Tissue Inhibitors of Metalloproteinase 1 (TIMP-1) and 3 (TIMP-3) as New Markers of Acute Kidney Injury After Massive Burns

BACKGROUND Acute kidney injury (AKI) is a common and serious complication after massive burn injury. One of the postulated etiologies is destruction of the extracellular matrix of nephrons, caused by a local imbalance between matrix metalloproteinases (MMPs) and specific inhibitors. The aim of this study was to analyze the dynamics of tissue inhibitors of metalloproteinases (TIMPs) during the first 5 days after massive thermal injury and the relationship with the risk of AKI. MATERIAL AND METHODS Thirty-three adults (22 men, 11 women) with severe burns were enrolled in the study. The values of TIMPs 1 to 4 were measured in blood serum and urine using the multiplex Luminex system. The associations between TIMPs and the risk of AKI were analyzed by using the generalized linear mixed models for repeated measurements. RESULTS Significant changes in serum and urine activities of TIMPs were confirmed, especially during the first 2 days after burn injury. Almost half of patients presented renal problems during the study. Significant differences between values of TIMPs in AKI and non-AKI status were also observed. However, a significant relationship between concentration of TIMPs and risk of AKI was confirmed only for urine TIMP-1 and serum TIMP-3. CONCLUSIONS The evaluation of TIMPs in the early stage after burn injury has potential benefits. The important roles of urine TIMP-1 and serum TIMP-3, as novel markers of the risk of AKI development, were confirmed. Other parameters require further analysis.

The systemic inflammation indexes after admission predict in-hospital mortality in patients with extensive burns

PURPOSE

To explore the clinical value of various complete blood count (CBC)-derived inflammation indicators to predict in-hospital mortality in patients with extensive burns.

METHODS

Systemic inflammation indexes, including lymphocyte-platelet ratio (LPR), neutrophil-lymphocyte ratio (NLR), neutrophil-monocyte ratio (NMR), monocyte-lymphocyte ratio (MLR), neutrophil-to-lymphocyte * platelet (NLPR), systemic inflammation index (SII), and systemic inflammation response index (SIRI) on days 1, 3, and 7 after admission were calculated in 135 patients with extensive burns.

RESULTS

We included 135 patients with extensive burns, including 97 survivors and 38 non-survivors. After adjusting for confounders, only the LPR on day 1, NLPR on days 3 and 7 were significantly associated with survival (OR= 1.237, 1.097, 1.104; 95 % CI: 1.055-1.451, 1.002-1.202, 1.005-1.212; respectively) in the analysis of multivariate logistic regression. The optimum cutoff values of the LPR on day 1 and NLPR on day 3 were 6.37 and 8.06, and the area under the curves (AUC) were 0.695 and 0.794, respectively. The AUC of NLPR on day 7 had the highest value, 0.814, and the optimum cut-off value was 3.84. The efficacy of LPR on day 1, NLPR on days 3 and 7 combined with the burn prognostic score index in predicting the prognosis of patients was higher than that of the burn index alone, and the three composite inflammatory indexes combined with PBI had the highest efficacy in predicting the prognosis (AUC = 0.994). Kaplan-Meier survival analysis showed poor prognosis in patients with higher LPR on day 1 and higher NLPR on days 3 and 7 (log-rank χ2 =9.623,31.564, 20.771, respectively; P < 0.01).

CONCLUSIONS

LPR on day 1 and NLPR on days 3 and 7 after admission are reliable predictors of prognosis in patients with severe extensive burns. The combination of the burn prognostic score index, LPR on day 1, and NLPR on days 3 and 7 was superior to the burn indexes alone in predicting a patient's prognosis.

Higher serum prealbumin levels are associated with higher graft take and wound healing in adult burn patients: A prospective observational trial

INTRODUCTION

Nutritional support is essential in burn care. There are few studies investigating the effect of nutrition on burn healing. The purpose of this study was to determine the relationship between perioperative serum prealbumin levels and the probability of autologous skin graft take in burned patients.

MATERIALS AND METHODS

A prospective observational study was carried out with burned adults recruited consecutively from April 2019 until September 2021. Serum prealbumin was determined perioperatively. The percentage of graft take was evaluated over the first 5 postoperative dressing changes. Time until full epithelialization (absence of wounds) was also registered.

RESULTS

A total of 60 patients were recruited, mostly middle-aged people with moderate flame burns. Serum prealbumin levels and graft take had a weak-moderate, nonlinear, statistically significant correlation. They were also an independent predictor of full epithelialization on the fifth dressing change, together with burn depth. Higher perioperative serum prealbumin levels were significantly associated with a reduction in time until full epithelialization.

CONCLUSIONS

Perioperative serum prealbumin levels are significantly correlated with the probability of split-thickness skin autograft take in burned patients and with a reduced time to achieve complete epithelialization. They were an independent predictor of full graft take.

Association of inflammatory biomarkers with overall survival in burn patients: a systematic review and meta-analysis

INTRODUCTION

The inflammatory response to burn injuries can lead to organ dysfunction that ultimately results in increased mortality and morbidity. This meta-analysis was conducted to determine the efficacy of inflammatory biomarkers, including the neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), procalcitonin (PCT), and C-reactive protein (CRP) as predictive tools of mortality among burn patients.

MATERIAL AND METHODS

The biomarker levels of survivors and non-survivors were consolidated according to guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Three main databases were searched electronically: PubMed, Web of Science, and Scopus, on December 8, 2022. The Newcastle-Ottawa Quality Assessment Scale (NOS) was used to evaluate and score the methodological quality of the included studies. The standard mean difference (SMD) with a 95% confidence interval (CI) was utilized.

RESULTS

Twenty-four studies were included in our systematic review and meta-analysis, (3636 total burn patients), of whom 2878 survived. We found that deceased burn patients had elevated levels of NLR (SMD = 0.60, 95% CI; 0.19-1.00, P < 0.001), CRP (SMD = 0.80, 95% CI; 0.02-1.58, P = 0.04), and PCT (SMD = 0.85, 95% CI; 0.45-1.24, P < 0.001), compared to survivors. However, we found no association between PLR and mortality among burn patients (SMD = 0.00, 95% CI; -0.14-0.15, P < 0.001). In addition, CRP was significantly higher in non-survivors (SMD = 0.80, 95% CI; 0.02-1.58, P =0.04). Similar results were also found about PCT (SMD = 0.85, 95% CI; 0.45-1.24, P < 0.001). When we analyzed the PCT data, collected in the first 24-48 hours, we found similar results; the PCT level was significantly higher in non-survivors in the immediate postinjury-period (SMD = 0.67, 95% CI; 0.31-1.02, P < 0.001). There was no publication bias among studies on the role of NLR in burn (Egger's test P = 0.91). The based cut-off values for NLR (13), CRP (71), and PCT (1.77) yielded sensitivities of 69.2%, 100%, and 93.33%, and specificities of 76%, 72.22%, and 72.22% respectively.

DISCUSSION/CONCLUSIONS

PCT is a marker of sepsis, therefore its elevated level is presumably associated with a higher incidence and severity of sepsis among non-survivors. In addition, NLR and CRP are promising biomarkers for predicting and guiding prevention against burn deaths in clinical settings.

[Predictive value of D-dimer for deep venous thrombosis of lower extremity in adult burn patients]

Objective: To investigate the predictive value of D-dimer for deep venous thrombosis (DVT) of lower extremity in adult burn patients. Methods: A retrospective case series study was conducted. The clinical data of 3 861 adult burn patients who met the inclusion criteria and were admitted to the Department of Burns of Zhengzhou First People's Hospital from January 1, 2015 to December 31, 2019 were collected. The patients were divided into DVT group (n=77) and non-DVT group (n=3 784) according to whether DVT of lower extremity occurred during hospitalization or not. Data of patients in the two groups were collected and compared, including the gender, age, total burn area, D-dimer level, with lower limb burn and inhalation injury or not on admission, with sepsis/septic shock, femoral vein indwelling central venous catheter (CVC), history of surgery, and infusion of concentrated red blood cells or not during hospitalization. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. The indicators with statistically significant differences between the two groups were analyzed with multivariate logistic regression analysis to screen the independent risk factors for DVT of lower extremity in 3 861 adult burn patients. The receiver operating characteristic (ROC) curve of the independent risk factors predicting DVT of lower extremity in 3 861 adult burn patients were drawn, and the area under the curve (AUC), the optimal threshold value, and the sensitivity and specificity under the optimal threshold value were calculated. The quality of the AUC was compared by Delong test, and the sensitivity and specificity under the optimal threshold value were compared using chi-square test. Results: There were no statistically significant differences in gender, occurrence of sepsis/septic shock or history of surgery during hospitalization between patients in the two groups (P>0.05), while there were statistically significant differences in age, total burn area, D-dimer level, lower limb burn and inhalation injury on admission, and femoral vein indwelling CVC and infusion of concentrated red blood cells during hospitalization between patients in the two groups (t=-8.17, with Z values of -5.04 and -10.83, respectively, χ2 values of 21.83, 5.37, 7.75, and 4.52, respectively, P<0.05 or P<0.01). Multivariate logistic regression analysis showed that age, total burn area, and D-dimer level were the independent risk factors for DVT of lower extremity in 3 861 adult burn patients (with odds ratios of 1.05, 1.02, and 1.14, respectively, 95% confidence intervals of 1.04-1.06, 1.00-1.03, and 1.10-1.20, respectively, P<0.05 or P<0.01). The AUCs of ROC of age, total burn area, and D-dimer level for predicting DVT of lower extremity in 3 861 adult burn patients were 0.74, 0.67, and 0.86, respectively (with 95% confidence intervals of 0.68-0.80, 0.60-0.74, and 0.83-0.89, respectively, P values<0.01), the optimal threshold values were 50.5 years old, 10.5% total body surface area, and 1.845 mg/L, respectively, the sensitivity under the optimal threshold values were 71.4%, 70.1%, and 87.0%, respectively, and the specificity under the optimal threshold values were 66.8%, 67.2%, and 72.9%, respectively. The AUC quality and sensitivity and specificity under the optimal threshold value of D-dimer level were significantly better than those of age (z=3.29, with χ2 values of 284.91 and 34.25, respectively, P<0.01) and total burn area (z=4.98, with χ2 values of 326.79 and 29.88, respectively, P<0.01), while the AUC quality and sensitivity and specificity under the optimal threshold values were similar between age and total burn area (P>0.05). Conclusions: D-dimer level is an independent risk factor for DVT of lower extremity in adult burn patients, its AUC quality and sensitivity and specificity under the optimal threshold value are better than those of age and total burn area, and it has good predictive value for DVT of lower extremity in adult burn patients.

Severity of thermal burn injury is associated with systemic neutrophil activation

Burn injuries elicit a unique and dynamic stress response which can lead to burn injury progression. Though neutrophils represent crucial players in the burn-induced immunological events, the dynamic secretion pattern and systemic levels of neutrophil-derived factors have not been investigated in detail so far. Serum levels of neutrophil elastase (NE), myeloperoxidase (MPO), citrullinated histone H3 (CitH3), and complement factor C3a were quantified in burn victims over 4 weeks post injury. Furthermore, the potential association with mortality, degree of burn injury, and inhalation trauma was evaluated. In addition, leukocyte, platelet, neutrophil, and lymphocyte counts were assessed. Lastly, we analyzed the association of neutrophil-derived factors with clinical severity scoring systems. Serum levels of NE, MPO, CitH3, and C3a were remarkably elevated in burn victims compared to healthy controls. Leukocyte and neutrophil counts were significantly increased on admission day and day 1, while relative lymphocytes were decreased in the first 7 days post burn trauma. Though neutrophil-derived factors did not predict mortality, patients suffering from 3rd degree burn injuries displayed increased CitH3 and NE levels. Accordingly, CitH3 and NE were elevated in cases with higher abbreviated burn severity indices (ABSI). Taken together, our data suggest a role for neutrophil activation and NETosis in burn injuries and burn injury progression. Targeting exacerbated neutrophil activation might represent a new therapeutic option for severe cases of burn injury.

Association of the Circulating Supar Levels with Inflammation, Fibrinolysis, and Outcome in Severe Burn Patients

BACKGROUND

Hyperfibrinolysis and pro/anti-inflammatory imbalance usually occur in the early stage of severe burns. Soluble urokinase-type plasminogen activator receptor (suPAR) is involved in fibrinolysis and inflammation. To date, the levels of circulating suPAR in non-survivors with severe burns remain unknown. This study aimed to investigate the early association between circulating suPAR levels and biomarkers of fibrinolysis, pro/anti-inflammatory, and prognosis.

METHODS

Sixty-four consecutive Chinese patients with severe burns and 26 healthy volunteers were enrolled in a prospective observational cohort. Clinical characteristics and laboratory data were collected prospectively. Blood samples were collected at 48 h post-burn, and suPAR and biomarkers of pro/anti-inflammatory and fibrinolysis were detected by enzyme-linked immunosorbent assays. Important indicators between non-survivors and survivors were compared. Linear regression analysis was performed to screen variables associated with suPAR. Logistic regression analysis and receiver operating characteristic curve (ROC) analysis were performed to evaluate the prognostic value of suPAR.

RESULT

Compared with the control group, the circulating suPAR levels in the survivors (P < 0.001) and non-survivors (P = 0.017) were higher. Compared with survivors, non-survivors had lower circulating suPAR levels at 48 h post-burn, and they showed a higher degree of fibrinolysis (higher D-dimer) and a lower TNF-α/IL-10 ratio. According to linear regression analysis, the variables independently associated with a lower suPAR level were lower platelet factor 4 (PF-4), urokinase-type plasminogen activator (uPA), and TNF-α/IL-10 levels and a higher D-dimer level. Logistic regression and ROC analyses indicated that a suPAR level ≤ 4.70 μg/L was independently associated with 30-day mortality.

CONCLUSION

Low circulating suPAR levels at 48 h post-burn in severe burn patients may reflect decreased TNF-α/IL-10 ratio and increased hyperfibrinolysis. suPAR can predict 30-day mortality in patients with severe burn.

Circulating Syndecan-1 and Tissue Factor Pathway Inhibitor, Biomarkers of Endothelial Dysfunction, Predict Mortality in Burn Patients

OBJECTIVE

The aim of this study is to evaluate the association between burn injury and admission plasma levels of Syndecan-1 (SDC-1) and Tissue Factor Pathway Inhibitor (TFPI), and their ability to predict 30-day mortality.

BACKGROUND

SDC-1 and TFPI are expressed by vascular endothelium and shed into the plasma as biomarkers of endothelial damage. Admission plasma biomarker levels have been associated with morbidity and mortality in trauma patients, but this has not been well characterized in burn patients.Methods: This cohort study enrolled burn patients admitted to a regional burn center between 2013 and 2017. Blood samples were collected within 4 h of admission and plasma SDC-1 and TFPI were quantified by ELISA. Demographics and injury characteristics were collected prospectively. The primary outcome was 30-day in-hospital mortality.

RESULTS

Of 158 patients, 74 met inclusion criteria. Most patients were male with median age of 41.5 years and burn TBSA of 20.5%. The overall mortality rate was 20.3%. Admission SDC-1 and TFPI were significantly higher among deceased patients. Plasma SDC-1 >34 ng/mL was associated with a 32-times higher likelihood of mortality [OR: 32.65 (95% CI, 2.67-399.78); P = 0.006] and a strong predictor of mortality (area under the ROC [AUROC] 0.92). TFPI was associated with a nine-times higher likelihood of mortality [OR: 9.59 (95% CI, 1.02-89.75); P = 0.002] and a fair predictor of mortality (AUROC 0.68).

CONCLUSIONS

SDC-1 and TFPI are associated with a higher risk of 30-day mortality. We propose the measurement of SDC-1 on admission to identify burn patients at high risk of mortality. However, further investigation with a larger sample size is warranted.

Circulating sFasL Levels Predict the Severity and Outcome of Burn Injury: A Prospective Observational Study

BACKGROUND

Severe burn injury activates shock, inflammation, and blood cell system, but inappropriate reactions may lead to adverse outcomes. Soluble Fas ligand (sFasL) participates in apoptosis and inflammatory response. The circulating sFasL levels we investigated in association with the burn severity, shock, inflammation, blood cells, and mortality in patients with severe burns.

METHODS

A total of 56 patients with severe burns were recruited. The levels of sFasL and the biomarkers reflecting shock, organ damage, inflammation, and blood cells at 48 h postburn were analyzed. We compared the practical situation of patients that stratified by median sFasL levels and investigated the predictive value of sFasL for mortality.

RESULTS

High circulating sFasL levels were associated with the higher degrees of burn index, shock index, lactate, N-terminal probrain natriuretic peptide, total bilirubin, blood urea nitrogen, creatinine, tumor necrosis factor-α, interleukin-1β, interleukin-8, intercellular adhesion molecule 1, and complement 3, and the lower degrees of oxygenation index, lymphocytes, and platelets. Multiple linear regression analysis showed that the higher tumor necrosis factor-α (P < 0.001) and the lower oxygenation index (P = 0.031) and lymphocytes (P = 0.043) were associated with the higher sFasL. High sFasL (a unit is 50 ng/L) (odds ratio [OR] 5.50 [95% CI 1.04-29.20], P = 0.045) was an independent predictor of increased mortality by multivariate logistic regression analysis.

CONCLUSIONS

High circulating sFasL at 48 h postburn in patients with severe burns reflect shock, proinflammatory response, organ damage, and lymphocyte reductions and predict 30-day mortality.

Serum albumin concentration on admission as a predictor of morbidity and mortality in patients with burn injuries

Efforts have been made to determine new predictors of morbidity and mortality in patients with severe burn injuries. This prospective cohort study aimed to determine the association of serum albumin concentration on admission and renal failure, pulmonary infection, sepsis, and death in patients with burn injuries. We included 141 patients, aged >18 years, who were admitted to our institution between April and August 2018. Among them, 59.1% were male and 83.8% had burns covering <20% of the body surface area. Scalds were the most common cause of burns (34.8%). Twelve patients died, of whom eight (66.6%) had an Abbreviated Burn Severity Index (ABSI) ≥8. Patients with serum albumin ≤2.2 g/dL had a higher mortality rate than those with >2.2 g/dL (odds ratios [OR]: 18.7; 95% confidence interval [CI]: 4.9-70.8). Serum albumin ≤2.2 g/dL was also significantly associated with pulmonary infection (OR: 13.1, 95%CI: 3.8-45.7), renal failure (OR: 30.2, 95% CI: 7.4-122.3), and sepsis (OR: 16.9, 95% CI: 4.9-58.3). Serum albumin concentration cut-points and ABSIs were determined to be death predictors using areas under the receiver operating characteristic curves (AUCs). The AUCs with albumin or ABSI alone were 0.89 (95% CI: 0.79-0.98) and 0.92 (95% CI: 0.87-0.96), respectively. The AUC including both albumin and ABSI was 0.96 (95% CI: 0.90-0.98), indicating that the combination is a better death predictor than either measure alone. We confirmed that burn patients with a serum albumin concentration ≤2.2 g/dL on admission have substantially increased morbidity and mortality.

Beyond cells: The extracellular circulating 20S proteasomes

Accumulating evidence arising from numerous clinical studies indicate that assembled and functional 20S proteasome complexes circulate freely in plasma. Elevated levels of this core proteolytic complex have been found in the plasma of patients suffering from blood, skin and solid cancers, autoimmune disorders, trauma and sepsis. Moreover, in various diseases, there is a positive correlation between circulating 20S proteasome (c20S) levels and treatment efficacy and survival rates, suggesting the involvement of this under-studied c20S complex in pathophysiology. However, many aspects of this system remain enigmatic, as we still do not know the origin, biological role or mechanisms of extracellular transport and regulation of c20S proteasomes. In this review, we provide an overview of the current understanding of the c20S proteasome system and discuss the remaining gaps in knowledge.

Dihydrotestosterone (DHT) Enhances Wound Healing of Major Burn Injury by Accelerating Resolution of Inflammation in Mice

Androgens have been known to inhibit cutaneous wound healing in men and male mice. However, in children with major burn injuries, a synthetic androgen was reported clinically to improve wound healing. The aim of this study is to investigate the role of dihydrotestosterone (DHT) as a new therapeutic approach in treating major burn injury. In the present study, mice received systemic androgen treatment post major burn injury. Wound healing rate and body weight were monitored over 21 days. The serum level of inflammatory cytokines/chemokines were measured using multiplex immunoassays. In addition, splenocyte enumeration was performed by flow cytometry. Healing phases of inflammation, re-epithelialization, cell proliferation and collagen deposition were also examined. In results, DHT treated mice lost less weight and displayed accelerated wound healing but has no impact on hypermetabolism. Mice, after burn injury, displayed acute systemic inflammatory responses over 21 days. DHT treatment shortened the systemic inflammatory response with reduced splenic weight and monocyte numbers on day 14 and 21. DHT treatment also reduced wound infiltrating macrophage numbers. In conclusion, DHT treatment facilitates local wound healing by accelerating the resolution of inflammation, but not through alterations of post-burn hypermetabolic response.

New markers for sepsis caused by Pseudomonas aeruginosa during burn infection

INTRODUCTION

Sepsis is a leading cause of mortality in burn patients. One of the major causes of sepsis in burn patients is Pseudomonas aeruginosa. We hypothesized that during dissemination from infected burn wounds and subsequent sepsis, P. aeruginosa affects the metabolome of the blood resulting in changes to specific metabolites that would serve as biomarkers for early diagnosis of sepsis caused by P. aeruginosa.

OBJECTIVES

To identify specific biomarkers in the blood after sepsis caused by P. aeruginosa infection of burns.

METHODS

Gas chromatography with time-of-flight mass spectrometry was used to compare the serum metabolome of mice that were thermally injured and infected with P. aeruginosa (B-I) to that of mice that were neither injured nor infected, mice that were injured but not infected, and mice that were infected but not injured.

RESULTS

Serum levels of 19 metabolites were significantly increased in the B-I group compared to controls while levels of eight metabolites were significantly decreased. Thymidine, thymine, uridine, and uracil (related to pyrimidine metabolism), malate and succinate (a possible sign of imbalance in the tricarboxylic acid cycle), 5-oxoproline (related to glutamine and glutathione metabolism), and trans-4-hydroxyproline (a major component of the protein collagen) were increased. Products of amino acid metabolism were significantly decreased in the B-I group, including methionine, tyrosine, indole-3-acetate, and indole-3-propionate.

CONCLUSION

In all, 26 metabolites were identified, including a unique combination of five metabolites (trans-4-hydroxyproline, 5-oxoproline, glycerol-3-galactoside, indole-3-acetate, and indole-3-propionate) that could serve as a set of biomarkers for early diagnosis of sepsis caused by P. aeruginosa in burn patients.

N-Terminal Brain Natriuretic Peptide First Week After Burn Injury

B-type natriuretic peptide has shown promising results as a biomarker for acute kidney injury in general intensive care patients. It may also indirectly reflect fluid balance of the circulation. Among burn patients, it has been observed to indicate excessive fluid resuscitation and organ dysfunction, although its clinical use to indicate acute kidney injury or guide fluid resuscitation has not been validated. The aim of this study was to evaluate whether the N-terminal pro-brain natriuretic peptide values are related to the amount of fluids given after severe burn injury and whether it can act as a novel biomarker for acute kidney injury in these patients. Nineteen consecutive burn patients were included. Plasma N-terminal pro-brain natriuretic peptide was measured daily during 1 week from admission. Other variables such as laboratory values and intravenous infusions were also recorded. The association between acute kidney injury and N-terminal pro-brain natriuretic peptide values was analyzed with a multivariable panel regression model, adjusted for burned total body surface area, age, body mass index, and laboratory values. N-terminal pro-brain natriuretic peptide values varied between single patients, and even more between the patients who developed acute kidney injury. Older age, lower body mass index, and cumulative infusions were independently associated with higher N-terminal pro-brain natriuretic peptide values, whereas acute kidney injury was not. N-terminal pro-brain natriuretic peptide values correlated with cumulative infusions given during the first week. The authors could not validate the role of N-terminal pro-brain natriuretic peptide as a biomarker for acute kidney injury in burns.

Albumin supplementation may have limited effects on prolonged hypoalbuminemia in major burn patients: An outcome and prognostic factor analysis

BACKGROUND

Burns that affect ≥20% of the total body surface area (TBSA) trigger a major inflammatory response in addition to capillary leakage and loss of serum proteins including albumin. Persistent hypoalbuminemia is therefore common in major burn patients. The purpose of this study was to determine whether human albumin solutions can benefit major burn patients with persistent hypoalbuminemia.

METHODS

We conducted a retrospective review of major burn patients with ≥20% of TBSA involved at Taipei Veterans General Hospital between January 2007 and December 2018. Thirty-eight patients were enrolled. Patient demographics, burn characteristics, fluid balance, laboratory results, and outcomes were recorded through chart review.

RESULT

No significant differences were found in the baseline characteristics of patients who received <25 mg/kg/%TBSA/day of human albumin solutions and those who received more than this amount. Renal replacement therapy, duration of mechanical ventilation, length of stay in the burn unit, and in-hospital mortality rate were not statistically different between the two groups. The serum C-reactive protein/albumin ratio was associated with in-hospital mortality (p = 0.036).

CONCLUSION

The administration of large amounts of albumin supplements for the correction of prolonged hypoalbuminemia in major burn patients had no significant benefits on mortality.

Impact of insufficient admission vitamin D serum concentrations on sepsis incidence and clinical outcomes in patients with thermal injury

INTRODUCTION

In burn patients, vitamin D has been studied primarily in the pediatric population and focused mainly on the correlation with bone marker measurements and incidence of fractures. There is an association between vitamin D deficiency and the development of sepsis in non-burn critically-ill patients. However, there is limited data on vitamin D concentrations and clinical outcomes in burn patients, such as sepsis. The objective of this study is to evaluate the impact of vitamin D concentrations on the incidence of sepsis in adult burn patients.

METHODS

This was a retrospective cohort of patients 18 years of age and older admitted between February 1, 2016 and February 28, 2018 to an American Burn Association (ABA) verified burn center with diagnosis of burn injury. The primary endpoint was incidence of sepsis using the ABA 2007 Sepsis Consensus Criteria between patients with adequate vitamin D concentrations (25[OH]D > 20 ng/mL) and insufficient vitamin D (25[OH]D < 20 ng/mL) concentrations measured on admission. Descriptive statistics were used for baseline demographics. Univariate analysis was conducted using Chi-square, Fisher's exact test or Mann-Whitney U test, as appropriate.

RESULTS

A total of 115 patients were screened and 107 patients were included in this study. Sixty three patients (58.9%) had insufficient vitamin D concentrations. Patient demographics were overall similar between groups. The median total body surface area burned was 14.6% in the insufficient vitamin D group, and 12.1% in the adequate vitamin D group (p = 0.2). There was a trend towards greater incidence of sepsis in the insufficient vitamin D group in the univariate analysis (15.9% vs. 4.5%, p = 0.07). The multivariable logistic regression analysis found that adequate vitamin D concentrations was associated with a reduction in the incidence of sepsis (OR 0.10, 95% CI 0.01-0.88). The insufficient vitamin D group had a longer median hospital LOS (19 [IQR 11-37] vs 11.5 [IQR 7-20] days, p < 0.05), longer intensive care unit LOS (17 [IQR 10-37] vs 5 [IQR 2-19.5] days, p < 0.05) and fewer ventilator free days (26 [IQR 18-28] vs 28 [IQR 27-28] days, p < 0.05). There was no difference in mortality between groups (p = 0.69).

CONCLUSIONS

Patients with adequate vitamin D concentrations on admission had a reduction in the incidence of sepsis as compared to patients with insufficient vitamin D concentrations. Insufficient vitamin D concentrations may contribute to other worsened clinical outcomes in burn patients. Our findings set the stage for future, multicenter studies to determine the role of vitamin D supplementation in burn patients.

Quantifying the effects of wound healing risk and potential on clinical measurements and outcomes of severely burned patients: A data-driven approach

INTRODUCTION

Given recent advances in computational power, the goal of this study was to quantify the effects of wound healing risk and potential on clinical measurements and outcomes of severely burned patients, with the hope of providing more insight on factors that affect wound healing.

METHODS

This retrospective study involved patients who had at least 10% TBSA% "burned" and three burn mappings each. To model risk to wounds, we defined the variable θ, a hypothetical threshold for TBSA% "open wound" used to demarcate "low-risk" from "high-risk" patients. Low-risk patients denoted those patients whose actual TBSA% "open wound" ≤θ, whereas high-risk patients denoted those patients whose actual TBSA% "open wound" >θ. To consider all possibilities of risk, 100 sub analyses were performed by (1) varying θ from 100% to 1% in decrements of 1%, (2) grouping all patients as either "low-risk" or "high-risk" for each θ, and (3) comparing all means and deviations of variables and outcomes between the two groups for each θ. Hence, this study employed a data-driven approach to capture trends in clinical measurements and outcomes. Plots and tables were also obtained.

RESULTS

For 303 patients, median age and weight were 43 [29-59] years and 85 [72-99]kg, respectively. Mean TBSA% "burned" was 25 [17-39] %, with a full-thickness burn of 4 [0-15] %. Average crystalloid volumes were 4.25±2.27mL/kg/TBSA% "burned" in the first 24h. Importantly, for high-risk patients, decreasing θ was matched by significant increases in PaO2-FiO2 ratio, platelet count, Glasgow coma score (GCS), and MAP. On the other hand, increasing their risk θ was also matched by significant increases in creatinine, bilirubin, lactate, blood, estimated blood loss, and 24-h and total fluid volumes. As expected, for low-risk patients, clinical measurements were more stable, despite decreasing or increasing θ. At a θ of 80%, statistical tests indicated much disparity between high-risk and low-risk patients for TBSA% "burned", full thickness burn, bilirubin (1.66±1.16mg/dL versus 0.83±0.65mg/dL, p=0.005), GCS (7±2 versus 12±3, p<0.001), MAP (42±22mm Hg versus 59±22mm Hg, p=0.004), 24-h blood, estimated blood loss, 24-h fluid, total fluid, and ICU length of stay (81±113 days versus 24±27 days, p=0.002). These differences were all statistically significant and remained significant down to θ=10%.

CONCLUSION

Wound healing risk and potential may be forecasted by many different clinical measurements and outcomes and has many implications on multi-organ function. Future work will be needed to further explain and understand these effects, in order to facilitate development of new predictive models for wound healing.

Trends and characteristics of cases when serial carboxyhemoglobins are obtained

BACKGROUND

Carboxyhemoglobin (COHb) levels are obtained when there is suspicion for carbon monoxide (CO) exposure. Serial COHb levels are sometimes obtained despite the well-established half-life of COHb with oxygen supplementation. We sought to evaluate the trends and characteristics associated with obtaining serial carboxyhemoglobin levels.

METHODS

A retrospective review was performed at an academic medical center for all inpatient and emergency department cases with either single COHb or serial COHb levels from 1 April 2010 through 31 March 2015. Data collected included age, gender, pregnancy status, smoking history, encounter month, admission status, oxygen administration, fire or burn history, vital signs, presenting symptoms, hyperbaric oxygen (HBO2) therapy use, initial pH, troponin, lactate, and COHb levels. The time and change in values between serial levels were also obtained.

RESULTS

624 cases were identified, with 106 (17%) having multiple carboxyhemoglobin levels. A mean of 2.6 (range 2 - 9) serial COHb levels were obtained. The average initial COHb was 8.9%. Subsequent serial levels were obtained on average at 353, 663 and 1,095 minutes and averaged 2.8%, 1.8% and 1.1% respectively. Serial COHb levels were obtained more commonly in burn patients, those admitted to the ICU and those who had HBO2 therapy. Four patients had an increase in COHb level on serial testing. The largest increase of these was from 2.0% to 3.9%.

CONCLUSION

Serial COHb levels were not infrequent in this study. No clinically significant increase in COHb was identified by serial testing. Further studies should examine the clinical utility of such practices.

Procalcitonin and Bacterial Sepsis in Burn Patients in South Africa

BACKGROUND

Burn patients are at high risk of infection, and as sepsis contributes significantly to morbidity and mortality, early diagnosis is essential. Procalcitonin (PCT) is a biomarker released in response to inflammation and specifically bacterial infection. This study aimed to determine the value of PCT as a diagnostic biomarker of sepsis in burns patients in Johannesburg, South Africa.

MATERIALS AND METHODS

All adult patients admitted to two burns intensive care units in Johannesburg over a 3-year study period were included in a retrospective data review. Records of 178 patients were accessible and reviewed.

RESULTS

The most significant risk factor for sepsis was percentage total body surface area burned (P = 0.012). A rise in PCT was a significant biomarker for bacterial infection in the early phase after a burn (P = 0.03) but not after day eight. PCT correlated with C-reactive protein as a biomarker for sepsis (P < 0.001), but not with other biomarkers. The mean PCT in patients who died was significantly higher on every study day until death compared with those who remained alive (P < 0.02, consistently). Patients on inotropes also had a significantly increased PCT level (P = 0.0001), as did those who were not discharged from intensive care unit by day 14.

CONCLUSIONS

PCT may be useful as an adjunct biomarker of infection in burn patients and has potential as a predictive biomarker of early discharge.

Renal clearance of heparin-binding protein and elimination during renal replacement therapy: Studies in ICU patients and healthy volunteers

Background

Heparin-binding protein (HBP) is released by neutrophils upon activation, and elevated plasma levels are seen in inflammatory states like sepsis, shock, cardiac arrest, and burns. However, little is known about the elimination of HBP. We wanted to study renal clearance of HBP in healthy individuals and in burn patients in intensive care units (ICUs). We also wished to examine the levels of HBP in the effluent of renal replacement circuits in ICU patients undergoing continuous renal replacement therapy (CRRT).

Methods

We measured plasma and urine levels of HBP and urine flow rate in 8 healthy individuals and 20 patients in a burn ICU. In 32 patients on CRRT, we measured levels of HBP in plasma and in the effluent of the CRRT circuit.

Results

Renal clearance of HBP (median (IQR) ml/min) was 0.19 (0.08–0.33) in healthy individuals and 0.30 (0.01–1.04) in burn ICU patients. In ICU patients with cystatin C levels exceeding 1.44 mg/l, clearance was 0.45 (0.15–2.81), and in patients with cystatin C below 1.44 mg/l clearance was lower 0.28 (0.14–0.55) (p = 0.04). Starting CRRT did not significantly alter plasma levels of HBP (p = 0.14), and the median HBP level in the effluent on CRRT was 9.1 ng/ml (IQR 7.8–14.4 ng/ml).

Conclusion

In healthy individuals and critically ill burn patients, renal clearance of HBP is low. It is increased when renal function is impaired. Starting CRRT in critically ill patients does not alter plasma levels of HBP significantly, but HBP can be found in the effluent.

It seems unlikely that impaired kidney function needs to be considered when interpreting concentrations of HBP in previous studies. Starting CRRT does not appear to be an effective way of reducing HBP concentrations.

Impact of hemoglobin breakdown products in the spectral analysis of burn wounds using spatial frequency domain spectroscopy

Burn wounds and wound healing invoke several biological processes that may complicate the interpretation of spectral imaging data. Through analysis of spatial frequency domain spectroscopy data (450 to 1000 nm) obtained from longitudinal investigations using a graded porcine burn wound healing model, we have identified features in the absorption spectrum that appear to suggest the presence of hemoglobin breakdown products, e.g., methemoglobin. Our results show that the calculated concentrations of methemoglobin directly correlate with burn severity, 24 h after the injury. In addition, tissue parameters such as oxygenation (StO2) and water fraction may be underestimated by 20% and 78%, respectively, if methemoglobin is not included in the spectral analysis.

Growth Factor Quantification of Platelet-Rich Plasma in Burn Patients Compared to Matched Healthy Volunteers

Platelet rich plasma (PRP) is blood plasma with a platelet concentration above baseline. When activated, PRP releases growth factors involved in all stages of wound healing, potentially boosting the healing process. To expand our knowledge of the effectiveness of PRP, it is crucial to know the content and composition of PRP products. In this study, growth factor quantification measurements of PRP from burn patients and gender- and age-matched controls were performed. The PRP of burn patients showed levels of growth factors comparable to those of the PRP of healthy volunteers. Considerable intra-individual variation in growth factor content was found. However, a correlation was found between the platelet count of the PRP and most of the growth factors measured.

After standard dosage of piperacillin plasma concentrations of drug are subtherapeutic in burn patients

Infections are a major problem in patients with burn diseases. Mortality is high despite antibiotic therapy as studies are controversial concerning drug underdosing. The aims of this prospective, observational study were to monitor plasma concentrations of piperacillin during standard piperacillin/tazobactam treatment in 20 burn patients and 16 controls from the intensive care unit (ICU) and to optimize doses by in silico analyses. Piperacillin/tazobactam (4/0.5 g, tid) was administered over 0.5 h. Blood samples were taken at 1, 4, and 7.5 h after the end of the infusion. Free piperacillin plasma concentrations were determined. Pharmacokinetic parameters and in silico analysis results were calculated using the freeware TDMx. The primary target was defined as percentage of the day (fT_>1xMIC; fT_>4xMIC) when piperacillin concentrations exceeded 1xMIC/4xMIC (minimum inhibitory concentration), considering a MIC breakpoint of 16 mg/L for Pseudomonas aeruginosa. In an off-label approach, two burn patients were treated with 8/1 g piperacillin/tazobactam, 3 h qid. fT_>1xMIC (55 ± 22% vs. 77 ± 24%) and fT_>4xMIC (17 ± 11% vs. 30 ± 11%) were lower in burn than in ICU patients after 4/0.5 g, 0.5 h, tid. In silico analyses indicated that fT_>1xMIC (93 ± 12% burn, 97 ± 4% ICU) and fT_>4xMIC (62 ± 23% burn, 84 ± 19% ICU) values increase by raising the piperacillin dosage to 8/1 g qid and prolonging the infusion time to 3 h. Off-label treatment results were similar to in silico data for burn patients (84%fT_>1xMIC and 47%fT_>4xMIC). Standard dosage regimens for piperacillin/tazobactam resulted in subtherapeutic piperacillin concentrations in burn and ICU patients. Dose adjustments via in silico analyses can help to optimize antibiotic therapy and to predict respective concentrations in vivo. Trial registration: NCT03335137, registered 07.11.2017, retrospectively.

Prediction of major adverse kidney events in critically ill burn patients

OBJECTIVE

We aimed at assessing the predictive value of plasmatic Neutrophil Gelatinase Associated Lipocalin (pNGAL) at admission and severity scores to predict major adverse kidney events (MAKE, defined as death and/or need for renal replacement therapy (RRT) and/or non-renal recovery at day 90) in critically ill burn patients.

MATERIAL AND METHODS

Single-center cohort study in a burn critical care unit in a tertiary center, including all consecutive severely burn patients (total burned body surface >20%) from January 2012 until January 2015 with a pNGAL dosage at admission. Reclassification of patients was assessed by Integrated Discrimination Improvement (IDI).

MEASUREMENTS AND RESULTS

87 patients were included. Mean age was 47.7 (IQ 25-75: 33.4-65.2) years; total burn body surface area was 40 (IQ 25-75: 30-55) % and ICU mortality 36%. 39 (44.8%) patients presented a MAKE, 32 (88.9%) patients died at day 90. pNGAL was higher in the MAKE group (423 [IQ 25-75: 327-518]pg/mL vs 184 [IQ 25-75: 147-220]pg/mL, p<0.001). In multivariate analysis, pNGAL and abbreviated burn severity index (ABSI) remained associated with MAKE (OR 1.005 [CI 95% 1.0005-1.009], p=0.03 and OR 1.682 [CI95%1.038-2.726], p=0.035 respectively). Adding pNGAL to abbreviated burn severity index, simplified organ failure assessment and the simplified acute physiology score 2 did outperform clinical scores for the prediction of MAKE and AKI and for most severe forms of AKI and allowed a statistically significant reclassification of patients compared to ABSI for MAKE, RRT, AKI at Day 7 and AKI during hospitalization with a number of patients needed to screen to detect one extra episode of MAKE was 44, 13 for severe AKI and 15 for AKI.

CONCLUSIONS

pNGAL at admission is associated with the risk of MAKE in this population, and outperform severity scores when associated. Interventional studies are now needed to assess if impact of biomarkers-guided strategies would improve outcome.

Procalcitonin kinetics after burn injury and burn surgery in septic and non-septic patients - a retrospective observational study

BACKGROUND

Early sepsis diagnosis is crucial for the correct management of burn patients, and it clearly influences outcomes. The systemic inflammatory response triggered by burns mimics sepsis presentation and complicates early sepsis diagnosis. Biomarkers were advocated to aid the diagnosis of early sepsis. Serum procalcitonin (PCT) exhibits fair accuracy and good correlation with sepsis severity, being used in diverse clinical settings. However, few studies have evaluated perioperative changes in PCT levels in burn patients. The present study evaluated PCT kinetics during the first days after burn injury and subsequent surgical interventions to assess PCT utility in distinguishing septic from non-septic inflammatory responses.

METHODS

This study was a retrospective observational study of all burn patients admitted to the Coimbra Burns Unit (Portugal) between January 2011 and December 2014 who presented with a total burn surface area ≥ 15% and who underwent subsequent surgery. PCT kinetics were investigated a) during the first five days after burn injury and b) preoperatively during the five days after surgery in three subsets of patients, including those with no preoperative and no postoperative sepsis (NN), no preoperative but postoperative sepsis (NS), and preoperative and postoperative sepsis (SS). A total of 145 patients met the selection criteria and were included in the analysis.

RESULTS

PCT levels in the first five days after burn injury were significantly higher in patients who developed at least one sepsis episode (n = 85) compared with patients who did not develop sepsis (n = 60). PCT values > 1.00 ng/mL were clearly associated with sepsis. Study participants (n = 145) underwent a total of 283 surgical interventions. Their distribution by preoperative/postoperative sepsis status was 142 (50.2%) in NN; 62 (21.9%) in NS; and 79 (27.9%) in SS. PCT values exhibited a parallel course in the three groups that peaked on the second postoperative day and returned to preoperative levels on the third day or later. The lowest PCT values were found in NN, and the highest values were observed in SS; the NS values were intermediate.

CONCLUSIONS

PCT kinetics coupled with a clinical examination may be helpful for sepsis diagnosis during the first days after burn injury and burn surgery.

Correlation between Depression, Posttraumatic Stress Disorder, and Inflammatory Factors in Patients with Severe Burn Injury

We aim to investigate the relation between depression, posttraumatic stress disorder (PTSD), and inflammatory factors in patients with severe burn injury. Psychological assessment was carried out using PTSD checklist (PCL) involving a 17-item self-report questionnaire (PCL-17) and the Hamilton Rating Scale for depression (HAMD-24). The serum IL-1β, IL-6, IL-8, and tumor necrosis factor-α (TNF-α) were determined using enzyme-linked immunosorbent assay. Correlation analysis was performed to analyze the correlation between the factors and scores of PTSD and depression. Compared with the PCL-17 score, HAMD-24 score, and inflammatory factors at month 3, a significant decrease was noticed in the PCL-17 score, HAMD-24 score, and inflammatory factors at months 6 and 9 (P < 0.01). For the HAMD-24 score, significant improvements were noticed in the anxiety/somatization, cognitive disorder, blocking, sleep disorders, and depression at months 3, 6, and 9. The levels of IL-1β, IL-8, and TNF-α were positively correlated with the PCL-17 score (P < 0.05). The levels of IL-1β, IL-6, IL-8, and TNF-α were positively correlated with the HAMD-24 score (P < 0.05). Patients with severe burn injury showed obvious stress alternation displaying specific depression-related characteristics, and inflammation may involve in the pathogenesis of PTSD and depression in burn patients.

Comparing isolated soy protein with flaxseed oil vs isolated soy protein with corn oil and wheat flour with corn oil consumption on muscle catabolism, liver function, blood lipid, and sugar in burn patients: a randomized clinical trial

BACKGROUND

There is controversy regarding whether increasing isolated soy protein (ISP) with or without flaxseed oil (FO), as functional foods, would lead to reduce muscle catabolism and cachexia in burn patients.

METHODS

One hundred and eighty-eight patients were assessed for eligibility in this randomized controlled trial. Of these, seventy-three eligible patients (total burn surface area 20-50%) were randomly assigned to three groups, labeled as Control (wheat flour [WF] + corn oil [CO]), ISP + FO, and ISP + CO, to receive these nutrients for three weeks. Weight, body mass index (BMI), serum hepatic enzymes (alanine transaminase [ALT], aspartate transaminase [AST], alkaline phosphatase [ALP]), systemic inflammatory response syndrome (SIRS), 24-h urinary urea nitrogen excretion (UUN), serum creatinine, 24-h urinary creatinine (UUC) excretion, fasting blood sugar (FBS), triglyceride (TG), and cholesterol were measured.

RESULTS

Using analysis of covariance models in the intention-to-treat population (n = 73), we found that at three weeks, patients in the ISP groups had lost significantly less in weight and BMI compared to those in the control group (all P < 0.01). Nitrogen retention and serum creatinine (primary outcomes) increased significantly in the ISP groups compared with the control group. Even after controlling for potential covariates in ANCOVA models, changes in these indices were still statistically significant (P = 0.008 and P = 0.005 for nitrogen balance and serum creatinine, respectively). However, no such significant differences were found between the ISP groups. On the other hand, 24-h UUN, and UUC excretion, serum hepatic enzymes, FBS, TG, and cholesterol were not significant between the groups (P > 0.05).

CONCLUSION

ISP and FO compared to WF and CO reduced muscle catabolism and increased body weight in burn patients.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials, IRCT2014051817740N1 . Registered on 27 June 2014.

Matrix metalloproteinase-2 and its correlation with basal membrane components laminin-5 and collagen type IV in paediatric burn patients measured with Surface Plasmon Resonance Imaging (SPRI) biosensors

The purpose of this study was the determination of matrix metalloproteinase-2 and its correlation with basal membrane components laminin-5 and collagen type IV in the blood plasma of burn patients measured with Surface Plasmon Resonance Imaging (SPRI) biosensors.

MATERIAL AND METHODS

31 children scalded by hot water who were managed at the Department of Paediatric Surgery between 2014-2015, after primarily presenting with burns in 4-20% TBSA were included into the study (age 9 months up to 14 years, mean age 2,5+1 years). There were 10 girls and 21 boys. Venous blood samples were drawn 2-6h, and 12-16h after the thermal injury, and on the subsequent days 3, 5 and 7. The matrix metalloproteinase-2, collagen type IV and laminin-5 concentrations were assessed using Surface Plasmon Resonance Imaging by the investigators blinded to the other data.

RESULTS

The MMP-2, laminin-5 and collagen type IV concentrations in the blood plasma of patients with burns, were highest 12-16h after thermal injury, the difference was statistically significant. The MMP-2, laminin-5 and collagen type IV concentrations measured 3 days, 5 days and 7 days after the thermal injury, slowly decreased over time, and on the 7th day reached the normal range, when compared with the concentration measured in controls.

CONCLUSION

Current work is the first follow-up study regarding MMP-2 in burns. MMP-2, laminin-5 and collagen type IV levels were elevated early after burn injury in the plasma of studied patients, and were highest 12-16h after the injury. MMP-2, laminin-5 and collagen type IV levels were not proportional to the severity of the burn. We believe in the possibility that the gradual decrease of MMP-2, collagen type IV and laminin-5 concentrations could be connected with the process of healing, but to prove it, more investigation is needed in this area. The SPR imaging biosensor is a good diagnostic tool for determination of MMP-2, laminin-5 and collagen type IV in blood plasma of patients with burns.

Divergent humoral responses to 23-valent pneumococcal polysaccharide vaccine in critically-ill burn and neurosurgical patients

INTRODUCTION

Critically ill hospitalized patients are at increased risk of infection so we assessed the immunogenicity of 23-valent pneumococcal polysaccharide vaccine (PPSV23) administered within six days of injury.

METHODS

This prospective observational study compared the immunogenicity of PPSV23 among critically ill burn and neurosurgical patients at a tertiary, academic medical center. Patients received PPSV23 vaccination within six days of ICU admission per standard of care. Consent was obtained to measure concentrations of vaccine-specific IgG to 14 of 23 serotype capsule-specific IgG in serum prior to and 14-35 days following PPSV23. A successful immunologic response was defined as both a ≥2-fold rise in capsule-specific IgG from baseline and concentrations of >1 mcg/mL to 10 of 14 measured vaccine serotypes. Immunologic response was compared between burn and neurosurgical patients. Multiple variable regression methods were used to explore associations of clinical and laboratory parameters to immunologic responses.

RESULTS

Among the 16 burn and 27 neurosurgical patients enrolled, 87.5% and 40.7% generated a successful response to the vaccine, respectively (p = 0.004). Both median post-PPSV23 IgG concentrations (7.79 [4.56-18.1] versus 2.93 [1.49-8.01] mcg/mL; p = 0.006) and fold rises (10.66 [7.44-14.56] versus 3.48 [1.13-6.59]; p<0.001) were significantly greater in burn compared with neurosurgical patients. Presence of burn injury was directly and days from injury to immunization were inversely correlated with successful immunologic response (both p<0.03). Burn injury was associated with both increased median antibody levels post-PPSV23 and fold rise to 14 vaccine serotypes (p<0.03), whereas absolute lymphocyte count was inversely correlated with median antibody concentrations (p = 0.034).

CONCLUSION

Critically ill burn patients can generate successful responses to PPSV23 during acute injury whereas responses among neurosurgical patients is comparatively blunted. Further study is needed to elucidate the mechanisms of differential antigen responsiveness in these populations, including the role of acute stress responses, as well as the durability of these antibody responses.

Red Cell Distribution Width (RDW) as a Prognostic Tool in Burn Patients

BACKGROUND

Red cell distribution width (RDW) is associated with mortality in patients with certain diseases. However, the relationship between RDW and burn patients remains unknown. The objective of this study was to evaluate the diagnostic and prognostic performance of RDW.

METHODS

Data of 149 patients admitted to the Burn ICU of the Changhai Hospital were retrospectively included in this study. Clinical and laboratory information of all subjects was extracted from medical records.

RESULTS

This study demonstrated that: 1) burn patients with higher RDW had increased mortality, third-degree burn, total burn surface area (TBSA), length of hospital stay, infection rate, WBC, temperature, and CRP; 2) TBSA and length of hospital stay were positively correlated with RDW. 3) RDW levels were higher in burn patients with infection than non-infected burn patients. 4) There were differences in time trend of RDW between survivors and non-survivors from burns.

CONCLUSIONS

RDW can provide useful information about burn severity and outcome. It may be used as a monitoring index for the illness of burn.

SPR imaging biosensor for the quantitation of fibronectin concentration in blood samples

The purpose of this study was presentation of a new biosensor capable of determination of fibronectin. This biosensor was based on the specific interaction of anti-fibronectin antibody produced in rabbit with fibronectin. The surface plasmon resonance imaging (SPRI) technique was used as a detecting method. Optimization and characterization properties of the biosensor were studied. The determination of fibronectin concentration in natural samples was done. The results were compared with a reference method (Enzyme-Linked Immunosorbent Assay-ELISA). The analytically useful dynamic response range of biosensor is between 5 and 400ngmL^-1. The detection limit is 1.5ngmL^-1 and limit quantification is 5ngmL^-1. The proposed SPRI biosensor showed good selectivity for potential interferences. It was applied to determine fibronectin concentrations in plasma of healthy donors and of patients after thermal injury. Good correlations between results obtained using the SPRI biosensor and ELISA test (correlation coefficients for healthy donors 0.996, for patients 0.984) were obtained. The average fibronectin concentration of healthy donors was 140.5±24.6μgmL ^-1 and the average fibronectin concentration of patients was 601.5±72.1μgmL ^-1, which was in agreement with results obtained by other investigators. The obtained results indicate that the developed biosensor may be a candidate for monitoring fibronectin concentration in blood samples.

Overexpression of ubiquitin carboxyl-terminal hydrolase L1 (UCHL1) in serum of children after thermal injury

PURPOSE

The study aims to determinate concentrations of ubiquitin C-terminal hydrolase 1 (UCHL1), which hydrolyzes amino acids from ubiquitin and cleave di-ubiquitins, in serum of children after thermal injury.

PATIENTS/METHODS

42 children scalded by hot water, managed at the Department of Pediatric Surgery, with burns in 4-20% TBSA were included into the study (age 9 months up to 14 years, mean age 2.5±1 years). Blood plasma UCHL1 concentration was assessed in 2-6h, 12-16h, 3d, 5d, and 7d after injury using surface plasmon resonance imaging biosensor. 18 healthy subjects admitted for planned surgeries served as controls.

RESULTS

The UCHL1 concentration in the blood plasma of patients with thermal injuries reached its peak 12-16h after thermal injury and slowly decreased over time, and still did not reach the normal range on the 7th day after thermal injury. Mean concentrations of UCHL1 after thermal injury were above the range measured in controls (0.12ng/ml): 2-6h after injury - 5.59ng/dl, 12-16h after injury - 9.16ng/dl, 3 days after injury - 6.94ng/dl, 5 days after 5.41ng/dl, 7 days after injury - 4.09ng/dl.

CONCLUSIONS

We observed sudden increase in the concentration of UCHL1 2-16h after thermal injury with the slow decrease in the UCHL1 concentration over the time. UCHL1 concentration was proportional to the severity of the burn. Further studies are needed to determine the mechanisms by which UCHL1 contributes to metabolic response following thermal injury.

T2 relaxation time measurements in the brains of scalded rats

This study aimed to evaluate the T2 relaxation time of the brain in severely scalded rats using a magnetic resonance (MR) T2 mapping sequence, and to investigate the correlation between T2 relaxation time and plasma glucose level. Twenty-eight Wistar rats were randomly divided into the scalded group (n=21) and control group (n=7). Magnetic resonance scans were performed with T1WI, T2WI, and T2-mapping sequences in the scalded group; the scans were performed 1 day prior to scalding and 1, 3, 5, and 7 days post-scalding; in addition, identical MR scans were performed in the control group at the same time points. T2-maps were generated and T2 relaxation times were acquired from the following brain regions: the hippocampus, thalamus, caudate-putamen, and cerebrum. Pathological changes of the hippocampus were observed. The plasma glucose level of each rat was measured before each MR scan, and a correlation analysis was performed between T2 relaxation time and plasma glucose level. We found that conventional T1WI and T2WI did not reveal any abnormal signals or morphological changes in the hippocampus, thalamus, caudate-putamen, or cerebrum post-scalding. Both the T2 relaxation times of the selected brain regions and plasma glucose levels increased 1, 3, and 5 days post-scalding, and returned to normal levels 7 days post-scalding. The most marked increase of T2 relaxation time was found in the hippocampus; similar changes were also revealed in the thalamus, caudate-putamen, and cerebrum. No correlation was found between T2 relaxation time and plasma glucose level in scalded rats. Pathological observation of the hippocampus showed edema 1, 3, and 5 days post-scalding, with recovery to normal findings at 7 days post-scalding. Thus, we concluded that T2 mapping is a sensitive method for detecting and monitoring scald injury in the rat brain. As the hippocampus is the main region for modulating a stress reaction, it showed significantly increased water content along with an increased plasma glucose level post-scalding.

Upon admission coagulation and platelet function in patients with thermal and electrical injuries

RATIONAL

There has been increased focus on hemostatic potential and function in the initial assessment of the patient with traumatic injuries, that not been extensively studied in patients with burns. We proposed to determine the hemostatic potential of patients with burns upon admission to the emergency department and contrasted their condition with that of healthy controls and patients with other traumatic injuries. In addition we assessed differences due to thermal versus electrical injury and evaluated the effect of burn size.

METHODS

This is a patient based prospective observational study conducted with delayed consented. Subjects at the highest level of trauma activation upon admission to the ED had a blood sample collected for research purposes and were subsequently consented. Hemostatic potential was measured by rapid thromelastography (r-TEG^®), thrombin generation by calibrated automated thrombogram (CAT) and platelet function by Multiplate^® using five activators. Burn subjects were compared to subjects with other traumatic injuries and controls. Within the burn subjects additional analysis compared mechanism (thermal vs. electrical) and burn size. Values are medians (IQR).

RESULTS

Two hundred and eighty two trauma patients (with burns n=40, 14%) and 27 controls were enrolled. Upon admission, compared to controls, subjects with burns or trauma were hyper-coagulable based on r-TEG and CAT, with increased rates of clot formation and thrombin generation. There were no differences in burns compared to other traumatic injuries. The presence of hyper-coagulation did not appear to be related to the type of burn or the percentage of total body surface area involved. Employing previous defined cut points for R-TEG driven therapeutic interventions burn patients had similar rates of hyper- and hypo-coagulation noted in patients with traumatic injuries.

CONCLUSION

Upon admission patients with burns are in a hyper-coagulable state similar to that of other trauma patients. Employing demonstrated cut points of hemostatic potential in trauma patients associated with increased risk of poor outcomes demonstrated the incidence in burn patients to be similar, suggesting that these values could be used in the early assessment of the patient with burns to guide treatment interventions.

Application of SPR Imaging Biosensor for the Measurement of 20S Proteasomes in Blood Plasma of Children with Thermal Injury

BACKGROUND

Determination of proteasome concentration in blood plasma in children with burns, with the Surface Plasmon Resonance Imaging biosensor.

MATERIAL AND METHODS

35 children scalded by hot water, with burns in 4-20% TBSA were included into the study (age 9 months up to 14 years, mean age 2,5+1 years). Blood plasma 20S proteasome concentration was assessed in 2-6h, 12-16h, 3d, 5d, and 7d after injury using Surface Plasmon Resonance Imaging biosensor.

RESULTS

Statistically significant elevation of circulating 20S proteasome concentration was noted in all groups 12-16 hours after the injury; however, differences were more evident in children with the more severe burns. Circulating 20S proteasome concentration in the plasma was increased until day 7 in the group with severe burns, until day 5 in the group with moderate burns and until day 3 in the group with minor burns. Circulating 20S proteasome concentration in the plasma was highly correlated with burn severity.

CONCLUSIONS

The SPR imaging biosensor can be used for determination of 20S proteasome in plasma of patients with burns. Circulating 20S proteasomes are elevated after burn injury and slowly reach the normal range during the wound healing process. Increase in circulating 20S proteasome concentration is proportional to the severity of the burn injury and do not correlate with age or sex.

Blast-Burn Combined Injury Followed by Immediate Seawater Immersion Induces Hemodynamic Changes and Metabolic Acidosis: An Experimental Study in a Canine Model

BACKGROUND

Severe burn-blast combined injury often causes systematic dysfunction related to blood coagulation, anticoagulation, and fibrinolysis. However, studies of burn-blast combined injury followed by immersion in seawater are rarely reported.

METHODS

A canine burn-blast combined injury model was established including blast injury caused by explosion immediately followed by burning with gelatinized gasoline flames. The dogs were randomly divided into four groups: burn-blast injury (BB group); burn-blast injury followed by seawater immersion for four hours (BBI group); only immersed in seawater (I group); and sham treatment with no injury or immersion (S group). Rectal temperature, hemodynamic parameters, arterial blood gas levels, and respiratory function were measured.

RESULTS

The dogs in the BB group showed relatively more stable hemodynamic features than those in the BBI group. The pH, base excess (BE), HCO3-, PaO2, and PaCO2 levels in the S, I, and BB groups after injury did not differ from those before injury (p > 0.05). The PaO2 level in the BBI group decreased initially after injury and returned to a normal level by 10 hours after injury. The pH, BE, HCO3-, and PaCO2 values in the BBI group decreased continuously after injury and were significantly less than those in the other groups (p < 0.05).

CONCLUSIONS

Burn-blast combined injury followed by seawater immersion induced hemodynamic changes and metabolic acidosis. Knowledge of the early symptoms and unique pathophysiology of the combined injury will be valuable in determining the appropriate management of such patients. Level of evidence: Prognostic study, level IV.

Burned Adults Develop Profound Glucose Intolerance

OBJECTIVES

Metabolic alterations after burn injury have been well described in children; however, in adult patients, glucose metabolism and insulin sensitivity are essentially unknown. We sought to characterize metabolic alterations and insulin resistance after burn injury and determine their magnitude and persistence at discharge.

DESIGN

Prospective, cohort study.

SETTING

Tertiary burn centre.

PATIENTS

Nondiabetic adults with an acute burn involving greater than or equal to 20% total body surface area.

INTERVENTIONS

An oral glucose tolerance test was administered at discharge.

MEASUREMENTS AND MAIN RESULTS

Glucose, insulin, and C-peptide levels were measured to derive surrogate measures of insulin resistance and β-cell function, including quantitative insulin sensitivity check index, homeostasis model assessment of β-cell function, homeostasis model assessment of insulin sensitivity, homeostasis model assessment of insulin resistance, and the composite whole-body insulin sensitivity index. Patients were grouped according to the degree of glucose tolerance: normal glucose tolerance, impaired fasting glucose/impaired glucose tolerance, or diabetes. Forty-five adults, 44 ± 15 years old and with 38% ± 14% total body surface area burned, underwent an oral glucose tolerance test at discharge. Median quantitative insulin sensitivity check index (0.348 [0.332-0.375]) and median homeostasis model assessment of insulin resistance (1.13 [0.69-1.45]) were abnormal, indicating insulin resistance and impaired insulin production at discharge. Two-thirds of patients (n = 28) met criteria for impaired fasting glucose/impaired glucose tolerance or diabetes.

CONCLUSIONS

We have demonstrated that burn-injured adults remain hyperglycemic, are insulin resistant, and express defects in insulin secretion at discharge. Patients with lower burn severity (total body surface area, 20-30%) express similar metabolic alterations as patients with larger burns (total body surface area, ≥ 30%). Glucose tolerance testing at discharge offers an opportunity for early identification of burn patients who may be at high risk of prediabetes and diabetes. Our findings demonstrated that two-thirds of burn patients had some degree of glucose intolerance. With this in mind, surveillance of glucose intolerance post discharge should be considered. As hyperglycemia and insulin resistance are associated with poor outcomes, studies should focus on how long these profound alterations persist.

The clinical significance of the MIF homolog d-dopachrome tautomerase (MIF-2) and its circulating receptor (sCD74) in burn

BACKGROUND

We reported earlier that the cytokine macrophage migration inhibitory factor (MIF) is a potential biomarker in burn injury. In the present study, we investigated the clinical significance of the newly discovered MIF family member d-dopachrome tautomerase (DDT or MIF-2) and their common soluble receptor CD74 (sCD74) in severely burned patients.

METHODS

DDT and sCD74 serum levels were measured 20 severely burned patients and 20 controls. Serum levels were correlated to the abbreviated burn severity index (ABSI) and total body surface area (TBSA) followed by receiver operating characteristic (ROC) analysis. Data were supported by gene expression dataset analysis of 31 burn patients and 28 healthy controls.

RESULTS

CD74 and DDT were increased in burn patients. Furthermore, CD74 and DDT also were elevated in septic non-survivors when compared to survivors. Serum levels of DDT showed a positive correlation with the ABSI and TBSA in the early stage after burn, and the predictive character of DDT was strongest at 24h. Serum levels of CD74 only correlated with the ABSI 5 days after injury.

CONCLUSIONS

DDT may assist in the monitoring of clinical outcome and prediction of sepsis during the early post-burn period. Soluble CD74 and MIF, by contrast, have limited value as an early predictor of death due to their delayed response to burn.

Serum Neopterin and Procalcitonin Levels in Relationship with Pediatric Burn Wound Infections

Infection and septic complications in burn patients can be monitored by procalcitonin (PCT) and neopterin plasma values. The aim of the study was to investigate serum neopterin and PCT levels with WBC (white blood cell) and CRP (C-reactive protein) levels in patient group (PG) and healthy control group (HCG) and to investigate the relationship of these markers with burn wound infections (BWI). As the PG, 23 patients between 0-12 ages and up to 30% Total Body Surface Area (TBSA) burned and 15 HCG were included. PCT, neopterin, WBC, and CRP results on the first, the seventh, the fourteenth and the 21st day have been compared. During the follow-up period, 11 patients with BWI and 12 patients without BWI were classified as infected and non-infected patients, respectively. PCT and neopterin levels were detected higher in patients with BWI but no significant difference were present. Also, PCT and neopterin levels within the first 24 hours following the burn were detected higher in PG than HCG. CRP and WBC levels were detected high due to burn trauma. PCT and neopterin levels were increased in patients with BWI. PCT levels were increased during the pre-infectious period, while neopterin levels increased during the post-infectious period.

Corticosteroid-binding globulin: modulating mechanisms of bioavailability of cortisol and its clinical implications

Corticosteroid-binding globulin (CBG) is the principal transport protein of glucocorticoids. Approximately 80-90% of serum cortisol binds to CBG with high affinity and only about 5% of cortisol remain unbound and is considered biologically active. CBG seems to modulate and influence the bioavailability of cortisol to local tissues. In this review, we will discuss physicochemical properties of CBG and structure of CBG in the mechanisms of binding and release of cortisol. This review describes several factors affecting CBG functions, such as genetic factors or temperature. Furthermore, clinical implications of CBG abnormalities and the measurement of CBG and its use for assessment of free cortisol levels are described in this review.

[The role of erythrocyte microvesiculation and hemoglobin glycation in hemorheological disordes during burn injury]

INTRODUCTION

Hemorheological disorders play an important part in pathogenesis of acute period of burn injury. This mechanism remains practically unstudied. Thus, unknown is the role of hemoglobin glycation and erythrocyte microvesiculation in the decrease in erythrocyte deformability after thermal trauma.

METHODS

Research was performed on 30 blood samples of burn patients in the acute period and 40 blood samples of healthy donors. The number of erythrocyte-derived microvesicles was determined by flow cytometry and then standardized in the samples; the microvesicles were preliminarily separated by ultracentrifugation at 100,000 g, for 60 minutes. Electrophoretic mobility of erythrocytes was measured in a processing chamber of the optical cuvette under the light microscope. Deformability of erythrocytes was assessed by the level of their extension in the artificial shear flow.

RESULTS

It was found that the amount of HbA₁c in red blood cells of burn patients demonstrated a 2-fold increase compared to healthy donors. In the experiments in vitro it was proved that deformability of erythrocytes correlates with the level of hemoglobin glycation. Hb glycation leads to the increased rigidity of erythrocytes also by increasing their microvesiculation. The number of microvesicles derived from red blood cells of burn patients demonstrated a 3.47-fold increase compared to healthy donors. An important reason for microvesiculation is the destabilization of lipid complex of erythrocyte membrane, which is accompanied by the increase in the erythrocyte negative charge. It can be concluded that Hb glycation and redistribution of erythrocyte membrane phospholipids are he important reasons for the increase erythrocyte microvesiculation and are accompanied by the decrease in erythrocyte deformability after thermal trauma.

[Clinical study on application of intermittent hemofiltration combined with hemoperfusion in the early stage of severe burn in the prevention and treatment of sepsis]

OBJECTIVE

To investigate the effects of application of intermittent hemofiltration combined with hemoperfusion (HP) in the early stage of severe burn in the prevention and treatment of sepsis.

METHODS

Forty severely burned patients, admitted to our burn ward from June 2011 to March 2013, conforming to the study criteria, were divided into conventional treatment group (CT, n=20) and blood purification group (BP, n=20) according to the random number table. Patients in group CT received CT according to the accepted principles of treatment for a severe burn. Patients in group BP received CT and intermittent hemofiltration combined with HP once respectively on post injury day (PID) 3, 5, and 7, spanning 6 to 8 hours for each treatment. On PID 3, 5, 7, 10, and 14, body temperature, heart rate, and respiratory rate were recorded; white blood cell count (WBC), neutrophil granulocytes, blood urea nitrogen (BUN), and creatinine were determined; levels of IL-1, IL-6, TNF-α, and high-mobility group box 1 (HMGB1) in serum were determined by ELISA; level of LPS in serum was determined with the chromogenic substrate limulus amebocyte lysate method; level of procalcitonin (PCT) in serum was determined by double antibody sandwich immune chemiluminescence method. The symptoms and signs of sepsis were observed during the treatment. Data were processed with Fisher's exact test, chi-square test, analysis of variance for repeated measurement, and LSD-t test.

RESULTS

(1) Except for that on PID 5, the mean body temperature of patients in group BP was significantly lower than that of group CT at each of the rest time points (with t values from 1.87 to 2.97, P values below 0.05). The heart rate was significantly slower in patients of group BP than in group CT from PID 3 to 14 (with t values from 1.78 to 3.59, P values below 0.05). Except for that on PID 3, the respiratory rate of patients in group BP was significantly slower than that of group CT at each of the rest time points (with t values from 1.93 to 2.85, P values below 0.05). (2) The levels of WBC, neutrophil granulocytes, BUN, and creatinine of patients in group BP were significantly lower than those of group CT (with t values from 1.78 to 4.23, P values below 0.05). (3) Except for that on PID 3, the level of IL-1 of patients in group BP was significantly lower than that of group CT at each of the rest time points (with t values from 1.97 to 4.16, P values below 0.05). Except for that on PID 7, the level of IL-6 of patients in group BP was significantly lower than that of group CT at each of the rest time points (with t values from 2.11 to 6.34, P values below 0.05). The levels of TNF-α and HMGB1 of patients in group BP were significantly lower than those of group CT from PID 3 to 14 (with t values from 1.98 to 5.29, P values below 0.05). (4) On PID 3, 5, 7, 10, and 14, the levels of LPS and PCT of patients in group BP were respectively (0.23 ± 0.07), (0.27 ± 0.09), (0.22 ± 0.06), (0.20 ± 0.08), (0.15 ± 0.07) EU/mL, and (0.44 ± 0.12), (0.67 ± 0.13), (0.74 ± 0.13), (0.64 ± 0.12), (0.71 ± 0.10) ng/mL, and they were lower than those of group CT [(0.37 ± 0.08), (0.45 ± 0.09), (0.56 ± 0.09), (0.48 ± 0.08), (0.40 ± 0.08) EU/mL, and (0.74 ± 0.11), (1.16 ± 0.12), (1.40 ± 0.13), (1.55 ± 0.15), (1.49 ± 0.14) ng/mL, with t values from 1.88 to 3.43, P values below 0.05]. (5) The incidence of sepsis of patients in group BP was obviously lower than that of group CT (χ² = 6.94, P<0.01).

CONCLUSIONS

Intermittent hemofiltration combined with HP can effectively improve blood biochemical indexes and vital signs and reduce the occurrence of burn sepsis by decreasing the levels of proinflammatory cytokines, LPS, and PCT.

Immunosuppressive effects of mesenchymal stem cell transplantation in rat burn models

OBJECTIVE

This study is to investigate the effects of mesenchymal stem cell (MSC) transplantation in burn treatment.

METHODS

Wharton's Jelly was stripped from neonatal umbilical cord, and human umbilical cord MSCs were then cultured. Burn models were constructed in male SD rats weighted at 200±5 g, and the rats were randomly divided into control and MSCs transplantation groups. The rats in transplantation group were injected subcutaneously with MSCs (2×10(6)) at 24 h after burning. Blood samples were collected at 0 d, 1 d, 2 d, 3 d, 5 d and 7 d after burning and the contents of white blood cells (WBC), C-reactive protein (CRP), interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10 ) were detected. The wound healing rate at 7 d, 14 d, 21 d and 28 d together with the wound healing time were compared and analyzed statistically by analysis of variance (ANOVA).

RESULTS

WBC and CRP in control group increased significantly at 1 d and 2 d, 2 d and 3 d, respectively. IFN-γ, IL-6 and IL-10 levels in serum showed increasing till 5th day and TNF-α arrived its peak value at 7th day. By contrast, WBC, CRP, TNF-α, IL-6 and IL-10 in the MSCs transplantation group showed slight increase after burning and the differences were verified by statistically analysis. IFN-γ showed no significant difference between the two groups. MSCs transplantation group showed significantly higher wound healing rate at 14 d, 21 d, 28 d and showed shorter wound healing time than control.

CONCLUSIONS

MSCs transplantation could suppress secondary inflammatory reaction by lowering inflammatory cytokines after burning, thus promoting wound healing and scald repair in burn animal model.

Matrix metalloproteinases -8 and -9 and tissue inhibitor of metalloproteinase-1 in burn patients. A prospective observational study

Introduction

Matrix metalloproteinases (MMPs) -8 and -9 are released from neutrophils in acute inflammation and may contribute to permeability changes in burn injury. In retrospective studies on sepsis, levels of MMP-8, MMP-9, and tissue inhibitor of metalloproteinase-1 (TIMP-1) differed from those of healthy controls, and TIMP-1 showed an association with outcome. Our objective was to investigate the relationship between these proteins and disease severity and outcome in burn patients.

Methods

In this prospective, observational, two-center study, we collected plasma samples from admission to day 21 post-burn, and burn blister fluid samples on admission. We compared MMP-8, -9, and TIMP-1 levels between TBSA<20% (N = 19) and TBSA>20% (N = 30) injured patients and healthy controls, and between 90-day survivors and non-survivors. MMP-8, -9, and TIMP-1 levels at 24-48 hours from injury, their maximal levels, and their time-adjusted means were compared between groups. Correlations with clinical parameters and the extent of burn were analyzed. MMP-8, -9, and TIMP-1 levels in burn blister fluids were also studied.

Results

Plasma MMP-8 and -9 were higher in patients than in healthy controls (P<0.001 and P = 0.016), but only MMP-8 differed between the TBSA<20% and TBSA>20% groups. MMP-8 and -9 were not associated with clinical severity or outcome measures. TIMP-1 differed significantly between patients and controls (P<0.001) and between TBSA<20% and TBSA>20% groups (P<0.002). TIMP-1 was associated with 90-day mortality and correlated with the extent of injury and clinical measures of disease severity. TIMP-1 may serve as a new biomarker in outcome prognostication of burn patients.

Whole blood neutrophil gelatinase-associated lipocalin predicts acute kidney injury in burn patients

BACKGROUND

Early detection of acute kidney injury (AKI) in severely burn-injured patients can help alter treatment to prevent progression to acute failure and reduce the need for renal replacement therapy. We hypothesized that whole blood neutrophil gelatinase-associated lipocalin (NGAL) will be increased in severely burn-injured patients who develop AKI during acute resuscitation.

MATERIALS AND METHODS

We performed a prospective observation study of adult burn patients with a 20% total body surface area (TBSA) burned or greater burn injury. Two-hour serial measurements of NGAL, serum creatinine (Cr), and hourly urine output (UO) were collected for 48 h after admission. Our primary goal was to correlate the risk of AKI in the first week after burn injury with serial NGAL levels in the first 48 h after admission. Our secondary goal was to determine if NGAL was an earlier independent predictor of AKI compared with Cr and UO.

RESULTS

We enrolled 30 adult (age ≥ 18 y) burn patients with the mean ± standard deviation age of 40.9 ± 15.4 and mean TBSA of 46.4 ± 22.4. Fourteen patients developed AKI within the first 7 d after burn injury. There were no differences in age, TBSA, fluid administration, mean arterial pressure, UO, and Cr between AKI and no-AKI patients. NGAL was significantly increased as early as 4 h after injury (182.67 ± 83.3 versus 107.37 ± 46.15) in the AKI group. Controlling for age, TBSA, and inhalation injury, NGAL was a predictor of AKI at 4 h after injury (odds ratio, 1.02) and remained predictive of AKI for the period of more than the first 24 h after admission. UO and Cr were not predictive of AKI in the first 24 h after admission.

CONCLUSIONS

Whole blood NGAL is markedly increased in burn patients who develop AKI in the first week after injury. In addition, NGAL is an early independent predictor of AKI during acute resuscitation for severe burn injury. UO and Cr are not predictive of AKI during this time period.

[INFLUENCE OF DINITROSYL IRON COMPLEXES ON OXIDATIVE METABOLISM UNDER EXPERIMENTAL THERMAL TRAUMA CONDITIONS]

We have studied the effect of dinitrosyl iron complexes (DNIC) on blood lipid peroxidation and antioxidant system under experimental thermal trauma (burn) conditions in three groups of rats, each containing 10 animals. Group 1 was intact control, groups 2 and 3 were subjected to model thermal trauma, and group 3 were daily intraperitoneally injected with 3 ml of 0.3 mM of aqueous DNIC solution for 10 days. In addition, the DNIC solution action was studied in vitro on isolated human blood with oxidative stress conditions induced by high doses of ozone. All blood samples (both in vitro and in vivo) were characterized with respect to lipid peroxidation, total antioxidant activity, and erythrocyte resistance to peroxidation. It is established that DNIC leads to optimization of blood pro- and antioxidant systems in animals subjected to thermal trauma associated with pronounced oxidative stress. This effect was manifested by clear reduction (normalization) of lipid peroxidation with noticeable increase in the antioxidant potential of blood plasma. This tendency was also observed for erythrocyte membranes. The antioxidant action of DNIC was also confirmed by the results of in vitro experiments on human blood with model of oxidative stress.

[Correlation between biochemical parameters of oxidative stress, endogenous intoxication and regulation of vascular tone in patients with burn injury]

Burn injury is accompanied by the formation of reactive oxygen species (ROS). Excessive production of ROS results in oxidative stress. Peroxidation damage of proteins causes their degradation and the formation of toxic fragments con- tributing to the development of endogenous intoxication. Furthermore, burns cause pronounced inflammatory reaction in the lesion site leading to poor circulation. The purpose of this study was an investigation of relationship between disturbances in the prooxidant/antioxidant system, severity of endogenous intoxication and disturbances of endogenous vascular regulation to assess the severity and prognosis of complications in patients with burn injury. 26 patients with- burn injury were investigated; they were divided into 2 groups according to the severity of injury on the basis of Frank index (FI): group 1--FI < 60 CU and group 2--FI ≥ 60 CU. The investigation of blood serum was performed on 1-3, 7, 14, 21 and 28 day after burn injury. Malondialdehyde (MDA), total antioxidant status (TAS), the level of middle weight molecules, stable metabolites of nitric oxide (NOx) and angiotensin-converting enzyme (ACE) activity were determined in the serum. Significant increase of MDA level, decrease of TAS and NOx level were found in two groups of patients throughout the observation period. We also found a disturbance in coupled interaction of NO and ACE. These data point to the development of oxidative stress and imbalance in endogenous regulation of vascular tone. There was a trend toward more pronounced oxidative stress in group 2. Significant correlations between parameters of oxidative stress, endogenous intoxication, endogenous factors of vascular regulation, depth of burn injury and FI were obtained in two groups. MDA, TAS can serve as one of the prognostic markers of condition severity of burned patients and therapy adequacy.

[Influence of dinitrosyl iron complexes on blood metabolism in rats with thermal trauma]

The dynamics in the oxidative and energy metabolism and enzyme systems of blood detoxification in animals with thermal trauma injected with dinitrosyl iron complexes was explored. The positive effect of dinitrosyl iron complexes on the state of blood pro- and antioxidant systems in animals with experimental thermal injury having profound oxidative stress is shown. This effect is observed as a considerable reduction of the intensity (normalization) of lipid peroxidation processes against significant elevation of antioxidant potential of blood plasma. This tendency was also fixed in erythrocyte membranes. It is also stated, that dinitrosyl iron complexes clearly normalized erythrocyte energy metabolism already by the 3rd day after trauma. In addition, infusions of dinitrosyl iron complexes caused marked stimulation of aldehyde dehydrogenase catalytic activity in burned rats via mechanism, associated with enzyme detoxification properties.

Ghrelin therapy improves survival after whole-body ionizing irradiation or combined with burn or wound: amelioration of leukocytopenia, thrombocytopenia, splenomegaly, and bone marrow injury

Exposure to ionizing radiation alone (RI) or combined with traumatic tissue injury (CI) is a crucial life-threatening factor in nuclear and radiological events. In our laboratory, mice exposed to (60)Co-γ-photon radiation (9.5 Gy, 0.4 Gy/min, bilateral) followed by 15% total-body-surface-area skin wounds (R-W CI) or burns (R-B CI) experienced an increment of ≥18% higher mortality over a 30-day observation period compared to RI alone. CI was accompanied by severe leukocytopenia, thrombocytopenia, erythropenia, and anemia. At the 30th day after injury, numbers of WBC and platelets still remained very low in surviving RI and CI mice. In contrast, their RBC, hemoglobin, and hematocrit were recovered towards preirradiation levels. Only RI induced splenomegaly. RI and CI resulted in bone-marrow cell depletion. In R-W CI mice, ghrelin (a hunger-stimulating peptide) therapy increased survival, mitigated body-weight loss, accelerated wound healing, and increased hematocrit. In R-B CI mice, ghrelin therapy increased survival and numbers of neutrophils, lymphocytes, and platelets and ameliorated bone-marrow cell depletion. In RI mice, this treatment increased survival, hemoglobin, and hematocrit and inhibited splenomegaly. Our novel results are the first to suggest that ghrelin therapy effectively improved survival by mitigating CI-induced leukocytopenia, thrombocytopenia, and bone-marrow injury or the RI-induced decreased hemoglobin and hematocrit.

Des-acyl-ghrelin (DAG) normalizes hyperlactacidemia and improves survival in a lethal rat model of burn trauma

Critical illness, including burn injury, results in elevated plasma lactate levels. Dysregulation of PI3K/Akt signaling has been shown to play a predominant role in the inactivation of skeletal muscle PDC and, hence, in hyperlactacidemia in rat models of sepsis and endotoxemia. This observation, and our previous finding that DAG can reverse burn-induced skeletal muscle proteolysis through the activation of PI3K/Akt pathway, led us to hypothesize that DAG may also attenuate hyperlactacidemia in burn injury. Our investigations revealed that burn injury significantly elevated both skeletal muscle lactate production and plasma lactate levels. Moreover, this was accompanied in skeletal muscle by a 5-7 fold increase in mRNA expression of pyruvate dehydrogenase kinases (PDK) 2 and 4, and a ∼30% reduction in PDC activity. DAG treatment of burn rats completely normalized not only the mRNA expression of the PDKs and PDC activity, but also hyperlactacidemia within 24h of burn injury. DAG also normalized epinephrine-induced lactate production by isolated skeletal muscles from normal rats. Moreover, DAG also improved survival in a lethal rat model of burn trauma. These findings with DAG may have clinical implications because chances of survival for critically ill patients are greatly improved if plasma lactate levels are normalized within 24h of injury.