A 46-year-old male from a foreign fishing vessel presents unconscious to the Emergency Department. He complained of visual disturbance prior to his deterioration.
The following blood results are obtained:
Parameter | Patient Value | Normal Adult Range |
Sodium | 144 mmol/L | 135 – 145 |
Potassium | 4.0 mmol/L | 3.5 – 5.0 |
Chloride | 102 mmol/L | 95 – 110 |
Bicarbonate | 8.2 mmol/L* | 22.0 – 30.0 |
Urea | 6.4 mmol/L | 3.0 – 7.0 |
Creatinine | 127 μmol/L* | 44 – 97 |
Glucose | 5.0 mmol/L | 3.5 – 7.8 |
Calcium (ionised) | 1.10 mmol/L | 1.03 – 1.23 |
Lactate | 4.1 mmol/L* | 0.6 – 2.4 |
Osmolality | 324 mOsm/kg* | 275 – 295 |
a) What is the most likely diagnosis? (10% marks)
b) What is the pathophysiology of the visual disturbance? (20% marks)
c) List three specific treatments you would institute. (15% marks)
a)
Methanol toxicity
b)
Methanol - > formaldehyde - > formate which is neurotoxic (especially retina and basal ganglia)
c)
Sodium bicarbonate
ADH inhibition with Ethanol (or fomepizole if available)
Dialysis
Cofactor therapy with either folic or folinic acid
So as to be fair to the other no-less-toxic alcohols, here is a table of the common alcohol toxidromes
Disorder | Toxin | Clinical and Laboratory Abnormalities |
---|---|---|
Alcoholic ketoacidosis |
|
|
Methanol intoxication |
|
|
Ethylene glycol intoxication |
|
|
Diethylene glycol intoxication |
|
|
Propylene glycol intoxication |
|
|
Isopropyl alcohol intoxication |
|
|
Management of toxic alcohol poisoning:
Decontamination
Enhanced elimination
Specific antidotes
Supportive management
Kraut, Jeffrey A., and Ira Kurtz. "Toxic alcohol ingestions: clinical features, diagnosis, and management." Clinical Journal of the American Society of Nephrology 3.1 (2008): 208-225.
Henderson, William R., and Jeffrey Brubacher. "Methanol and ethylene glycol poisoning: a case study and review of current literature." Cjem 4.1 (2002): 34-40.