Ultrafiltration Rate and Residual Kidney Function Decline: Yet Another Good Reason to Ask About Urine

Harnessing the eccrine sweat glands for the management of interdialytic weight gain - a pilot study

Hemodialysis patients are susceptible to excess volume accumulation, particularly over the 2-day interval (long interdialytic gap), resulting in higher interdialytic weight gain (IDWG). We thought to determine whether a novel device designed to enhance fluid and salt loss by activating the eccrine sweat glands can mitigate IDWG. Patients eligible for the study were undergoing regular hemodialysis for ≥3 months, without residual renal function, and with IDWG (as a percentage of IDWG/dry body weight) ≥2.5%. Treatments were administered at the patient's home. The primary performance endpoint was differences in weight gain over long interdialytic period with the device compared to the control period. Secondary exploratory endpoints included the need for ultrafiltration (UF) rate > 10 mL/kg/h in the post-interval dialysis. Five patients were enrolled into the pilot study (age range 26 to 69 years, 3 women). The hourly mean weight loss from sweat was 186 ± 45 g/h. The average procedure length was 4.5 h with an average fluid loss of 899 ± 283 grams per procedure. The average least-squares mean absolute difference of IDWG between the control and treatment periods was -2.0%; (95% confidence interval [CI], -2.9% to -1.2%, p < 0001). The reduction in IDWG was associated a reduction in UF rates, from 9.23 ± 3.7 mL/kg/h to 5.55 ± 2.45 mL/kg/h between the control and treatment periods (p < 0.001), resulting in a safe UF rate (<10 mL/kg/h) in all post-treatment sessions. We conclude that enhancing sweat rate can mitigate IDWG in hemodialysis patients.

Population pharmacokinetics and individualized dosing of vancomycin for critically ill patients receiving continuous renal replacement therapy: the role of residual diuresis

Background: Vancomycin dosing is difficult in critically ill patients receiving continuous renal replacement therapy (CRRT). Previous population pharmacokinetic (PopPK) models seldom consider the effect of residual diuresis, a significant factor of elimination, and thus have poor external utility. This study aimed to build a PopPK model of vancomycin that incorporates daily urine volume to better describe the elimination of vancomycin in these patients. Methods: We performed a multicenter retrospective study that included critically ill patients who received intermittent intravenous vancomycin and CRRT. The PopPK model was developed using the NONMEM program. Goodness-of-fit plots and bootstrap analysis were employed to evaluate the final model. Monte Carlo simulation was performed to explore the optimal dosage regimen with a target area under the curve of ≥400 mg/L h and 400-600 mg/L h. Results: Overall, 113 observations available from 71 patients were included in the PopPK model. The pharmacokinetics could be well illustrated by a one-compartment model with first-order elimination, with the 24-h urine volume as a significant covariate of clearance. The final typical clearance was 1.05 L/h, and the mean volume of distribution was 69.0 L. For patients with anuria or oliguria, a maintenance dosage regimen of 750 mg q12h is recommended. Conclusion: Vancomycin pharmacokinetics in critically ill patients receiving CRRT were well described by the developed PopPK model, which incorporates 24-h urine volume as a covariate. This study will help to better understand vancomycin elimination and benefit precision dosing in these patients.

Implementing a fluid volume management program to decrease intra-dialytic hypotensive events in a paediatric in-centre haemodialysis unit: a quality improvement project

BACKGROUND

Intra-dialytic hypotension (IDH) is the most common serious adverse event in paediatric haemodialysis (HD). Repeated IDH results in chronic multi-organ damage and increased mortality. At the Hospital for Sick Children, Toronto, retrospective data from all in-centre HD sessions revealed frequently occurring IDH events (16.5 ± 5.6% of HD sessions per week). Based on literature review and clinical expertise, fluid volume management was selected as a potential modifiable risk factor to decrease IDH. Root causes identified as contributing to IDH were incorporated into a Paediatric haemodialysis fluid volume management (PedHDfluid) program using the Model for Improvement methodology including rapid cycles of change.

METHODS

Multiple measures were evaluated including (i) Outcome: IDH events per number of HD sessions per week; (ii) Process: number of changes to estimated dry weight per number of HD sessions per week; (iii) Balancing: time spent on dry weight meeting per week. Data was analysed using statistical process control charts. We aimed to decrease IDH in our dialysis unit to < 10% of HD sessions per week over a 6-month period by implementing a PedHDfluid program, including a multifaceted dry weight assessment protocol, multidisciplinary meetings and electronic health records "Dry Weight Evaluation flow sheet/synopsis".

RESULTS

The project resulted in a decline in IDH events from 16.5 ± 5.6% to 8.8 ± 3.3% of HD sessions per week. More frequent dry weight changes and increased awareness of fluid removal goals were noted.

CONCLUSIONS

A multidisciplinary approach including regular assessment, guidelines and systematic discussion, with an embedded electronic health record assessment and data gathering tool may sustainably reduce IDH events. A higher resolution version of the Graphical abstract is available as Supplementary information.

Precision medicine approach to dialysis including incremental and decremental dialysis regimens

PURPOSE OF REVIEW

Conventional standardization of haemodialysis for treatment of end-stage kidney disease (ESKD) is predicated upon the fixed construct of one disease stage and one patient category. Increasingly recognized are subgroups of patients for whom less-intensive haemodialysis, such as incremental or decremental haemodialysis, could be employed.

RECENT FINDINGS

Almost 30% of patients with incident ESKD have clinical and residual kidney function (RFK) parameters that could accommodate less-intensive haemodialysis. In one study, patients with incident ESKD and substantial RKF treated with low-dose haemodialysis had similar mortality rate as those treated with standard-dose haemodialysis, adding to the evidence that endogenous kidney function -- when present -- can complement less-intensive haemodialysis schedules. Hazards related to incremental haemodialysis include insidious development of fluid overload and higher rates of fluid removal. Finally, deintensification of haemodialysis treatment could be employed in patients with ESKD who seek conservative care.

SUMMARY

A shift in approach to ESKD from a dichotomous frame -- disease presence versus absence -- to stages of dialysis-dependent kidney disease, each stage associated with attuned haemodialysis intensity, has been proposed. Haemodialysis standardization and personalization -- often considered mutually exclusive -- can be combined in incremental haemodialysis. Data from ongoing and future randomized clinical trials, comparing less-intensive with standard haemodialysis schedules, are required to change practice.