The impact of co-morbidities on a 6-year survival after methanol mass poisoning outbreak: possible role of metabolic formaldehyde

Abstract

Context: The influence of co-morbid conditions on the outcome of acute methanol poisoning in mass poisoning outbreaks is not known. Objective: The objective of this is to study the impact of burden of co-morbidities, complications, and methanol-induced brain lesions on hospital, follow-up, and total mortality. Methods: All patients hospitalized with methanol poisoning during a mass poisoning outbreak were followed in a prospective cohort study until death or final follow-up after 6 years. The age-adjusted Charlson co-morbidity index (ACCI) score was calculated for each patient. A multivariate Cox regression model was used to calculate the adjusted hazards ratio (HR) for death. The survival was modeled using the Kaplan-Meier method. Results: Of 108 patients (mean age with SD 50.9 ± 2.6 years), 24 (54.4 ± 5.9 years) died during hospitalization (mean survival with SD 8 ± 4 days) and 84 (49.9 ± 3.0 years; p ¼ .159) were discharged, including 27 with methanol-induced brain lesions. Of the discharged patients, 15 (56.3 ± 6.8 years) died during the follow-up (mean survival 37 ± 11 months) and 69 (48.5 ± 3.3 years; p ¼ .044) survived. The hospital mortality was 22%, the follow-up mortality was 18%; the total mortality was 36%. Cardiac/respiratory arrest, acute respiratory failure, multiorgan failure syndrome, and arterial hypotension increased the HR for hospital and total (but not follow-up) mortality after adjustment for age, sex, and arterial pH (all p < .05). All patients who died in the hospital had at least one complication. A higher ACCI score was associated with greater total mortality (HR 1.22; 1.00-1.48 95% CI; p ¼ .046). Of those who died, 35 (90%) had a moderate-to-high ACCI. The Kaplan-Meier curve demonstrated that patients with a high ACCI had greater follow-up mortality compared to ones with low (p ¼ .027) or moderate (p ¼ .020) scores. For the patients who died during follow-up, cancers of different localizations were responsible for 7/15 (47%) of the deaths. Conclusions: The character and number of complications affected hospital but not follow-up mortality, while the burden of co-morbidities affected follow-up mortality. Methanol-induced brain lesions did not affect follow-up mortality. Relatively high cancer mortality rate may be associated with acute exposure to metabolic formaldehyde produced by methanol oxidation.

A cross-sectional multicenter linkage study of hospital admissions and mortality due to methanol poisoning in Iranian adults during the COVID-19 pandemic

“…In methanol poisoning, the outcome is typically defined by the level of consciousness on arrival, the severity of the acidosis, and also ability of respiratory compensation of metabolic acidosis. Vice versa, a lack of ability to hyperventilate when acidotic has been shown as a poor prognostic factor 15 , 17 , 18 .…”

Estimation of long-term costs of postacute care in survivors of the methanol poisoning outbreak

“…These patients were examined in four rounds (5 months, then 2, 4 and 6 years after discharge) in the General University Hospital in Prague according to the same predefined study protocol described in detail in previous publications. 13 22 25–27 …”

Methanol-induced optic neuropathy: a still-present problem

“…Studies investigating 6 year mortality after methanol poisoning in patients suffering from Me-ION in both the Czech (Zakharov et al 2020 ) and Estonian (Paasma et al 2009 ) populations showed 18% and 30% death rate values, respectively. What is worth emphasizing, in the study by Zakharov et al, 47% of deaths were associated with the occurrence of neoplastic, which was probably related to the carcinogenic effect of acute exposure to methanol and its metabolites, especially formaldehyde, and secondary, significantly increased oxidative stress (Zakharov et al 2020 ).…”

“…Studies investigating 6 year mortality after methanol poisoning in patients suffering from Me-ION in both the Czech (Zakharov et al 2020 ) and Estonian (Paasma et al 2009 ) populations showed 18% and 30% death rate values, respectively. What is worth emphasizing, in the study by Zakharov et al, 47% of deaths were associated with the occurrence of neoplastic, which was probably related to the carcinogenic effect of acute exposure to methanol and its metabolites, especially formaldehyde, and secondary, significantly increased oxidative stress (Zakharov et al 2020 ). In the Estonian population, characterized by a similar age structure, but with a higher ratio of females to males compared to the Czech population (31/69 vs. 20/80%), it was shown that the dominant cause of death in the studied group was alcohol intoxication, which occurred in 27% of patients (Paasma et al 2009 ).…”