Time-varying discrimination accuracy of longitudinal biomarkers for the prediction of mortality compared to assessment at fixed time point in severe burns patients.

BACKGROUND: The progression of biomarkers over time is considered an indicator of disease progression and helps in the early detection of disease, thereby reducing disease-related mortality. Their ability to predict outcomes has been evaluated using conventional cross-sectional methods. This study investigated the prognostic performance of biomarkers over time. METHODS: Patients aged > 18 years admitted to the burn intensive care unit within 24 h of a burn incident were enrolled. Information regarding longitudinal biomarkers, including white blood cells; platelet count; lactate, creatinine, and total bilirubin levels; and prothrombin time (PT), were retrieved from a clinical database. Time-dependent receiver operating characteristic curves using cumulative/dynamic and incident/dynamic (ID) approaches were used to evaluate prognostic performance. RESULTS: Overall, 2259 patients were included and divided into survival and non-survival groups. By determining the area under the curve using the ID approach, platelets showed the highest c-index [0.930 (0.919-0.941)] across all time points. Conversely, the c-index of PT and creatinine levels were 0.862 (0.843-0.881) and 0.828 (0.809-0.848), respectively. CONCLUSIONS: Platelet count was the best prognostic marker, followed by PT. Total bilirubin and creatinine levels also showed good prognostic ability. Although lactate was a strong predictor, it showed relatively poor prognostic performance in burns patients.

Reliability of resting energy expenditure in major burns: Comparison between measured and predictive equations.

BACKGROUND & AIMS: Poor outcomes can result from inadequate energy intake. We aimed to investigate the reliability of resting energy expenditure (REE) measured by indirect calorimetry (IC) with REE calculated using predictive equations for nutritional support in patients with major burns. METHODS: REE was measured using IC and compared with predictive equations in 215 adult severe burns patients from Jan 2011 to Jun 2015. Agreement between IC and predictive equations was assessed using Bland-Altman methods. RESULTS: All predictive equations, including newly developed Hangang equation, were compared with REE measured using IC. The mean measured REE was 1712 kcal/d. Bland-Altman analysis showed that 1.2 times HBE, Thumb 25, and Ireton-Jones equations had higher accuracy and reliability. The concordance correlation coefficient was higher (0.49) in the Ireton-Jones equation, and root mean square error (RMSE) was lowest (471.5) in the Thumb 25 equation. The proportion of patients with predicted REE within ±10% of measured REE was highest with Thumb 25 (52.5%). In the validation set, the Hangang equation showed the highest Lin's concordance correlation coefficient (0.67) and the lowest RMSE (311.4). Other equations for burns patients had higher mean bias and overestimated REE when compared with IC results. CONCLUSIONS: This study suggests that Thumb 25 can be used as an alternative method for estimating energy requirements of patients with major burns when IC is not available or applicable. However, for these patients with significant variation in metabolism over time, an alternative equation is the new Hangang equation.

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.

Assessment of biochemical markers in the early post-burn period for predicting acute kidney injury and mortality in patients with major burn injury: comparison of serum creatinine, serum cystatin-C, plasma and urine neutrophil gelatinase-associated lipocalin.

INTRODUCTION: The reported mortality rates range from 28% to 100% in burn patients who develop acute kidney injury (AKI) and from 50% to 100% among such patients treated with renal replacement therapy. Recently, the serum cystatin C and plasma and urine neutrophil gelatinase-associated lipocalin (NGAL) levels have been introduced as early biomarkers for AKI; the levels of these biomarkers are known to increase 24 to 48 hours before the serum creatinine levels increase. In this study, we aimed to estimate the diagnostic utility of the cystatin C and plasma and urine NGAL levels in the early post-burn period as biomarkers for predicting AKI and mortality in patients with major burn injuries. METHODS: From May 2011 to July 2012, 90 consecutive patients with a burn wound area comprising ≥ 20% of the total body surface area (TBSA) were enrolled in this study. Whole blood and urine samples were obtained for measuring the serum creatinine, serum cystatin C, and urine and plasma NGAL levels at 0, 3, 6, 12, 24, and 48 hours after admission. Receiver operating characteristic curve, area under the curve, and multivariate logistic regression analyses were performed to assess the predictive values of these biomarkers for AKI and mortality. RESULTS: In the multivariate logistic regression analysis, all variables, including age, percentage TBSA burned, sex, inhalation injury, and serum creatinine levels, serum cystatin C levels, and plasma and urine NGAL levels were independently associated with AKI development. Moreover, age, sex, percentage TBSA burned, and plasma and urine NGAL levels were independently associated with mortality. However, inhalation injury and the serum creatinine and cystatin C levels were not independently associated with mortality. CONCLUSIONS: Massively burned patients who maintained high plasma and urine NGAL levels until 12 hours after admission were at the risk of developing early AKI and early mortality with burn shock. However, the plasma and urine NGAL levels in the early post-burn period failed to predict late AKI and non-burn shock mortality in this study. Nevertheless, the plasma and urine NGAL levels were independently associated with AKI development and mortality within 48 hours after admission.

Investigation of relationship between inhalation injury assessment and prognosis in burn patients.

PURPOSE: Inhalation injury is one of the most severe morbidity and mortality factors in burn patients. The purpose of this study is to analyze the impact of inhalation injury to the prognosis of burn patients and to investigate the relationship between the inhalation injury assessment and the prognosis of patients. METHODS: Bronchoscopy was performed in 170 patients who had the suspicion of inhalation injury and the patients were reviewed retrospectively from January 2008 to December 2009. Mortality was compared between the factors of brochoscopic findings, age, total body surface area (TBSA) burned, carboxyhemoglobin (COHb) level, PaO(2)/FiO(2) (P/F) ratio. RESULTS: Of 170 patients, 28 patients had no inhalation bronchoscopic finding. 109 patients had mild inhalation, 31 patients had moderate inhalation, only 2 patients had severe inhalation findings. The patients of moderate and severe inhalation findings had higher mortality (48.5%) than mild inhalation patients (31.1%). The larger total burnsurface area in inhalation patients, the greater the mortality. When compared to total admitted burn patients during the same period, inhalation patients showed higher mortality in the patients between 10 to 40% total burn surface area. Inhalation patients whose P/F ratio was below 300 showed higher mortality than above 300. But inhalation patients whose COHb level was below 1.5 had no difference in mortality with patients above 1.5. The COHb level and P/F ratio was the statistically different factors between inhalation patients and non-inhalation group in the mortality. CONCLUSION: Bronchoscopic findings, age, TBSA burned, P/F ratio were related with mortality in inhalation patients. When the international standardization of bronchoscopic classification developed, it can be possible to assess the inhalation patients more objectively and that will lead to the advancement in inhalation treatment and research.