.5 and 2.75 mm were respectively chosen as the optimal threshold values of inhalation injury rating at admission and BWT at admission, with sensitivity of 87.50%, 83.33% and specificity of 77.78%, 96.00%, respectively. Conclusions: The BWT of survived and dead patients with severe burn and inhalation injury increases significantly post burn, while the BWT of survived patients restores to normal level faster. BWT can be used to assess the severity of inhalation injury and to predict death in severely burned patients combined with inhalation injury.

45 Increased Dead Space Fraction in Patients with Inhalation Injury

Inhalation injury increases morbidity and mortality in burn patients. The pathology involves injury to large airways and V/Q mismatch, and differs from ARDS and pneumonia. We noted large differences between end-tidal CO2 (ETCO2) and PaCO2 in patients with inhalation injury. This difference is an indirect measure of dead space. We reviewed our experience with inhalation injury and the correlation of increased dead space with outcomes: mortality, ventilator associated pneumonia (VAP), and ventilator days (VNTd.) Following IRB approval we identified 51 adult patients with burns and inhalation injuries in our admission records from 2011–2015. Data collected includes: demographics, burn size, length of stay (LOS), ventilator days (VNTd), blood gas results, ETCO2, presence of VAP, and mortality. We calculated the dead space fraction (DSF) using the Enghoff-Modified Bohr Equation (difference between PaCO2 and ETCO2, divided by PaCO2.) We also calculated the Modified Baux Score (MBS.) We used Student’s T-tests to compare DSF between survivors and non-survivors, and between patients with and without VAP. We used bivariate correlation analysis to explore the relation between DSF and VNTd, DSF and MBS, and DSF and burn size. Values expressed as mean± SD. The 51 patients had a mean age of 52 ± 16.1 years and a mean burn size of 17.5 ± 25.2% resulting in a mean MBS of 87 ± 26.8. Mean LOS was 11.9 ± 15.0 days. In this sample 10 patients died (19.6%) and 6 developed VAP (11.8%). Mean DSF was 0.38 ± 0.22. Student’s T-tests found the DSF to be significantly lower in survivors (mean 0.34 ± 0.21) compared to non-survivors (mean 0.52 ± 0.24), p=0.027) but not between patients with VAP (mean 0.47 ± 0.31) and without (mean 0.36 ± 0.20, p=0.259.) Bivariate correlation analysis identified a weak correlation between DSF and VNTd, but this was not statistically significant (Pearson correlation coefficient 0.281, p=0.075.) Bivariate analysis identified a significant correlation between DSF and MBS (Pearson coefficient 0.524, p<0.001) and a stronger correlation between DSF and burn size (Pearson coefficient 0.606, p<0.001.) The dead space fraction (DSF) is often increased in patients with inhalation injury. DSF was significantly higher in patients who died with inhalation injury compared to survivors. DSF tended to be higher in patients with VAP, but the difference was not statistically significant. DSF correlates with the MBS and burn size. Further study of DSF and its role in inhalation injury is warranted. Dead space fraction (DSF) is easy to calculate from PaCO2 and ETCO2 and may be useful in measuring the severity of inhalation injury, the patient’s prognosis, and response to treatment.

Does inhalation injury predict mortality in burns patients or require redefinition?

Inhalation injury is known to be an important factor in predicting mortality in burns patients. However, the diagnosis is complicated by the heterogeneous presentation and inability to determine the severity of inhalation injury. The purpose of this study was to identify clinical features of inhalation injury that affect mortality and the values that could predict the outcome more precisely in burns patients with inhalation injury. This retrospective observational study included 676 burns patients who were over 18 years of age and hospitalized in the Burns Intensive Care Unit between January 2012 and December 2015. We analyzed variables that are already known to be prognostic factors (age, percentage of total body surface area (%TBSA) burned, and inhalation injury) and factors associated with inhalation injury (carboxyhemoglobin and PaO2/FiO2 [PF] ratio) by univariate and multivariate logistic regression. Age group (odds ratio [OR] 1.069, p<0.001), %TBSA burned (OR 1.100, p<0.001), and mechanical ventilation (OR 3.774, p<0.001) were identified to be significant predictive factors. The findings for presence of inhalation injury, PF ratio, and carboxyhemoglobin were not statistically significant in multivariate logistic regression. Being in the upper inhalation group, the lower inhalation group, and having a PF ratio <100 were identified to be significant predictors only in univariate logistic regression analysis (OR 4.438, p<0.001; OR 2.379, p<0.001; and OR 2.765, p<0.001, respectively). History and physical findings are not appropriate for diagnosis of inhalation injury and do not predict mortality. Mechanical ventilation should be recognized as a risk factor for mortality in burns patients with inhalation injury.