Iron as an emerging therapeutic target in critically ill patients.

The multiple roles of iron in the body have been known for decades, particularly its involvement in iron overload diseases such as hemochromatosis. More recently, compelling evidence has emerged regarding the critical role of non-transferrin bound iron (NTBI), also known as catalytic iron, in the care of critically ill patients in intensive care units (ICUs). These trace amounts of iron constitute a small percentage of the serum iron, yet they are heavily implicated in the exacerbation of diseases, primarily by catalyzing the formation of reactive oxygen species, which promote oxidative stress. Additionally, catalytic iron activates macrophages and facilitates the growth of pathogens. This review aims to shed light on this underappreciated phenomenon and explore the various common sources of NTBI in ICU patients, which lead to transient iron dysregulation during acute phases of disease. Iron serves as the linchpin of a vicious cycle in many ICU pathologies that are often multifactorial. The clinical evidence showing its detrimental impact on patient outcomes will be outlined in the major ICU pathologies. Finally, different therapeutic strategies will be reviewed, including the targeting of proteins involved in iron metabolism, conventional chelation therapy, and the combination of renal replacement therapy with chelation therapy.

High-dose IV magnesium in mesothelioma patients receiving surgery with hyperthermic intraoperative cisplatin: Pilot studies and design of a phase II randomized clinical trial.

INTRODUCTION: Hyperthermic intraoperative cisplatin (HIOC) is associated with acute kidney injury (AKI). Administration of high-dose magnesium attenuates cisplatin-induced AKI (CP-AKI) in animal models but has not been rigorously examined in humans. METHODS: We tested the feasibility and safety of different doses of magnesium in mesothelioma patients receiving HIOC. In Pilot Study 1, we administered a 36-h continuous infusion of magnesium at 0.5 g/h, targeting serum magnesium levels between 3 and 4.8 mg/dL. In Pilot Study 2A, we administered a 6 g bolus followed by an infusion starting at 2 g/h, titrated to achieve levels between 4 and 6 mg/dL. We eliminated the bolus in Pilot Study 2B. RESULTS: In Pilot Study 1, all five patients enrolled completed the study; however, median postoperative Mg levels were only 2.4 mg/dL. In Pilot Study 2A, two of four patients (50%) were withdrawn due to bradycardia during the bolus. In Pilot Study 2B, two patients completed the study whereas two developed postoperative bradycardia attributed to the magnesium. CONCLUSIONS: A 0.5 g/h infusion for 36 h did not achieve therapeutic magnesium levels, while an infusion at 2 g/h was associated with bradycardia. These studies informed the design of a randomized clinical trial testing whether intravenously Mg attenuates HIOC-associated AKI.

Acute kidney injury after cytoreductive surgery and hyperthermic intraoperative cisplatin chemotherapy for malignant pleural mesothelioma.

OBJECTIVES: Cytoreductive surgery with hyperthermic intraoperative chemotherapy with cisplatin has been used successfully to treat malignant pleural mesothelioma, a highly aggressive malignancy that is rapidly fatal in most cases. We hypothesized that the combination of ischemic injury with nephrotoxic injury from cisplatin would result in high rates of acute kidney injury. METHODS: We conducted an observational study in 503 patients to study the risks and outcomes of acute kidney injury after surgical resection of malignant pleural mesothelioma. Eligible subjects underwent extrapleural pneumonectomy or pleurectomy/decortication with or without hyperthermic intraoperative chemotherapy. Acute kidney injury was defined as an increase in creatinine of 26.5 µmol/L or greater within 48 hours of surgery or a 50% or greater increase over 7 days. RESULTS: Acute kidney injury developed in 243 patients (48.3%). Severe acute kidney injury requiring renal replacement therapy developed in 16 patients (3.2%). Major significant predictors for acute kidney injury included male sex (odds ratio, 2.98; P < .001), intraoperative cisplatin administration (odds ratio, 3.12; P < .001), previous cisplatin exposure (odds ratio, 1.96; P = .02), hypertension (odds ratio, 1.57; P = .02), and longer surgical time (odds ratio, 1.15 per hour; P = .02). Compared with patients without acute kidney injury, those with severe acute kidney injury had longer length of stay (26 vs 13 days) and a 2.71-fold increased risk of death in multivariable-adjusted models. CONCLUSIONS: Acute kidney injury is common after cytoreductive surgery with hyperthermic intraoperative chemotherapy with cisplatin and is associated with poor long-term outcomes. Strategies to prevent postoperative acute kidney injury are needed to improve multimodal treatment of malignant pleural mesothelioma.

Interpretation and review of health-related quality of life data in CKD patients receiving treatment for anemia.

Recent evidence suggests that targeting higher hemoglobin values with erythropoiesis stimulating agents (ESAs) may lack mortality benefits and may even result in adverse cardiovascular complications when used in chronic kidney disease patients. However, ESAs are frequently reported to result in improvements in health-related quality of life (HRQOL). The purpose of this review is to evaluate the magnitude and nature of ESA-associated improvements in HRQOL, as well as to understand how to interpret the clinical significance of HRQOL data. HRQOL findings should be analyzed not by statistical significance but rather by using a minimal clinically important difference approach, or, alternatively, a distribution-based approach (such as Cohen's effect size). HRQOL domains that are most improved with ESAs relate to physical symptoms, vitality, energy, and performance; domains of social functioning and mental health show modest improvement, whereas the domains of emotional functioning and pain show very little improvement. Additional domains not measured by commonly used instruments (such as the SF-36) that have been shown to improve with ESAs include sleep, cognitive functioning, and sexual functioning. The maximal increase in HRQOL per incremental increase in hemoglobin appears to occur in the range of 10-12 g/dl. Beyond this range, additional normalization of hemoglobin (to 12-14 g/dl) results in continued (albeit blunted) improvements in HRQOL.