Regional citrate anticoagulation for continuous renal replacement therapy in severe burns—A retrospective analysis of a protocol-guided approach

Long-term renal function after burn-related acute kidney injury with continuous renal replacement therapy

Acute kidney injury (AKI) is a common complication of severe burn injury and is associated with significant morbidity and mortality. Continuous Renal Replacement Therapy (CRRT) is the preferred treatment for stage 3 AKI due to severe burn. This retrospective cohort study at a single institution aimed to examine the long-term renal outcomes after discharge of burn survivors who underwent CRRT during their ICU stay between 2012-2021 due to burn-related AKI, hypothesizing a return to baseline renal function in the long term. Among the 31 patients meeting inclusion criteria, 22 survived their burn injuries, resulting in a 29 % mortality rate. No significant disparities were observed in demographics, comorbidities, burn characteristics, or critical care interventions between survivors and non-survivors. Serum creatinine and eGFR values normalized for 91 % of patients at discharge. Impressively, 91 % of survivors demonstrated a return to baseline renal function during long-term (>3 years) follow-up. Furthermore, only 18 % underwent dialysis after discharge, primarily within the first year. Cumulative mortality rates were 18.2 %, 22.7 %, and 31.8 % at 1, 3, and > 3 years after discharge, respectively. Causes of death were primarily non-renal. These results suggest that burn-related AKI with CRRT results in lower rates of conversion to ongoing renal dysfunction compared to general ICU cohorts. Despite limitations, this study contributes vital insights into the underexplored issue of long-term outcomes after dicharge in this patient population.

Optimizing the timing of renal replacement therapy in burn patients with acute kidney injury

Acute kidney injury is a common complication in burn ICU patients and is associated with a high mortality rate. The optimal timing for starting renal replacement therapy (RRT) remains unknown; there is no established universal definition for early and late RRT initiation. The aims of the present narrative review are to briefly analyze the available recently published data on the timing of initiation of RRT in critically ill patients and to discuss the optimal timing of RRT in critically ill burn patients with acute kidney injury. When considering renal replacement therapy for acute kidney injury patients, physicians face the dilemma of balancing the hazards of starting too early, exposing patient to an unnecessary therapy with possible complications and costs related to treatment, and preventing a significant proportion of patients from spontaneous recovery of their renal function against the potential life-threatening harm of initiating RRT) too late. Evidence suggests that with appropriate care up to 80% of burn patients experience recovery of kidney function and the need for RRT seems to be very rare after hospital discharge. In the absence of life-threatening complications, the optimal time and thresholds for starting RRT in burn patients are uncertain. High heterogeneity exists between studies on RRT timing in burn patients.

Continuous renal replacement therapy under special conditions like sepsis, burn, cardiac failure, neurotrauma, and liver failure

Continuous renal replacement therapy (CRRT) in sepsis does have a role in removing excessive fluid, and also role in removal of mediators although not proven today, and to allow fluid space in order to feed. In these conditions, continuous renal replacement therapy can improve morbidity but never mortality so far. Regarding sepsis, timing has become a more important issue after decades and is currently more discussed than dosing. Rationale of blood purification has evolved a lot in the last years regarding sepsis with the discovery of many types of sorbent allowing ideas from science fiction to become reality in 2021. Undoubtedly, COVID-19 has reactivated the interest of blood purification in sepsis but also in COVID-19. Burn is even more dependent about removal of excessive fluid as compared to sepsis. Regarding cardiac failure, ultrafiltration can improve the quality of life and morbidity when diuretics are becoming inefficient but can never improve mortality. Regarding brain injury, CRRTs have several advantages as compared to intermittent hemodialysis. In liver failure, there have been no randomized controlled trials to examine whether single-pass albumin dialysis offers advantages over standard supportive care, and there is always the cost of albumin.

Meta-Analysis of Renal Replacement Therapy for Burn Patients: Incidence Rate, Mortality, and Renal Outcome

Background: Renal replacement therapy (RRT) was often needed by some severe burn patients with acute kidney injury (AKI). The primary aim of this study was to review incidence rate and mortality of RRT in severe burn patients. Second aims were to review RRT complications and renal outcome.

Methods: We searched multiple databases for studies published between 1 January 1960 and 31 December 2019. Studies about adult populations with burn injury, providing epidemiologic data on prevalence or mortality of RRT, were included.

Results: A total of selected 57 studies, including 27,437 patients were enrolled in our analysis. The prevalence rates of RRT were 8.34% (95% CI 7.18–9.5%) in all burn patients and 37.05% (95% CI 29.85–44.24%) in AKI patients. The mortality of all burn patients with RRT was 65.52% (95% CI 58.41–72.64%). The prevalence rates of RRT in sample size≥100 group were 6.86% (95% CI 5.70–8.03%), which was lower than that of <100 group (17.61%, 95% CI 13.39–21.82%). With the increase of TBSA, the prevalence of RRT may have the increasing trend. The prevalence rates of RRT in Asian group was 12.75% (95% CI 9.50–16.00%), which was higher than that of European (10.45%, 95% CI 7.30–13.61%) and North America group (5.61%, 95% CI 4.27–6.95%). The prevalence rates of RRT in 2010–2019 group was 12.22% (95% CI 10.09–14.35%), which was higher than that of 2009–2000 group (5.17%, 95% CI 2.88–7.46%). The prevalence rates of RRT in 1989 and before group was the lowest, which was 1.56% (95% CI 0–3.68%). However, there was no significant correlation between the year of publication and the mortality of burn patients with RRT. Dialysis-requiring AKI in burn patients could increases the risk of chronic kidney disease progression and end-stage renal disease. About 35% of RRT patients need to maintain haemodialysis temporarily, even if they survive and leave hospital.

Conclusions: The prevalence rate of RRT is about 6–8%; approximately, one-third of burn patients with AKI need RRT. The prevalence rate of RRT increased over time, but the mortality did not change. The prevalence rates of RRT in Asian group was higher than that of European and North America group.

Early Initiation of Renal Replacement Therapy Among Burned Patients With Acute Kidney Injury

BACKGROUND

Burned patients with acute kidney injury (AKI) requiring renal replacement therapy (RRT) have exceedingly high mortality rates of 73% to 100%. Since January 2011, we have been adopting an early RRT approach in managing burned patients with AKI. Our hypothesis was that early initiation of RRT leads to improved outcome and survival among burned patients with AKI.

METHODOLOGY

We conducted a retrospective analysis of Burns Database in Singapore General Hospital from January 2011 to February 2016. Indications for dialysis included serum creatinine of greater than 1.5 times baseline or urine output of less than 0.5 mL/kg per hour for at least 6 consecutive hours. Patients with similar condition from January 2006 to December 2010 were recruited for comparison.

RESULT

A total of 27 patients with burns and AKI were recruited from January 2011 to February 2016. The mean age was 45.4 years and 88.9% were male. The mean total burn surface area (TBSA) was 54.8%. The total volume of fluid resuscitation was 2.7 mL/kg per TBSA. The time from onset of burn to RRT was 6.4 days. Most patients presented with stage 1 AKI (51.9%), whereas 22.2% and 25.9% had stage 2 and stage 3 AKI, respectively. Most patients (74.1%) received CRRT and 18.5% received SLED. The mortality rate was 37.0% with majority of death (70%) due to sepsis/multiorgan failure. Only 1 patient required long-term RRT after discharge, and there was no occurrence of abdominal compartment syndrome. The mean age of 15 patients from 2006 to 2010 was 47.8 years. The mean TBSA was 49.5%. Only 26.7% of patients were started on RRT. The mortality rate was 66.7%, which was higher than that of subjects from 2011 to 2016 (37.0%) (P = 0.039).

CONCLUSIONS

Optimal timing of RRT for burned patients with AKI has not been established and data on early RRT approach are scarce. The findings of our study suggested that early RRT was associated with lower mortality rates among burned victims with AKI.

Early anticoagulation therapy for severe burns complicated by inhalation injury in a rabbit model

The aim of the present study was to determine the effects of early anticoagulation treatment on severe burns complicated by inhalation injury in a rabbit model. Under anesthetization, an electrical burns instrument (100°C) was used to scald the backs of rabbits for 15 sec, which established a 30% III severe burns model. Treatment of the rabbits with early anticoagulation effectively improved the severe burns complicated by inhalation injury-induced lung injury, reduced PaO₂, PaCO₂ and SPO₂ levels, suppressed the expression of tumor necrosis factor-α, interleukin (IL)-1β and IL-6, and increased the activity of IL-10. In addition, it was found that early anticoagulation treatment effectively suppressed the activities of caspase-3 and caspase-9, upregulated the protein expression of vascular endothelial growth factor (VEGF) and decreased the protein expression of protease-activated receptor 1 (PAR1) in the severe burns model. It was concluded that early anticoagulation treatment affected the severe burns complicated by inhalation injury in a rabbit model through the upregulation of VEGF and downregulation of PAR1 signaling pathways. Thus, early anticoagulation is a potential therapeutic option for severe burns complicated by inhalation injury.

Early and Late Acute Kidney Injury in Severely Burned Patients

Background

This study evaluated factors influencing early and late occurrence of AKI in severely burned patients and assessed the relationship between time of occurrence of AKI and mortality of AKI patients.

Material/Methods

Renal function was evaluated at 3 time points: at admission, at the critical point or middle point of hospitalization, and at the endpoint for which death or a discharge from the center was considered. AKI criteria were: decrease in GFR of less than 60 ml/min at admission, decrease in GFR of more than 75% compared to baseline, and decrease in the daily diuresis of less than 500 ml/24 h.

Results

At admission, 15.1% of the patients had eGFR <60 ml/min. AKI occurred in 38.5% of cases. The occurrence of AKI was associated with: elderly age (p<0.001), female sex (p=0.017), overweight and obesity (p=0.055); extent and depth of burns, respiratory failure, low protein concentration (for all p<0.001), low blood pressure (p=0.014), and high WBC (p=0.010). Early AKI was detected in 28% of patients. Mortality was 100% with the initial GFR ≥60, 100% with the initial GFR <60 and early deterioration of renal function, 80% with the initial GFR <60 and late worsening, and 60% with the initial GFR <60 and no worsening. Late AKI was observed in 10% of patients and mortality in this group was 79.2%. Mortality in the entire group with AKI was 88.0% versus 24.5%.

Conclusions

The frequent occurrence of AKI, especially early, worsens the prognosis for survival. Assessment of renal function should be included in the prognostic scales for burned patients.

Assessment of urinary kidney injury molecule-1 and interleukin-18 in the early post-burn period to predict acute kidney injury for various degrees of burn injury

Background

Burn patients with AKI have a higher mortality, rapid diagnosis and early treatment of AKI are necessary. Recent studies have demonstrated that urinary KIM-1 and IL-18 are potential biomarkers of early-stage AKI, however, changes in urinary KIM-1 and IL-18 levels are unclear in patients with burns. The aim of our study was to determine whether combined KIM-1 and IL-18 are more sensitive than traditional markers in detecting kidney injury in patients with burns.

Methods

Ninety-five burn patients hospitalized at the Burns and Plastic Surgery Center of our hospital from April 2013 to September 2013 were enrolled into this prospective study and divided into mild- (n = 37), moderate- (n = 30) and severe-burn groups (n = 28) by burn injury surface area. In the moderate- and severe-burn groups, patients were subcategorized to either the acute kidney injury (AKI) group, in which serum creatinine (Scr) increased to ≥26.5 μmol/L within 48 h, or the non-AKI group. Fifteen healthy subjects were selected as a control group. Blood specimens were collected to determine blood urea nitrogen (BUN), Scr, and other biochemical indicators. Urine samples collected at admission and 48 h after admission were analyzed for KIM-1 and IL-18. Correlations among urinary KIM-1 and IL-18, burn degree, and clinical biochemical indicators were investigated.

Results

AKI occurred in 11.2 % of burn patients (none in the mild-burn group). AKI developed 48 h after admission in 10.0 % of the moderate- and 28.6 % of the severe-burn groups. Urinary KIM-1 concentration in the moderate- and severe-burn groups was significantly higher than that in the control group; urinary IL-18 concentrations did not differ significantly among the burn and control groups. The AKI group had significantly higher concentrations of urinary KIM-1 and IL-18 than the non-AKI group, both at admission (p = 0.001 and p < 0.001, respectively) and 48 h later (p = 0.001 and p < 0.001, respectively). Both urinary KIM-1 and IL-18 increased before Scr. Receiver operating-curve (ROC) analysis demonstrated that KIM-1 combined with IL-18 predicted AKI with 72.7 % sensitivity and 92.8 % specificity. The area under the ROC curve was 0.904.

Conclusions

Our results suggest that urinary KIM-1 and IL-18 may be used as early, sensitive indicators of AKI in patients with burns of varying degrees and provide clinical clues that can be used in early prevention of AKI.