Alcohol Flashcards
What do Drug Toxicologists do?
Detect and identify the presence of drugs and poisons in body fluids, tissues, and organs
Drugs can be either . . .
Illegal, legal, or pharmaceutical
Where do drug toxicologists work?
Health facilities such as hospitals and clinics as well as crime labs
The role of the toxicologist?
First attempt to narrow down type of toxic substance based on victim’s symptoms, postmortem pathological exam, exam of victim’s personal effects, nearby presence of empty drug containers or household chemicals
Next, they use general screening procedures
Test for small quantities that may be remaining
Must be aware that the body always processes substances so test for the metabolite
Must also assess for substance’s toxicity
What is the most frequently requested test?
Presence of alcohol
Why must drug toxicologists test for the metabolite?
Few substances enter and completely leave the body in the same chemical state since most are metabolized
What is the most widely abused drug in western countries?
Alcohol
Most of the worst effects of alcohol are not due to the alcohol, but from what?
psychomotor impairment
Due to the prevalence of abuse, laws have been instituted to regulate alcohol abuse, such as . . . ?
Driving while under the influence– intoxication
The degree of intoxication can be influenced by what factors?
Body weight
Rate of absorption through stomach and small intestines directly into the blood stream (influenced by presence/absence of food)
Total time taken to consume the alcohol
Type of alcohol consumed– diluted/undiluted
The longer total time required for complete absorption, the lower will be the peak alcohol concentration
Alcohol and the law
A BAC of .08% or .10% in most states in equivalent to intoxication for most drivers
What is the Federal standard for bus and truck operators?
.04%
When is BAC the highest?
An hour after consumption
What does “DUI” stand for?
Driving Under the Influence
Why are legislative limits for DUI different?
Depends on country and jurisdiction
What must be available to accurately determine BAC at time of arrest
Uniform testing
What happens when comparing testing vs. time of arrest?
Allowable level of analytical inaccuracy
- Usually between 0.2g/L (g of alcohol per L of blood)
Generally, blood alcohol level drops how many mg/dL per hour?
15 to 20 mg/dL per hour
How many hours would a person with a BAL of 120 mg/dL (1.2 g/L) take to reach a negligible level?
6 to 8 hours
Driving laws
implied consent comes with obtaining a license to operate a motor vehicle
Driver has a choice:
Submit to test
Subject to loss of license for a given period of time
Legalizing alcohol
Methods had to be developed to assess levels of intoxication at the time of arrest
These had to be reliable to withstand court presentation
They also needed to be standardized throughout jurisdictions
Most commonly encountered in terms of DUI
Ethanol
Methanol
Highly toxic
Mainly wood grain alcohols
May cause blindness
Which two drugs cause impairment but are not consumed regularly?
Isopropanol and ethylene glycol (antifreeze)
While alcohol is the most common source, ethanol is present in what?
Gasoline
Industry solvents
Household products
Pharmaceuticals (hand sanitizers, mouthwash)
Sources of methanol
tends to be in methyl alcohol and wood alcohol
Methanol is mainly located in what?
Consumer products– windshield wiping fluid, carburetor cleaners, copy machine toner
Formaldehyde
Ethylene Glycol is found in which consumer products?
Antifreeze
Hydraulic fluids
Drying agents
Ink
0.02 BAC
Relaxation, slight body warmth
0.05 BAC
Sedation, slowed reaction time
0.10 BAC
Slurred speech, poor coordination, slowed thinking
0.20 BAC
Trouble walking, double vision, nausea, vomiting
0.30 BAC
May pass out, tremors, memory loss, cool body temperature
0.40 BAC
Trouble breathing, coma, possible death
0.50 BAC and greater
Death
Female demographic difference in intoxication
Higher blood ethanol levels after ingesting equal doses
More susceptible to alcohol-induced hepatitis and cirrhosis
Asians demographic difference in intoxication
50% have inactive ALDH, which increases the risk of esophageal, stomach, colon, lung, head and neck cancers
Effects of Ethanol on the brain
it depresses the Central Nervous System (CNS)
Extent of depression is directly proportional to concentration of alcohol within the nerve cells
How ethanol effects the brain
Eventually alcohol will effect the central and rear portions of the brain
Which portions of the brain are the most resistant and last to fail due to ethanol?
In the medulla, which regulates respiration and heart activity
Most ethanol tests rely on what?
blood
The medium for distributing alcohol throughout the body
blood
Research confirms the direct proportional relationship of . . .
Blood alcohol concentration to brain alcohol concentration
Maximum Blood Alcohol Content (BAC) may not be reached until 2-3 hours after time of consumption
Alcohol is readily absorbed through what?
stomach and small intestine
What percentage of an oral dose is uniformly absorbed?
100%
Ethanol transfers readily to what?
the bloodstream, portioning into all tissues, particularly those with a high water content
The most common, preventable cause of mental retardation in children?
Fetal Alcohol Syndrome
Diagnostic criteria for Fetal Alcohol Syndrome?
Heavy maternal alcohol consumption
Pre and postnatal growth retardation
Craniofacial malformations (e.g., microcephaly)
Mental retardation
Because of the toxicity of ethanol, excessive alcohol consumption can damage major organs such as . . .
Liver and heart
Liver and Ethanol
results in cirrhosis or alcohol-induced hepatitis
Heart and Ethanol
Results in alcoholic cardiomyopathy
Ethanol also _______ the risk of stroke, hemorrhaging, as well as pancreatic problems
increases
Effects of methanol
Most commonly from ingestion
Asymptomatic for 12 to 24 hours before:
Formic acidemia (low blood pH from formic acid)
Ocular toxicity
Coma
Death
Main target of methanol
retinas
Severe visual disturbances from ethanol develop between _____ to _____ hours after ingestion
18 to 48 hours
Can range from photophobia (light sensitivity) to complete blindness
Effects of Ethylene Glycol
Mainly through ingestion or absorption (dermal)
Acute poisoning entails . . .
Inebriation (dose dependent) and neurotoxic symptoms
12-24 hours: cardiopulmonary stage
Tachycardia to cardiac failure
Tachypnea to pulmonary edema
24-72 hours: Renal toxicity stage
Metabolic acidosis (low pH) can progress in all stages
Ethylene glycol is distributed through what?
Total body water
Ethylene glycol (EG) can cause _______ (calcium oxalate or hippuric acid) in the kidneys and brain
crystals
Limited chronic toxicity potential, no evidence of carcinogenicity and does not affect ______
Reproductive processes
** Alcohol’s movement through the circulatory system
After alcohol is ingested, it moves down the esophagus into the stomach– where about 20% of the alcohol is absorbed through the stomach lining into the portal vein
Remaining 80% is absorbed into the blood through the lining of the small intestines
Once in the blood, it is transported to the liver, heart, lungs, back to heart to be distributed to all parts of body
During period of alcohol absorption, alcohol concentration within arterial (oxygenated) blood will be considerably higher than in venous (deoxygenated) blood
This has ramifications for sampling for prosecution
Liver begins the elimination process of 95-98% of the alcohol by _________
oxidation
Enzymes involved in detoxification (biotransformation)
Alcohol dehydrogenase
Aldehyde dehydrogenase
Acetaldehyde and acetic acid
Detoxification via excretion
Remaining 2-5% is excreted unchanged in the breath, urine, and perspiration
Amount exhaled is in direct proportion to concentration of _______
Alcohol in the blood
Elimination or ______ rate can vary by 30% between individuals, but average is 0.017% w/v (weight/volume) per hour
“burn off”
Driving
complex process requiring psychomotor tasks, hand-eye coordination, muscle control, and cognitive tasks
What causes slowing of nerve conduction resulting in slower reaction times?
Alcohol
Identification methods for alcohol impairment
Smell
Bloodshot eyes
Unusual behavior
Demeanor: flat, dull, excited
Unusually large/small pupils
Unusual eye movements
Impaired motor skills
Presence of alcohol containers or drug paraphernalia
Clinical signs and symptoms will determine if the officer needs to do any tests for impairment
Who performs Field Sobriety Tests?
Police officers
Normally performed to ascertain the degree of the suspect’s physical impairment and whether or not an evidential test is justified
Field Sobriety Test
These Field Sobriety Tests are psychophysical, which involves what?
The ability to think and do at the same time
Physiological Field Sobriety Test
Horizontal gaze nystagmus (HGN)
Divided attention Field Sobriety Test
One-Leg Stand Test (OLST)
Walk and Turn Test (WATT)
Most accurate field sobriety test?
Horizontal gaze nystagmus
77% accuracy rating in detecting blood alcohol content levels of .10% or higher
What is nystagmus?
Involuntary jerking or bouncing of the eyeball
Why does HGN involve?
Moving an object (usually a finger or pen) horizontally in front of the suspect
Usually about one foot away from the suspect’s face at eye-level
Jerking movements in the eye before the gaze reaches a 45-degree angle is indicative of a possible blood alcohol content level over .05%
One-Leg Stand Test
When properly administered, 65% accurate in determining if a driver has a blood alcohol content level above .10%
Proper stance for One-Leg Stand test?
Hands at side
One leg about six inches above the ground
Suspect to count upward starting at 1,000
Signs of intoxication for One-Leg Stand test?
Swaying while balancing
Using the arms to keep balance
Hopping on the anchor foot in order to maintain balance
Resting the raised foot on the ground three or more times during the required thirty seconds
Walk and Turn Test
68% accurate in identifying blood alcohol content levels of .10% and above
Putting one foot in front of the other in a straight line, toe touching the back of the last heel
Suspect takes nine steps, turns around and comes back
Hands must be at sides, watching the feet, and steps counted aloud
Walk and Turn Test signs of intoxication
Inability to stay balanced while receiving instructions
Starting or stopping the test before indicated
Failure to touch heel-to-toe
Stepping off of the line
Using arms to balance
Improperly turning
Using the incorrect number of steps
Breath tests
Roadside breath tests are done upon suspicion of toxicity
Preliminary testing and later tests will be performed for confirmation
Most known roadside test
Breathalyzer
Breathalyzer
A device for collecting and measuring the alcohol content of alveolar breath
Breathalyzer test process
A subject blows into a mouthpiece
Trapped alveolar breath can be analyzed
Any alcohol present in the sample dissolves in a solution and is oxidized to acetic acid
A spectrophotometer takes a reading of acetic acid content
Indirectly determines the quantity of alcohol consumed (it is not quantitating alcohol but the amount of alcohol that has been oxidized)
Infrared
Designed to minimize operator error and free of chemical reagents
Operates on infrared light absorption and/or fuel cells
Infrared light absorption uses filters selected to a wavelength of infrared light at which alcohol will absorb
Gas Chromatography
Alcohol is separated from other volatiles in blood
Compares resultant alcohol peak area to ones obtained with known blood-alcohol standards
Collection and preservation of blood
The collection of blood for analysis is done depending on certain factors
What factor of collection and preservation of blood matters most to us?
Whether the suspect is alive or deceased
Collection on a living suspect
Must be drawn by a qualified person (phlebotomy license)
Must use a sterile needle
Cleanse with a non-alcoholic disinfectant
Seal blood sample in an airtight container with an anticoagulant (usually EDTA, or a “purple top tube”
Place in refrigerated storage for delivery to toxicology
Collection of postmortem samples
Requires added precautions
Must account for bacterial action so collect from several different body sites (each sample is kept in separate airtight containers with an anticoagulant and refrigerated; each must be labeled correctly)
Collect urine and vitreous humor fluids (both usually do not suffer from postmortem ethyl alcohol production to any significant extent)
