Bioimpedance-Guided Fluid Management in Hemodialysis Patients

Chiu

Clinical Journal of the American Society of Nephrology

et al. 2015

132

Background and objectives Fluid overload is a common characteristic associated with renal progression in CKD. Additionally, fluid overload is an independent predictor of all-cause or cardiovascular mortality in patients on dialysis, but its influence on patients not on dialysis is uncertain. The aim of the study was to assess the relationship between the severity of fluid status and clinical outcomes in an advanced CKD cohort.Design, setting, participants, & measurements In total, 478 predialysis patients with stages 4 and 5 CKD in the integrated CKD care program were enrolled from January of 2011 to December of 2011 and followed-up until August of 2013. The clinical outcomes included cardiovascular morbidity and all-cause mortality. The relative hydration status (overhydration/extracellular water) was used as the presentation of the severity of fluid status and measured using a body composition monitor. Overhydration/extracellular water .7% was defined as fluid overload.Results Over a median follow-up period of 23.2 (12.6-26.4) months, 66 (13.8%) patients reached all-cause mortality or cardiovascular morbidity. The adjusted hazard ratio of the combined outcome of all-cause mortality or cardiovascular morbidity for every 1% higher overhydration/extracellular water was 1.08 (95% confidence interval, 1.04 to 1.12; P,0.001). The adjusted overhydration/extracellular water for the combined outcome of all-cause mortality or cardiovascular morbidity in participants with overhydration/extracellular water $7% compared with those with overhydration/extracellular water ,7% was 1.93 (95% confidence interval, 1.01 to 3.69; P=0.04). In subgroup analysis, higher overhydration/extracellular water was consistently associated with increased risk for the combined outcome independent of diabetes, cardiovascular disease, and serum albumin. There was no significant interaction between all subgroups.Conclusions These findings suggest that fluid overload is an independent risk factor of the combined outcome of all-cause mortality or cardiovascular morbidity in patients with advanced CKD.

Section: Discussionmentioning

confidence: 99%

Association of Fluid Overload with Cardiovascular Morbidity and All-Cause Mortality in Stages 4 and 5 CKD

Chiu

Clinical Journal of the American Society of Nephrology

et al. 2015

132

Clinical Journal of the American Society of Nephrology

“…Furthermore, our data suggest that bioimpedance parameters, such as fluid overload volume, could predict the effect of volume depletion on the severity of OSA. The use of bioimpedance to optimize fluid balance in patients on hemodialysis has been validated and is proposed as an objective method to adapt the ultrafiltration volume during hemodialysis sessions (31,32,39,40). Our results suggest a potential application of this technique in patients with ESRD and OSA to reduce the severity of their sleep breathing disorder by optimizing their hydration status.…”

Section: Discussionmentioning

confidence: 82%

Obstructive Sleep Apnea Severity and Overnight Body Fluid Shift before and after Hemodialysis

Ogna

Mihalache

et al. 2015

Background and objectives Obstructive sleep apnea is associated with significantly increased cardiovascular morbidity and mortality. Fluid overload may promote obstructive sleep apnea in patients with ESRD through an overnight fluid shift from the legs to the neck soft tissues. Body fluid shift and severity of obstructive sleep apnea before and after hemodialysis were compared in patients with ESRD.Design, setting, participants, & measurements Seventeen patients with hemodialysis and moderate to severe obstructive sleep apnea were included. Polysomnographies were performed the night before and after hemodialysis to assess obstructive sleep apnea, and bioimpedance was used to measure fluid overload and leg fluid volume.Results The mean overnight rostral fluid shift was 1.2760.41 L prehemodialysis; it correlated positively with fluid overload volume (r=0.39; P=0.02) and was significantly lower posthemodialysis (0.7860.38 L; P,0.001). There was no significant difference in the mean obstructive apnea-hypopnea index before and after hemodialysis (46.8622.0 versus 42.1618.6 per hour; P=0.21), but obstructive apnea-hypopnea index was significantly lower posthemodialysis (210.1610.8 per hour) in the group of 12 patients, with a concomitant reduction of fluid overload compared with participants without change in fluid overload (obstructive apnea-hypopnea index +8.2616.1 per hour; P,0.01). A lower fluid overload after hemodialysis was significantly correlated (r=0.49; P=0.04) with a lower obstructive apnea-hypopnea index. Fluid overload-assessed by bioimpedance-was the best predictor of the change in obstructive apnea-hypopnea index observed after hemodialysis (standardized r=20.68; P=0.01) in multivariate regression analysis.Conclusions Fluid overload influences overnight rostral fluid shift and obstructive sleep apnea severity in patients with ESRD undergoing intermittent hemodialysis. Although no benefit of hemodialysis on obstructive sleep apnea severity was observed in the whole group, the change in obstructive apnea-hypopnea index was significantly correlated with the change in fluid overload after hemodialysis. Moreover, the subgroup with lower fluid overload posthemodialysis showed a significantly lower obstructive sleep apnea severity, which provides a strong incentive to further study whether optimizing fluid status in patients with obstructive sleep apnea and ESRD will improve the obstructive apnea-hypopnea index.

“…The above monitoring strategy is in line with clinical opinion regarding the necessary frequency of bioimpedance testing in an adult dialysis population, and is also consistent with the approach used in two of the trials included in the systematic review of clinical effectiveness. 60,81 It is less intensive than the testing strategies applied in the other RCTs included in the clinical effectiveness review, which varied from once per week 101 to once every 6 weeks. 63 It is assumed in the base-case cost-effectiveness scenarios that quarterly testing can deliver effects in keeping with those observed across all the included randomised trials.…”

Section: Monitoring Strategies Evaluatedmentioning

confidence: 99%

Multiple-frequency bioimpedance devices for fluid management in people with chronic kidney disease receiving dialysis: a systematic review and economic evaluation

Scotland

Cruickshank

Jacobsen

et al. 2018

Health Technol Assess

BackgroundChronic kidney disease (CKD) is a long-term condition requiring treatment such as conservative management, kidney transplantation or dialysis. To optimise the volume of fluid removed during dialysis (to avoid underhydration or overhydration), people are assigned a ‘target weight’, which is commonly assessed using clinical methods, such as weight gain between dialysis sessions, pre- and post-dialysis blood pressure and patient-reported symptoms. However, these methods are not precise, and measurement devices based on bioimpedance technology are increasingly used in dialysis centres. Current evidence on the role of bioimpedance devices for fluid management in people with CKD receiving dialysis is limited.ObjectivesTo evaluate the clinical effectiveness and cost-effectiveness of multiple-frequency bioimpedance devices versus standard clinical assessment for fluid management in people with CKD receiving dialysis.Data sourcesWe searched major electronic databases [e.g. MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Science Citation Index and Cochrane Central Register of Controlled Trials (CENTRAL)] conference abstracts and ongoing studies. There were no date restrictions. Searches were undertaken between June and October 2016.Review methodsEvidence was considered from randomised controlled trials (RCTs) comparing fluid management by multiple-frequency bioimpedance devices and standard clinical assessment in people receiving dialysis, and non-randomised studies evaluating the use of the devices for fluid management in people receiving dialysis. One reviewer extracted data and assessed the risk of bias of included studies. A second reviewer cross-checked the extracted data. Standard meta-analyses techniques were used to combine results from included studies. A Markov model was developed to assess the cost-effectiveness of the interventions.ResultsFive RCTs (with 904 adult participants) and eight non-randomised studies (with 4915 adult participants) assessing the use of the Body Composition Monitor [(BCM) Fresenius Medical Care, Bad Homburg vor der Höhe, Germany] were included. Both absolute overhydration and relative overhydration were significantly lower in patients evaluated using BCM measurements than for those evaluated using standard clinical methods [weighted mean difference –0.44, 95% confidence interval (CI) –0.72 to –0.15,p = 0.003,I2 = 49%; and weighted mean difference –1.84, 95% CI –3.65 to –0.03;p = 0.05,I2 = 52%, respectively]. Pooled effects of bioimpedance monitoring on systolic blood pressure (SBP) (mean difference –2.46 mmHg, 95% CI –5.07 to 0.15 mmHg;p = 0.06,I2 = 0%), arterial stiffness (mean difference –1.18, 95% CI –3.14 to 0.78;p = 0.24,I2 = 92%) and mortality (hazard ratio = 0.689, 95% CI 0.23 to 2.08;p = 0.51) were not statistically significant. The economic evaluation showed that, when dialysis costs were included in the model, the probability of bioimpedance monitoring being cost-effective ranged from 13% to 26% at a willingness-to-pay threshold of £20,000 per quality-adjusted life-year gained. With dialysis costs excluded, the corresponding probabilities of cost-effectiveness ranged from 61% to 67%.LimitationsLack of evidence on clinically relevant outcomes, children receiving dialysis, and any multifrequency bioimpedance devices, other than the BCM.ConclusionsBCM used in addition to clinical assessment may lower overhydration and potentially improve intermediate outcomes, such as SBP, but effects on mortality have not been demonstrated. If dialysis costs are not considered, the incremental cost-effectiveness ratio falls below £20,000, with modest effects on mortality and/or hospitalisation rates. The current findings are not generalisable to paediatric populations nor across other multifrequency bioimpedance devices.Future workServices that routinely use the BCM should report clinically relevant intermediate and long-term outcomes before and after introduction of the device to extend the current evidence base.Study registrationThis study is registered as PROSPERO CRD42016041785.FundingThe National Institute for Health Research Health Technology Assessment programme.