Fluctuations in serum ethanol concentration in the treatment of acute methanol poisoning: a prospective study of 21 patients.
OBJECTIVE
During the 2012 outbreak of mass methanol poisonings in the Czech Republic, ethanol, in the main, was used as an antidote. The complex pharmacokinetics of ethanol made it difficult to maintain the requisite 1000-1500 mg/L serum ethanol levels (S-EtOH). The aim of this study was to measure the fluctuations in S-EtOH during the treatment.


METHODS
A prospective case series in 21 patients, median age 52 (27-79 years), 13 males and 8 females. Serum ethanol, methanol and formate were measured every 2-6 hours during the treatment. Follow-up clinical examination was carried out in 15/18 survivors.


RESULTS
The majority of patients (17/21) were late presenters and on admission, almost half (10/21) had suffered a severe grade of intoxication according to the Poisoning Severity Score (PSS). The mean observation time was 90±20 h. The mean period of consistent maintenance of S-EtOH within the recommended therapeutic range lasted 28±7% of the total observation time. For 29±8% of the time, S-EtOH was >1500 mg/L with "peaks" of up to 3500 mg/L. For 44±10% of the observation time, S-EtOH was <1000 mg/L. The mean duration of sub-therapeutic concentration of S-EtOH and toxic serum levels of methanol >200 mg/L or formate >20 mg/L lasted 20±10% and 18±11% of the time of observation, respectively. Complications occurred in 14 (67%) of cases including significant fluctuations of S-EtOH in 9; aspiration pneumonia in 3 and delirium tremens in 2 cases. Other complications included sepsis, bleeding, acidosis rebound, intolerance and set clotting. The outcomes were: 11 survivors free of health impairment, 7 with sequelae and 3 deaths. There was no significant difference in mean duration of sub-therapeutic and supra-therapeutic concentrations of serum ethanol in patients who survived without sequelae and those with poor outcome (P > 0.05).


CONCLUSIONS
Administration of ethanol according to the present guidelines of the AACT/EAPCCT is effective and relatively safe in the treatment of methanol poisoning during a mass outbreak(31). Physicians have to be most aware of fluctuations in serum ethanol at the end of short sessions of IHD and after changes in route from intravenous to oral. Rigorous monitoring of serum ethanol concentrations is pivotal for severely poisoned patients with PSS 3 and where there is suspected conversion of significant amounts of methanol to formic acid.
Toxicological information center, Department of Occupational Medicine, 1st Faculty of Medicine, Charles University in Prague and General University Hospital, Prague, Czech Republic.
Sergey
S
Zakharov
Department of Biomimetic Electrochemistry, J. Heyrovsky Institute of Physical Chemistry of AS CR, v.v.i, Prague.|Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague and General University Hospital, Prague.
Tomas
T
Navratil
Department of Clinical Biochemistry, Tomas Bata Regional Hospital, Zlin.
Tomas
T
Salek
Department of Toxicology and Forensic Medicine, 1st Faculty of Medicine, Charles University in Prague and General University Hospital, Prague.
Ivana
I
Kurcova
Toxicological information center, Department of Occupational Medicine, 1st Faculty of Medicine, Charles University in Prague and General University Hospital, Prague, Czech Republic.
Daniela
D
Pelclova
D000328:Adult; D000368:Aged; D000931:Antidotes / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004359:Drug Therapy, Combination; D000431:Ethanol / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D000077604:Fomepizole; D006801:Humans; D008297:Male; D000432:Methanol / Q000506:poisoning*; D008875:Middle Aged; D011446:Prospective Studies; D011720:Pyrazoles / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics; D016896:Treatment Outcome
D000931:Antidotes; D011720:Pyrazoles; D000431:Ethanol; D000077604:Fomepizole; D000432:Methanol
CNS sequelae; adverse events; antidote; ethanol; methanol poisoning; treatment outcome; variations in serum levels; visual sequelae