Pediatric emergency medicine trisk 3099 3099
Bạn đang xem bản rút gọn của tài liệu. Xem và tải ngay bản đầy đủ của tài liệu tại đây (45.85 KB, 1 trang )
results are often not available when making decisions regarding early clinical
management. Though not sensitive or specific, an elevated osmolar gap may be
used as an early surrogate marker of toxic alcohol poisoning. Additionally, serum
methanol concentration can be estimated by the formula (osmolar gap × 3 =
methanol in mg/dL). A methanol concentration greater than 20 mg/dL is
considered toxic.
There are three specific treatments for methanol intoxication: sodium
bicarbonate, folic acid, and fomepizole (which has largely replaced ethanol).
Sodium bicarbonate should be administered to correct metabolic acidosis: this
improves physiologic functioning and may help prevent formate from reaching
sensitive tissues. Folate is provided because of its role in formic acid disposition
within the tetrahydrofolate cycle. Customary doses are 1 mg/kg IV every 6 hours.
Fomepizole, an alcohol dehydrogenase inhibitor, can prevent the metabolism of
methanol to its toxic metabolites in cases where the methanol level exceeds 20
mg/dL. If fomepizole is unavailable, ethanol, which has a higher affinity for
alcohol dehydrogenase than methanol, may be provided to competitively block
further production of toxic metabolites.
The loading dose of fomepizole is 15 mg/kg, which may be given IV or orally.
The maintenance dose is 10 mg/kg every 12 hours for four doses, then 15 mg/kg
every 12 hours thereafter. More frequent dosing is required during hemodialysis.
If fomepizole in unavailable, ethanol is administered with the goal of
maintaining serum ethanol concentrations of at least 100 mg/dL. Ethanol may be
given by continuous IV infusion (600 mg/kg bolus followed by 110 mg/kg/hr) or
by oral administration. During dialysis, ethanol dosing may need to be doubled to
maintain sufficient blood ethanol content to effectively block the metabolism of
methanol. IV ethanol is preferred but has the problems of lack of availability,
hyperosmolarity (precluding its administration in small veins), and the need to
administer large fluid volumes. When the oral route is used, it must be
remembered that proof designation of a beverage is twice the alcohol
concentration expressed as a percentage (e.g., 80 proof equals 40% alcohol).
Children must be closely monitored for the complications of ethanol
administration, including mental status depression, hypoglycemia, and
hypothermia.
Hemodialysis is recommended for children who demonstrate significant
metabolic acidosis, end-organ injury (including coma or seizures), and/or acute
kidney injury; this suggests the presence toxic metabolites amenable to
extracorporeal removal. When alcohol dehydrogenase is blocked, methanol has a
very long time to elimination, primarily via exhalation; therefore, dialysis can
