IntroductionIn ICUs, both fluid overload and oliguria are common complications associated with increased mortality among critically ill patients, particularly in acute kidney injury (AKI). Although fluid overload is an expected complication of oliguria, it remains unclear whether their effects on mortality are independent of each other. The aim of this study is to evaluate the impact of both fluid balance and urine volume on outcomes and determine whether they behave as independent predictors of mortality in adult ICU patients with AKI.MethodsWe performed a secondary analysis of data from a multicenter, prospective cohort study in 10 Italian ICUs. AKI was defined by renal sequential organ failure assessment (SOFA) score (creatinine >3.5 mg/dL or urine output (UO) <500 mL/d). Oliguria was defined as a UO <500 mL/d. Mean fluid balance (MFB) and mean urine volume (MUV) were calculated as the arithmetic mean of all daily values. Use of diuretics was noted daily. To assess the impact of MFB and MUV on mortality of AKI patients, multivariate analysis was performed by Cox regression.ResultsOf the 601 included patients, 132 had AKI during their ICU stay and the mortality in this group was 50%. Non-surviving AKI patients had higher MFB (1.31 ± 1.24 versus 0.17 ± 0.72 L/day; P <0.001) and lower MUV (1.28 ± 0.90 versus 2.35 ± 0.98 L/day; P <0.001) as compared to survivors. In the multivariate analysis, MFB (adjusted hazard ratio (HR) 1.67 per L/day, 95%CI 1.33 to 2.09; <0.001) and MUV (adjusted HR 0.47 per L/day, 95%CI 0.33 to 0.67; <0.001) remained independent risk factors for 28-day mortality after adjustment for age, gender, diabetes, hypertension, diuretic use, non-renal SOFA and sepsis. Diuretic use was associated with better survival in this population (adjusted HR 0.25, 95%CI 0.12 to 0.52; <0.001).ConclusionsIn this multicenter ICU study, a higher fluid balance and a lower urine volume were both important factors associated with 28-day mortality of AKI patients.

Background: Several methods have been developed to assess the hydration status in chronic hemodialysis (HD) patients. The aim of this study was to compare body bioimpedance spectroscopy (BIS) with ultrasound (US) lung comet score (ULCs), B-type natriuretic peptide (BNP) and inferior vena cava diameter (IVCD) by US for the estimation of dry weight before and after HD and to analyze all methods in terms of fluid status variations induced by HD. An additional aim of this study was to establish the interoperator reproducibility of these methods. Methods: Two nephrologists evaluated BIS, ULCs, IVCD during inspiration (min) and expiration (max), the inferior vena cava collapsibility index (IVCCI) as well as BNP before and after HD in 30 patients. The same operators measured BIS, ULCs and IVCD in 28 HD patients in a blinded fashion. Results: There was a significant reduction in BIS, ULCs, IVCD and BNP after HD (p < 0.001), but a less significant reduction in IVCCI (p = 0.13). There was a significant correlation between BIS and ULCs, BNP and indexed IVCD (IVCDi)min (p < 0.05) before and after HD, and between BIS and IVCDimax only before HD. Conclusion: All methods were able to describe hyperhydration before and after HD, except for IVCCI after HD. All techniques correlated with BIS before HD. After HD, ULCs correlated better with BIS than IVCD in terms of evaluation of fluid status. It could be expected that the ULCs can give a real-time evaluation of interstitial water. The reproducibility of the measurement of BIS, IVCD and ULCs between the two operators was high.

Background. We analyzed the incidence, risk factors, and prognosis of acute kidney injury (AKI) in a cohort of patients undergoing major abdominal surgery. Methods. A total of 450 patients were retrospectively studied. AKI was defined by an increase in serum creatinine (SCr) ≥ 0.3 mg/dl or by an increase in SCr ≥ 50% and/or by a decrease in urine output to 0.5 ml/kg/hour for 6 hours, in the first 48 hours after surgery. Logistic regression method was used to determine predictors of AKI and in-hospital mortality. A two-tailed P value <0.05 was considered significant. Results. One hundred one patients (22.4%) had postoperative AKI. Age (adjusted odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01–1.05), nonrenal Revised Cardiac Risk Index score (adjusted OR 1.9, 95% CI 1.3–3.1, P = 0.003), intraoperative erythrocytes transfusions (adjusted OR 2.2, 95% CI 1.4–3.5, P <.0001), and nonrenal Simplified Acute Physiology Score II (adjusted OR 1.03, 95% CI 1.01–1.06, P = 0.0191) were associated with postoperative AKI. AKI was associated with increased in-hospital mortality (20.8% versus 2.3%, P <.0001; unadjusted OR 11.2, 95% CI 4.8–26.2, P <.0001; adjusted OR 3.7, 95% CI 1.2–11.7, P = 0.024). Conclusion. AKI was common in patients undergoing major abdominal surgery and was associated with in-hospital mortality.

BackgroundAcute kidney injury (AKI) is frequent during hospitalization and may contribute to adverse consequences. We aimed to evaluate long-term adverse renal function and mortality after postoperative AKI in a cohort of patients undergoing major abdominal surgery.MethodsWe performed a retrospective analysis of adult patients who underwent major non-vascular abdominal surgery between January 2010 and February 2011 at the Department of Surgery II of Hospital de Santa Maria–Centro Hospitalar Lisboa Norte, Portugal. Exclusion criteria were as follows: chronic kidney disease on renal replacement therapy, undergoing renal replacement therapy the week before surgery, death before discharge and loss to follow-up through January 2014. Patients were categorized according to the development of postoperative AKI in the first 48 h after surgery using the Kidney Disease: Improving Global Outcomes classification. AKI was defined by an increase in absolute serum creatinine (SCr) ≥0.3 mg/dL or by a percentage increase in SCr ≥50% and/or by a decrease in urine output to <0.5 mL/kg/h for >6 h. Adverse renal outcomes (need for long-term dialysis and/or a 25% decrease in estimated glomerular filtration rate after hospital discharge) and mortality after discharge were evaluated. Cumulative mortality was analysed with the Kaplan–Meier method and log-rank test and outcome predictive factors with the Cox regression. Significance was set at P < 0.05.ResultsOf 390 selected patients, 72 (18.5%) developed postoperative AKI. The median follow-up was 38 months. Adverse renal outcomes and death after hospital discharge were more frequent among AKI patients (47.2 versus 22.0%, P < 0.0001; and 47.2 versus 20.5%, P < 0.0001, respectively). The 4 year cumulative probability of death was 44.4% for AKI patients, while it was 19.8% for patients with no AKI (log-rank test, P < 0.0001). In multivariate analysis, AKI was a risk factor for adverse renal outcomes (adjusted hazard ratio 1.6, P = 0.046) and mortality (adjusted hazard ratio 1.4, P = 0.043).ConclusionsAKI after major abdominal surgery was independently associated with the risk of long-term need for dialysis and/or renal function decline and with the risk of death after hospital discharge.

Extracorporeal organ support in patients with dysfunction of vital organs like the kidney, heart, and liver has proven helpful in bridging the patients to recovery or more definitive therapy. Mechanical ventilation in patients with respiratory failure, although indispensable, has been associated with worsening injury to the lungs, termed ventilator-induced lung injury. Application of lung-protective ventilation strategies are limited by inevitable hypercapnia and hypercapnic acidosis. Various alternative extracorporeal strategies, proposed more than 30 years ago, to combat hypercapnia are now more readily available. In particular, the venovenous approach to effective carbon dioxide removal, which involves minimal invasiveness comparable to renal replacement therapy, appears to be very promising. The clinical applications of these extracorporeal carbon dioxide removal therapies may extend beyond just lung protection in ventilated patients. This article summarizes the rationale, technology and clinical application of various extracorporeal lung assist techniques available for clinical use, and some of the future perspectives in the field.

Background: Achievement of euvolemia is a fundamental challenge in the peritoneal dialysis (PD) population. Bioimpedance spectroscopy (BIS) is one of the best techniques for routine assessment of hydration status (HS) in PD, but in recent years, the role of brain natriuretic peptides (BNP) in the assessment of volume status has gained interest. The aim of this study was to investigate the relation between BNP and volume status as measured by BIS in PD patients and to assess how these variables correlate according to the time that a patient has been on PD. Methods: We prospectively studied 68 PD patients from whom measurements of BNP and assessments of HS by BIS were performed every 3 months. Three groups were defined based on HS: group A, measurements of HS <-1.1 liters (underhydrated); group B, measurements of HS between -1.1 and +1.1 liters (normohydrated), and group C, measurements of HS >+1.1 liters (overhydrated). Measurements were also separated according to the time on PD (<6 vs. ≥6 months). Correlation between HS and BNP was performed using Spearman's correlation. Results: We performed a total of 478 measurements of HS and BNP. There was a statistically significant difference in BNP (p < 0.001) among three HS groups, with higher levels of BNP detected in overhydrated patients. We found a positive correlation between HS and BNP (r_s = 0.28; p <0.001) that seemed stronger in the first 6 months on PD (r_s = 0.42; p = 0.006). Conclusions: BNP correlated positively with fluid overload measured by HS, and this correlation was stronger in the first 6 months on PD.

Background Membranous nephropathy (MN) can be associated with hepatitis infection and less commonly with human immunodeficiency virus (HIV) infection. The significance of anti-phospholipase A2 receptor (PLA2R) and anti-thrombospondin type 1 domain-containing 7A (THSD7A) antibodies in this setting is unclear. Methods We describe the clinical, histopathological and outcome data of 19 patients with MN and hepatitis B virus (HBV), hepatitis C virus (HCV) or HIV infection identified through our renal biopsy database and the association with anti-PLA2R antibodies and anti-THSD7A antibodies. Results The cohort consisted of 19 patients, 8 male and 11 female, with a median age of 42 years (range 23–74). HBV infection was found in six cases, HCV in four and HIV in nine (two HIV patients had HBV co-infection and one HCV co-infection). PLA2R staining on biopsy was positive in 10/19 patients: 4 with HBV-MN, 3 with HCV-MN and 3 with HIV-MN and circulating anti-PLA2R antibodies were detected in 7/10 cases. THSD7A staining on biopsy was positive in three PLA2R-negative cases, one with HBV-MN and two with HIV-MN. Mean proteinuria was higher in the PLA2R-positive group and the median urinary protein:creatinine ratio (uPCR) was 963 mg/mmol (range 22–2406) compared with the PLA2R-negative group [median uPCR 548 mg/mmol (range 65–1898); P = 0.18 Mann–Whitney]. Spontaneous remission occurred in 6/19 patients and after-treatment remission occurred in 7/11 patients. Renal function was preserved in all but two patients who required haemodialysis 2 and 11 years from diagnosis. Conclusions We describe a cohort of patients with MN associated with viral infection, including rare cases of HIV-MN with PLA2R and THSD7A positivity. The mechanism of coincidental or viral-related MN needs to be investigated further.

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