Does Marijuana Smoking Increase the Odds of Surgical Site Infection After Orthopaedic Surgery? A Retrospective Cohort Study.

OBJECTIVES: Does marijuana smoking increase the risk of surgical site infection (SSI) after open reduction and internal fixation of fractures? DESIGN: Retrospective. SETTING: Single academic level 1 trauma center in Southern California. PATIENT SELECTION CRITERIA: Adult patients who underwent open treatment for closed fractures between January 2009 and December 2021, had hardware placed, and had at least 6 months of postoperative follow-up. OUTCOME MEASURES AND COMPARISONS: Risk factors associated with the development of SSI were compared between current inhalational marijuana users and nonmarijuana users. RESULTS: Complete data were available on 4802 patients after exclusion of 82 who did not have a complete variable set. At the time of surgery, 24% (1133 patients) were current users of marijuana. At the final follow-up (minimum 6 months), there was a 1.6% infection rate (75 patients). The average age of the infection-free group was 46.1 ± 23.1 years, and the average age of the SSI group was 47.0 ± 20.3 (P = 0.73) years. In total, 2703 patients (57%) in the infection-free group were male compared with 48 (64%) in the SSI group (P = 0.49). On multivariate analysis, longer operative times (OR 1.002 [95% CI, 1.001-1.004]), diabetic status (OR 2.084 [95% CI, 1.225-3.547]), and current tobacco use (OR 2.493 [95% CI, 1.514-4.106]) (P < 0.01 for all) were associated with an increased risk of SSI; however, current marijuana use was not (OR 0.678 [95% CI, 0.228-2.013], P = 0.48). CONCLUSIONS: Tobacco use, diabetes, and longer operative times were associated with the development of SSI after open reduction and internal fixation of fractures; however, marijuana smoking was not shown to be associated with the development of SSI. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Cannabinoids detected in exhaled breath condensate after cannabis use.

Cannabinoids can be detected in breath after cannabis use, but different breath matrices need to be explored as studies to date with filter-based devices that collect breath aerosols have not demonstrated that breath-based measurements can reliably identify recent cannabis use. Exhaled breath condensate (EBC) is an unexplored aqueous breath matrix that contains condensed volatile compounds and water vapor in addition to aerosols. EBC was collected from participants both before and at two time points (0.7 ± 0.2 h and 1.7 ± 0.3 h) after observed cannabis use. Eleven different cannabinoids were monitored with liquid chromatography tandem mass spectrometry. Five different cannabinoids, including Δ9-tetrahydrocannabinol (THC), were detected in EBC collected from cannabis users. THC was detected in some EBC samples before cannabis use, despite the requested abstinence period. THC was detected in all EBC samples collected at 0.7 h post use and decreased for all participants at 1.7 h. Non-THC cannabinoids were only detected after cannabis use. THC concentrations in EBC samples collected at 0.7 h showed no trend with sample metrics like mass or number of breaths. EBC sampling devices deserve further investigation with respect to modes of cannabis use (e.g, edibles), post use time points, and optimization of cannabinoid recovery.

Cannabis, Tobacco Use, and COVID-19 Outcomes.

Importance: It is unclear whether cannabis use is associated with adverse health outcomes in patients with COVID-19 when accounting for known risk factors, including tobacco use. Objective: To examine whether cannabis and tobacco use are associated with adverse health outcomes from COVID-19 in the context of other known risk factors. Design, Setting, and Participants: This retrospective cohort study used electronic health record data from February 1, 2020, to January 31, 2022. This study included patients who were identified as having COVID-19 during at least 1 medical visit at a large academic medical center in the Midwest US. Exposures: Current cannabis use and tobacco smoking, as documented in the medical encounter. Main Outcomes and Measures: Health outcomes of hospitalization, intensive care unit (ICU) admission, and all-cause mortality following COVID-19 infection. The association between substance use (cannabis and tobacco) and these COVID-19 outcomes was assessed using multivariable modeling. Results: A total of 72 501 patients with COVID-19 were included (mean [SD] age, 48.9 [19.3] years; 43 315 [59.7%] female; 9710 [13.4%] had current smoking; 17 654 [24.4%] had former smoking; and 7060 [9.7%] had current use of cannabis). Current tobacco smoking was significantly associated with increased risk of hospitalization (odds ratio [OR], 1.72; 95% CI, 1.62-1.82; P < .001), ICU admission (OR, 1.22; 95% CI, 1.10-1.34; P < .001), and all-cause mortality (OR, 1.37, 95% CI, 1.20-1.57; P < .001) after adjusting for other factors. Cannabis use was significantly associated with increased risk of hospitalization (OR, 1.80; 95% CI, 1.68-1.93; P < .001) and ICU admission (OR, 1.27; 95% CI, 1.14-1.41; P < .001) but not with all-cause mortality (OR, 0.97; 95% CI, 0.82-1.14, P = .69) after adjusting for tobacco smoking, vaccination, comorbidity, diagnosis date, and demographic factors. Conclusions and Relevance: The findings of this cohort study suggest that cannabis use may be an independent risk factor for COVID-19-related complications, even after considering cigarette smoking, vaccination status, comorbidities, and other risk factors.

Cardiovascular and Respiratory Effects of Cannabis Use by Route of Administration: A Systematic Review.

Aim: Knowledge of the cardiovascular and respiratory effects of cannabis use by route of administration is unclear. This evidence is necessary to increase clinical and public health awareness given the recent trend in cannabis legalization, normalization, and surge in the availability and usage of various forms of cannabis products. Methods: Search was conducted in Web of Science, ProQuest, Psych INFO, Scopus, Embase, and Medline databases, and subsequently in the references of retrieved articles. Peer-reviewed articles published between 2009 and 2023, that reported on cardiovascular and respiratory effects of cannabis use by route of administration were included. Studies with no report of the route of administration and combined use of other illicit substances were excluded. The review was guided by Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Results: Of the 1873 articles retrieved, 42 met inclusion criteria encompassing six case reports, 21 reviews, and 15 empirical studies. Four administration routes were identified: smoking, vaping, oral ingestion, and dabbing. Smoking was the most common route of administration and was associated with both respiratory effects, such as bronchitis, dyspnea, and chronic obstructive lung disease, and cardiovascular effects including tachycardia, ventricular arrhythmias, and myocardial infarction. Cannabis edibles were associated with minimal respiratory effects. Tachycardia was the most common cardiovascular effect and was associated with all routes of administration. Conclusion: Cannabis use does cause cardiovascular and respiratory effects, but the conclusion remains tentative of the cardiovascular and respiratory effects by route of administration due to methodological limitations of the studies.

The Effect of Marijuana-Smoking on Dental Caries Experience.

OBJECTIVE: This cross-sectional study aims to examine the effect of marijuana-smoking on dental caries experience and to explore the potential combined effects of tobacco and marijuana cigarette-smoking. METHODS: We used data from the 2011-2014 National Health and Nutrition Examination Survey (NHANES). We examined demographics, tobacco- and marijuana-smoking, dental examination, and dietary intake. Caries was measured as decayed, missing, filled teeth (DMFT). Data analysis included univariate, bivariate analyses, and linear regression model (LRM) to examine the association between marijuana-smoking and DMFT. RESULTS: Mean DMFT score was lowest for nonsmokers (8.72) and highest for current marijuana smokers (9.87) (P < .0001); however, LRM results revealed that marijuana-smoking was not associated with caries. Adjusted DMFT was the highest for current tobacco and former marijuana smokers (ß estimate = 1.18; 95% CI, -0.27 to 2.62), but the relationship was not statistically significant. CONCLUSIONS: After controlling for potential confounders, there was no significant association between marijuana-smoking and dental caries experience. However, when marijuana and tobacco were smoked concurrently, there was a notable increase in DMFT, although the difference was not statistically significant. Future research should be directed towards exploring the effects of different forms of marijuana consumption, such as edibles and drinkables, on caries development. Health promotion programmes should be aimed at educating the public regarding the combined health impacts of smoking both marijuana and tobacco, considering the potential heightened caries risk.

Recreational Marijuana Legalization and Workplace Injuries Among Younger Workers.

This case-control study uses state-by-year workplace injury data to assess recreational marijuana legalization adoption and workplace injuries among younger workers aged 20 to 34 years.

A semi-naturalistic open-label study examining the effect of prescribed medical cannabis use on simulated driving performance.

BACKGROUND: Despite increasing medical cannabis use, research has yet to establish whether and to what extent products containing delta-9-tetrahydrocannabinol (THC) impact driving performance among patients. Stable doses of prescribed cannabinoid products during long-term treatment may alleviate clinical symptoms affecting cognitive and psychomotor performance. AIM: To examine the effects of open-label prescribed medical cannabis use on simulated driving performance among patients. METHODS: In a semi-naturalistic laboratory study, 40 adults (55% male) aged between 23 and 80 years, consumed their own prescribed medical cannabis product. Driving performance outcomes including standard deviation of lateral position (SDLP), the standard deviation of speed (SDS), mean speed and steering variability were evaluated using the Forum8 driving simulator at baseline (pre-dosing), 2.5 h and 5 -h (post-dosing). Perceived driving effort (PDE) was self-reported after each drive. Oral fluid and whole blood samples were collected at multiple timepoints and analysed for THC via liquid chromatography-mass spectrometry. RESULTS: A significant main effect of time was observed for mean speed (p = 0.014) and PDE (p = 0.020), with patients displaying modest stabilisation of vehicle control, increased adherence to speed limits and reductions in PDE post-dosing, relative to baseline. SDLP (p = 0.015) and PDE (p = 0.043) were elevated for those who consumed oil relative to flower-based products. Detectable THC concentrations were observed in oral fluid at 6-h post-dosing (range = 0-24 ng/mL). CONCLUSIONS: This semi-naturalistic study suggests that the consumption of medical cannabis containing THC (1.13-39.18 mg/dose) has a negligible impact on driving performance when used as prescribed.

Association Between Cannabis Use and Opioid Consumption, Pain, and Respiratory Complications After Surgery: A Retrospective Cohort Analysis.

BACKGROUND: Cannabis is a widely used illicit drug with effects on different pain pathways. However, interactions between cannabis and postoperative pain are unclear. Cannabis smoking also affects the lungs, but the impact of cannabis use on postoperative pulmonary complications is unknown. We hypothesized that preoperative cannabis use in adults having elective surgery is associated with higher postoperative opioid consumption. Secondarily, we tested the hypothesis that cannabis use is associated with higher pain scores, hypoxemia (oxygen saturation [Sp o2 ]/fraction of inspired oxygen [F io2 ] ratio), and higher postoperative pulmonary complications compared to nonuse of cannabis. METHODS: In this retrospective study, we included adult patients who had elective surgeries at Cleveland Clinic Main Campus between January 2010 and December 2020. The exposure was use of cannabis within 30 days before surgery, and the control group never used cannabis. Patients who had regional anesthesia or chronic pain diagnosis were excluded. The primary outcome was postoperative opioid consumption; 3 secondary outcomes were time-weighted average (TWA) postoperative pain score, TWA Sp o2 /F io2 ratio, and composite of pulmonary complications after surgery. We assessed the association between cannabis use and opioid consumption during the first 24 postoperative hours using linear regression on log-transformed opioid consumption with a propensity score-based method (inverse probability of treatment weighting [IPTW]) adjusting for confounders. We further adjusted for imbalanced confounding variables after IPTW was applied. RESULTS: In total, 1683 of 34,521 patients were identified as cannabis users. Cannabis use was associated with increased opioid consumption, with an adjusted ratio of geometric means (95% confidence interval [CI]) of 1.30 (1.22-1.38; P < .0001) for cannabis users versus nonusers. Secondarily, (1) cannabis use was associated with increased TWA pain score, with a difference in means of 0.57 (95% CI, 0.46-0.67; P < .0001); (2) cannabis use was not associated with TWA Sp o2 /F io2 , with an adjusted difference in means of 0.5 (95% CI, -3.1 to 4.2; P = .76); and (3) cannabis use was not associated with a collapsed composite of pulmonary complications, with estimated odds ratio of 0.90 (95% CI, 0.71-1.13; P = .34). CONCLUSIONS: Adult cannabis users undergoing surgeries were found to have significantly higher postoperative opioid consumption and pain scores than nonusers. Cannabis use did not have a clinically meaningful association with hypoxia or composite pulmonary complications.

Cannabis use among cancer patients and survivors in the United States: a systematic review.

BACKGROUND: How cannabis products are being used by cancer patients and survivors in the United States is poorly understood. This study reviewed observational data to understand the modes, patterns, reasons, discontinuation, and adverse experiences of cannabis use. METHODS: PubMed and PsycINFO database searches were conducted between May 2022 and November 2022. Of the 1162 studies identified, 27 studies met the inclusion criteria. The intercoder agreement was strong (0.81). RESULTS: The majority (74%) of the studies were cross-sectional in design. Study samples were approximately equal proportions of men and women and majority White participants. The prevalence of cannabis use based on national samples ranged between 4.8% and 22%. The most common modes of cannabis intake were topical application (80%), smoking (73%), vaping (12%), and ingestion of edible products (10%). Younger age, male gender, being a current or former smoker, and higher socioeconomic status were associated with greater likelihood of cannabis use. The main motive for cannabis use was management of symptoms due to cancer or cancer treatment such as pain, nausea, lack of sleep, and anxiety. A majority of the participants across studies reported that cannabis helped reduce these symptoms. Lack of symptom improvement, side effects such as fatigue and paranoia, cost, and social stigma were identified as some of the reasons for discontinuing cannabis use. CONCLUSIONS: It appears that cannabis may help cancer patients and survivors manage symptoms. However, more longitudinal studies are needed to determine whether positive experiences of cannabis use outweigh adverse experiences over time in this vulnerable population.

The Puzzle of Marijuana Use and Forced Vital Capacity.

In study after study, marijuana use has been found to be associated with increased forced vital capacity (FVC). This is puzzling, because marijuana is commonly consumed by inhalation of its smoke, and smoke exposure of any kind is not generally considered a cause of increased FVC. Although this observation was first made decades ago, a satisfactory explanation remains elusive. In this review we survey the evidence supporting the relationship between marijuana use and increased FVC, discuss potential threats to validity when inferring causation, and, presupposing a possible causal relationship, pose two key questions. First, what are possible physiologic or pathophysiologic mechanisms by which marijuana use might increase FVC? Second, why might this effect be consistently observed with marijuana use but not with tobacco use? Explanations for the first question include lung and chest growth and remodeling from strenuous marijuana smoke inhalation and reductions in lung elastic recoil from marijuana smoke exposure. Explanations for the second include differences between marijuana and tobacco in smoke composition and patterns of consumption, such as smoking topography. Finally, the possibility that smoke, whether from marijuana or tobacco, might have nonmonotonic effects on FVC depending on the degree of exposure is explored. In synthesizing a curated breadth of epidemiologic and physiologic science, we leverage a perplexing observation to generate potential insights and avenues for further research into the biological effects of smoke, from marijuana or otherwise, on the respiratory system.

Effects of cannabis smoking on the respiratory system: A state-of-the-art review.

The diminished perception of the health risks associated with the consumption of cannabis (marijuana) lead to a progressive increase in its inhalational use in many countries. Cannabis can be smoked through the use of joints, spliffs and blunts, and it can be vaporised with the use of hookah or e-cigarettes. Delta-9 tetrahydrocannabinol (THC) is the main psychoactive component of cannabis smoke but contains numerous other substances. While the recreational use of cannabis smoking has been legalised in several countries, its health consequences have been underestimated and undervalued. The purpose of this review is to critically review the impact of cannabis smoke on the respiratory system. Cannabis smoke irritates the bronchial tree and is strongly associated with symptoms of chronic bronchitis, with histological signs of airway inflammation and remodelling. Altered fungicidal and antibacterial activity of alveolar macrophages, with greater susceptibility to respiratory infections, is also reported. The association with invasive pulmonary aspergillosis in immunocompromised subjects is particularly concerning. Although cannabis has been shown to produce a rapid bronchodilator effect, its chronic use is associated with poor control of asthma by numerous studies. Cannabis smoking also represents a risk factor for the development of bullous lung disease, spontaneous pneumothorax and hypersensitivity pneumonitis. On the other hand, no association with the development of chronic obstructive pulmonary disease was found. Finally, a growing number of studies report an independent association of cannabis smoking with the development of lung cancer. In conclusion, unequivocal evidence established that cannabis smoking is harmful to the respiratory system. Cannabis smoking has a wide range of negative effects on respiratory symptoms in both healthy subjects and patients with chronic lung disease. Given that the most common and cheapest way of assumption of cannabis is by smoking, healthcare providers should be prepared to provide counselling on cannabis smoking cessation and inform the public and decision-makers.

Birth outcomes following in utero co-exposure to tobacco and marijuana.

BACKGROUND: With recent changes in tobacco and marijuana use patterns, it becomes crucial to understand how the prenatal co-use of these substances impacts birth outcomes. The goal of this study was to examine the risk of adverse birth outcomes among infants born to women who used tobacco and marijuana concurrently throughout pregnancy compared to infants of women who used tobacco alone. METHODS: This study involved a retrospective chart review of pregnant women identified via self-report or biochemical testing who used tobacco products alone (N = 71) or tobacco and marijuana simultaneously (N = 127) at any point throughout pregnancy. Differences in birth outcomes between these groups, including APGAR (appearance, pulse, grimace, activity, and respiration) scores, respiratory distress, neonatal intensive care unit admission, intrauterine growth restriction, birth weight, birth length, head circumference, gestational age, and length of hospital stay, were analyzed using linear regression and odds ratio analysis. RESULTS: There were no significant differences in outcomes for infants of women who used tobacco and marijuana compared to infants of women who used tobacco alone during pregnancy. Rates of adverse birth outcomes were high among women who used tobacco compared to what would be expected in unexposed pregnancies. CONCLUSIONS: Tobacco and marijuana co-use during pregnancy was not associated with an additional risk of adverse birth outcomes compared to tobacco use alone. Women should be educated on potential risks of marijuana, and especially, tobacco use during pregnancy. These results will inform clinical recommendations for pregnant women using tobacco and marijuana, aiming to decrease preventable adverse outcomes for patients and infants.

Impairment of Endothelial Function by Aerosol From Marijuana Leaf Vaporizers.

BACKGROUND: Marijuana leaf vaporizers, which heat plant material and sublimate Δ-9-tetrahydrocannabinol without combustion, are popular alternatives to smoking cannabis that are generally perceived to be less harmful. We have shown that smoke from tobacco and marijuana, as well as aerosol from e-cigarettes and heated tobacco products, impair vascular endothelial function in rats measured as arterial flow-mediated dilation (FMD). METHODS AND RESULTS: We exposed 8 rats per group to aerosol generated by 2 vaporizer systems (Volcano and handheld Yocan) using marijuana with varying Δ-9-tetrahydrocannabinol levels, in a single pulsatile exposure session of 2 s/min over 5 minutes, and measured changes in FMD. To model secondhand exposure, we exposed rats for 1 minute to diluted aerosol approximating release of uninhaled Volcano aerosol into typical residential rooms. Exposure to aerosol from marijuana with and without cannabinoids impaired FMD by ≈50%. FMD was similarly impaired by aerosols from Yocan (237 °C), and from Volcano at both its standard temperature (185 °C) and the minimum sublimation temperature of Δ-9-tetrahydrocannabinol (157 °C), although the low-temperature aerosol condition did not effectively deliver Δ-9-tetrahydrocannabinol to the circulation. Modeled secondhand exposure based on diluted Volcano aerosol also impaired FMD. FMD was not affected in rats exposed to clean air or water vapor passed through the Volcano system. CONCLUSIONS: Acute direct exposure and modeled secondhand exposure to marijuana leaf vaporizer aerosol, regardless of cannabinoid concentration or aerosol generation temperature, impair endothelial function in rats comparably to marijuana smoke. Our findings indicate that use of leaf vaporizers is unlikely to reduce the vascular risk burden of smoking marijuana.

Casual Pot Use Is Harmful to Teens.

Study found similar risks among teens with and without cannabis use disorder.

Perceived risk of harm for different methods of cannabis consumption: A brief report.

BACKGROUND: Emerging adults' (EAs; ages 18-25) perceived risk of cannabis-related harms has decreased in recent decades, potentially contributing to their high prevalence of cannabis consumption. With the changing cannabis policy and product landscape, it is critical to understand perceived risk related to different consumption methods (e.g., smoking, dabbing). We examined differences in cannabis risk perceptions by method and consumption patterns. METHODS: EAs recruited from an emergency department (N=359, 71.3% female, 53.5% Black) completed assessments on individual characteristics, cannabis/other substance use, and perceived risk of cannabis-related harm for four different methods (smoking, vaping, dabbing, ingestion) and two use frequencies (occasional, regular). Analyses examined associations between variables of interest and three mutually exclusive groups: no cannabis use, smoking-only, and multiple/other methods. RESULTS: Forty-two percent of EAs reported no past 3-month cannabis use, 22.8% reported smoking only, and 35.1% reported consumption via multiple/other methods. Among all participants, the methods and frequency with the largest number of EAs endorsing any perceived risk from cannabis were dabbing and vaping cannabis regularly; smoking occasionally had the smallest number of EAs endorsing perceived risk. A greater proportion of EAs in the no use group viewed vaping cannabis regularly as having the most risk (63.6%), whereas the largest proportion of EAs in the smoking-only (64.6%) and multiple/other methods (47.2%) groups perceived dabbing regularly as having the most risk. CONCLUSIONS: This work shows that EAs vary in perceptions of risk across methods of cannabis use and can inform potential directions for public health and policy efforts.