Sodium modelling to reduce intradialytic hypotension during haemodialysis for acute kidney injury in the intensive care unit

Abstract

Aim Intradialytic hypotension often complicates haemodialysis for patients with acute kidney injury (AKI), and may impact renal recovery. Sodium modeling is sometimes used as prophylaxis against intradialytic hypotension in the chronic haemodialysis population, but there is little evidence for its use among critically ill patients with AKI. Methods A retrospective cohort with AKI requiring intermittent haemodialysis in the intensive care unit from 2001–2008 was used to study the association of prophylactic sodium modeling and multiple outcomes. Outcomes included a composite of in-hospital death or dialysis dependence at hospital discharge, as well as intradialytic hypotension, ultrafiltration goal achievement, and net ultrafiltration volume. Associations were estimated using logistic regression, mixed linear models, and generalized estimating equations adjusting for demographic and clinical characteristics. Results 191 individuals who underwent 892 sessions were identified; sodium modeling was prescribed in 27.1% of the sessions. In adjusted analyses, sodium modeling was not significantly associated with intradialytic hypotension (p=0.67) or with the ultrafiltration goal achievement (p=0.06). Sodium modeling during the first dialysis session was numerically associated with lower risk for the composite of in-hospital death or dialysis dependence: adjusted OR (95% CI) 0.39 (0.15–1.02; p=0.06); however, this association did not reach statistical significance. Conclusion We did not observe statistically significant associations between sodium modeling and improved outcomes among AKI patients receiving intermittent dialysis in the intensive care unit. However, suggestive findings warrant further study.

Interventions to prevent hemodynamic instability during renal replacement therapy in critically ill patients: a systematic review

“…This can be combined with UF profiling where the UF rate is highest with higher dialysate sodium to maximize fluid removal and is reduced along with dialysate sodium concentration. The study by Lynch et al [ 21 ], using sodium modeling in IHD, was unable to show a significant reduction in HIRRT. Nonetheless, this was a retrospective study where sodium modeling was prescribed by treating clinicians in only 27% of sessions, likely contributing to baseline differences in co-morbidities between the two groups including higher pre-IHD vasopressor requirements in the sodium modeling group.…”

Intradialytic hypotension in acute kidney injury requiring renal replacement therapy

“…In a retrospective study of 191 patients with AKI‐RRT in the ICU, Lynch et al compared the risk of intradialytic hypotension, adequacy of UF, and clinical outcomes in patients treated with or without sodium modeling (used in 27.1% of dialysis sessions). The authors were unable to find statistically significant advantages of sodium modeling, but acknowledged the relatively small sample size and lack of randomization; they suggested based on their findings that a trial involving 626 patients randomized to two dialysate sodium concentrations/strategies would be adequately powered to detect clinically significant differences …”

Renal Replacement Therapy Practices in India: A Nationwide Survey

“…Hemodynamic instability during RRT is a common phenomenon which is seen in all modalities of RRT used. The incidence of hemodynamic instability as reported in various studies is very variable and complicates around 10–70% of IHD sessions, 18 40–60% of SLED, 19 and 50% of CRRT sessions. 20 The commonly used interventions to tackle hemodynamic instability during RRT include use of higher dialysate sodium or sodium modeling, lower dialysate temperature, and slower blood flow rate.…”