Pathogenesis and management of vascular calcification in CKD and dialysis patients.

Patients with chronic kidney disease (CKD) have a predisposition to develop vascular calcification due to dysregulated homeostatic mechanisms, which lead to an imbalance in the circulatory promoters and inhibitors of vascular calcification, leading to a net calcification stress. These factors promote ectopic calcification and induce vascular smooth muscle cells to undergo osteogenic differentiation and actively calcify the vascular media. The article summarizes clinically relevant pathogenic mechanisms of vascular calcification in patients with CKD and in dialysis patients and summarizes novel therapeutic interventions. In addition to the management of traditional cardiovascular risk factors, patients with CKD-mineral and bone disorder need close attention in the management of the mineral metabolism to prevent adverse effects on the bone and vascular compartments. This article reviews current evidence and therapeutic guidelines in the management of mineral metabolism in CKD and dialysis.

A Survey Study of Self-Rated Patients' Knowledge About AKI in a Post-Discharge AKI Clinic.

BACKGROUND: Survivors of acute kidney injury (AKI) are at risk of adverse outcomes. Post-discharge nephrology care may improve patients' AKI knowledge and prevent post-AKI complications. OBJECTIVE: The purpose of this study was to examine patients' awareness about their AKI diagnosis and self-rated knowledge and severity of AKI before and after their first post-discharge AKI Clinic encounter. DESIGN: We conducted a pre- and post-survey study among AKI survivors who attended a post-discharge AKI Clinic. SETTING: AKI Clinic at the University of Kentucky Medical Center (October 2016 to December 2017). Education about AKI was based on transformative learning theory and provided through printed materials and interdisciplinary interactions between patients/caregivers and nurses, pharmacists, and nephrologists. PATIENTS: A total of 104 patients completed the survey and were included in the analysis. MEASUREMENTS: Three survey questions were administered before and after the first AKI Clinic encounter: Question 1 (yes-no) for awareness, and questions 2 and 3 (Likert scale, 1 = lowest to 5 = highest) for self-rated knowledge and severity of AKI. METHODS: Two mixed-model analysis of variance (ANOVA) was used for between-group (AKI severity) and within-group (pre- and post-encounter) comparisons. Logistic regression was used to examine parameters associated with the within-group change in self-perceived knowledge. RESULTS: Twenty-two out of 104 (21%) patients were not aware of their AKI diagnosis before the clinic encounter. Patients' self-ratings of their AKI knowledge significantly increased after the first AKI Clinic encounter (mean ± SEM: pre-visit = 1.94 ± 0.12 to post-visit = 3.88 ± 0.09, P = .001), even after adjustment for age, gender, Kidney Disease Improving Global Outcomes (KDIGO) severity stage, or poverty level. Patients with AKI stage 3 self-rated their AKI as more severe than patients with AKI stage 1 or 2. LIMITATIONS: Our study population may not be representative of the general AKI survivor population. Administered surveys are subject to response-shift bias. CONCLUSIONS: Patients' self-perceived knowledge about AKI significantly increased following the first post-discharge AKI Clinic encounter that included interdisciplinary education. This is the first survey study examining self-perceived AKI knowledge in AKI survivors. Further examination of AKI literacy in survivors of AKI and its effect on post-AKI outcomes is needed. TRIAL REGISTRATION: Not applicable.

CONTEXTE: Les survivants d'un épisode d'insuffisance rénale aiguë (IRA) risquent de souffrir de pathologies associées. Un suivi en néphrologie après la sortie de l'hôpital pourrait accroître les connaissances des patients sur la maladie et prévenir les complications. OBJECTIF: L'étude était bipartite : i) savoir si les patients connaissaient leur diagnostic; ii) mesurer, par auto-évaluation, les connaissances des patients sur l'IRA et sur sa gravité, avant et après une consultation dans une clinique d'IRA. TYPE D'ÉTUDE: Un sondage mené auprès de survivants d'un épisode d'IRA, avant et après une consultation en clinique d'IRA suivant leur congé de l'hôpital. CADRE: La clinique d'IRA du centre médical de l'université du Kentucky (d'octobre 2016 à décembre 2017). L'information fournie suivait la théorie de l'apprentissage transformationnel et était transmise sous forme de documents imprimés et d'interactions interdisciplinaires entre les patients/fournisseurs de soins et les infirmières, les pharmaciens et les néphrologues. PARTICIPANTS: L'étude porte sur 104 patients ayant complété le sondage. MESURES: Trois questions ont été posées aux patients avant et après une première consultation à la clinique. Une question portait sur leur connaissance du diagnostic (oui -non) et deux autres auto-évaluaient leurs connaissances sur l'IRA et sa gravité (échelle de Likert, de 1 [plus faible] à 5 [plus élevé]). MÉTHODOLOGIE: Deux modèles mixtes d'analyse de variance ont été employés pour établir des comparaisons inter-groupes (gravité de l'IRA) et intra-groupes (pré et post-consultation). Une régression logistique a été utilisée pour analyser les paramètres associés aux changements du niveau auto-évalué des connaissances dans un même groupe. RÉSULTATS: Des 104 patients inclus à l'étude, 22 (21 %) ignoraient leur diagnostic d'IRA avant la consultation. L'auto-évaluation des connaissances a augmenté après la première consultation (moyenne ± SEM : 1,94 ± 0,12 [pré-visite]; 3,88 ± 0,09 [post-visite], p=0,001) et ce, même après les ajustements en regard de l'âge et du sexe du patient, du stade de la maladie selon le KDIGO (Kidney Disease Improving Global Outcomes) ou du niveau de revenus. Les patients atteints d'une IRA de stade 3 ont davantage surévalué la gravité de leur maladie que les patients de stades 1 ou 2. LIMITES: La population étudiée pourrait ne pas être représentative de la population générale des survivants d'un épisode d'IRA. Les sondages sont sujets aux biais liés aux changements de réponses. CONCLUSION: L'auto-évaluation des connaissances a augmenté significativement après une première consultation à la clinique d'IRA lorsque celle-ci incluait de l'information interdisciplinaire. Il s'agit de la première étude portant sur l'auto-évaluation des connaissances de survivants d'un épisode d'IRA. Il est nécessaire d'examiner davantage la littératie de l'IRA chez les survivants de la maladie et ses effets sur les pathologies qui en découlent.

The Role of Sodium Bicarbonate in the Management of Some Toxic Ingestions.

Adverse reactions to commonly prescribed medications and to substances of abuse may result in severe toxicity associated with increased morbidity and mortality. According to the Center for Disease Control, in 2013, at least 2113 human fatalities attributed to poisonings occurred in the United States of America. In this article, we review the data regarding the impact of systemic sodium bicarbonate administration in the management of certain poisonings including sodium channel blocker toxicities, salicylate overdose, and ingestion of some toxic alcohols and in various pharmacological toxicities. Based on the available literature and empiric experience, the administration of sodium bicarbonate appears to be beneficial in the management of a patient with the above-mentioned toxidromes. However, most of the available evidence originates from case reports, case series, and expert consensus recommendations. The potential mechanisms of sodium bicarbonate include high sodium load and the development of metabolic alkalosis with resultant decreased tissue penetration of the toxic substance with subsequent increased urinary excretion. While receiving sodium bicarbonate, patients must be monitored for the development of associated side effects including electrolyte abnormalities, the progression of metabolic alkalosis, volume overload, worsening respiratory status, and/or worsening metabolic acidosis. Patients with oliguric/anuric renal failure and advanced decompensated heart failure should not receive sodium bicarbonate.

The Role of Renal Replacement Therapy in the Management of Pharmacologic Poisonings.

Pharmacologic toxicities are common and range from mild to life-threatening. The aim of this study is to review and update the data on the role of renal replacement therapy (RRT) in the management of various pharmacologic poisonings. We aim to provide a focused review on the role of RRT in the management of pharmacological toxicities. Relevant publications were searched in MEDLINE with the following search terms alone or in combination: pharmacologic toxicity, hemodialysis, hemofiltration, renal replacement therapy, toxicology, poisonings, critical illness, and intensive care. The studies showed that a pharmacologic substance should meet several prerequisites to be deemed dialyzable. These variables include having a low molecular weight (<500 Da) and low degree of protein binding (<80%), being water-soluble, and having a low volume of distribution (<1 L/kg). RRT should be strongly considered in critically ill patients presenting with toxic alcohol ingestion, salicylate overdose, severe valproic acid toxicity, metformin overdose, and lithium poisoning. The role of RRT in other pharmacologic toxicities is less certain and should be considered on a case-by-case basis.

Postoperative hyperkalemia.

Hyperkalemia occurs frequently in hospitalized patients and is of particular concern for those who have undergone surgery, with postoperative care provided by clinicians of many disciplines. This review describes the normal physiology and how multiple perioperative factors can disrupt potassium homeostasis and lead to severe elevations in plasma potassium concentration. The pathophysiologic basis of diverse causes of hyperkalemia was used to broadly classify etiologies into those with altered potassium distribution (e.g. increased potassium release from cells or other transcellular shifts), reduced urinary excretion (e.g. reduced sodium delivery, volume depletion, and hypoaldosteronism), or an exogenous potassium load (e.g. blood transfusions). Surgical conditions of particular concern involve: rhabdomyolysis from malpositioning, trauma or medications; bariatric surgery; vascular procedures with tissue ischemia; acidosis; hypovolemia; and volume or blood product resuscitation. Certain acute conditions and chronic co-morbidities present particular risk. These include chronic kidney disease, diabetes mellitus, many outpatient preoperative medications (e.g. beta blockers, salt substitutes), and inpatient agents (e.g. succinylcholine, hyperosmolar volume expanders). Clinicians need to be aware of these pathophysiologic mechanisms for developing perioperative hyperkalemia as many of the risks can be minimized or avoided.

Life-threatening hyperkalemia in a patient with normal renal function.

With media focus on benefits from reducing sodium intake, there is increased popularity of salt substitutes, typically potassium chloride. While viewed by the public as a healthy alternative to standard table salt, less appreciated is the severe risk with certain comorbidities and medications. We report the case of an elderly female with chronically high salt substitute intake, normal renal function, diabetes, hypertension treated with angiotensin-converting enzyme inhibitor and beta blockade, who developed life-threatening hyperkalemia after a minimally invasive outpatient procedure. We describe the pathophysiology of the disruption in potassium homeostasis and emphasize the importance of dietary history and educating high-risk patients to avoid salt substitutes.

Bilateral renal infarction: an uncommon presentation of fibromuscular dysplasia.

While fibromuscular dysplasia (FMD) is an established cause of secondary hypertension, its association with renal infarction is less well recognized. We report a middle-aged man who presented with complaints of loin pain and severe hypertension. Computed tomography angiography of the abdomen revealed bilateral renal infarction with multiple short-segment arterial dissection compatible with FMD in the absence of systemic vasculitis and other risk factors for thromboembolic events. Bilateral renal infarction complicating FMD is extremely rare and has so far been reported only in a handful of cases. Physicians encountering cases of otherwise unexplained renal infarction/ischemia need to be aware of this complication.