15. Symptoms
• depend on both the serum concentration and individual ethanol metabolism
Serum ethanol level Symptoms
less than 25 mg/dL warmth and well-being.
25-50 mg/dL. Euphoria and decreased
judgment
50-100 mg/dL. Incoordination, decreased
reaction time/reflexes
100-250 mg/dL Cerebellar dysfunction (ie,
ataxia, slurred speech,
nystagmus)
greater than 250 mg/dL Coma
greater than 400 mg/dL respiratory depression, loss of
protective reflexes, and death
21. Epidemiology
Uncommon in patients with acute ethanol
intoxication
Most frequent in patients who have long term
ethanol intake, liver disease and develop
syndrome after period of a binge drinking
Associated with reduced food intake,
vomiting
Mortality is low 1%
22. Pathophysiology
Precursor of ketone
Ketogenesis attributed to
lipolysis, FFA generation from low
insulin level and increased level
of epinephrine, cortisol, glucagon
Excess production of acetoacetic
acid and β-hydroxybutyric acid
24. Laboratory Findings
Metabolic acidosis ,usually wide AG
Mixed acid-base disorders
HCMA is uncommon
Hyponatremia, hypokalemia, hypophosphatemia
Serum osmolality often normal
Elevated sOsm from elevated serum ethanol or
ketone
Serum ethanol level often undetectable
Blood glucose low, normal or high
25. Treatment
Resolution of AKA occurs after administration
of dextrose and/or saline
Restore volume deficit and provide glucose to
prevent hypoglycemia
32. Clinical Features
Symptoms familiar with ethanol
But occur in long duration toxication and CNS
depression
Nystagmus, coma, respiratory depression
and hypotension
33. Lab
High osmolal gap
Ketosis
Without wide AG metabolic acidosis
34. Laboratory Facts
Serum level 60 mg/dL increase serum osmolarity 10
mOsm/kg
Acidosis is rare : parent and metabolite are not
organic aicd
High serum or urine acetone level without acidosis is
suggestive of recent isopropanol ingestion
Renal failure in setting of significant hypotension
Hypoglycemia : result from interference of
gluconeogenesis by isopropanol
35. Treatment
Supportive treatment
Inhibition of alcohol dehydrogenase is not indicated
because acetone is less toxic than isopropanol
Hemodialysis
Isopropanol level > 400 mg/dL
Significant CNS depression, renal failure or
hypotension
If acidosis is significant investigate for other
cause
38. Character
Colorless
Volatile liquid
Distinctive odor
Rapid absorption
Minimum lethal dose for adults is 10 mL
39. Pharmacokinetics
MW 32 g/mol
Vd 0.6 L/kg
Rapid absorption after ingestion Peak 30-90 min
Highest concentration at kidney, liver and G.I. tract
Vitreous humor, optic nerve : high level
Elimination half-life 14-18 hr without treatment
Excretion : 90-95% by liver
2-5% by renal
Other by respiratory system
41. Clinical Features
Onset may be delayed
Early: mucosal irritation, N/V, abdominal pain
Late : CNS depression, No early phase of
elation
Visual disturbances (looking into snow
field)
Wide anion gap metabolic acidosis
42. Symptomatology
Early period
CNS depression
Effect of methanol before metabolized
Latent period
Accumulation of formate
Last 14-18 hr
Followed by systemic findings
43. Diagnosis of methanol poisoning
History
Wide anion gap metabolic acidosis and
osmolar gap
DDx.
Ethylene glycol, DKA, Paraldehyde, Isoniazid,
Salicylates, Iron, Lactic acidosis, Phenformin,
Uremia
44. Methanol blood concentration
mg/dL normal methanol blood
concentation from endogenous sources
mg/dL Asymptomatic
mg/dL Serious poisoning
- mg/dL Risk of fatality
46. Systemic Findings
Metabolic acidosis
pH < 7.0 strongest predictor of mortality
Mortality increased 20 times pH <7.0 Vs >7.0
CNS effects
Headache
Lethargy, delirium
Convulsion, coma…increased mortality 10 times
47. Systemic Findings
Ocular findings
Direct cytotoxic effect of formate on retina
Photophobia
Central scotoma
Visual field defects
Fixed pupils and difficulty with light adaptation
Pupillary dysfunction : strong predictor of mortality
Fundoscopic signs : hyperemia, disk edema,
possible optic atrophy
49. Diagnosis of methanol poisoning
History
Wide anion gap metabolic acidosis and
osmolar gap
DDx.
Ethylene glycol, DKA, Paraldehyde, Isoniazid,
Salicylates, Iron, Lactic acidosis, Phenformin,
Uremia
50. Anion Gap
High anion gap metabolic acidosis
Formate accumulation
Lactate production
Early or later after co-ingestion with MetOH+EtOH
may have little or no acidosis
51. Osmolar Gap
Methanol produce osmolar gap
Serum level 32 mg/dL increased measured serum
osmolarity 10 mOsm/kg
Normal osmolar gap <10 mOsm/kg
Present later after ingestion and methanol
converted to formate
Formate not contribute to serum osmolarity
because it is balanced by sodium
52.
53. Methanol blood concentration
mg/dL normal methanol blood
concentation from endogenous sources
mg/dL Asymptomatic
mg/dL Serious poisoning
- mg/dL Risk of fatality
54. Treatment
Take BS, BUN, Cr, methanol, ethanol level
Glucose + Thiamine + Naloxone
Supportive care
Correction of acidosis : NaHCO
Administration of fomepizole or ethanol
Dialysis
55. Ethanol
Indication
Plasma level > 20 mg/dL
Recent history of methanol ingestion with
serum osmolal gap > 10 mOsm/L
Strong clinical suspicion of methanol
poisoning with at least two of the following
Arterial pH < 7.3
Serum HCO3- <20 mEq/L
Osmolal gap > 20 mOsm/L
AACT Recommendation, 2002
65. Clinical features
3 Phases
Phase 1: - hrs.
Slurred speech and ataxia. But without the odor of
ethanol on their breath
Phase 2: - hrs.
Cardiopulmonary, CHF, ARDS
Phase 3 : - hrs.
Nephrotoxicity, oligulic renal failure, ATN
66. Renal Toxicity
Direct toxic effect from metabolites of
ethylene glycol
Hydronephrosis and obstruction from calcium
oxalate crystal
Most renal damage is reversible
Renal recovery may take a few month
68. Calcium oxalate crystal
Monohydrate form Dihydrate form
Dumbbell shape Octahedral shape
More common More specific
Ingestion of high Require higher
vitamin C and high oxalate concentration
urate-containing food for its formation
More indicative of
intoxication
70. Treatment
Supportive treatment
Airway protection
Circulatory support
Correction of metabolic abnormalities
Control seizure
71. Treatment
No role for activated charcoal, cathartics or
gastric lavage
Asymptomatic hypocalcemia
Risk of ↑ formation of calcium oxalate crystal
Alcoholic persons and malnourished should
be given thiamine and pyridoxine
72. Antidote
Indication
Plasma concentration > 20 mg/dL
Recent ingestion and Osmolar gap > 10
mOsm/kg or high clinical suspicion
AND 2 of the followings
pH < 7.3
Serum bicarbonate < 20 mmol/L
Osmolar gap > 10 mOsm/kg
Urinary oxalate crystals
73. Antidote
Ethanol
FDA not approved
Loading dose 0.6 g ethanol/kg
Constant infusion to keep blood alcohol
level 100-200 mg/dL
Average maintenance dose 100 mg/kg/hr
Blood alcohol checked every 1-2 hr until
steady state then 2-4 hr
74. Antidote
Fomepizole
FDA approved
Loading dose 15 mg/kg
Followed bt 10 mg/kg every 12 hr for 48 hrs
After 48 hrs, 15 mg/kg every 12 hr
Continued until serum ethylene glycol level
< 20 mg/dL, asymptomatic and normal pH
In dialysis, fomepizole need to be dosed
every 4 hr
75. Hemodialysis
Indication
pH < 7.3
Respiratory failure or hypotension
ARF unresponsive to standard therapy
Ethylene glycol level > 50 mg/dL*
* May be treated with fomepizole without hemodialysis