Jaechul Yoon

Inhalation injury in burn patients: Establishing the link between diagnosis and prognosis

This study was to re-evaluate inhalation injury as a prognostic factor in burn patients and to determine the factors that should be considered when refining the definition of inhalation injury. A total of 192 burn patients (152 men, 40 women; mean age, 46.1±13.8 years) who were suspected to have an inhalation injury and underwent bronchoscopy between January 2010 and June 2012 were included in this prospective observational study. All patients underwent bronchoscopy within 24h of sustaining the burn. The bronchoscopic findings were classified as normal, mild, moderate, and severe. Mechanical ventilation was administered, when required. Age, percentage of TBSA burned, ABSI score, requirement of mechanical ventilation and PF ratio, but not inhalation injury, COHb level, and bronchoscopic grades, significantly differed between the survivors and non-survivors (p<0.05). Mechanical ventilation (adjusted odds ratio [OR]: 9.787) and severe inhalation injury on bronchoscopy (adjusted OR: 45.357) were independent predictors of mortality on multivariate logistic regression analysis. Inhalation injury diagnosed through history does not predict mortality from burns. Other components such as severity of inhalation injury determined using bronchoscopy, and administration of mechanical ventilation might help predict the morbidity and mortality of burn patients with inhalation injury and all of the factors should be considered when the definition of inhalation injury is refined.

The application of cultured epithelial autografts improves survival in burns

This prospective observational study was performed to analyze the clinical outcomes of patients with massive burns treated using cultured epithelial autografts (CEAs) and to determine the association of this treatment with survival outcomes. During 2006–2013, total 177 massive‐burns subjects treated with (96 subjects) or without (81 subjects) CEAs. Data were analyzed using the independent t test or chi‐square test. Multivariate logistic regression, Kaplan–Meier survival, and Cox regression analyses were performed to evaluate the factors that influenced mortality. Age, percentage of total body surface area burned, incidence of inhalation injury, allograft‐application rate, Abbreviated Burn Severity Index score, length of hospital stay, and mortality significantly differed between the CEA and noncultured epithelial autograft groups. Mortality and other clinical parameters did not differ between the sheet‐type and spray‐type CEA groups. Allograft application (odds ratio, 4.44; p < 0.01) significantly influenced CEA application. The CEA group showed significantly higher survival rates (p = 0.05). Cultured epithelial autografting had a hazard ratio of 0.55 (p = 0.02) and 0.59 (p = 0.05) according to the uni‐ and multivariate Cox regression analysis, respectively. In conclusion, early and aggressive allograft application is required to facilitate CEA application. Furthermore, the use of CEAs was associated with a lower mortality, but this result should be interpreted with caution as the groups were not randomized.

Evaluation of diagnostic biomarkers for acute kidney injury in major burn patients

Purpose Acute kidney injury (AKI) in major burn patients is a common complication with high morbidity and mortality. The mainstream treatment is early diagnosis and rapid termination and prevention of the underlying insult. Therefore, its essential to identify early biomarkers predicting AKI. Methods A total of 85 patients who were admitted to the burn intensive care unit from June 2012 to July 2013 were included in this prospective cohort study. Ten biomarkers (blood urea nitrogen, serum creatinine, urine creatinine, cystatin C, cystatin C glomerular filtration rate, AST, lacate dehydrogenase [LD], creatine kinase, lactic acid, and myoglobin) were obtained at time of admission and evaluated as diagnostic biomarkers to predicting AKI and early AKI. Results Out of 85 patients, 35 patients were dead and overall mortality was 41.2%. The mean age was 49.4 years and mean percentage of total body surface area was 53.2%. Area under the curve (AUC) of receiver operating characteristic curve of biomarkers on predicting AKI were 0.746, 0.718, and 0.717 in LD, lactic acid, and serum creatinine, respectively. AUC of cystatin C predicting AKI was much lower at 0.555. AUC of biomarkers on predicting early AKI were 0.833, 0.816, 0.790, and 0.759 in LD, serum creatinine, AST, and serum myoglobin. Conclusion LD, lactic acid and serum creatinine were acceptable as diagnostic biomarkers of AKI and LD, serum creatinine, AST, and serum myoglobin were reasonable as diagnostic biomarkers of early AKI. However, cystatin C was an unfavorable biomarker in major burn patients.

Serum cystatin C and microalbuminuria in burn patients with acute kidney injury.

This study was aimed at evaluating the effectiveness of serum cystatin C and microalbuminuria as diagnostic markers for acute kidney injury (AKI) in major burn patients.

Analysis of prognostic factors for acute kidney injury with continuous renal replacement therapy in severely burned patients

BACKGROUND Acute kidney injury (AKI) is a critical complications in severely burned patients associated with high morbidity and mortality. The purpose of this study was to investigate the impact of severity of AKI at the time of continuous renal replacement therapy (CRRT) start on patient outcome and to identify the prognostic factors in severely burned patients with CRRT application. METHODS From January 2007 to June 2010, 84 burn patients with more than 40% of total body surface area (TBSA) burned who treated with continuous renal replacement therapy for acute kidney injury were analyzed retrospectively. RESULTS There was no significant difference of mortality by the severity of AKI at the time of CRRT start. However, the mean TBSA burned, abbreviated burn severity index, arterial pH, partial pressure of carbon dioxide (PaCO2) and blood urea nitrogen (BUN)/creatinine (Cr) ratio had a statistical significance to predict mortality in receiver operation characteristic curve. In a multivariate logistic regression analysis, only sepsis had an independent association with mortality. CONCLUSIONS The severity of the AKI at the time of CRRT start did not have significant relationship with patient outcome. CRRT can be applied to minimize the complication of AKI including electrolyte imbalance and volume overload. Because only the presence of sepsis was independently associated with mortality, treatment for sepsis should be focused to improve the survival of the severely burned patients with CRRT.

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.

Assessment of Plasma Neutrophil Gelatinase-Associated Lipocalin for Early Detection of Acute Kidney Injury and Prediction of Mortality in Severely Burned Patients

The purpose of this study was to assess the plasma neutrophil gelatinase-associated lipocalin (NGAL) for early detection of acute kidney injury (AKI) and prediction of mortality in severely burned patients. From January 2014 to September 2015, 76 consecutive patients with more than 20% of TBSA burned were enrolled. Blood samples for plasma NGAL were collected at 0, 7, 14, 21, and 28 days after admission and analyzed with injury severity, clinical outcome, and AKI development. Plasma NGAL was significantly affected by the TBSA burned, AKI, and mortality, and it was significantly increased after operation and septic shock. Plasma NGAL was significantly increased within 7 days before AKI development in total patients (P < .001) and septic shock patients (P < .001) but not significantly increased in patients without septic shock (P = .167). Though, in a receiver operating characteristic curve analysis for predicting AKI, continuous renal replacement therapy application, and mortality, plasma NGAL was statistically significant; plasma NGAL was not independently associated with mortality in a multivariate logistic regression analysis. Plasma NGAL should be interpreted carefully in the major burn patients because it can reflect both inflammatory condition and AKI.

Diagnostic performance of plasma and urine neutrophil gelatinase-associated lipocalin, cystatin C, and creatinine for acute kidney injury in burn patients: A prospective cohort study

Background Diagnosing acute kidney injury quickly is imperative since it is known as an independent risk factor for mortality in burn patients. We evaluated the diagnostic power of creatinine, cystatin, serum and urine neutrophil gelatinase-associated lipocalin at different time periods and observed the changes from baseline for each biomarker. Methods This was a prospective observation study from January 2015 to February 2016. A total of 84 patients were enrolled consecutively. Serum creatinine, serum cystatin C, and serum and urine neutrophil gelatinase-associated lipocalin were measured at admission, 7th, 14th, 21st, and 28th days after admission. All samples were collected until acute kidney injury developed. Results Acute kidney injury developed in 35 patients. The mean age was 49.6 years with a male predominance. The median urine neutrophil gelatinase-associated lipocalin was the lowest (11.6 ng/dL) at admission, and the highest at 85.5 ng/dL on day 7. Mean creatinine level was the highest (0.88 mg/dL) at admission and the median creatinine level was the lowest (0.56 mg/dL) on the 14th day. The area under the curve of creatinine levels was the highest with 0.857 during the 1st week. The area under the curve of urine neutrophil gelatinase-associated lipocalin was the highest with 0.803 during the 5th week. Conclusions Within 1 week of acute kidney injury, creatinine level was the optimal biomarker for diagnosis while urine neutrophil gelatinase-associated lipocalin showed better diagnostic performance following the 4- week period.

Subgroup analysis of continuous renal replacement therapy in severely burned patients

Continuous renal replacement therapy (CRRT) is administered to critically ill patients with renal injuries as renal replacement or renal support. We aimed to identify predictors of mortality among burn patients receiving CRRT, and to investigate clinical differences according to acute kidney injury (AKI) status. This retrospective observational study evaluated 216 Korean burn patients who received CRRT at a burn intensive care unit. Patients were categorized by AKI status. Data were collected regarding arterial pH, laboratory results, ratio of arterial oxygen partial pressure to fractional inspired oxygen (PF ratio), and urine production. Among surviving patients, CRRT duration and the sequential organ failure assessment score were 6.5 days and 4.7 in the non-AKI group and 23.4 days and 7.4 in the AKI group, respectively (p = 0.003 and p = 0.008). On logistic regression analyses, mortality was significantly associated with a pH of <7.2 (p = 0.004), potassium levels of >5.0 mEg/L (p = 0.045), creatinine levels of >2.0 mg/dL (p = 0.011), lactate levels of >2 mmol/L (p<0.001), a PF ratio of <200 (p = 0.042), and a platelet count of <100,000/μL (p<0.001). In the AKI group, poor outcomes were associated with a pH of <7.2, potassium levels of <5.0 mEg/L, lactate levels of >2 mmol/L, and a platelet count of <100,000/μL, while good outcomes were associated with creatinine levels of >2 mg/dL. In the non-AKI group, poor outcomes were associated with lactate levels of >1.5 mmol/L, a PF ratio of <200, and a platelet count of <100,000/μL, while good outcomes were associated with creatinine levels of >1.2 mg/dL. Duration of the CRRT application and the requirement for either renal replacement or renal support at the initiation of CRRT application are important considerations depending on its application.