The authors reply: intermittent high-efficiency hemodialysis remains preferable to CKRT in late ethylene glycol poisoning

Abstract

We thank Ghannoum et al. for their observation [1, 2]. After receiving the tweet by the EXTRIP workgroup [3], we reviewed our half-life calculations. Upon further investigation, we discovered that the first ethylene glycol concentration was collected at 23:13 and resulted at 07:46 am. We incorrectly used the result time, not the collection time, in our calculations. We apologize for this oversight. We have verified that the second and third ethylene glycol measurements and times are correct. These yield a correct half-life of 5.8 h and an elimination rate constant of 0.12 h−1 during continuous kidney replacement therapy (CKRT) as reported by Ghannoum et al. The second and third ethylene glycol concentrations were collected while the patient was on CKRT and fomepizole, and thus are more appropriate to use for half-life calculation. The critical care and nephrology teams discussed the patient’s case and selected CKRT due to the hemodynamic instability and severe metabolic derangements. The Kidney Disease: Improving Global Outcomes guidelines suggest CKRT over standard intermittent hemodialysis (IHD) in hemodynamically unstable patients to avoid fluid shifts associated with rapid solute removal and higher blood flow rate with IHD [4]. The difference between CKRT and IHD in hemodynamically unstable patients who are treated with vasopressors remains an ongoing debate. The evidence on fomepizole dosing during CKRT and the modality of CKRT in patients with ethylene glycol poisoning are scarce. Our case provides a detailed description of the fomepizole dosing and the CKRT modality that was used. We also agree with Ghannoum et al. that IHD remains the recommended extracorporeal treatment for ethylene glycol poisoning. However, CKRT may be used in hemodynamically unstable patients or when intermittent hemodialysis is unavailable.