Fluid overload and inflammation--a vicious cycle

Hypervolemia in Dialysis Patients Impairs STAT3 Signaling and Upregulates miR-142-3p: Effects on IL-10 and IL-6

Fluid overload in hemodialysis patients (HD) has been proven to be associated with inflammation. Elevated levels of the pro-inflammatory cytokine interleukin-6 (IL-6) appear to be inadequately counterbalanced by the anti-inflammatory cytokine interleukin-10 (IL-10). We initiated a cross-sectional study enrolling 40 HD patients who were categorized by a bioimpedance measurement in normovolemic (N; 23) and hypervolemic (H; 17) groups to test whether IL-10- and IL-6-related signal transduction pathways (signal transducer of transcript 3: STAT3) and/or a post-transcriptional regulating mechanism (miR-142) are impaired by hypervolemia. IL-10/IL-6 transcript and protein production by PBMCs (peripheral blood mononuclear cells) were determined. Phospho-flow cytometry was used to detect the phosphorylated forms of STAT3 (pY705 and pS727). miR-142-3p/5p levels were detected by qPCR. Hypervolemic patients were older, more frequently had diabetes, and showed higher CRP levels. IL-10 transcripts were elevated in H patients but not IL-10 protein levels. In spite of the elevated mRNA expression of the suppressor of cytokine expression 3 (SOCS3), IL-6 mRNA and protein expression were increased in immune cells of H patients. The percentage of cells staining positive for STAT3 (pY705) were comparable in both groups; in STAT3 (pS727), however, the signal needed for full transactivation was decreased in H patients. miR-142-3p, a proven target of IL-10 and IL-6, was significantly elevated in H patients. Insufficient phosphorylation of STAT3 may impair inflammatory and anti-inflammatory cytokine signaling. How far degradative mechanisms induced by elevated miR-142-3p levels contribute to an inefficient anti-inflammatory IL-10 signaling remains elusive.

Association between fluid overload and mortality in children with sepsis: a systematic review and meta-analysis

BACKGROUND

Sepsis is one of the main causes of morbidity and mortality worldwide. Fluid resuscitation is among the most common interventions and is associated with fluid overload (FO) in some patients. The objective of this systematic review and meta-analysis was to summarise the available evidence on the association between FO and morbimortality in children with sepsis.

METHODS

A systematic search was carried out in PubMed/Medline, Embase, Cochrane and Google Scholar up to December 2022 (PROSPERO 408148), including studies in children with sepsis which reported more than 10% FO 24 hours after admission to intensive care. The risk of bias was assessed using the Newcastle-Ottawa scale. Heterogeneity was assessed using I2, considering it absent if <25% and high if >75%. A sensitivity analysis was run to explore the impact of the methodological quality on the size of the effect. Mantel-Haenszel's model of random effects was used for the analysis. The primary outcome was to determine the risk of mortality associated with FO and the secondary outcomes were the need for mechanical ventilation (MV), multiple organ dysfunction syndrome (MODS) and length of hospital stay associated with FO.

RESULTS

A total of 9 studies (2312 patients) were included, all of which were observational. Children with FO had a higher mortality than patients without overload (46% vs 26%; OR 5.06; 95% CI 1.77 to 14.48; p<0.01). We found no association between %FO and the risk of MODS (OR: 0.97; 95% CI 0.13 to 7.12; p=0.98). Children with FO required MV more often (83% vs 47%; OR: 4.78; 95% CI 2.51 to 9.11; p<0.01) and had a longer hospital stay (8 days (RIQ 6.5-13.2) vs 7 days (RIQ 6.1-11.5); p<0.01).

CONCLUSION

In children with sepsis, more than 10% FO 24 hours after intensive care admission is associated with higher mortality, the need for MV and length of hospital stay.

C-reactive protein levels are associated with periodontitis and periodontal inflamed surface area in adults with end-stage renal disease

BACKGROUND

Several studies have shown the relationship between periodontal disease and chronic kidney disease, but there is little evidence to assess the impact of the amount of inflamed periodontal tissue on the levels of systemic inflammatory markers. So the aim of this study is determine the association between high-sensitivity C-reactive protein (hsCRP) and both periodontitis and periodontal inflamed surface area (PISA) in adults with end-stage renal disease (ESRD).

METHODS

Cross-sectional study was conducted with 176 adults with ESRD on regular hemodialysis. The participants were submitted to a full-mouth periodontal examination to determine the occurrence of periodontitis and PISA. Regression analysis was performed to test the independent association between periodontal conditions and serum hsCRP levels.

RESULTS

A total of 98.9% of the participants had periodontitis, with stages III and IV found in 26.1% and 52.9%, respectively. Mean hsCRP and PISA was 6.57 (SD: 6.03) mg/L and 217.15 (SD: 271.50), respectively. In the adjusted analysis, mean serum hsCRP levels were significantly higher in patients with stage III and IV generalized periodontitis compared with no/localized/generalized stages I-II (7.67 mg/L versus 5.72 mg/L, P = 0.028). After adjustments for confounding variables, individuals with PISA >490.56 mm² (85th percentile) had a 3.26-fold greater chance of having hsCRP above 5 mg/L than their counterparts (OR = 3.26; 95% CI: 1.25 to 8.49).

CONCLUSION

The inflammatory burden imposed by periodontitis can increase serum hsCRP levels in adults with end-stage renal disease.

Early postoperative weight gain is associated with increased risk of graft failure in living donor liver transplant recipients

Fluid overload (FO) has been shown to adversely affect multiple organs and survival in critically ill patients. Liver transplantation (LT) carries the risk of massive transfusion, which frequently results in FO. We investigated the association of postoperative weight gain with graft failure, early allograft dysfunction (EAD), and overall mortality in LT. 1833 living donor LT (LDLT) recipients were retrospectively analysed. Patients were divided into 2 groups according to postoperative weight gain (<3% group [n = 1391] and ≥3% group [n = 442]) by using maximally selected log-rank statistics for graft failure. Multivariate Cox and logistic regression analyses were performed. The ≥3% group was associated with graft failure (adjusted HR [aHR], 1.763; 95% CI, 1.248–2.490; P = 0.001). When postoperative weight change was used as a continuous variable, the aHR for each 1% increase in postoperative weight was 1.045 (95% CI, 1.009–1.082; P = 0.015). In addition, the ≥3% group was associated with EAD (adjusted OR [aOR], 1.553; 95% CI, 1.024–2.356; P = 0.038) and overall mortality (aHR, 1.731; 95% CI, 1.182–2.535; P = 0.005). In conclusion, postoperative weight gain may be independently associated with increased risk of graft failure, EAD, and mortality in LDLT recipients.

Implementation of preemptive fluid strategy as a bundle to prevent fluid overload in children with acute respiratory distress syndrome and sepsis

BACKGROUND

Fluid overload (FO) is associated with unfavorable outcomes in critically ill children. Clinicians are encouraged to avoid FO; however, strategies to avoid FO are not well-described in pediatrics. Our aim was to implement a bundle strategy to prevent FO in children with sepsis and pARDS and to compare the outcomes with a historical cohort.

METHODS

A quality improvement initiative, known as preemptive fluid strategy (PFS) was implemented to prevent early FO, in a 12-bed general PICU. Infants on mechanical ventilation (MV) fulfilling pARDS and sepsis criteria were prospectively recruited. For comparison, data from a historical cohort from 2015, with the same inclusion and exclusion criteria, was retrospectively reviewed. The PFS bundle consisted of 1. maintenance of intravenous fluids (MIVF) at 50% of requirements; 2. drug volume reduction; 3. dynamic monitoring of preload markers to determine the need for fluid bolus administration; 4. early use of diuretics; and 5. early initiation of enteral feeds. The historical cohort treatment, the standard fluid strategy (SFS), were based on physician preferences. Peak fluid overload (PFO) was the primary outcome. PFO was defined as the highest FO during the first 72 h. FO was calculated as (cumulative fluid input - cumulative output)/kg*100. Fluid input/output were registered every 12 h for 72 h.

RESULTS

Thirty-seven patients were included in the PFS group (54% male, 6 mo (IQR 2,11)) and 39 with SFS (64%male, 3 mo (IQR1,7)). PFO was lower in PFS (6.31% [IQR4.4-10]) compared to SFS (12% [IQR8.4-15.8]). FO was lower in PFS compared to CFS as early as 12 h after admission [2.4(1.4,3.7) v/s 4.3(1.5,5.5), p < 0.01] and maintained during the study. These differences were due to less fluid input (MIVF and fluid boluses). There were no differences in the renal function test. PRBC requirements were lower during the first 24 h in the PFS (5%) compared to SFS (28%, p < 0.05). MV duration was 81 h (58,98) in PFS and 118 h (85154) in SFS(p < 0.05). PICU LOS in PFS was 5 (4, 7) and in SFS was 8 (6, 10) days.

CONCLUSION

Implementation of a bundle to prevent FO in children on MV with pARDS and sepsis resulted in less PFO. We observed a decrease in MV duration and PICU LOS. Future studies are needed to address if PFS might have a positive impact on health outcomes.

Bioimpedance-defined overhydration predicts survival in end stage kidney failure (ESKF): systematic review and subgroup meta-analysis

Both overhydration and comorbidity predict mortality in end-stage kidney failure (ESKF) but it is not clear whether these are independent of one another. We undertook a systematic review of studies reporting outcomes in adult dialysis patients in which comorbidity and overhydration, quantified by whole body bioimpedance (BI), were reported. PubMed, EMBASE, PsychInfo and the Cochrane trial database were searched (1990-2017). Independent reviewers appraised studies including methodological quality (assessed using QUIPS). Primary outcome was mortality, with secondary outcomes including hospitalisation and cardiovascular events. Of 4028 citations identified, 46 matched inclusion criteria (42 cohorts; 60790 patients; 8187 deaths; 95% haemodialysis/5% peritoneal dialysis). BI measures included phase angle/BI vector (41%), overhydration index (39%) and extra:intracellular water ratio (20%). 38 of 42 cohorts had multivariable survival analyses (MVSA) adjusting for age (92%), gender (66%), diabetes (63%), albumin (58%), inflammation (CRP/IL6-37%), non-BI nutritional markers (24%) and echocardiographic data (8%). BI-defined overhydration (BI-OH) independently predicted mortality in 32 observational cohorts. Meta-analysis revealed overhydration >15% (HR 2.28, 95% CI 1.56-3.34, P < 0.001) and a 1-degree decrease in phase angle (HR 1.74, 95% CI 1.37-2.21, P < 0.001) predicted mortality. BI-OH predicts mortality in dialysis patients independent of the influence of comorbidity.

Fluid Overload and Inflammation Axis

Extracellular fluid overload (FO), which is assessed using bioimpedance technologies, is an important predictor of outcome in dialysis patients and in patients with early stages of chronic kidney disease. While traditional cardiovascular abnormalities are assumed to mediate this risk, recently also, the importance of noncardiovascular factors, such as systemic inflammation and malnutrition has been shown. While both FO and inflammation are independent risk factors for mortality, recent studies have shown that their combined presence can lead to a cumulative risk profile. From a pathophysiologic viewpoint, FO and inflammation can also be mutually reinforcing. Inflammation could contribute to FO by hypoalbuminemia, capillary leakage, and a (unnoticed) decline in lean and/or fat tissue mass resulting in incorrect estimation of dry weight. Reciprocally, FO could lead to inflammation by the translocation of endotoxins through a congested bowel wall or by a proinflammatory effect of tissue sodium. The relative importance of these putative factors is, however, not clear yet and epidemiological studies have shown no clear temporal direction regarding the relationship between FO and inflammation. FO and inflammation appear to be part of (dynamic) clusters of risk factors, including malnutrition and hyponatremia. Technology-guided fluid management of the often vulnerable dialysis patient with FO and inflammation cannot yet be based on evidence from randomized controlled trials, in which these specific patients were in general not included. In the absence of those trials, treatment should be based on identifying actionable causes of inflammation and on the judicious removal of excess volume based on frequent clinical reassessment.

Cardiovascular risk of circulating endotoxin level in prevalent hemodialysis patients

Background

Cardiovascular diseases (CVDs) are a major cause of morbidity and mortality in patients with end stage renal disease (ESRD). Circulating endotoxins may have toxic effect on myocardial functions and are speculated as pathogens of accelerated atherosclerosis and hemodialysis (HD) patients.

Objective

We aimed to assess the possible relation between circulating endotoxin levels and left ventricular functions parameters, common carotid artery intimal media thickness (CIMT) in prevalent HD patients.

Patients and Methods

Forty stable prevalent HD patients with mean age (47.97 ± 14.42) year using regular conventional hemodialysis sessions in Ain shams university hemodialysis unit, Cairo, Egypt were randomly selected. Diabetics, congestive heart failure and those with history of myocardial infarction or coronary artery disease were excluded from the study. All patients were studied by CBC and routine chemistry, as well as hs CRP, Intact PTH, lipid profile and endotoxin level by ELISA before and after the HD session, Delta change of endotoxin (pre dialysis endotoxin-post dialysis endotoxin) was calculated, resting Doppler echocardiographic and carotid duplex.

Results

Mean of Pre-HD session serum endotoxin level was (0.356 ± 0.090) EU/mL and the mean of post -HD endotoxin levels was (0.367 ± 0.110) EU/mL. Significant positive correlation between post dialysis endotoxin, MV E/A ratio and grades of left ventricular diastolic dysfunction (P < 0.05) and significant correlation between delta change in endotoxin and EF% (r = -0.36,P = 0.02). By stepwise linear regression analysis for determinants of MVE/A post -HD endotoxin level independently associated with MV E/A ratio (ß = 0.350, P = 0.027). We did not detect any significant correlation between CCA atherosclerosis and neither pre nor post- HD endotoxin level nor with delta change of pre and post HD endotoxin levels.

Conclusion

Acute increase in post dialytic circulating endotoxin level in prevalent HD patients may be associated with both left ventricular systolic and diastolic dysfunction and that attempts to reduce endotoxin level may have a positive impact on cardiovascular complications in HD Patients.

Fluid overload and outcomes in critically ill children: A single center prospective cohort study

OBJECTIVE

To prospectively evaluate the association between fluid overload (FO) and clinical outcomes, mortality, mechanical ventilation (MV), and duration and length of stay in a pediatric intensive care unit (PICU).

METHODS

Over a 12-month period, patients who were on MV for >24h or vasoactive support were prospectively included. Demographic and clinical data were recorded. Daily FO was calculated as [(fluid in-fluid out)/admission weight]×100%. Multivariate stepwise logistic regression analysis was used to determine predictors of survival.

RESULTS

224 patients were included; median age was 3.3 (IQR 0.7, 9.9) years, mortality was 15.6%. The median peak FO (PFO) was 12.5% (IQR 5, 25), PFO>10% was present in 55.8% of patients, and PFO>20% was present in 33%. The PFO in non-survivors was 17.8% (IQR 8, 30) and 11% (IQR 4, 23) in survivors (p=0.028). A survival analysis showed no association between PFO and mortality. A multivariate analysis identified vasoactive support, >3 organ failures and acute kidney injury (AKI) but not FO as independent risk factors for mortality. FO was associated with MV duration and PICU length of stay.

CONCLUSION

FO is frequent in a general PICU population, but PFO is not an independent risk factor for mortality. Future studies of FO should focus on patients with AKI and multiorgan failure for better classification of severity and potential interventions.

Impact of fluid status and inflammation and their interaction on survival: a study in an international hemodialysis patient cohort

In hemodialysis patients extracellular fluid overload is a predictor of all-cause and cardiovascular mortality, and a relation with inflammation has been reported in previous studies. The magnitude and nature of this interaction and the effects of moderate fluid overload and extracellular fluid depletion on survival are still unclear. We present the results of an international cohort study in 8883 hemodialysis patients from the European MONDO initiative database where, during a three-month baseline period, fluid status was assessed using bioimpedance and inflammation by C-reactive protein. All-cause mortality was recorded during 12 months of follow up. In a second analysis a three-month baseline period was added to the first baseline period, and changes in fluid and inflammation status were related to all-cause mortality during six-month follow up. Both pre-dialysis estimated fluid overload and fluid depletion were associated with an increased mortality, already apparent at moderate levels of estimated pre-dialysis fluid overload (1.1-2.5L); hazard ratio 1.64 (95% confidence interval 1.35-1.98). In contrast, post-dialysis estimated fluid depletion was associated with a survival benefit (0.74 [0.62-0.90]). The concurrent presence of fluid overload and inflammation was associated with the highest risk of death. Thus, while pre-dialysis fluid overload was associated with inflammation, even in the absence of inflammation, fluid overload remained a significant risk factor for short-term mortality, even following improvement of fluid status.

C-reactive Protein: Repeated Measurements will Improve Dialysis Patient Care

Systemic inflammation is a common feature in the uremic phenotype and associates with poor outcomes. The awareness regarding the importance of inflammation assessment in chronic kidney disease (CKD) patients has risen in recent years, and despite the development of novel biomarkers, C-reactive protein (CRP) is still the most measured inflammatory parameter. Notwithstanding, the possible weak points of CRP determination, this biomarker has demonstrated being useful both for guidance in clinical practice and for risk estimation. In addition, regular determination of CRP among dialysis patients has been associated with better outcomes in different dialysis facilities. Because persistent inflammation may be a silent reflection of various pathophysiologic alterations in CKD, it is crucial that inflammatory markers are regularly monitored and therapeutic attempts be made to target this inflammation.

Fluid accumulation threshold measured by acute body weight change after admission in general surgical intensive care units: how much should be concerning?

Background

The objective of this study (ClinicalTrials.gov: NCT01351506) was to identify the threshold level of fluid accumulation measured by acute body weight (BW) change during the first week in a general surgical intensive care unit (ICU), which is associated with ICU mortality and other adverse outcomes.

Methods

Four hundred sixty-five patients were prospectively followed for a 28-day period. The maximum BW change threshold during the first week was evaluated by the maximum percentage change in BW from the ICU admission weight (Max%ΔBW). Daily screening of adverse events in the ICU were recorded. The cutoff point of Max%ΔBW on ICU mortality was defined by considering the area under the receiver operating characteristic (ROC) curve, intersection of the sensitivity and specificity, and the Youden Index. Univariable and multivariable regression analyses were used to demonstrate the associations. Statistical significance was defined as P<0.05.

Results

The appropriate cutoff value of Max%ΔBW threshold was 5%. Regarding the multivariable regression model, in overall patients, the occurrence of the following adverse events (expressed as adjusted odds ratio [95% confidence interval]) were significantly associated with a Max%ΔBW of >5%: ICU mortality (2.38 [1.25–4.54]) (P=0.008), ICU mortality in patients without renal replacement therapy (RRT) (2.47 [1.21–5.06]) (P=0.013), reintubation within 72 hours (2.51 [1.04–6.00]) (P=0.039), RRT requirement (2.67 [1.13–6.33]) (P=0.026), and delirium (1.97 [1.08–3.57]) (P=0.025). Regarding the postoperative subgroup, a Max%ΔBW value of more than 5% was significantly associated with: ICU mortality (3.87 [1.38–10.85]) (P=0.010), ICU mortality in patients without RRT (6.32 [1.85–21.64]) (P=0.003), reintubation within 72 hours (4.44 [1.30–15.16]) (P=0.017), and vasopressor requirement (2.04 [1.04–4.01]) (P=0.037).

Conclusion

Fluid accumulation, measured as acute BW change of more than the threshold of 5% during the first week of ICU admission, is associated with adverse outcomes of higher ICU mortality, especially in the patients without RRT, with reintubation within 72 hours, with RRT requirement, with vasopressor requirement, and with delirium. Some of these effects were higher in postoperative patients. This threshold value might be an indicator for caution during fluid management in surgical ICU.

Non-Linear Heart Rate Variability Indices in the Frequent Hemodialysis Network Trials of Chronic Hemodialysis Patients

BACKGROUND

Non-linear heart rate variability (HRV) indices were hypothesized to correlate with cardiac function, fluid overload and physical performance in hemodialysis patients.

METHODS

Twenty-four-hour Holter electrocardiograms were recorded in patients enrolled in the Frequent Hemodialysis Network (FHN) Daily Dialysis Trial. Correlations between non-linear HRV indices and left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), extracellular volume (ECV)/total body water (TBW) ratio, the SF-36 Physical Health Composite (PHC) and Physical Functioning (PF) scores were tested.

RESULTS

We studied 210 subjects (average age 49.8 ± 13.5 years, 62% men, 42% diabetics). In non-diabetic patients, multiscale entropy (MSE) slope sample entropy (SampEn) and approximate entropy (ApEn) correlated positively with LVEF, PF and PHC and inversely with LVEDV and ECV/TBW. Spectral power slope correlated positively with ECV/TBW (r = 0.27). Irregularity measures (MSE ApEn and MSE SampEn) correlated positively with LVEDV (r = 0.19 and 0.20).

CONCLUSION

Non-linear HRV indices indicated an association between a deteriorated heart rate regulatory system and impaired cardiac function, fluid accumulation and poor physical condition.

Effects of Crit-Line® monitor use on patient outcomes and epoetin alfa dosing following onset of hemodialysis: a propensity score-matched study

BACKGROUND

The Crit-Line® monitor (CLM) is a device for monitoring hematocrit, oxygen saturation and change in intravascular blood volume during hemodialysis. Prior studies have evaluated CLM use in dialysis patients, but not specifically in those new to dialysis.

METHODS

In this retrospective analysis, 199 patients initiating dialysis at 8 facilities routinely using CLM were compared with 796 propensity score-matched non-CLM patients initiating dialysis at facilities not using CLM. Outcomes were considered over the first 180 days on dialysis.

RESULTS

Overall, the CLM group had higher StdKt/V (p = 0.06) and received lower doses of intravenous iron than the non-CLM group (p < 0.001). Erythropoiesis-stimulating agent doses were lower in the CLM group in months 1-5. Serum iron and transferrin saturation levels were higher overall for the CLM group than the non-CLM group (p = 0.004 and 0.01, respectively). Hemoglobin levels and time to first hospitalization were similar for both groups.

CONCLUSION

Use of CLM is associated with lower erythropoiesis-stimulating agent and iron use in incident hemodialysis patients.

Heart rate response to blood pressure variations: sympathetic activation versus baroreflex response in patients with end-stage renal disease

Background

Continuous systolic blood pressure (SBP) and interbeat intervals (IBI) recordings reveal sequences of consecutive beats in which SBP and heart rate change in opposite direction, representing negative feedback baroreflex mechanisms, as well as sequences in which SBP and heart rate change in the same direction (non-baroreflex), believed to represent feedforward control mechanisms. The present study was undertaken to assess the relationship between baroreflex and non-baroreflex sequences in end stage renal insufficiency.

Methodology/Principal Findings

Continuous beat-to-beat SBP and IBI monitoring was performed in patients on chronic hemodialysis (HD, n=72), in age-matched patients after renal transplantation (TX, n=41) and healthy (control) individuals (C, n=34). The proportion of baroreflex and nonbaroreflex episodes and the b coefficients (the regression line slope of SBP-IBI correlation) were determined using a newly developed 1 minute sliding window method, the classical sequence technique and the "Z" coefficient method. Analysis using the 1 minute sliding window showed an increased proportion of baroreflex episodes in controls and HD, and predominance of nonbaroreflex episodes in TX. An increased proportion of nonbaroreflex episodes in TX patients relative to HD was also revealed by the "Z" method. Baroreflex and nonbaroreflex b coefficients obtained by all methods were markedly decreased in HD. This alteration was reversed at least partly in TX. In HD, both baroreflex and nonbaroreflex b coefficients were inversely correlated to age and CRP levels; in TX, the nonbaroreflex b coefficient was influenced by the type of calcineurin inhibitor.

Conclusion/Significance

Renal status affects the contribution of baroreflex and nonbaroreflex mechanisms and the strength of SBP-IBI relationship. The predominant contribution of nonbaroreflex mechanisms in TX may be suggestive of enhanced central sympathetic control. Our data may be relevant for understanding of the pathogenesis and selection of appropriate treatment of post-transplant hypertension.