Intraoperative continuous renal replacement therapy during liver transplantation: a pilot randomized-controlled trial (INCEPTION)

PURPOSE

To evaluate the feasibility of intraoperative continuous renal replacement therapy (IoCRRT) during liver transplantation (LT), in terms of recruitment, protocol adherence, and ascertainment of follow-up.

METHODS

In this pilot randomized open-label controlled trial in adults receiving LT with a Model for End-Stage Liver Disease (MELD) score ≥ 25 and preoperative acute kidney injury (RIFLE - RISK or higher) and/or estimated glomerular filtration rate < 60 mL·min^-1·1.73 m^-2, patients were randomized to receive IoCRRT or standard of care (SOC). Primary endpoints were feasibility and adverse events. Primary analysis was intention-to-treat (n = 32) and secondary analysis was per-protocol (n = 28).

RESULTS

The trial was stopped early because of slow patient accrual and inadequate funding. Sixty patients were enrolled and 32 (53%) were randomized (n = 15 IoCRRT; n = 17 SOC). Mean (standard deviation) MELD was 36 (8), 81% (n = 26) had cirrhosis; 69% (n = 22) received preoperative RRT; 66% (n = 21) received LT from the intensive care unit. Four patients (n = 2 IoCRRT, n = 2 SOC) did not receive LT post-randomization. Seven patients (41%) allocated to SOC crossed over intraoperatively to IoCRRT. Three patients were lost to follow-up at one year. No adverse events occurred related to IoCRRT. There were no differences in survival at one year (IoCRRT, 71% [n = 10/14] vs SOC, 93% [n = 14/15]; risk ratio, 0.77; 95% confidence interval, 0.54 to 1.1). In the per-protocol analysis (n = 28 received IoCRRT after randomization - n = 20 IoCRRT, n = 8 SOC), one-year survival was 92% and perioperative complications were similar between groups. Only one patient was receiving dialysis one year after LT.

CONCLUSION

In this pilot randomized trial, IoCRRT was feasible and safe with no difference in complications. Crossover rates were high. Despite high preoperative severity of illness, one-year survival was excellent. These data can inform the design of a larger multicentre trial.

TRIAL REGISTRATION

www.clinicalTrials.gov (NCT01575015); registered 12 April, 2012.

Controversies in fluid therapy: Type, dose and toxicity

Fluid therapy is perhaps the most common intervention received by acutely ill hospitalized patients; however, a number of critical questions on the efficacy and safety of the type and dose remain. In this review, recent insights derived from randomized trials in terms of fluid type, dose and toxicity are discussed. We contend that the prescription of fluid therapy is context-specific and that any fluid can be harmful if administered inappropriately. When contrasting ‘‘crystalloid vs colloid’’, differences in efficacy are modest but differences in safety are significant. Differences in chloride load and strong ion difference across solutions appear to be clinically important. Phases of fluid therapy in acutely ill patients are recognized, including acute resuscitation, maintaining homeostasis, and recovery phases. Quantitative toxicity (fluid overload) is associated with adverse outcomes and can be mitigated when fluid therapy based on functional hemodynamic parameters that predict volume responsiveness and minimization of non-essential fluid. Qualitative toxicity (fluid type), in particular for iatrogenic acute kidney injury and metabolic acidosis, remain a concern for synthetic colloids and isotonic saline, respectively. Physiologically balanced crystalloids may be the ‘‘default’’ fluid for acutely ill patients and the role for colloids, in particular hydroxyethyl starch, is increasingly unclear. We contend the prescription of fluid therapy is analogous to the prescription of any drug used in critically ill patients.

Pathophysiology and management of septic acute kidney injury

Acute kidney injury (AKI) is a commonly encountered complication in critically ill children and portends a worse prognosis. Sepsis-induced AKI (SAKI) is a leading contributor to AKI in children and significantly modifies the risk for less favorable outcome. It has increasingly become clear that SAKI represents a unique and distinct cause of AKI. Studies focused on renal hemodynamics, bioenergetics, and immune-mediated injury have provided further insights into the pathobiology of SAKI; however, many of the nuanced mechanisms remain incompletely understood. Although there have been numerous strategies evaluated for the prevention and management of SAKI, no specific intervention has proven unequivocally efficacious. Currently, the mainstays for managing SAKI focus on alleviating ongoing kidney damage by optimizing systemic and kidney hemodynamic support, avoiding nephrotoxins, and mitigating the anticipated complications of kidney failure. The timely referral for renal support to manage azotemia, metabolic derangements, and fluid accumulation remains critical for this population. The extracorporeal removal of inflammatory mediators has shown some potential benefit in limiting systemic and kidney immune-mediated injury; however, the precise role of these technologies in the management of SAKI has yet to be defined.

A case of sodium chlorite toxicity managed with concurrent renal replacement therapy and red cell exchange

INTRODUCTION

Sodium chlorite is a powerful oxidizing agent with multiple commercial applications. We report the presentation and management of a single case of human toxicity of sodium chlorite.

CASE REPORT

A 65-year-old man presented to hospital after accidentally ingesting a small amount of a sodium chlorite solution. His principal manifestations were mild methemoglobinemia, severe oxidative hemolysis, disseminated intravascular coagulation, and anuric acute kidney injury. He was managed with intermittent hemodialysis, followed by continuous venovenous hemofiltration for management of acute kidney injury and in an effort to remove free plasma chlorite. Concurrently, he underwent two red cell exchanges, as well as a plasma exchange, to reduce the burden of red cells affected by chlorite. These interventions resulted in the cessation of hemolysis with stabilization of serum hemoglobin and platelets. The patient survived and subsequently recovered normal renal function.

DISCUSSION

This is only the second case of sodium chlorite intoxication reported in the medical literature and the first to report the use of renal replacement therapy in combination with red cell exchange in its management.

Hyponatremia and congestive heart failure: a marker of increased mortality and a target for therapy

Heart failure is one of the most common chronic medical conditions in the developed world. It is characterized by neurohormonal activation of multiple systems that can lead to clinical deterioration and significant morbidity and mortality. In this regard, hyponatremia is due to inappropriate and continued vasopressin activity despite hypoosmolality and volume overload. Hyponatremia is also due to diuretic use in an attempt to manage volume overload. When hyponatremia occurs, it is a marker of heart failure severity and identifies patients with increased mortality. The recent introduction of specific vasopressin-receptor antagonists offers a targeted pharmacological approach to these pathophysiological derangements. Thus far, clinical trials with vasopressin-receptor antagonists have demonstrated an increase in free-water excretion, improvement in serum sodium, modest improvements in dyspnea but no improvement in mortality. Continued clinical trials with these agents are needed to determine their specific role in the treatment of both chronic and decompensated heart failure.

Review article: Renal support in critical illness

PURPOSE

This review provides a focused and comprehensive update on established and emerging evidence in acute renal replacement therapy (RRT) for critically ill patients with acute kidney injury (AKI).

PRINCIPAL FINDINGS

There have been considerable technological innovations in the methods and techniques for provision of extracorporeal RRT in critical illness. These have greatly expanded our capability to provide both renal and non-renal life-sustaining organ support for critically ill patients. Recent data suggest earlier initiation of RRT in AKI may confer an advantage for survival and renal recovery. Two large trials have recently shown no added benefit to augmented RRT dose delivery in AKI. Observational data have also suggested that fluid accumulation in critically ill patients with AKI is associated with worse clinical outcome. However, several fundamental clinical questions remain to be answered, including issues regarding the time to ideally initiate/discontinue RRT, the role of high-volume hemofiltration or other blood purification techniques in sepsis, and extracorporeal support for combined liver-kidney failure. Extracorporeal support with RRT in sepsis, rhabdomyolysis, and liver failure are discussed, along with strategies for drug dosing and management of RRT in sodium disorders.

CONCLUSIONS

We anticipate that this field will continue to expand to promote research and innovation, hopefully for the benefit of sick critically ill patients.

Immunofluorescence studies on amphibian myoblast differentiation

Differentiating myoblasts from urodele amphibians were cultivated in vitro and treated by immunofluorescence techniques and (or) inhibitors of RNA and protein syntheses. These experiments lead to the conclusion that the differentiation of these cells is directed by long-lived m-RNAs which are already present in morphologically undifferentiated cells and may act for at least 6 days. Contrary to observations on cultivated myogenic cells from other groups, the fusion of urodele myoblasts is not a prerequisite for a normal and functional differentiation (contractions) since isolated myoblasts differentiate quite normally. The appearance and further evolution of myosin and actin occur synchronously in this biological system.