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Background: Interest in point-of-care ultrasound (POCUS) and lung ultrasound (LUS) is growing in the nephrology and dialysis field, and the number of nephrologists skilled in what is proving to be the "5th pillar of bedside physical examination" is increasing. Patients on hemodialysis (HD) are at high risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) and developing coronavirus disease 2019 (COVID-19) serious complications. Despite this, to our knowledge there are no studies to date that show the role of LUS in this setting, while there are many in the emergency room, where LUS proved to be an important tool, providing risk stratification and guiding management strategies and resource allocation. Therefore, it is not clear whether the usefulness and cut-offs of LUS highlighted in studies in the general population are reliable in dialysis, or whether variations, precautions and adjustments to this specific situation are necessary. Methods: This was a 1-year monocentric prospective observational cohort study of 56 HD patients with COVID-19. Patients underwent a monitoring protocol that included at first evaluation bedside LUS, using a 12-scan scoring system, by the same nephrologist. All data were prospectively and systematically collected. Outcomes. hospitalization rate, combined outcome [non-invasive ventilation (NIV + death)], mortality. Descriptive variables are presented as medians (interquartile range), or percentage. Univariate and multivariate analysis, as well as Kaplan-Meier (K-M) survival curves, were carried out. P was fixed at .05. Results: Median age was 78 years, 90% had at least one comorbidity (46% diabetics), 55% were hospitalized and 23% deaths. Median duration of disease was 23 days (14-34). A LUS score ≥11 represented a 13-fold risk of hospitalization, a 16.5-fold risk of combined outcome (NIV + death) vs risk factors such as age [odds ratio (OR) 1.6], diabetes (OR 1.2), male sex (OR 1.3) and obesity (OR 1.25), and a 7.7-fold risk of mortality. In the logistic regression, LUS score ≥11 is associated with the combined outcome with a hazard ratio (HR) of 6.1 vs inflammations indices such as CRP ≥9 mg/dL (HR 5.5) and interleukin-6 (IL-6) ≥62 pg/mL (HR 5.4). In K-M curves, survival drops significantly with LUS score above 11. Conclusions: In our experience of COVID-19 HD patients, LUS appeared to be an effective and easy tool, predicting the need for NIV and mortality better than "classic" known COVID-19 risk factors such as age, diabetes, male sex and obesity, and even better than inflammations indices such as CRP and IL-6. These results are consistent with those of the studies in the emergency room setting, but with a lower LUS score cut-off (11 vs 16-18). This is probably due to the higher global frailty and peculiarity of HD population, and emphasizes how nephrologists should themselves use LUS and POCUS as a part of their everyday clinical practice, adapting it to the peculiarity of the HD ward.
RESUMO
BACKGROUND: Patients with multiple myeloma often have kidney involvement with acute kidney injury which is frequently due to cast nephropathy. Hemodiafiltration with endogenous reinfusion (HFR) allows removal from the circulation of significant amounts of free light chains (FLCs) responsible for tubular damage. METHODS: Between 2014 and 2018, 13 patients affected by multiple myeloma (64% λ chain and 36% k), including 10 cases with biopsy-proven cast nephropathy, were treated with this technique. Each patient had high free light chains levels at diagnosis: median 8586 mg/l for λ and 4200 mg/l for k, and stage III acute kidney injury (median serum creatinine 7.5 mg/dl). We initially performed daily HFR-Supra sessions and then modulated them based on renal response (mean 10 sessions/patient). At the same time, the patients also received various chemotherapy regimens, depending on their hematological criteria. RESULTS: Forty-six percent of patients showed at least partial renal function recovery within the third month, thus allowing dialysis discontinuation; 38% remained on dialysis. Two patients died. The mean reduction rate of free light chains at the end of the HFR-Supra cycle was 85% (k) and 40% (λ), respectively. Serum albumin remained stable during the whole treatment. DISCUSSION: In our experience, the synergistic effect of chemotherapy and HFR-Supra led to a recovery of renal function in 6 out of 13 patients presenting with severe dialysis-requiring acute kidney injury. HFR-Supra allowed stable albumin levels, with high free light chains removal rate, at a relatively low costs.
