Acute Cardiorenal Syndrome: An Update.

The complex dynamic pathophysiological interplay between the heart and kidney causes a vicious cycle of worsening renal and/or cardiovascular function. Acute decompensated heart failure causing worsening renal function defines Type 1 cardiorenal syndrome (CRS). Altered hemodynamics coupled with a multitude of nonhemodynamic factors namely pathological activation of the renin angiotensin aldosterone system and systemic inflammatory pathways mechanistically incite CRS type 1. A multipronged diagnostic approach utilizing laboratory markers, noninvasive and/or invasive modalities must be implemented to enable timely initiation of effective treatment strategies. In this review, we discuss the pathophysiology, diagnosis, and emerging treatment options for CRS type 1.

Pruritus in chronic kidney disease.

PURPOSE OF REVIEW: Among the many difficult symptoms that patients with kidney disease experience, pruritus is one of the most frequent and troubling. Because a substantial amount of new information has accumulated, we seek here to review the subject. RECENT FINDINGS: Pruritus is not only a common problematic symptom among patients with kidney disease, but its considerably more frequent than nephrologists recognize. The result for patients is not just uncomfortable itch but degraded quality of life as well. The pathogenesis is increasingly understood, but many aspects remain to be fully resolved. Importantly, research is progressing on treatment, leading to the first approved medication in the United States, difelikefalin, in August, 2021. SUMMARY: As nephrology is progressing to a greater focus on patient symptoms, recognition of the importance of pruritus has led to increased interest and improved diagnosis and treatment options.

Local anesthetics for the Nephrologist.

Several specialists in medicine use local anesthetics. In patients with kidney disease, these agents are used during catheter insertions for hemodialysis and peritoneal dialysis, arteriovenous fistula and graft procedures, kidney transplantation, parathyroidectomy, kidney biopsies, and dental and skin procedures. Patients on chronic hemodialysis use a topical application prior to use of needles for arteriovenous fistula cannulation before starting dialysis. They are also used to manage acute and chronic pain conditions, in regional nerve blockade and in multi-modal enhanced recovery protocols. Despite their frequent use by both physicians and patients, data on the use of local anesthetics in patients with kidney impairment are not well reported. This review will summarize the use of local anesthetics in chronic kidney disease, describe their pharmacology and the impact of lower estimated glomerular filtration rate on their pharmacokinetics, and suggest dose regulation in those with kidney dysfunction.

Erratum to: Local anesthetics for the Nephrologist.

[This corrects the article DOI: 10.1093/ckj/sfab121.].

Electrolyte and Acid-Base Disorders Associated with Cancer Immunotherapy.

Novel immunotherapy drugs have changed the landscape of cancer medicine. Immune checkpoint inhibitors and chimeric antigen receptor T cells are being used and investigated in almost all types of cancers. Immune-related adverse events have been associated with immunotherapies. AKI has been the most commonly associated kidney adverse event. In this review, we showcase the several associated electrolyte disorders seen with immunotherapy. Immune checkpoint inhibitors can lead to hyponatremia by several mechanisms, with the syndrome of inappropriate antidiuresis being the most common. Endocrine causes of hyponatremia are rare. Hypokalemia is not uncommon and is associated with both proximal and distal renal tubular acidosis. Hypercalcemia associated with immune checkpoint inhibitors has led to some interesting observations, including immune checkpoint inhibitor-induced parathyroid hormone-related peptide production, sarcoid-like granulomas, and hyperprogression of the disease. Hypocalcemia and hyperphosphatemia may be seen with immune checkpoint inhibitor-induced tumor lysis syndrome. Chimeric antigen receptor T cell therapy-associated electrolyte disorders are also common. This is associated chiefly with hyponatremia, although other electrolyte abnormalities can occur. Early recognition and prompt diagnosis may help providers manage the mechanistically varied and novel electrolyte disorders associated with immunotherapy.

Hypomagnesemia in Patients With Cancer: The Forgotten Ion.

Magnesium is crucial for various cellular and enzymatic processes, yet it often is overlooked or underappreciated. Hypomagnesemia, a deficiency of magnesium in the blood, is a frequent problem in cancer patients and can lead to severe symptoms and morbidity. In this review, we provide an in-depth analysis of the physiology and regulation of magnesium, and signs and symptoms of hypomagnesemia in cancer patients. We also examine the causes and mechanisms of magnesium imbalances in cancer patients, specifically focusing on cancer-specific therapies that can lead to hypomagnesemia. Finally, we provide updates on the management of hypomagnesemia, including oral and parenteral supplementation, as well as the role of drugs in cases that are resistant to treatment. This review aims to raise awareness among health care providers caring for cancer patients about the significance of monitoring magnesium levels in cancer patients and function as a guide. Future clinical studies should focus on magnesium monitoring, its impact on cancer progression, and its potential for preventing acute kidney injury.

Hypomagnesemia in the Cancer Patient.

Hypomagnesemia is a common medical problem that contributes to the morbidity and mortality of patients with cancer. This review summarizes magnesium physiology and highlights the mechanisms underlying magnesium disturbances due to cancer and cancer treatment. The causes of hypomagnesemia can be categorized according to the pathophysiologic mechanism: decreased intake, transcellular shift, gastrointestinal losses, and kidney losses. Patients with cancer are at risk for opportunistic infections, frequently experience cardiovascular complications, and often receive classes of medications that cause or exacerbate hypomagnesemia. Also, cancer-specific therapies are responsible for hypomagnesemia, including platinum-based chemotherapy, anti-EGF receptor mAbs, human EGF receptor-2 target inhibitors (HER2), and calcineurin inhibitors. Urinary indices, such as the fractional excretion of magnesium, can provide useful information about the etiology. The management of hypomagnesemia depends on the magnitude of hypomagnesemia and the underlying cause. We recommended checking serum magnesium at the beginning of treatment and as part of routine monitoring throughout cancer treatment. Opportunities exist for potential research and practice improvement, including further characterization of hypomagnesemia regarding the clinical effect on cancer outcomes, preventing hypomagnesemia in patients receiving high-risk anticancer agents, and developing effective therapeutic strategies.

COVID-19 in Hospitalized Patients on Chronic Peritoneal Dialysis: A Case Series.

BACKGROUND: The COVID-19 pandemic has affected the end-stage kidney disease (ESKD) population, with high mortality rates reported among patients on hemodialysis. However, the degree to which it has affected the peritoneal dialysis (PD) population in the United States has not yet been elucidated. In this report, we describe the clinical characteristics, presentations, clinical course, and outcomes of ESKD patients on PD hospitalized with COVID-19. METHODS: We describe the characteristics, presentation, and outcomes of adult ESKD patients on chronic PD hospitalized with CO-VID-19 in our 13 major hospitals in the NY health system using descriptive statistical analysis. RESULTS: Of 419 hospitalized patients with ESKD, 11 were on chronic PD therapy (2.6%). Among those 11, 3 patients required mechanical ventilation, 2 of whom died. Of the entire cohort, 9 of the 11 patients (82%) were discharged alive. While fever was a common presentation, more than half of our patients also presented with diarrhea. Interestingly, 3 patients were diagnosed with culture-negative peritonitis during their hospitalization. Seven patients reported positive SARS-CoV-2 exposure from a member of their household. CONCLUSION: Hospitalized patients on PD with COVID-19 had a relatively mild course, and majority of them were discharged home.

COVID-19-Associated Kidney Injury: A Case Series of Kidney Biopsy Findings.

BACKGROUND: Reports show that AKI is a common complication of severe coronavirus disease 2019 (COVID-19) in hospitalized patients. Studies have also observed proteinuria and microscopic hematuria in such patients. Although a recent autopsy series of patients who died with severe COVID-19 in China found acute tubular necrosis in the kidney, a few patient reports have also described collapsing glomerulopathy in COVID-19. METHODS: We evaluated biopsied kidney samples from ten patients at our institution who had COVID-19 and clinical features of AKI, including proteinuria with or without hematuria. We documented clinical features, pathologic findings, and outcomes. RESULTS: Our analysis included ten patients who underwent kidney biopsy (mean age: 65 years); five patients were black, three were Hispanic, and two were white. All patients had proteinuria. Eight patients had severe AKI, necessitating RRT. All biopsy samples showed varying degrees of acute tubular necrosis, and one patient had associated widespread myoglobin casts. In addition, two patients had findings of thrombotic microangiopathy, one had pauci-immune crescentic GN, and another had global as well as segmental glomerulosclerosis with features of healed collapsing glomerulopathy. Interestingly, although the patients had confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by RT-PCR, immunohistochemical staining of kidney biopsy samples for SARS-CoV-2 was negative in all ten patients. Also, ultrastructural examination by electron microscopy showed no evidence of viral particles in the biopsy samples. CONCLUSIONS: The most common finding in our kidney biopsy samples from ten hospitalized patients with AKI and COVID-19 was acute tubular necrosis. There was no evidence of SARS-CoV-2 in the biopsied kidney tissue.

Systemic p-ANCA vasculitis with fatal outcome, arising in the setting of methimazole use.

Here we report a fatal case of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) due to methimazole use in a 64-year-old woman. She was initially hospitalized for abdominal pain and possible colitis, and subsequently developed hematuria, renal failure, and hemoptysis. The serologic work-up revealed positive antinuclear antibody (ANA) and perinuclear-antineutrophilic cytoplasm antibodies (p-ANCA), with positive antimyeloperoxidase. Three weeks following admission, the patient was found to be pulseless, and expired. At autopsy, microscopic review included widespread transmural necrotizing vasculitis and crescentic glomerulonephritis in the kidney, and diffuse pulmonary alveolar hemorrhage; focal coronary artery intimal vasculitis and necrotizing pericarditis were also noted. Several drugs have been associated with the development of ANCA-positive diseases, including propylthiouracil, hydralazine, allopurinol, penicillamine, and levamisole in cocaine. Association of ANCA vasculitis with methimazole exposure is less known, and severe presentation with fatal outcome, as seen in our patient, is exceedingly rare. We reviewed clinical and histopathologic features of drug-induced ANCA vasculitis associated with methimazole to raise awareness of this potentially life-threatening complication associated with this agent.