Acute kidney injury in hematopoietic stem cell transplantation Purpose of review Acute kidney injury (AKI) in the setting of hematopoietic stem cell transplantation (HSCT) is common in pediatric and adult patients. The incidence ranges from 12 to 66%, and development of AKI in the posttransplant course is independently associated with higher mortality. Recent findings Patients who undergo HSCT have many risk factors for developing AKI, including sepsis, use of nephrotoxic medications, graft versus host disease (GVHD), and veno-occlusive disease (VOD). In addition, engraftment syndrome/cytokine storm, transplant-associated thrombotic microangiopathy (TA-TMA), and less common infections with specific renal manifestations, such as BK and adenovirus nephritis, may lead to kidney injury. There has been significant advancement in the understanding of TA-TMA in particular, especially the role of the complement system in its pathophysiology. The role of early dialysis has been explored in the pediatric population, but not well studied in adult HSCT recipients Summary This review provides an update on the risk factors, causes, and treatment approaches to HSCT-associated AKI. Video abstracthttp://links.lww.com/COCC/A29

Persistent pollutants: focus on perfluorinated compounds and kidney Purpose of review There is increasing interest in the environmental and human damage caused by pollutants. Big efforts are continuously made to monitor their levels and identify safe thresholds. For this purpose, an essential step is to prioritize harmful substances and understand their effect on human body. Perfluorinated compounds (PFCs) deserve particular attention because of their wide diffusion and potential correlation with different diseases including glucose intolerance, hyperlipidaemia, thyroid diseases, gestational diabetes mellitus and hypertension, testicular and genitourinary cancer as well as impaired kidney function. This review focuses on the renal effects of PFCs, with the attempt to clarify their occurrence and pathogenetic mechanisms. Recent findings We reviewed MEDLINE and EMBASE citations between 31 October 2017 and 31 May 2019 and selected human studies measuring PFCs exposure, kidney function markers and the ability of haemodialysis to remove PFCs from the circulating blood. It has been currently clarified that exposure to PFCs is linked with an impaired kidney function and that they can be removed by blood purification. Summary Further studies are required on the potential synergic negative effect of PFCs co-exposure with other pollutants as well as animal studies about the removal capacity of different haemodialysis membranes.

Drug-induced acute kidney injury: diverse mechanisms of tubular injury Purpose of review Medications are a relatively common cause of acute kidney injury (AKI), especially in hospitalized patients who are exposed to numerous agents. Drug-related acute tubular/tubulointerstitial injury is the most common cause of AKI associated with these agents. Toxic effects of drugs and their renal handling often lead to various forms of AKI. Recent findings The inherent nephrotoxicity of drugs and their transport and metabolism by the kidneys play an important role in the occurrence of acute tubular injury. Apical transport of the aminoglycosides by endocytosis and apical pinocytosis of filtered hydroxyethyl starch into cells lead to acute tubular dysfunction. Transport of tenofovir and cisplatin by organic anion and cation transporters in the basolateral surface of the proximal tubule, respectively, are associated with intracellular drug accumulation and injury. Intratubular deposition of drug crystals with associated AKI occurs with several drugs, in particular the anticancer agent methotrexate. A potentially new mechanism of drug-induced AKI was described with vancomycin – acute vancomycin-related cast nephropathy. Immune-mediated acute tubulointerstitial injury is another cause of drug-induced AKI, as seen with immune checkpoint inhibitors. Summary Drugs lead to AKI through mechanisms that involve their inherent toxicity as well as their transport and handling by the kidneys.

Acute kidney injury in interstitial nephritis Purpose of review The purpose of this review is to describe the most common causes of acute interstitial nephritis (AIN), the diagnostic work-up and the therapeutic management. Recent findings Several case series and registries have found an increasing incidence of AIN, especially among older patients. Drug-induced AIN still represents the most common cause. Early withdrawal of the culprit drug together with corticosteroid therapy remain the mainstay of treatment, although recent studies have shown that prolonged treatment beyond 8 weeks does not further improve kidney function recovery. Summary AIN is a common cause of acute kidney injury, and therefore, physicians should suspect this entity especially in patients exposed to multiple medications. While immune-allergic reaction to numerous drugs is the most common cause of AIN, other underlying systemic diseases may also be involved, and therefore, every patient should undergo a complete diagnostic evaluation. Kidney biopsy provides the definitive diagnosis of AIN, and certain histologic features may help to identify the underlying condition. In drug-induced AIN, an early discontinuation of the culprit drug is the mainstay of therapy, and unless a rapid recovery of kidney function is observed, a course of glucocorticoid therapy should be initiated.

Trauma-associated acute kidney injury Purpose of review A summary of recent research into the epidemiology, cause, management and outcomes of trauma-associated acute kidney injury (AKI). There is an increasing focus on subtypes of AKI to better target clinical management and future research. Recent findings AKI associated with trauma occurs in 20–24% of patients admitted to ICU. On the basis of creatinine and/or urine output, AKI occurs in the first few days of traumatic illness. Although various associations have been identified, shock and high-volume blood transfusion are the most consistent risks for development of trauma-associated AKI. Short-term outcomes appear worse for patients with AKI, but extent of longer term kidney function recovery remains unknown. Recent research in the general critical care population is beginning to better inform AKI management; however, currently, preventive and supportive strategies remain the mainstay of AKI management after trauma. Summary Well-designed, prospective research is required to better understand the phenotype, pathophysiology and recovery trajectory of trauma-associated AKI. Only then can potentially unique therapeutic targets be developed for this common subtype of AKI.

Acute kidney injury associated with glomerular diseases Purpose of review This review focuses on acute kidney injury (AKI) associated with glomerular diseases and specifically the mechanisms of development of AKI in the wide spectrum of glomerulopathies. Recent findings The immune system and the kidneys are closely linked. In healthy individuals, the kidneys contribute to immune homeostasis, whereas components of the immune system mediate many acute forms of kidney disease. Both crescentic and noncrescentic forms of acute glomerulonephritis can present as AKI. The diagnosis of glomerular diseases underlying AKI requires a high degree of suspicion coupled with an algorithmic approach to laboratory investigations. Renal biopsy represents the gold standard for the diagnosis of medical conditions of the kidney. The main clinical–biological presentations of glomerular diseases are acute nephritic syndrome, nephrotic syndrome and rapidly progressive glomerulonephritis (RPGN). All these presentations can be worsened by AKI both in the onset and in the clinical course. Heavy proteinuria and macroscopic hematuria can be directly involved in the development of AKI. Summary AKI associated with glomerular diseases is not uncommon. Sometimes it represents an emergency case. The understanding of the various mechanisms underlying kidney diseases is improving, and may aid in their prevention and treatment.

Acute kidney injury in pregnancy Purpose of review Pregnancy-related acute kidney injury (Pr-AKI) is associated with increased maternal and fetal morbidity and mortality and remains a large public health problem. Recent findings Pr-AKI incidence has globally decreased over time for the most part. However, the cause presents a disparity between developing and developed countries, reflecting differences in socioeconomic factors and healthcare infrastructure – with the noteworthy outlier of increased incidence in the United States and Canada. Although Pr-AKI can be secondary to conditions affecting the general population, in most cases it is pregnancy specific. Septic abortion, hyperemesis gravidarum, and hemorrhage have become less prevalent with access to healthcare but are being displaced by thrombotic microangiopathies, such as preeclampsia, hemolysis, elevated liver enzymes, low platelets syndrome, thrombotic thrombocytopenic purpura, and pregnancy-associated hemolytic-uremic syndromes, as well as acute fatty liver of pregnancy. Understanding these conditions plays a pivotal role in the timely diagnosis and enhancement of therapeutic approaches. Summary In this review, we focus on the renal physiology of the pregnancy, epidemiology, and specific conditions known to cause Pr-AKI, summarizing diagnostic definition, insights in pathophysiology, clinical considerations, and novel treatment approaches, thus providing the reader a framework of clinically relevant information for interdisciplinary management.

Acute respiratory failure: nonintubation assist methods for the acutely deteriorating patient Purpose of review Noninvasive ventilation is strongly recommended in acute hypercapnic respiratory failure, whereas high-flow nasal oxygen therapy could be an alternative in de novo respiratory failure. Recent findings High-flow nasal oxygen may improve the outcome of patients de novo respiratory failure as compared with standard oxygen. Its success within 2 h after initiation is well predicted by a ROX index (ratio of SpO2/FiO2 to respiratory rate) greater than 4.88, as failure when less than 3.85 at 12 h after initiation. However, the superiority of high-flow nasal oxygen to standard oxygen has not been confirmed in immunocompromised patients. Although noninvasive ventilation may be deleterious through barotrauma in patients with de novo respiratory failure, its use seems to be an optimal strategy for preoxygenation before intubation in preventing severe hypoxemia in most hypoxemic patients. In mild hypoxemic patient, high-flow nasal oxygen may be more efficient than bag-valve mask in preventing severe adverse events. After anesthetic induction further positive-pressure ventilation can better secure intubation procedure than absence of ventilation. Summary Despite the growing use of high-flow nasal oxygen, new studies are needed to confirm its superiority to standard oxygen in de novo respiratory failure and others causes of acute respiratory failure in place of standard oxygen.

Emergent airway management of the critically ill patient: current opinion in critical care Purpose of review To describe techniques to facilitate safe intubation in critically ill patients. Recent findings Despite advances in the treatment of critically ill patients, endotracheal intubation remains a high-risk procedure associated with complications that can lead to appreciable morbidity and mortality. In addition to the usual anatomical factors that can predict a difficult intubation, incorporating pathophysiological considerations and crisis resource management may enhance safety and mitigate risk. Enhancing preoxygenation with high-flow oxygen or noninvasive ventilation, the early use of intravenous fluids and/or vasopressors to prevent hypotension and videolaryngoscopy for first pass success are all promising additions to airway management. Facilitating intubation by either sedation with paralysis or allowing patients to continue to breathe spontaneously are reasonable options for airway management. These approaches have potential advantages and disadvantages. Summary Recognizing the unique challenges of endotracheal intubation in critically ill patients is paramount in limiting further deterioration during this high-risk procedure. A safe approach to intubation focuses on recognizing risk factors that predict c