Aging and hemoglobin-induced acute kidney injury

Acute kidney injury in pediatric burn patients

BACKGROUND

Acute kidney injury (AKI) is a common and important complication of burn injury. Although there are numerous adult studies, data regarding AKI in pediatric burn patients are scarce. Here, we aimed to evaluate the frequency, clinical features, and prognosis of AKI among pediatric burn injury patients.

METHODS

This is a retrospective cohort study. Patients aged between 1 month and 18 years who had been followed up between the years 2011 and 2017 were included, and patients with previous kidney disease were excluded. Demographic data, laboratory and clinical variables, management strategies, and outcome data were obtained from the hospital records. Factors associated with AKI were determined by logistic regression analysis.

RESULTS

A total of 697 patients had been followed up, and 87 (12.5%) had AKI. Older age, refugee status, prolonged duration between the incident and time of hospitalization, presence of sepsis, severity and type of burn, volume of fluid administration, intubation status, and accompanying organ failure were all associated with the development of AKI. According to multivariate logistic regression analysis, the most statistically significant factors associated with the development of AKI were older age and increased serum hemoglobin values. In terms of outcomes, length of stay and mortality increased in patients with AKI when compared with patients without AKI.

CONCLUSION

Similar to adults, AKI is an important and common complication of burn injury in pediatric burn patients and is associated with increased length of stay, morbidity, and mortality. Early recognition and prompt and appropriate management are crucial to avoid morbidity and mortality.

A model for acute kidney injury in severe burn patients

INTRODUCTION

In patients with severe burns, morbidity and mortality are high. One factor related to poor prognosis is acute kidney injury. According to the AKIN criteria, acute kidney injury has 3 stages based on urine output, serum creatinine level, and renal replacement therapy. In this study, we aimed to create a decision tree for estimating risk of acute kidney injury in patients with severe burn injuries.

METHODS

We retrospectively evaluated 437 adult patients with ≥20% total burn surface area injury who were treated at the Baskent University Ankara and Konya Burn Centers from January 2000 to March 2020. Patients who had high-voltage burn and previous history of kidney disease were excluded. Patient demographics, medical history, mechanism of injury, presence of inhalation injury, depth of burn, laboratory values, presence of oliguria, need for renal replacement therapy, central venous pressure, and prognosis were evaluated. These data were used in a "decision tree method" to create the Baskent University model to estimate risk of acute kidney injury in severe burn patients.

RESULTS

Our model provided an accuracy of 71.09% for risk estimation. Of 172 patients, 78 (45%) had different degrees of acute kidney injury, with 26 of these (15.1%) receiving renal replacement therapy. Our model showed that total burn surface area was the most important factor for estimation of acute kidney injury occurrence. Other important factors included serum creatinine value, burn injury severity score, hemoglobin value, neutrophil-to-lymphocyte ratio, and platelet count.

CONCLUSION

The Baskent University model for acute kidney injury may be helpful to determine risk of acute kidney injury in burn patients. This determination would allow appropriate treatment to be given to high-risk patients in the early period, reducing the incidence of acute kidney injury.

Targeting HO-1 by Epigallocatechin-3-Gallate Reduces Contrast-Induced Renal Injury via Anti-Oxidative Stress and Anti-Inflammation Pathways

Both oxidative stress and inflammation are involved in the pathogenesis of contrast-induced nephropathy (CIN). Epigallocatechin-3-gallate (EGCG), a purified catechin from green tea, has antioxidant and anti-inflammatory effects. However, it is unknown whether or not EGCG is effective in treating CIN. Our present study found that intravenous administration of EGCG, either before or just after the establishment of CIN, had a protective effect, determined by normalization of serum creatinine and blood urea nitrogen levels, improvement in renal histopathological scoring and alleviation of apoptosis, accompanied by decreased oxidative stress and inflammation. Because EGCG is a potent inducer of the antioxidant heme oxygenase-1 (HO-1), we studied HO-1 signaling in CIN. HO-1 levels were increased in CIN; treatment with EGCG further increased HO-1 levels, accompanied by an increase in Nrf2, a regulator of antioxidant proteins. Interestingly, blockade of HO-1 with protoporphyrin IX zinc(II) (ZnPP) prevented the protective effect of EGCG on CIN. ZnPP also blocked the ability of EGCG to increase the activity of an antioxidant (superoxide dismutase), and decrease markers of oxidative stress (myeloperoxidase and malondialdehyde) and inflammation (myeloperoxidase and IL-1β), indicating that HO-1 is the upstream molecule that regulates the EGCG-mediated protection. To determine further the role of HO-1 on the EGCG-mediated inhibition of inflammation, we studied the effect of EGCG on the NLRP3 inflammasome, an upstream signaling of IL-1β. EGCG down-regulated NLRP3 expression, which was blocked by ZnPP, indicating that HO-1 links EGCG with NLRP3. Therefore, EGCG, via up-regulation of HO-1, protects against CIN by amelioration of oxidative stress and inflammation.