Observational study of visual testing efficacy in detecting cannabis usage

Drug recognition and examination programs are widely used to detect drug impairment in motor vehicle operators. Visual tests are a key assessment in the detection of cannabis-related impairment. Participants were recruited via social media from the medical cannabis community in Southwestern Ontario, Canada. Twenty-two participants completed the full observational trial design. The majority (n = 13 or 59.1%) were male, with a mean age of 36 years (SD = 9.4; range: 24–59). Participants underwent the following protocol: 1) First round of testing (vital signs, bio sample collection, visual tests, subjective data, neurocognitive testing) (Baseline phase); 2) Consumption of cannabis via inhalation; 3) Second round of testing 30 minutes following consumption (THC phase); 4) Additional rounds of testing at 90, 150, and 210 minutes following consumption (Recovery phase). Visual assessment data and vital signs did not follow typical patterns associated with acute cannabis intoxication. With blood THC levels more than double the Canadian legal limit (5 ng/mL), visual testing results were not diagnostic for cannabis impairment, as participants maintained normal pupil sizes and normal ocular convergence patterns. Visual testing is a key component in standardized examinations used for detecting cannabis-related impairment in Canadian drivers; however, our data indicate that visual testing may not be an effective diagnostic tool for the specific population of medical cannabis users.

Investigating Head-On Crash Severity Involving Commercial Motor Vehicles in Kentucky

This study examines various features affecting the severity associated with commercial motor vehicle (CMV, i.e., large truck and bus) head-on collisions on Kentucky highways. Recent five-year (2015–2019) crash data and variables rarely explored before (e.g., presence of centerline rumble strips, type of passing zone, and terrain type) were collected and prepared using Google Maps. A total of 378 CMV-related head-on collisions were analyzed. The generalized ordered probit (GOP) model was employed to identify the significant factors affecting the severity level resulting from CMV head-on collisions. The model allows the coefficients to vary across the injury severity categories for reliable parameter estimations. From the preliminary investigation, rolling terrains had the highest share of severe CMV head-on crashes (62% and 71% for multilane and two-lane roadways, respectively). The presence of centerline rumble strips could reduce severe crash outcomes along multilane and two-lane facilities. The GOP model identified various significant predictors of minor and severe injuries from CMV head-on crashes. Occupants wearing seatbelt were 39.3% less likely to sustain severe head-on crash injuries. From the roadway characteristics, presence of median cable and concrete barriers could significantly reduce the probability of severe head-on crash injuries, with median cables being more effective. With regard to the driver characteristics, drug impairment and speeding increased the risk of sustaining fatal/serious injuries by 39.5% and 26.4%, respectively. Necessary safety recommendations are proposed to reduce the severity of CMV head-on-related collisions. One example is installing median cable barriers along roadway stretches with a history of head-on CMV-related crashes.

Differences in Women’s Substance-Related Sexual Assaults: Force, Impairment, and Combined Assault Types

This study furthers previous research on sexual assaults (SAs) involving substances and/or force by examining effects of perpetrator behaviors of alcohol and/or drug impairment level (none, impaired, incapacitated) and/or force during SA in relationship to various assault and recovery outcomes. A diverse sample of 632 women from a large Midwestern city participated in a study on women’s experiences with SA. Of this sample of substance-involved SAs, 37.3% ( n = 236) reported a forcible-only unimpaired assault, 50.6% ( n = 320) reported a combined impairment/incapacitation and force assault, and 12% ( n = 76) reported an impaired/incapacitated-only assault. Multivariate analyses of covariance (MANCOVAs) and chi-square analyses compared assault types as defined by combined alcohol and/or drug impairment level and/or force to determine how these assaults differed in demographics, other assault characteristics, and post-assault experiences. Assault types differed on several demographic, assault, and post-assault factors with most differences showing that the combined assault type was related to worse outcomes than forcible-type assaults, including greater reexperiencing, avoidance, and numbing post-traumatic stress disorder (PTSD) symptoms. Implications for clinical intervention include recognizing that assaults involving substance use and force are traumatic and warrant individualized treatment.

Oral Fluid and Drug Impairment: Pairing Toxicology with Drug Recognition Expert Observations

According to the Governors Highway Safety Association, drugs are detected more frequently in fatally injured drivers than alcohol. Due to the variety of drugs (prescribed and/or illicit) and their various physiological effects on the body, it is difficult for law enforcement to detect/prosecute drug impairment. While blood and urine are typical biological specimens used to test for drugs, oral fluid is an attractive alternative matrix. Drugs are incorporated into oral fluid by oral contamination (chewing or smoking) or from the bloodstream. Oral fluid is non-invasive and easy to collect without the need for a trained professional to obtain the sample, unlike urine or blood. This study analyzes paired oral fluid and urine with drug recognition expert (DRE) observations. Authentic oral fluid samples (n = 20) were collected via Quantisal™ devices from arrestees under an institutional review board-approved protocol. Urine samples (n = 18) were collected with EZ-SCREEN® cups that presumptively screened for Δ9-tetrahydrocannabinol (cannabinoids), opiates, methamphetamine, cocaine, methadone, phencyclidine, amphetamine, benzodiazepines and oxycodone. Impairment observations (n = 18) were recorded from officers undergoing DRE certification. Oral fluid samples were screened using an Agilent Technologies 1290 Infinity liquid chromatograph (LC) coupled to an Agilent Technologies 6530 Accurate Mass Time-of-Flight mass spectrometer (MS). Personal compound and database libraries were produced in-house containing 64 drugs of abuse. An Agilent 1290 Infinity LC system equipped with an Agilent 6470 Triple Quadrupole MS was used for quantification of buprenorphine, heroin markers (6-acetylmorphine, morphine) and synthetic opioids. Subjects were 23–54 years old; 11 (55%) were male and 9 (45%) were female. Evaluator opinion of drug class was confirmed in oral fluid 90% of time and in urine 85% of the time in reference to scope of testing by the LC–MS methods employed (excludes cannabis and central nervous system depressants). Data indicate that oral fluid may be a viable source for confirming driving under the influence of drugs.

Marijuana Legalization in Canada: Insights for Workplaces from Case Law Analysis

The legalization of marijuana in Canada is expected to have a significant impact on workplaces, requiring the development or updating of company drug-related policies and procedures. To help employment relations stakeholders with this change, recommendations are made based on an analysis of 93 past arbitration/tribunal/court cases involving marijuana-related policy violations, drawn from the Labour Source database. Issues addressed include language and communication of the work rule, reasonableness of drug tests, standard of proof, duty to accommodate, and mitigating factors. Based on the study of those 93 court cases, some recommendations can be formulated. First, employers need to clearly state their drug-related policies, taking into consideration safety-sensitivity and any substance abuse culture. This may include prohibition of possession, use, and distribution of drugs at the workplace or working under the influence, and the need to report any medical drug use that requires accommodation. Drug tests should only be done when there is a bona fide occupational requirement or where safety is a concern, such as post-incident or when there is reasonable suspicion of drug impairment. Also, it is important to understand that positive drug test results can only show past drug use but not the level of impairment or whether the drug was used while on a work shift. Therefore, to support an offence violation and discipline, corroborating evidence from multiple witnesses and sources are often necessary. Supervisors should be trained to identify the characteristics related to marijuana and drug impairment and the procedures to follow when an incident occurs. Employers must be cognizant of the duty to accommodate medical marijuana users or recreational users who are addicted, under human rights protection for disability. Such accommodation may include work reassignment or a leave of absence. In deciding on a penalty, other than past performance and disciplinary records and personal extenuating circumstances, arbitrators may consider rehabilitation situations to assess the prognosis and viability of the employment relationship. Employers and unions are advised to stay abreast of latest developments in the laws, drug test technologies and medical research related to marijuana use.

MP15: Profile and circumstances of cycling injuries: Data from an urban emergency department

Introduction: Cycling as a form of active transportation is popular in many urban communities. However, little is known about the prevalence and circumstances of cycling injuries, particularly injuries resulting from single bicycle crashes which are not recorded in road trauma surveillance systems based on police crash reports. This study aimed to examine the profile and circumstances of cycling injuries seen in an urban emergency department (ED). Methods: This was a cross-sectional historical chart review study. All injured patients attending our ED are electronically flagged according to mechanism of injury. We reviewed the medical charts of all ED visits in 2015 that were flagged as “Cyclist Injury” or “Fall” to identify all cyclists who were injured while travelling on public roads (including sidewalks). Off road injuries were excluded. Results: In 2015, a total of 6450 ED presentations were flagged as cyclist injury (n=694) or fall (n=5756), and 667 cycling injuries met our inclusion criteria. Of these, 73 (11%) were admitted to hospital. The most common mechanisms of injury were fall from bicycle (51%), crash into stationary object (16%), and collisions with moving motor vehicles (25%). Potential contributing factors included alcohol or drug impairment (11%), road hazards (9%), avoidance manoeuvre (5%) and dooring (3%), although the cause of the crash was generally poorly documented in the medical charts. The most common injured body regions were upper extremity (55%) followed by head and neck (34%). Most injuries were abrasions/lacerations and fractures. Conclusion: Two thirds of cyclist injuries in this series were caused by single bicycle incidents, events not captured in official road trauma statistics which are based on police crash reports. The large majority of injured cyclists were treated and released from the ED. In most cases, the cause of the crash was poorly documented. This data highlights the limitations of using police crash reports or hospital admission records for road trauma surveillance and the significant knowledge gap in our understanding of causative factors leading to cycling injuries.

Cannabis and tolerance: acute drug impairment as a function of cannabis use history

Cannabis use history as predictor of neurocognitive response to cannabis intoxication remains subject to scientific and policy debates. The present study assessed the influence of cannabis on neurocognition in cannabis users whose cannabis use history ranged from infrequent to daily use. Drug users (N = 122) received acute doses of cannabis (300 μg/kg THC), cocaine HCl (300 mg) and placebo. Cocaine served as active control for demonstrating neurocognitive test sensitivity. Executive function, impulse control, attention, psychomotor function and subjective intoxication were significantly worse after cannabis administration relative to placebo. Cocaine improved psychomotor function and attention, impaired impulse control and increased feelings of intoxication. Acute effects of cannabis and cocaine on neurocognitive performance were similar across cannabis users irrespective of their cannabis use history. Absence of tolerance implies that that frequent cannabis use and intoxication can be expected to interfere with neurocognitive performance in many daily environments such as school, work or traffic.