Is Continuous Renal Replacement Therapy an option for hyperkalemic cardiocirculatory arrest?

During advanced life support, potentially reversible causes should be actively pursued using the “4Hs and 4Ts” approach.1Lott C. Truhlar A. Alfonzo A. et al.European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances.Resuscitation. 2021; 161: 152-219Abstract Full Text Full Text PDF PubMed Scopus (228) Google Scholar If the serum potassium is ≥6.5 mmol/L early in the resuscitation, hyperkaliemia should be considered as the potential cause.2Alfonzo A. Harris A. Baines R. Chu A. Mann S. Clinical practice guidelines treatment of acute hyperkalaemia in adults. The Renal Association, London2020Google Scholar Guidelines recommend the administration of intravenous calcium chloride, insulin/glucose and bicarbonate.1Lott C. Truhlar A. Alfonzo A. et al.European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances.Resuscitation. 2021; 161: 152-219Abstract Full Text Full Text PDF PubMed Scopus (228) Google Scholar, 2Alfonzo A. Harris A. Baines R. Chu A. Mann S. Clinical practice guidelines treatment of acute hyperkalaemia in adults. The Renal Association, London2020Google Scholar However, these are frequently ineffective and renal replacement therapy (RRT) in combination with high-quality cardiopulmonary resuscitation (HQ-CPR) should be considered. This is especially true if return of spontaneous circulation is not achieved within 15 minutes or with an initial serum potassium ≥9.5 mmol/L.2Alfonzo A. Harris A. Baines R. Chu A. Mann S. Clinical practice guidelines treatment of acute hyperkalaemia in adults. The Renal Association, London2020Google Scholar Both conventional hemodialysis (cHD) and continuous renal replacement therapy (CRRT) have been described with safety and efficiency in hyperkalemic cardiocirculatory arrest (HCA).2Alfonzo A. Harris A. Baines R. Chu A. Mann S. Clinical practice guidelines treatment of acute hyperkalaemia in adults. The Renal Association, London2020Google Scholar, 3Kose N. Bilgin F. Successful treatment of a patient with cardiac arrest due to hyperkalemia by prolonged cardiopulmonary resuscitation along with hemodialysis: A case report and review of the literature.Medicina (Kaunas). 2021; 57PubMed Google Scholar However, in all case reports describing CRRT it was associated with veno-arterial extracorporeal life support (V-A ECLS) for augmented systemic perfusion.2Alfonzo A. Harris A. Baines R. Chu A. Mann S. Clinical practice guidelines treatment of acute hyperkalaemia in adults. The Renal Association, London2020Google Scholar In hospitals there is great heterogeneity in the availability of either V-A ECLS or cHD equipment, and there may be a tendency to use CRRT because of defibrillation compatibility.4International Electrotechnical Commission IEC 60601-2-4. Particular requirements for the basic safety and essential performance of cardiac defibrillators. Medical electrical equipment. International Electrotechnical Commission, Geneva, Switzerland2018Google Scholar Indeed, most cHD equipment is not defibrillation-proof contrary to CRRT.2Alfonzo A. Harris A. Baines R. Chu A. Mann S. Clinical practice guidelines treatment of acute hyperkalaemia in adults. The Renal Association, London2020Google Scholar Published case reports and guidelines only give generic prescribing indications for RRT.2Alfonzo A. Harris A. Baines R. Chu A. Mann S. Clinical practice guidelines treatment of acute hyperkalaemia in adults. The Renal Association, London2020Google Scholar, 3Kose N. Bilgin F. Successful treatment of a patient with cardiac arrest due to hyperkalemia by prolonged cardiopulmonary resuscitation along with hemodialysis: A case report and review of the literature.Medicina (Kaunas). 2021; 57PubMed Google Scholar Using a previously published two-compartment model,5Ciandrini A. Severi S. Cavalcanti S. et al.Model-based analysis of potassium removal during hemodialysis.Artif Organs. 2009; 33: 835-843Crossref PubMed Scopus (16) Google Scholar we simulated potassium kinetics during a cHD session with a potassium concentration of 9.5 mmol/L at dialysis initiation. For dialysis parameterization we used: (1) blood flow rate (Qb) of 200 cc/min, the average blood flow obtainable in patient in HCA during HQ-CPR with a conventional provisory catheter2Alfonzo A. Harris A. Baines R. Chu A. Mann S. Clinical practice guidelines treatment of acute hyperkalaemia in adults. The Renal Association, London2020Google Scholar; (2) dialysate flow rate (Qd) of 500 mL/min, the normal dialysate flow; and (3) potassium dialysate concentration of 2 mmoL/L, the lowest readily available concentration. We then simulated potassium kinetics during CRRT sessions. We considered a multiFiltratePRO machine with an AV1000 filter in continuous venovenous hemodialysis (CVVHD) mode with: (1) Qb of 200 cc/min; (2) Qd of 4.800 cc/h, the maximum flow rate of the equipment maintaining a Qb/Qd ratio of 2.5 which allows a near-complete saturation of the dialysate; and (3) potassium dialysate concentration of 0 mmoL/L which is the lowest commercially available concentration. Finally, we tested a continuous venovenous hemodiafiltration (CVVHDF) by adding a replacement fluid with a 0 mmoL/L potassium dialysate concentration at a flow rate (Qf) of 1.440 cc/h, the maximum value for a filtration fraction of ≤20%. The results of the simulation (Fig. 1) were overlapping with the published data referring to patients with HCA with cHD during HQ-CPR.2Alfonzo A. Harris A. Baines R. Chu A. Mann S. Clinical practice guidelines treatment of acute hyperkalaemia in adults. The Renal Association, London2020Google Scholar, 3Kose N. Bilgin F. Successful treatment of a patient with cardiac arrest due to hyperkalemia by prolonged cardiopulmonary resuscitation along with hemodialysis: A case report and review of the literature.Medicina (Kaunas). 2021; 57PubMed Google Scholar CRRT is less efficient than cHD with the need for an additional 23 minutes in CVVHDF and 38 minutes in CVVHD to reach a potassium concentration of 6.5 mmol/L, even with optimized parameters. This simulation provides evidence to support the fact that cHD remains the standard RRT in HCA. CRRT should only be used when cHD is not available and CVVHDF (using the above optimized parameters) should be the preferred mode of therapy. The authors whose names are listed immediately below certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.