Transcript Alcohols, Aldehydes and Ketones

Alcohols, Aldehydes and Ketones
Introduction
• 3 most common alcohol poisonings are: ethanol,
methanol and isopropanol.
• Alcohol ingestions account for 14/1000 hospital admins
• Up to 72% of trauma patients were + for alcohol in their
blood
• 1998 ethanol accounted for 33,269 exposures reported
to PCC, 973 were major toxicities and 42 resulted in
death
• 1998, isopropanol, 19,301 reported, 83 major toxicity, 3
deaths
• 1998 methanol, 1041 reported, 24 major, 10 deaths
Introduction, cont.
• Acute intoxication with any alcohol may result in:
–
–
–
–
coma
death due to respiratory depression
CV collapse due to CNS depression
aspiration of vomitus
• Children under the age of 5 - have high incidence
of exposure
• Recreational misuse very high among teens and
young adults
Alcohols
• Ethyl alcohol - grain alcohol - C2H5OH
• Derived from fermentation of sugars in fruits, cereals
and vegetables
• Present in aftershaves, colognes, perfumes, OTC meds,
mouthwashes, and a myriad of alcoholic beverages
• Colorless, flammable, volatile liquid, toxin
• Proof = twice the per cent by volume; gun powder
was soaked in an alcoholic beverage and ignited, if it
exploded then it was “100 proof” is was at least 50%
alcohol
• a direct CNS depressant - both motor and sensory
Ethanol, cont.
• Uses
–
–
–
–
–
–
–
–
preservative
solvent
vehicle for other drugs (tinctures, elixirs, spirits)
disinfectant
hardens the skin
cools the skin
injectable nerve block
stimulates appetite and aids in digestion
Ethanol
• Rapidly absorbed from stomach and sm intestine
• Peak levels reached in 30-90 minutes post ingestion
• Metabolism by liver by alcohol and aldehyde
dehydrogenases
• ethanol - acetaldehyde - acetic acid - C02 + H20
• Primary source of ingested ethanol is alcoholic
beverages
• Associated problems with ethanol ingestion:
hypoglycemia, heqad trauma, carbon dioxide narcosis,
hypoxia
Ethanol, cont.
• Metabolism - you metabolize about 1
drink/hr.
– 13-25mg alcohol/deciliter/hour
– in alcoholics this rate increases to 3050mg/dL/hr
• 12 oz. beer = 3 oz wine = 1 oz whiskey = 15 ml of
ethanol
• New Texas State law has lowered legal limit
to 0.08% (so 0.8 ml 90% ethanol/kg = 0.08%
BAC)
To calculate BAC
•
•
•
•
•
1 ml 90% ethanol/kg BW gives BAC 0.1 %
so for a 220 lb. Male
convert to kg.
100 kg
so 100 ml or approx. 3 1/2 ounces of 90%
or 180 proof.
• New Texas Law = 0.08 so revised formula
0.8 ml 90% ethanol/kg BW = BAC 0.08%
Ethanol, cont.
• Short term effects - intoxication and mood
alteration
• Long term effects
–
–
–
–
–
–
hepatic cirrhosis
esophageal cancer
pancreatic disorders
Wernicke’s syndrome
B vitamin deficiencies
malnutrition
Ethanol, cont.
• Alcohol should never be taken with other
CNS depressants
• Treatment
– keep patient from injuring themselves through
falls, etc.
– protect and maintain airway
Alcohols, cont.
• Methanol - methyl alcohol, wood alcohol
• Sources - no medicinal use, used in industry and
cleaning fluids, solvents, paints, varnishes, Sterno Fuel,
gasohol, windshield washer fluid (30-40% methanol),
and “moonshine”, etc.
• Fatal dose is between 30 and 240ml
• Metabolism
methanol - formaldehyde - formic acid - CO2 + H2O
• CNS depressant
• Profound metabolic acidosis and blindness
Methanol, cont.
• Formic acid inhibits cytochrome oxidase in the
fundus of the eye
–
–
–
–
disrupts axoplasmic flow
axons swell causing visual impairment
edema of optic disc
degradation of formic acid is folate dependent
• Visual disturbances seen in 50% of cases of
toxicity
–
–
–
–
blurred vision
yellow spots
snowstorm like vision
photophobia
Methanol, cont.
• Clinical presentation of ingestion
–
–
–
–
–
–
–
headache
vertigo
nausea, vomiting and diarrhea
painful, tender abdomen
colic and gastritis
dyspnea and tachypnea - Kussmaul’s respiration
ocular signs
Methanol, cont.
• Treatment of methanol ingestion
– provide airway, breathing support
– folic acid (potentiates the folate-dependent
metabolism of formic acid to CO2 and H2O)
– ethanol - tie up enzyme system
– supportive care
Alcohols, cont.
• Isopropyl alcohol - rubbing alcohol (70% isopropanol)
• Second most commonly ingested alcohol
• Sources
– rubbing alcohol, window cleaners, antifreeze, detergents,
jewelry cleaners, solvents, disinfectants
• Ingestion typically seen in chronic alcoholics, children
(can be secondary to inhalation or topical absorption
from sponge baths) and suicide attempts
• Lethal dose is 240 ml
• Metabolized much slower than ethanol
Isopropyl alcohol, cont.
• Clinical presentation of ingestion
–
–
–
–
–
headache, dizziness
ataxia
nystagmus
abdominal pain, nausea, vomiting, hematemesis
patient is intoxicated but no smell of alcohol to
breath (breath may smell fruity like acetone Isopropanol metabolized to acetone by ADH)
Isopropyl alcohol, cont.
• Treatment
–
–
–
–
gastric lavage
activated charcoal
maintain airway
supportive care
Ethylene glycol
• Clear, colorless, odorless, viscous fluid with a
bittersweet taste
• Sources - antifreeze (has fluorescein dye added to show
leaks)
• About 500 cases reported a year in humans
• Ethylene glycol by itself is relatively non toxic but its
metabolites are highly toxic
ethylene glycol + alcohol dehydrogenase glycoaldehyde + aldehyde dehydrogenase - glycolic
acid - glyoxalate - oxalate (combines with calcium to
form calcium oxalate crystals)
Ethylene glycol, cont.
• Basis of toxicity
– lethal dose in an adult = 100 ml
– tissue destruction - precipitation of calcium
oxalate in tissues, especially in the renal cortex,
brain, liver, lungs, blood vessels and
pericardium
– severe metabolic acidosis (glycolic acid)
Ethylene glycol, cont.
Clinical presentation
• Phase I - 30 min - 12 hrs post ingestion, patient
may appear inebriated, nauseated, vomiting,
ataxia, no alcohol smell on breath
• Phase II - 12 -14 hours later, tachycardia, elevated
BP, pulmonary edema, tachypnea, cardiac failure,
secondary to deposition of calcium oxalate
crystals in the vascular tree, lungs and heart
• Phase III - 24-72 hours after ingestion, flank pain,
costovertebral angle tenderness, oliguric acute
renal failure
Ethylene glycol, cont.
• Diagnosis
– drunk patient with NO alcohol smell on their
breath
– calcium oxalate crystals in the urine
– clinical evidence of renal failure
– Kussmaul’s respiration
Ethylene glycol, cont.
• Treatment
– treat acidosis
– ethyl alcohol (blocks metabolism of EG by binding
ADH)
– Thiamine (Thiamilate) - Vitamin B-1 is watersoluble and utilized in many cellular functions that
involve energy formation and utilization. Promotes
conversion of glyoxalate to a nontoxic metabolite,
alpha-hydroxy-beta-ketoadipate.
– water-soluble vitamin B-complex (a cofactor in
conversion of glycolic acid to non-oxalate
compounds)
Aldehydes
• Formaldehyde
– Uses - adhesives for plywood and veneers and
preservatives (formalin - 50% solution)
– Irritating to mucous membranes
• Levels of 0.5 - 1 PPM - detectable by odor
• 2-3 PPM - mild irritation
• 4-5 PPM - intolerable to most people
– Levels of 1 PPM common in new homes
Formaldehyde, cont.
• Clinical presentation
–
–
–
–
–
–
runny nose
sore throat
headache
cough
drying and redness of skin
can cause cancer in mice and rats, no evidence
of human carcinogenesis
• Treatment - give fresh air and wash off skin
Ketones
• Acetone
– Sources - component of industrial glues, solvents,
fingernail polish remover
– Relatively non toxic - ingestion of 200 - 400 ml
may not be serious
– Has a characteristic odor and narcotic like
properties (CNS depressant)
– Threshold limit is 1000 PPM for workers exposed
to 8 hours/day
Acetone, cont.
• Clinical signs
– with inhalation - cough, bronchial irritation,
headache, fatigue
– with ingestion - vomiting and nausea, metabolic
acidosis, CNS depression (in severe cases)
• Treatment
– give fresh air
– give emetic
– treat acidosis and maintain airway