A Systematic Bibliometric Analysis of High-Impact Articles in Critical Care Nephrology.

INTRODUCTION: Critical care nephrology is a subspecialty that merges critical care and nephrology in response to shared pathobiology, clinical care, and technological innovations. To date, there has been no description of the highest impact articles. Accordingly, we systematically identified high impact articles in critical care nephrology. METHODS: This was a bibliometric analysis. The search was developed by a research librarian. Web of Science was searched for articles published between January 1, 2000 and December 31, 2020. Articles required a minimum of 30 citations, publication in English language, and reporting of primary (or secondary) original data. Articles were screened by two reviewers for eligibility and further adjudicated by three experts. The "Top 100" articles were hierarchically ranked by adjudication, citations in the 2 years following publication and journal impact factor (IF). For each article, we extracted detailed bibliometric data. Risk of bias was assessed for randomized trials by the Cochrane Risk of Bias tool. Analyses were descriptive. RESULTS: The search yielded 2,805 articles. Following initial screening, 307 articles were selected for full review and adjudication. The Top 100 articles were published across 20 journals (median [IQR] IF 10.6 [8.9-56.3]), 38% were published in the 5 years ending in 2020 and 62% were open access. The agreement between adjudicators was excellent (intraclass correlation, 0.96; 95% CI, 0.84-0.99). Of the Top 100, 44% were randomized trials, 35% were observational, 14% were systematic reviews, 6% were nonrandomized interventional studies and one article was a consensus document. The risk of bias among randomized trials was low. Common subgroup themes were RRT (42%), AKI (30%), fluids/resuscitation (14%), pediatrics (10%), interventions (8%), and perioperative care (6%). The citations for the Top 100 articles were 175 (95-393) and 9 were cited >1,000 times. CONCLUSION: Critical care nephrology has matured as an important subspecialty of critical care and nephrology. These high impact papers have focused largely on original studies, mostly clinical trials, within a few core themes. This list can be leveraged for curricula development, to stimulate research, and for quality assurance.

Cardiorenal Interactions: A Review.

A complex interaction occurs between cardiac and renal function. They are intricately tied together, and a range of disorders in both the heart and kidneys can alter the function of the other. The pathophysiology is complex, and these conditions are termed cardiorenal syndromes. They can be acute and/or chronic in nature, they result in and from hemodynamic consequences, systemic congestion, and metabolic abnormalities, and they lead to dysfunction of both the heart and kidneys. The aim of this article is to provide a review for cardiologists and intensivists who are treating patients for whom cardiac and renal interactions may complicate their picture. We review acute kidney injuries, management of the complications of renal dysfunction, renal replacement therapy, and cardiorenal syndromes.

Il existe une interaction complexe entre la fonction cardiaque et la fonction rénale. Elles sont étroitement liées, et un éventail de troubles cardiaques et rénaux peuvent altérer la fonction de l'autre. Ces maladies dont la physiopathologie est complexe sont appelées syndromes cardiorénaux. Elles peuvent être aiguës et/ou chroniques de nature, elles entraînent des conséquences hémodynamiques, une congestion systémique et des anomalies métaboliques, ou résultent de celles-ci, et elles mènent à la dysfonction du cœur ou des reins. L'objectif du présent article est d'offrir une revue aux cardiologues et aux intensivistes qui traitent des patients dont les interactions cardiaques et rénales peuvent compliquer leur tableau. Nous passons en revue les atteintes rénales aiguës, la prise en charge des complications de la dysfonction rénale, le traitement de substitution rénale et les syndromes cardiorénaux.

A 58-Year-Old Man With Episodic Hypercapnic Respiratory Failure.

CASE PRESENTATION: A 58-year-old man presented to the ED with a 1-week history of progressive weight loss, generalized weakness, unsteadiness, and dizziness. In hospital, he experienced a witnessed episode of loss of consciousness with no observable respirations that lasted for 15 minutes. His arterial blood gas demonstrated hypercapnic respiratory failure, and he required mask ventilation and vasoactive medications. Similar episodes occurred several more times over the course of the night that required the patient to be intubated. The paroxysmal episodes persisted necessitating continued invasive ventilatory support and admission to the ICU. The episodes occurred in both awake and asleep states and required the ventilator settings to dictate a minimum rate, but minimal ventilatory support otherwise. Further history revealed other symptomatic complaints of vertigo, dysphagia, and hypophonia that had progressed over a 2-month period. The patient's medical history was pertinent for a diagnosis of prostatic carcinoma 3 years previously that was found to be castrate resistant. He had metastases to his hip, ribs, and thoracic spine. Previous treatments had included bicalutamide, docetaxel, and abiraterone; he was receiving leuprolide therapy on presentation.

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.

RéSUMé: OBJECTIF: Notre but était d'évaluer la faisabilité d'un traitement substitutif peropératoire continu de l'insuffisance rénale pendant une greffe hépatique, notamment en matière de recrutement, d'adhésion au protocole, et de suivi. MéTHODE: Dans cette étude randomisée contrôlée non aveugle pilote réalisée auprès d'adultes recevant une greffe hépatique avec un score MELD (Model for End-Stage Liver Disease) ≥ 25 et une insuffisance rénale aiguë préopératoire (RIFLE - RISQUÉ ou plus élevé) et/ou un taux de filtration glomérulaire estimé < 60 mL·min−1·1,73 m−2, les patients ont été randomisés à recevoir un traitement substitutif peropératoire continu de l'insuffisance rénale (le traitement) ou les soins habituels (la norme). Les critères d'évaluation principaux étaient la faisabilité et les événements indésirables. L'analyse principale était l'analyse du projet thérapeutique (intention-to-treat; n = 32) et l'analyse secondaire était l'analyse selon le protocole (n = 28). RéSULTATS: L'étude a été précocement interrompue en raison du recrutement lent de patients et du manque de fonds. Soixante patients ont été recrutés et 32 (53 %) ont été randomisés (n = 15 traitement; n = 17 norme). Le score MELD moyen (écart type) était de 36 (8), 81 % (n = 26) des patients souffraient de cirrhose; 69 % (n = 22) ont reçu un traitement substitutif de l'insuffisance rénale préopératoire; 66 % (n = 21) ont reçu une greffe hépatique à partir de l'unité de soins intensifs. Quatre patients (n = 2 traitement, n = 2 norme) n'ont pas reçu de greffe hépatique après la randomisation. Sept patients (41 %) alloués au groupe norme sont passés dans le groupe traitement en période peropératoire. Trois patients ont été perdus au suivi au cours de la première année. Aucun événement indésirable n'est survenu en association au traitement substitutif peropératoire continu de l'insuffisance rénale. Aucune différence en matière de survie à un an n'a été observée (traitement, 71 % [n = 10/14] vs norme, 93 % [n = 14/15]; risque relatif, 0,77; intervalle de confiance 95 %, 0,54 à 1,1). Dans l'analyse selon le protocole (n = 28 ont reçu un traitement après la randomisation - n = 20 traitement, n = 8 norme), la survie à un an était de 92 % et les complications périopératoires étaient semblables dans les deux groupes. Un seul patient recevait de la dialyse un an après la greffe hépatique. CONCLUSION: Dans cette étude randomisée pilote, le traitement substitutif peropératoire continu de l'insuffisance rénale s'est avéré faisable et sécuritaire, et aucune différence en matière de complications n'a été observée. Les taux de transfert d'un groupe à l'autre étaient élevés. Malgré une sévérité préopératoire élevée de la maladie, la survie à un an était excellente. Ces données peuvent être utiles pour concevoir une étude multicentrique plus importante. ENREGISTREMENT DE L'éTUDE: www.clinicalTrials.gov (NCT01575015); enregistrée le 12 avril 2012.

Serum sodium shift in hyponatremic patients undergoing liver transplantation: a retrospective cohort study.

INTRODUCTION: We aimed to describe the pre-operative incidence of hyponatremia in patients undergoing liver transplantation (LTx), as well as the rate and consequences of rapid peri-operative sodium rises in these patients. METHODS: This was a retrospective before and after observational study performed at a University-affiliated LTx center between January 2007 and June 2013. The primary exposure was pre-operative hyponatremia, defined as a serum sodium (SNa) <133 mmol/L. The primary outcome was occurrence of a rapid SNa shift, defined as ≥10 mmol/L in the first 24 h following LTx. The rates of rapid peri-operative SNa shift were compared before and after a focused quality assurance (QA) initiative performed in July 2009. RESULTS: Of 366 LTx, 69 (18.9%) had pre-operative hyponatremia, 6 (8.7%) of whom had a rapid rise in serum sodium (SNa). Rapid rise was associated with a greater intra-operative positive fluid balance (p < 0.001) and use of intra-operative continuous renal replacement therapy (CRRT) (p = 0.017). A rapid rise in SNa was associated with more neurological investigations in the post-transplant period (brain computed tomography, electroencephalogram, swallow studies), increased neurological deficits (p = 0.006), more abnormal swallowing assessments (p = 0.003), a tendency for more neurology consultations (p = 0.058), increased discharge to a rehabilitation or long-term care facility (p < 0.001), and increased 6-month mortality (p < 0.001). Following a QA initiative, rapid peri-operative rises in SNa among hyponatremic patients was significantly reduced (20% vs. 0%, p < 0.003). CONCLUSION: Pre-operative hyponatremia and rapid peri-operative SNa shifts are associated with a more complicated post-operative course and worse outcomes following LTx. Increased education and awareness, along with process changes, such as standardizing CRRT prescription, can reduce iatrogenic rapid peri-operative shifts in SNa.

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.

[Review article: Acute kidney injury in critical illness].

PURPOSE: This review provides a focused and comprehensive update on emerging evidence related to acute kidney injury (AKI). PRINCIPAL FINDINGS: Acute kidney injury is a significant clinical problem that increasingly complicates the course of hospitalization and portends worse clinical outcome for sick hospitalized patients. The recent introduction of consensus criteria for the diagnosis of AKI (i.e., RIFLE/AKIN classification) have greatly improved our capacity not only to standardize the diagnosis and classification of severity of AKI, but also to facilitate conducting comparative epidemiologic studies in an effort to better understand the burden of adult and pediatric AKI and its syndromes (i.e., septic, cardio-renal, hepato-renal). The characterization of several novel AKI-specific biomarkers (i.e., neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, and interleukin-18) is extending our understanding of the pathophysiology of AKI. Moreover, these biomarkers appear to have clinical relevance for early detection and they provide prognostic value. These innovations are aiding in the design of epidemiologic surveys and randomized trials of therapeutic interventions. Strategies for prevention and conservative management of AKI across a range of clinical settings are discussed, including sepsis, hepato-renal syndrome, cardio-renal syndrome, rhabdomyolysis and in the perioperative setting. CONCLUSIONS: Acute kidney injury is an escalating clinical problem in hospitalized patients. Recent advances in AKI have improved knowledge of its pathogenesis, diagnosis, and prognosis; however, considerable research effort is needed. There are still relatively few interventions proven to alter the natural history of established AKI in hospitalized settings, and its development foretells less favourable outcomes.