Understanding urine output in critically ill patients

Urine output often is used as a marker of acute kidney injury but also to guide fluid resuscitation in critically ill patients. Although decrease of urine output may be associated to a decrease of glomerular filtration rate due to decrease of renal blood flow or renal perfusion pressure, neurohormonal factors and functional changes may influence diuresis and natriuresis in critically ill patients. The purpose of this review is to discuss the mechanisms of diuresis regulation, which may help to interpret the urine output in critically ill patients and the appropriate treatment to be initiated in case of changes in urine output

Management of hyperkalemia in the acutely ill patient.

PURPOSE:To review the mechanisms of action, expected efficacy and side effects of strategies to control hyperkalemia in acutely ill patients. METHODS:We searched MEDLINE and EMBASE for relevant papers published in English between Jan 1, 1938, and July 1, 2018, in accordance with the PRISMA Statement using the following terms: "hyperkalemia," "intensive care," "acute kidney injury," "acute kidney failure," "hyperkalemia treatment," "renal replacement therapy," "dialysis," "sodium bicarbonate," "emergency," "acute." Reports from within the past 10 years were selected preferentially, together with highly relevant older publications. RESULTS:Hyperkalemia is a potentially life-threatening electrolyte abnormality and may cause cardiac electrophysiological disturbances in the acutely ill patient. Frequently used therapies for hyperkalemia may, however, also be associated with morbidity. Therapeutics may include the simultaneous administration of insulin and glucose (associated with frequent dysglycemic complications), β-2 agonists (associated with potential cardiac ischemia and arrhythmias), hypertonic sodium bicarbonate infusion in the acidotic patient (representing a large hypertonic sodium load) and renal replacement therapy (effective but invasive). Potassium-lowering drugs can cause rapid decrease in serum potassium level leading to cardiac hyperexcitability and rhythm disorders. CONCLUSIONS:Treatment of hyperkalemia should not only focus on the ability of specific therapies to lower serum potassium level but also on their potential side effects. Tailoring treatment to the patient condition and situation may limit the risks

The strategy of antibiotic use in critically ill neutropenic patients

Suspicion of sepsis in neutropenic patients requires immediate antimicrobial treatment. The initial regimen in critically ill patients should cover both Gram-positive and Gram-negative pathogens, including Pseudomonas aeruginosa. However, the risk of selecting multidrug-resistant pathogens should be considered when using broad-spectrum antibiotics for a prolonged period of time. The choice of the first-line empirical drugs should take into account the underlying malignancy, local bacterial ecology, clinical presentation and severity of acute illness. This review provides an up-to-date guide that will assist physicians in choosing the best strategy regarding the use of antibiotics in neutropenic patients, with a special focus on critically ill patients, based on the above-mentioned considerations and on the most recent international guidelines and literature

The elusive task of biomarkers of renal injury

Neutrophil gelatinase-associated lipocalin (NGAL) is one of the most promising candidate biomarkers of renal injury, with expression in renal tissue increasing dramatically after ischemia-reperfusion injury but not in the case of pure pre-renal failure. In a recent issue of Critical Care, Di Somma and colleagues reported that NGAL could improve the classification of acute kidney injury compared with clinical assessment and showed that NGAL was associated with poor prognosis. NGAL may therefore carry different information than biomarkers of renal function. This study finally provides additional evidence for the highly complex relationship between renal function and renal injury

Pathophysiology of COVID-19-associated acute kidney injury

Although respiratory failure and hypoxaemia are the main manifestations of COVID-19, kidney involvement is also common. Available evidence supports a number of potential pathophysiological pathways through which acute kidney injury (AKI) can develop in the context of SARS-CoV-2 infection. Histopathological findings have highlighted both similarities and differences between AKI in patients with COVID-19 and in those with AKI in non-COVID-related sepsis. Acute tubular injury is common, although it is often mild, despite markedly reduced kidney function. Systemic haemodynamic instability very likely contributes to tubular injury. Despite descriptions of COVID-19 as a cytokine storm syndrome, levels of circulating cytokines are often lower in patients with COVID-19 than in patients with acute respiratory distress syndrome with causes other than COVID-19. Tissue inflammation and local immune cell infiltration have been repeatedly observed and might have a critical role in kidney injury, as might endothelial injury and microvascular thrombi. Findings of high viral load in patients who have died with AKI suggest a contribution of viral invasion in the kidneys, although the issue of renal tropism remains controversial. An impaired type I interferon response has also been reported in patients with severe COVID-19. In light of these observations, the potential pathophysiological mechanisms of COVID-19-associated AKI may provide insights into therapeutic strategies

Sepsis and septic shock in patients with malignancies : a Groupe de Recherche Respiratoire en Réanimation Onco-Hématologique study

Objectives: Cancer affects up to 20% of critically ill patients, and sepsis is one of the leading reasons for ICU admission in this setting. Early signals suggested that survival might be increasing in this population. However, confirmation studies have been lacking. The goal of this study was to assess trends in survival rates over time in cancer patients admitted to the ICU for sepsis or septic shock over the last 2 decades. Data Source: Seven European ICUs. Study Selection: A hierarchical model taking into account the year of admission and the source dataset as random variables was used to identify risk factors for day 30 mortality. Data Extraction: Data from cancer patients admitted to ICUs for sepsis or septic shock were extracted from the Groupe de Recherche Respiratoire en Reanimation Onco-Hematologique database (1994-2015). Data Synthesis: Overall, 2,062 patients (62% men, median [interquartile range] age 59 yr [48-67 yr]) were included in the study. Underlying malignancies were solid tumors (n = 362; 17.6%) or hematologic malignancies (n = 1,700; 82.4%), including acute leukemia (n = 591; 28.7%), non-Hodgkin lymphoma (n = 461; 22.3%), and myeloma (n = 244; 11.8%). Two-hundred fifty patients (12%) underwent allogeneic hematopoietic stem cell transplantation and 640 (31.0%) were neutropenic at ICU admission. Day 30 mortality was 39.9% (823 deaths). The year of ICU admission was associated with significant decrease in day 30 mortality over time (odds ratio, 0.96; 95% CI, 0.93-0.98; p = 0.001). Mechanical ventilation (odds ratio, 3.25; 95% CI, 2.52-4.19; p < 0.01) and vasopressors use (odds ratio, 1.42; 95% CI, 1.10-1.83; p < 0.01) were independently associated with day 30 mortality, whereas underlying malignancy, allogeneic hematopoietic stem cell transplantation, and neutropenia were not. Conclusions: Survival in critically ill oncology and hematology patients with sepsis improved significantly over time. As outcomes improve, clinicians should consider updating admission policies and goals of care in this population