September/October - West Virginia State Medical Association

| Scientific Article
Ethylene Glycol and Methanol Poisonings: Case Series
and Review
Carol A. Montjoy, MD
Fellow, West Virginia University, Robert
C. Byrd Health Sciences Center
Aamer Rahman, MD
Pulmonary/CCM, Piedmont Pulmonary
Consultants
Luis Teba, MD
Professor, West Virginia University
School of Medicine
Abstract
Introduction: Ethylene glycol (EG)
and methanol (MTH) are common
industrial solvents and are responsible for
accidental, suicidal, and epidemic
poisonings. 1 Since the clinical signs and
symptoms associated with EG and MTH
poisoning are nonspecific, it is important
for the medical community to consider
these toxicities given that early treatment
prevents death. 2 The hallmark of toxic
alcohol poisoning is a combination of a
high anion gap metabolic acidosis and
osmolar gap. 3 In order to determine
laboratory abnormalities and outcomes
associated with EG and MTH ingestion at
our institution, a retrospective chart
review was obtained.
Materials and Methods: A
retrospective chart review of all adult
patients admitted to our institution with a
diagnosis of EG or MTH intoxication
during a 15-year period was done. Age,
sex, EG and MTH levels, degree of
acidosis, initial anion and osmolar gaps,
renal dysfunction, length of stay in the
hospital, need for dialysis, and ADH
(alcohol dehydrogenase) blockade
treatment were recorded. Hospital
outcome included renal function and need
for dialysis at hospital discharge.
Results: The study population
consisted of 14 patients.The mean pH
was 7.02. The mean anion gap and
osmolar gap were 21 meq/l and 48
mOsm/l correspondingly. All patients
underwent treatment with either ethanol
or fomepizole and hemodialysis. At
discharge, three patients had renal
insufficiency not requiring dialysis; one
remained on dialysis, while seven
regained normal renal function.
Conclusion: Most patients with EG
and MTH intoxication have a decreased
level of consciousness making an
adequate history unobtainable. One must
rely on laboratory data for clues in making
a diagnosis of intoxication. A review of the
clinical features, pharmacokinetics,
laboratory analysis, and management of
EG and MTH poisoning is included in this
discussion to help raise medical
community awareness of this entity.
Introduction
Ethylene glycol (EG) and methanol
(MTH) poisonings are important
health problems because of their
severe morbidity and mortality. 1
Since many of the clinical signs and
symptoms associated with EG and
MTH poisonings are nonspecific,
it is important for the clinician to
consider these toxicities since early
treatment offers the best prognosis
and prevents death. 2 Many hospitals
are unable to perform EG and MTH
measurements in a timely fashion;
which in this case, a combination
of a metabolic acidosis associated
with a high anion gap and osmolar
gap is considered the hallmark
of toxic alcohol intoxication. 3,4
We undertook a retrospective
chart review of all adult patients
admitted with a diagnosis of EG
or MTH intoxication in order to
identify laboratory abnormalities
associated with ingestion as well as to
determine outcomes. A review of the
clinical features, pharmacokinetics,
laboratory analysis, and management
of EG and MTH poisonings is
included in the discussion.
Materials and Methods
A retrospective chart review of
all adult patients admitted to our
institution with a diagnosis of EG or
MTH intoxication during a 15-year
period was done. Age, sex, type
of poisoning, EG and MTH levels,
degree of acidosis, initial anion
gap (AG) and osmolar gap (OG),
need for mechanical ventilation,
antidote use, renal dysfunction,
need for dialysis, and length
of hospital stay were recorded.
Hospital outcomes included renal
function, need for dialysis at
hospital discharge, and mortality.
The equation used to calculate
the OG:
OG = Measured serum osmolarity (mOsm/L)
– Calculated serum osmolarity (mOsm/L),
where the measured serum
osmolarity was obtained via
the freezing point depression
method. The calculated serum
osmolarity was determined
by the following equation:
2*Na + Glu/18 + BUN/2.8.
When an alcohol drip was used as
an antidote, standard guidelines of
the American Academy of Clinical
Toxicology Practice Guidelines, were
used which included a loading dose
of 7 ml/kg of a 10% ethanol solution
given over thirty minutes, followed
by a continuous infusion of 1-2 ml/
kg/hr of a 10% ethanol solution in
order to maintain the serum ethanol
levels between 100 to 150 mg/dl.5
Results
Eleven of the 14 patients were men,
ages 19 to 59 (mean 43). Ethylene
glycol accounted for ten of the toxic
alcohol levels. The mean serum EG
and MTH levels were 111mg/dl
(range 9 to 290) and 142mg/dl
(range 52 to 230) respectively. The
mean pH was 7.02 (range 6.54 to
7.43). All patients had an increased
anion gap metabolic acidosis and
osmolar gap, (excluding one patient
for whom data were unavailable)
with a mean anion gap of 21 meq/l
(range 15 to 31) and mean osmolar
gap of 48 mOsm/l (range 29 to 81)
correspondingly. Eleven required
mechanical ventilation. Twelve
were treated with an ethanol drip
September/October 2010 | Vol. 106 17