Role of sodium zirconium cyclosilicate (szc) in acute kidney injury (aki)-induced hyperkalemia

Introduction: Potassium binders are the mainstay for the management of hyperkalemia (hyperK) during AKI. Sodium Polystyrene Sulfonate (SPS) have been used for long time without proven efficacy. Newer binders are currently available, however head-to-head comparison of their efficacy in the ICU are lacking. Therefore, we explored whether intensive therapy with sodium zirconium cyclosilicate (SZC) compared to SPS in addition to standard therapy [ST] can effectively reduce hyperK and reduce the need for renal replacement therapy (RRT) Methods: We performed a retrospective analysis of 104 patients with AKI stage 3 matched for SOFA score, baseline GFR and comorbidities. Patient were treated with ST (iv insuline-dextrose ± loop diuretics) and either SPS or SZC. A total of 54 received SZC and 51 patients received SPS for up to 72 hr. Resolution of hyperK (K< 5.5 mEq/L), resolution of hyperK within 6hr, relapsed in hyperK, refractory hyperK requiring RRT and renal recovery (decrease in creat > 50%) were evaluated during ICU stay. Data was analyzed by 2-way ANOVA and T-test. Results: Main causes for AKI were septic and cardiogenic shock. Mean age was 57±3 (54% male). Both groups received similar dose of ST based on institutional protocol and had similar urine output. Resolution of hyperK during treatment period was significantly better for SZC (SZC 45/53 [85%] vs SPS 12/51 [23%], p< 0.05). A large proportion (42/45 [93%]) of patients on SZC had resolution of hyperK in < 6hr compared to 25% (3/12) on SPS (p< 0.05). In those patients who achieved resolution of hyperK within 6hr, relapse in hyperK occurred in 83% (10/12) in SPS compared to only 19% in SZC (8/42) [p< 0.05]. Need for RRT due to refractory hyperK occurred 96% (49/51) of patients on SPS compared to 30% (16/53) on SZC (p< 0.05). Renal recovery occurred in 70% (37/53) of patients on SZC compared to 6% (3/51) of patients on SPS (p< 0.05). Conclusions: SZC in addition to ST is a faster and more effective therapy than SPS to manage hyperK in AKI. The use of SZC reduced the need for emergent RRT due to refractory hyperK. Furthermore, patients who had a sustained response to SZC had more renal recovery than non-responders or those treated with SPS, which may suggest that if hyperK is managed effectively it should not be considered an absolute indication for RRT.