#3073 Should we expand the indications for hemodialysis in lithium intoxications beyond the EXTRIP recommendations?
Authors: Shabaka Amir , Barriopedro Mario Botella , Triska Eugenia Landaluce , Pérez Javier Vian , Ortega María José , Belotto Miguel Martínez , Procaccini Fabio , Menendez Veronica Rubio , Mendoza Ana , Sanz Juan Manuel Acedo , De Pedro Maria Patricia Sanz , Juarez Gema Maria Fernandez 
Published: May 2024

Abstract

Background and Aims
EXTRIP Workgroup (EW) recommends renal replacement therapy (RRT) in lithium poisoning when serum lithium levels &gt;4 mmol/l in cases of impaired kidney function, decreased consciousness, seizures or dysrhythmias, and suggests RRT in cases of serum lithium &gt;5 mmol/l or when there is confusion or the expected time to obtain lithium levels &lt;1 mmol/l with optimal management exceeds 36 hours. The aim of this study was to assess the benefit of RRT in the conditions recommended and suggested by the EW, and evaluate the benefit from RRT in other conditions of lithium poisoning.

Method
We conducted a retrospective mutli-centre observational study that included patients with a diagnosis of lithium poisoning from January 2006 to December 2022. Demographic data, kidney function and comorbidities, clinical presentation including neurologic, cardiac and renal manifestations, type of intoxication, previous poisonings or concomitant intake of other toxic substances and treatments used were registered. In patients receiving RRT, the type of RRT, duration and number of sessions were registered. Lithium levels during hospitalization were recorded, and time for lithium levels &lt;1 mmol/l was calculated. The primary outcomes were death from lithium poisoning and persistent neurologic deficits (syndrome of irreversible lithium-effectuated neurotoxicity, SILENT).

Results
The study included 179 cases of lithium poisoning (62.6% chronic lithium poisoning, 34.6% acute on chronic and 2.8% acute poisoning),with a mean age of 56.3 ± 15.4 years, and patients were predominantly females (57%). 130 patients (72.6%) presented neurological manifestations, out of which 33 patients (18.4%) presented a decreased conscious level or generalized convulsions, and 40 patients (22.3%) presented confusion. 98 patients (54.7%) presented acute kidney injury (AKI) and 21 patients (11.7%) presented life-threatening dysrhythmias.
68 patients (38%) were treated with RRT. 31 patients (17.3%) developed persistent neurological deficits (SILENT) and only 2 patients (1.1%) died of lithium poisoning during hospitalization.
Concerning patients in whom hemodialysis was recommended according to EW guidelines, only 34 out of 53 patients (64.2%) received RRT. In this group of patients, those who received RRT developed less frequently SILENT (11.8% vs 36.8%, p = 0.031)
Regarding patients in whom hemodialysis is suggested according to EW, only 34 out of 106 patients (32.1%) received RRT. Overall, combining patients in whom dialysis is recommended or suggested according to EW, SILENT developed less frequently in those who received RRT (13.2% vs 20.4%)
Beyond the recommendations by the EW, we found that patients with lithium levels &gt; 2 mEq/l with AKI and any neurological manifestations presented less frequently SILENT when receiving RRT (7% vs 26%, p = 0.033). We also observed that patients who received RRT had a shorter in-hospital stay (3.3 [IQR 2-7] days vs 9.4 [IQR 5-11] days, p = 0.01).

Conclusion
Patients presenting with lithium poisoning and impaired kidney function or any neurological manifestations who received RRT presented less frequently persistent neurologic deficits (SILENT) after discharge, regardless of lithium levels or type of poisoning. We suggest that EXTRIP should recommend RRT in any patient with lithium poisoning who presents with neurological symptoms or impaired kidney function, regardless of lithium levels.