Intermittent versus continuous renal replacement therapy in acute methanol poisoning: comparison of clinical effectiveness in mass poisoning outbreaks

Abstract

BackgroundIntermittent hemodialysis (IHD) is the modality of choice in the extracorporeal treatment (ECTR) of acute methanol poisoning. However, the comparative clinical effectiveness of intermittent versus continuous modalities (CRRT) is unknown. During an outbreak of mass methanol poisoning, we therefore studied the effect of IHD versus CRRT on mortality and the prevalence of visual/central nervous system (CNS) sequelae in survivors.MethodsThe study was designed as prospective observational cohort study. Patients hospitalized with a diagnosis of acute methanol poisoning were identified for the study. Exploratory factor analysis and multivariate logistic regression were applied to determine the effect of ECTR modality on the outcome.ResultsData were obtained from 41 patients treated with IHD and 40 patients with CRRT. The follow-up time in survivors was two years. Both groups of patients were comparable by age, time to presentation, laboratory data, clinical features, and other treatment applied. The CRRT group was more acidemic (arterial blood pH 6.96 ± 0.08 vs. 7.17 ± 0.07; p < 0.001) and more severely poisoned (25/40 vs. 9/41 patients with Glasgow Coma Scale (GCS) ≤ 8; p < 0.001). The median intensive care unit length of stay (4 (range 1–16) days vs. 4 (1–22) days; p = 0.703) and the number of patients with complications during the treatment (11/41 vs. 13/40 patients; p = 0.576) did not differ between the groups. The mortality was higher in the CRRT group (15/40 vs. 5/41; p = 0.008). The number of survivors without sequelae of poisoning was higher in the IHD group (23/41 vs. 10/40; p = 0.004). There was a significant association of ECTR modality with both mortality and the number of survivors with visual and CNS sequelae of poisoning, but this association was not present after adjustment for arterial blood pH and GCS on admission (all p > 0.05).ConclusionsIn spite of the faster correction of the acidosis and the quicker removal of the toxic metabolite in intermittent dialysis, we did not find significant differences in the treatment outcomes between the two groups after adjusting for the degree of acidemia and the severity of poisoning on admission. These findings support the strategy of “use what you have” in situations with large outbreaks and limited dialysis capacity.

Progressive Chronic Retinal Axonal Loss Following Acute Methanol-induced Optic Neuropathy: Four-Year Prospective Cohort Study

“…16,17 Hemodialysis was applied to eliminate formic acid and methanol and to correct acidemia. 18,19 Folates were administered to substitute the internal pool. 20…”

Consensus statements on the approach to patients in a methanol poisoning outbreak

“…We recognize that ethanol dosing is often difficult [19], but we also recognize that fomepizole may be scarce or unavailable in settings where MPOs may arise. Considering the variable availability and expense of fomepizole, we recommend (Level 1B) a "use what you have" approach [22] to the selection of ethanol or fomepizole.…”

“…Typically, in the event of mass outbreaks, the lack of both dialysis machines and laboratory equipment makes alternative strategies necessary [1]. Although IHD is more effective than CRRT for methanol clearance and correcting acidemia [29,30], to simplify decision-making in an MPO we recommend the "use what you have" model as documented in the Czech Republic [22].…”

Inhalational Methanol Intoxication: Emerging Issues in the Netherlands Resulting From Illegal Drug Production

“…Swift antidotal treatment (fomepizole or ethanol), concomitant hemodialysis, and folinic acid are necessary. [3][4][5] Toxicologists should be aware of this infrequent but potentially increasing route of exposure to methanol in order to reach a swift diagnosis and provide proper treatment. Delay of adequate treatment might result in severe morbidity or even death.…”