Is my driving impaired?

Dr Richard EversSynergy Health Laboratory Services

SHLS

Laboratory Services division of Synergy Health•Based in Abergavenny, South Wales•Established in 1986•On-site Toxicology, Pathology and PCR suites

Services from SHLS

• Drug and Alcohol screening• Urine• Saliva• Hair• Breath Alcohol

• Drug and Alcohol sample collection services

• Clinical Pathology testing services

• Training services

What do we mean by “Impaired”

• Road Traffic Act (1988) Section 6B – CODE OF PRACTICE FOR PRELIMINARY

IMPAIRMENT TESTS (DfT 2004)• Designed to determine of you are unfit to

drive

Field Impairment Test

• Pupillary Examination – Look ahead– Keep eyes open– Pupil size– Rednes or watery

Modified Romberg Balance Test

• Stand to attention– Tilt head back and close eyes– Return head to upright and open eyes after 30

seconds– Note balance control and timing

Walk and Turn Test

• Stand still on a line– Nine heel-to-toe steps, turn and nine steps

back, counting out loud– Correct counting and steps– Deviation from line

One Leg Stand

• Stand still– Raise right foot 6-8 inches parallel to ground– Look ahead– Repeat for left foot– Record balance

Finger to nose test

• Hold both hands out in front with index fingers extended– Close eyes– Touch tip of the nose– Alternate hands on command– Record balance, missing nose

or using the wrong hand

Drink drive levels

• England and Wales– Blood 80mg/100mL– Breath 35µg/100mL– Urine 107mg/100mL

• Scotland– Blood 50mg/100mL– Breath 22µg/100mL– Urine 67mg/100mL

Drink drive stats 2013

• 683,631 tests– 71,675 positive (10.5%)

• 232,709 accidents (6,524 HGV)– 53% breathalysed (65% HGV)– 1.6% positive (0.4% HGV)

• 17% of deaths positive

DfT National Statistics (www.gov.uk)

Drink drive stats – Why test?

• Traffic offense (37%)– 6% Positive

• Collision (32.7%)– 8% Positive

• Suspicion (18.7%)– 18.7% Positive – 18.9% alcohol present below limit

DfT (www.gov.uk)

Drug drive stats

• 1132 convictions for drug driving (2012)– 19% of surveyed admit to driving while unfit– 7% due to illegal drugs

• 902 arrests March – May 2015– 45% of tests positive– 1 arrest every 2½ days– 1 test per day

IAM & Daily Mail

FOI requests

Is cannabis a problem?

• From US Data

Drug drive levels

DrugCutoff (µg/L) Drug

Cutoff (µg/L)

Amphetamine 250 LSD 1

Benzoylecgonine 50 Methadone 500

Clonazepam 50 Methamphetamine 10

Cocaine 10 Ecstasy 10

Cannabis 2 6-monoacetylmorphine 5

Diazepam 550 Morphine 80

Flunitrazepam 300 Oxazepam 300

Ketamine 20 Temazepam 1000

Lorazepam 100    

DT5000

• Wide test menu – Cannabis– Cocaine– Opiates– Benzodiazepines

• Home Office Type Approved– Cannabis

Cannabis

• Legal Limit 2µg/L THC in blood• Driving Simulator

– Controlled cannabis use– Measured impairment

• 8µg/L THC gives similar impairment to 0.50‰ Alcohol

Long term cannabis use

• Cannabis users confined to a drug free R&D facility

• Daily blood cannabis levels• >2µg/L for 18 days

hangover• You do not have to have drugs in your system to

be impaired• Driving simulator with a hangover gives a similar

level of impairment to BAC 0.40‰• Longer sleep following drinking leads to less

impairment (!!!)• “chronic use of all illicit drugs is associated with

some cognitive and/or psychomotor impairment, and can lead to a decrease in driving performance even when the subject is no longer intoxicated” - EMCCDA

Amphetamine

• Controlled administration studies– Amphetamine no more harmful to cause

accident• Post-accident testing figures

– Amphetamine 6x more likely to cause death• Amphetamine increases risk taking• Dexedrine given to fighter pilots

San Francisco Bay Bridge, 2007• M/V Cosco Busan hit the

pier in fog• 53,500 gallons of fuel oil

spilt• $3.6 million repair bill• $70 million environmental

cleanup• Pilot tested BEFORE

accident and negative for SAMHSA 5 and alcohol

Stimulant/depressant mix• Pilot was taking:

– Lorazepam– Diazepam– Modafinil– Propoxyphene– Hydrocodone– Pentazocine (narcotic analgesic)

• Narcotics & sedatives – send you to sleep• Modafinil – wakes you up

• Similar patterns of use with amphetamines and benzodiazepines• Cocaine and heroin

Is my driving impaired?

• Alcohol – legal limit• Drugs – legal limit for some• Tiredness – limit on driving hours• Cold / ‘Flu – no law• Hangover – no law

Thank You