Evaluation of the utilization of extracorporeal toxin removal in lithium poisoning patients in Hong Kong

Background: Extracorporeal toxin removal is used for enhanced elimination in severe lithium poisoning. The Extracorporeal TReatments In Poisoning workgroup provides recommendations on the use of extracorporeal toxin removal in poisoning. Objectives: Our aim was to identify the pattern for using extracorporeal toxin removal in managing lithium poisoning in Hong Kong and compare the outcomes in extracorporeal toxin removal-treated patients and non-extracorporeal toxin removal-treated patients if indicated for treatment as defined by The Extracorporeal TReatments In Poisoning criteria. Methods: Lithium poisoning presented between year 2009 and 2019 in Hong Kong Poison Information Centre (HKPIC) database was categorized into extracorporeal toxin removal-treated group and non-extracorporeal toxin removal-treated group. Comparative analyses were performed. Results: Among 112 lithium-poisoned patients, 21% were treated with extracorporeal toxin removal. Larger proportion of patients had fulfilled at least one Extracorporeal TReatments In Poisoning criteria for extracorporeal toxin removal in the extracorporeal toxin removal-treated group (87% vs 18%, p < 0.005). The extracorporeal toxin removal-treat group patients were more commonly presented with impaired consciousness, seizure and dysrhythmia (p < 0.05). They also got higher admission (3.62 mmol/L vs 2.18 mmol/L, p < 0.05) and peak (4.15 mmol/L vs 2.28 mmol/L, p < 0.05) serum lithium concentrations, as well as a significantly higher serum creatinine concentration upon presentation (263.74 µmol/L vs 98.66 µmol/L, p < 0.05). Extracorporeal toxin removal-treat group patients more frequently had a severe poisoning outcome (91.3% vs 9%, p < 0.05) and developed complications (69.6% vs 13.5%, p < 0.05). Logistic regression identified seizure, peak serum lithium concentration, and serum creatinine concentration upon presentation as risk factors for severe poisoning outcome. In subgroup analysis on patients with at least one indication for extracorporeal toxin removal as defined by Extracorporeal TReatments In Poisoning criteria, the proportion of severe poisoning remained higher in the extracorporeal toxin removal-treated group (90% vs 43.7%, p < 0.05). Complication rate was not significantly different between the two groups. Conclusion: Clinically severe lithium poisoning patients were treated with extracorporeal toxin removal in Hong Kong. Extracorporeal TReatments In Poisoning criteria can serve as a reference in considering extracorporeal toxin removal treatment for lithium poisoning patients. Nevertheless, Extracorporeal TReatments In Poisoning criteria recommend more extracorporeal toxin removal treatment than it was actually done. Lithium poisoning patients with positive Extracorporeal TReatments In Poisoning criteria have been managed without extracorporeal toxin removal. No statistically significant adverse outcome was observed in these cases.