Marijuana and Lung Disease

Recurrent Spontaneous Pneumothorax Secondary to Marijuana and Tobacco Abuse

Primary spontaneous pneumothorax occurs in patients without apparent clinical lung disease, with a higher incidence in tall, thin males between the ages of 10 and 30. Tension pneumothorax is a life-threatening condition that can develop within minutes due to progressive air accumulation in the pleural space; mechanical pressure can lead to significant cardiorespiratory compromise. Tobacco association with a higher incidence of spontaneous pneumothorax has been well documented, but marijuana and spontaneous pneumothorax connection has not been well studied. However, it has been observed that patients who use marijuana and tobacco simultaneously have a higher incidence of spontaneous tension and larger pneumothoraces, as well as longer postoperative stay and higher recurrence than cigarette-only users. We present a case of a 26-year-old young male with a history only significant for excessive tobacco and marijuana smoking who developed multiple recurrent spontaneous pneumothorax and had to undergo right-sided video-assisted thoracoscopic surgery (VATS) with minimally invasive thoracotomy and had a prolonged hospital stay. With our case report, we hope to add to the evidence the effects of combined marijuana and tobacco smoking on bullous lung disease and pneumothorax while emphasizing the importance of conducting a detailed substance use history in patients with spontaneous pneumothorax.

Cannabis and Cannabinoids in the Perioperative Period

Cannabis use is increasingly common, and with a growing number of jurisdictions implementing legalization frameworks, it is likely that providers will encounter more patients who use cannabis. Therefore, it is important for providers to understand the implications of cannabis use and practical considerations for the perioperative period. Cannabis affects multiple organ systems and may influence intraoperative anesthesia, as well as postoperative pain management. The effects of cannabis and key anesthetic considerations are reviewed here.

Comparative study of pulmonary functions test among different substances abusers

BACKGROUND

Substance use is a problem that affects people all over the world and is prevalent in different age groups. The lungs in particular, with their unique exposure to the environment and the bloodstream, are vulnerable to damage from substance use and can affect lung function. Efforts have generally focused on cigarettes, while there is little research on different substances of use. The study aimed to detect changes in pulmonary function tests in different substance users.

METHODS

An analytical cross-sectional study was carried out among different substance users at the Abdalaal Elidridi Psychiatric Hospital. A total of 60 adults were included: 16 cannabis users, 16 heroin users, 16 methamphetamine users, and 12 alcohol users. Participants used only one substance. Height and weight were measured, and BMI was calculated. For each participant, pulmonary function tests (PFTs) including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio and peak expiratory flow rate (PEFR) were measured using an electronic spirometer, and the results were compared with normal reference values for Sudanese subjects matched for age, sex, and height.

RESULTS

A high prevalence of lung function abnormalities (100.0%) is seen in all abusers. Obstructive lung disease is found in 80.0% of patients, and restrictive lung disease is found in 20.0% of cases. The measured FEV1/FVC ratio in different substance groups was lower than the expected normal values of (88.2 ± 2.9%). The mean FEV1/FVC ratio of alcohol was (83.6 ± 7.6%), for heroin, it was (77.3 ± 15.8%), for methamphetamine, it was (77.7 ± 17.8%) and for cannabis, it was (71.03 ± 11.3%), the latter was significantly lower than the other two groups (P < 0.001). Duration of substance use was inversely correlated with the FEV1/FVC ratio (r = -0.378, P 0.001), indicating that a longer duration of substance use correlates with lower FEV1/FVC ratios.

CONCLUSIONS

Obstructive lung abnormalities are frequent in substance abusers. All types of substances have a major deleterious effect on PFTs and harm the respiratory system. More action should be taken to address the effects of substances on the lungs. Awareness, early detection, and intervention are essential.

Chemical exposure and alveolar macrophages responses: 'the role of pulmonary defense mechanism in inhalation injuries'

Epidemiological and clinical studies have indicated an association between particulate matter (PM) exposure and acute and chronic pulmonary inflammation, which may be registered as increased mortality and morbidity. Despite the increasing evidence, the pathophysiology mechanism of these PMs is still not fully characterised. Pulmonary alveolar macrophages (PAMs), as a predominant cell in the lung, play a critically important role in these pathological mechanisms. Toxin exposure triggers events associated with macrophage activation, including oxidative stress, acute damage, tissue disruption, remodelling and fibrosis. Targeting macrophage may potentially be employed to treat these types of lung inflammation without affecting the natural immune response to bacterial infections. Biological toxins, their sources of exposure, physical and other properties, and their effects on the individuals are summarised in this article. Inhaled particulates from air pollution and toxic gases containing chemicals can interact with alveolar epithelial cells and immune cells in the airways. PAMs can sense ambient pollutants and be stimulated, triggering cellular signalling pathways. These cells are highly adaptable and can change their function and phenotype in response to inhaled agents. PAMs also have the ability to polarise and undergo plasticity in response to tissue damage, while maintaining resistance to exposure to inhaled agents.

[Diffuse alveolar hemorrhage in cannabis smokers. A systematic literature review]

Cannabis is the most widely used illicit psychoactive substance in France. It can be responsible for numerous pulmonary complications, including diffuse alveolar hemorrhage (DAH). The objective of this systematic review of the literature was to present data concerning the relationship between cannabis smoking and DAH, which has rarely been reported in the literature. The review was based on a Medline search covering the 1980-2022 period and utilizing data drawn from 10 articles. DAH diagnosis is based on an association of hemoptysis, anemia and diffuse alveolar opacities on chest radiography with siderophages in the Bronchoalveolar Lavage Fluid (BAL). The 11 patients identified in this review were daily or regular cannabis smokers; in 4 cases they presented recent or recurrent hemoptysis with anemia; imaging revealed diffuse alveolar opacities in 10 of them, while BAL endoscopy highlighted a diffuse hemorrhage in the bronchial tree, and siderophages were observed in 6 cases. While evolution was favorable when cannabis consumption was discontinued, resumption occasioned DAH recurrence, and one patient died. Advice to quit should systematically be accompanied by addictological follow-up.

Modulation of pulmonary immune function by inhaled cannabis products and consequences for lung disease

The lungs, in addition to participating in gas exchange, represent the first line of defense against inhaled pathogens and respiratory toxicants. Cells lining the airways and alveoli include epithelial cells and alveolar macrophages, the latter being resident innate immune cells important in surfactant recycling, protection against bacterial invasion and modulation of lung immune homeostasis. Environmental exposure to toxicants found in cigarette smoke, air pollution and cannabis can alter the number and function of immune cells in the lungs. Cannabis (marijuana) is a plant-derived product that is typically inhaled in the form of smoke from a joint. However, alternative delivery methods such as vaping, which heats the plant without combustion, are becoming more common. Cannabis use has increased in recent years, coinciding with more countries legalizing cannabis for both recreational and medicinal purposes. Cannabis may have numerous health benefits owing to the presence of cannabinoids that dampen immune function and therefore tame inflammation that is associated with chronic diseases such as arthritis. The health effects that could come with cannabis use remain poorly understood, particularly inhaled cannabis products that may directly impact the pulmonary immune system. Herein, we first describe the bioactive phytochemicals present in cannabis, with an emphasis on cannabinoids and their ability to interact with the endocannabinoid system. We also review the current state-of-knowledge as to how inhaled cannabis/cannabinoids can shape immune response in the lungs and discuss the potential consequences of altered pulmonary immunity. Overall, more research is needed to understand how cannabis inhalation shapes the pulmonary immune response to balance physiological and beneficial responses with potential deleterious consequences on the lungs.

ASRA Pain Medicine consensus guidelines on the management of the perioperative patient on cannabis and cannabinoids

BACKGROUND

The past two decades have seen an increase in cannabis use due to both regulatory changes and an interest in potential therapeutic effects of the substance, yet many aspects of the substance and their health implications remain controversial or unclear.

METHODS

In November 2020, the American Society of Regional Anesthesia and Pain Medicine charged the Cannabis Working Group to develop guidelines for the perioperative use of cannabis. The Perioperative Use of Cannabis and Cannabinoids Guidelines Committee was charged with drafting responses to the nine key questions using a modified Delphi method with the overall goal of producing a document focused on the safe management of surgical patients using cannabinoids. A consensus recommendation required ≥75% agreement.

RESULTS

Nine questions were selected, with 100% consensus achieved on third-round voting. Topics addressed included perioperative screening, postponement of elective surgery, concomitant use of opioid and cannabis perioperatively, implications for parturients, adjustment in anesthetic and analgesics intraoperatively, postoperative monitoring, cannabis use disorder, and postoperative concerns. Surgical patients using cannabinoids are at potential increased risk for negative perioperative outcomes.

CONCLUSIONS

Specific clinical recommendations for perioperative management of cannabis and cannabinoids were successfully created.

Tobacco Use and Respiratory Symptoms Among Adults: Findings From the Longitudinal Population Assessment of Tobacco and Health (PATH) Study 2014-2016

INTRODUCTION

We examined the relationship between current tobacco use and functionally important respiratory symptoms.

METHODS

Longitudinal cohort study of 16 295 US adults without COPD in Waves 2-3 (W2-3, 2014-2016) of the Population Assessment of Tobacco and Health Study. Exposure-Ten mutually exclusive categories of tobacco use including single product, multiple product, former, and never use (reference). Outcome-Seven questions assessing wheezing/cough were summed to create a respiratory symptom index; cutoffs of ≥2 and ≥3 were associated with functional limitations and poorer health. Multivariable regressions examined both cutoffs cross-sectionally and change over approximately 12 months, adjusting for confounders.

RESULTS

All tobacco use categories featuring cigarettes (>2/3's of users) were associated with higher risk (vs. never users) for functionally important respiratory symptoms at W2, for example, at symptom severity ≥ 3, risk ratio for exclusive cigarette use was 2.34 [95% CI, 1.92, 2.85] and for worsening symptoms at W3 was 2.80 [2.08, 3.76]. There was largely no increased symptom risk for exclusive use of cigars, smokeless tobacco, hookah, or e-cigarettes (adjustment for pack-years and marijuana attenuated the cross-sectional e-cigarette association from 1.53(95% CI 0.98, 2.40) to 1.05 (0.67, 1.63); RRs for these products were also significantly lower compared to exclusive use of cigarettes. The longitudinal e-cigarette-respiratory symptom association was sensitive to the respiratory index cutoff level; exclusive e-cigarette use was associated with worsening symptoms at an index cutoff ≥ 2 (RR = 1.63 [1.02, 2.59]) and with symptom improvement at an index cutoff of ≥ 3 (RR = 1.64 [1.04, 2.58]).

CONCLUSIONS

Past and current cigarette smoking drove functionally important respiratory symptoms, while exclusive use of other tobacco products was largely not associated. However, the relationship between e-cigarette use and symptoms was sensitive to adjustment for pack-years and symptom severity.

IMPLICATIONS

How noncigarette tobacco products affect respiratory symptoms is not clear; some studies implicate e-cigarettes. We examined functionally important respiratory symptoms (wheezing/nighttime cough) among US adults without COPD. The majority of adult tobacco users smoke cigarettes and have higher risk of respiratory symptoms and worsening of symptoms, regardless of other products used with them. Exclusive use of other tobacco products (e-cigarettes, cigars, smokeless, hookah) was largely not associated with functionally important respiratory symptoms and risks associated with their use was significantly lower than for cigarettes. The association for e-cigarettes was greatly attenuated by adjustment for cigarette pack-years and sensitive to how symptoms were defined.

Risk of somatic diseases in patients with eating disorders: the role of comorbid substance use disorders

AIMS

Eating disorders (EDs) and substance use disorders (SUDs) often co-occur, and both involve somatic diseases. So far, no study has considered whether comorbid SUDs may impact somatic disease risk in patients with EDs. Therefore, this study aimed to examine the impact of comorbid SUDs on the risk of 11 somatic disease categories in patients with anorexia nervosa (AN), bulimia nervosa (BN) and unspecified eating disorder (USED) compared to matched controls.

METHODS

A retrospective cohort study was conducted using Danish nationwide registries. The study population included 20 759 patients with EDs and 83 036 controls matched on month and year of birth, sex and ethnicity. Hazard ratios (HRs) were calculated to compare the risk of being diagnosed with a somatic disease (within 11 categories defined by the ICD-10) following first ED diagnosis (index date) between ED patients and controls both with and without SUDs (alcohol, cannabis or hard drugs).

RESULTS

The ED cohort and matched controls were followed for 227 538 and 939 628 person-years, respectively. For ED patients with SUDs, the risk pattern for being diagnosed with different somatic diseases (relative to controls without SUDs) varied according to type of ED and SUD [adjusted HRs ranged from 0.95 (99% CI = 0.57; 1.59) to 4.17 (2.68, 6.47)]. The risk estimates observed among ED patients with SUDs were generally higher than those observed among ED patients without SUDs [adjusted HRs ranged from 1.08 (99% CI = 0.95, 1.22) to 2.56 (2.31, 2.84)]. Abuse of alcohol only had a non-synergistic effect on six disease categories in AN patients and five in BN and USED patients. Abuse of cannabis (with/without alcohol) had a non-synergistic effect on five disease categories in AN and BN patients and two in USED patients. Abuse of hard drugs (with/without alcohol or cannabis) had a non-synergistic effect on nine disease categories in AN patients, eight in BN patients and seven in USED patients.

CONCLUSIONS

The present study documents non-synergistic but not synergistic harmful somatic consequences of SUDs among patients with different EDs, with AN and hard drugs being the most predominant factors. Hence, EDs and SUDs did not interact and result in greater somatic disease risk than that caused by the independent effects. Since EDs and SUDs have independent effects on many somatic diseases, it is important to monitor and treat ED patients for SUD comorbidity to prevent exacerbated physical damage in this vulnerable population.

[Inhaled marijuana and the lung, a toxic cocktail?]

Unlike the well-documented effects of tobacco smoke on the lung, the effects of cannabis smoke remain controversial, the main bias consisting in co-consumption of tobacco. That said, the composition of joint smoke is close to that of cigarettes, containing many compounds that are carcinogenic and/or alter the respiratory epithelium. Confirmed respiratory effects in chronic cannabis smokers include aggravated chronic bronchitis symptoms, a cumulative effect with tobacco on COPD and emphysema occurrence, an increased risk of bullous emphysema, and pneumothorax with heightened risk of recurrence after pleural symphysis. Recent prospective studies have shown a negative impact on lung function, with not only damage to the airways, but also DLCO alteration and an accelerated drop in FEV1. Finally, cannabis smoking is very common among young patients with lung cancer. Its consumption could lead to a different lung cancer profile, potentially more undifferentiated and less accessible to targeted therapy. Questioning about cannabis consumption must be systematic and targeted medical care should be offered.

Cannabis use and risks of respiratory and all-cause morbidity and mortality: a population-based, data-linkage, cohort study

INTRODUCTION

Although cannabis is frequently used worldwide, its impact on respiratory health is characterised by controversy.

OBJECTIVE

To evaluate the association between cannabis use and respiratory-related emergency room (ER) visits and hospitalisations.

METHODS

A retrospective, population-based, cohort study was carried out, linking health survey and health administrative data for residents of Ontario, Canada, aged 12-65 years, between January 2009 and December 2015. Individuals self-reporting cannabis use within the past year were matched to control individuals (people who reported never using cannabis, or used cannabis only once, and more than 12 months ago) in upwards of a 1:3 ratio on 31 different variables, using propensity score matching methods. Respiratory-related and all-cause ER visits or hospitalisations, and all-cause mortality, were evaluated up to 12 months following the index date.

RESULTS

We identified 35 114 individuals who had either used cannabis in the past year or were controls, of whom 6425 (18.3%) used cannabis in the past year. From this group, 4807 (74.8%) were propensity-score matched to 10 395 control individuals. In the propensity score matched cohort, there was no significant difference in odds of respiratory-related ER visit or hospitalisation between cannabis users and the control group (OR 0.91, 95% CI 0.77 to 1.09). Compared with control individuals, cannabis users had significantly increased odds of all-cause ER visit or hospitalisation (OR 1.22, 95% CI 1.13 to 1.31) and there was no significant difference with respect to all-cause mortality (OR 0.99, 95% CI 0.49 to 2.02).

CONCLUSIONS

Although no significant association was observed between cannabis use and respiratory-related ER visits or hospitalisations, the risk of an equally important morbidity outcome, all-cause ER visit or hospitalisation, was significantly greater among cannabis users than among control individuals. Therefore, cannabis use is associated with increased risk for serious adverse health events and its recreational consumption is not benign.

Cannabis suppresses antitumor immunity by inhibiting JAK/STAT signaling in T cells through CNR2

The combination of immune checkpoint blockade (ICB) with chemotherapy significantly improves clinical benefit of cancer treatment. Since chemotherapy is often associated with adverse events, concomitant treatment with drugs managing side effects of chemotherapy is frequently used in the combination therapy. However, whether these ancillary drugs could impede immunotherapy remains unknown. Here, we showed that ^∆9-tetrahydrocannabinol (THC), the key ingredient of drugs approved for the treatment of chemotherapy-caused nausea, reduced the therapeutic effect of PD-1 blockade. The endogenous cannabinoid anandamide (AEA) also impeded antitumor immunity, indicating an immunosuppressive role of the endogenous cannabinoid system (ECS). Consistently, high levels of AEA in the sera were associated with poor overall survival in cancer patients. We further found that cannabinoids impaired the function of tumor-specific T cells through CNR2. Using a knock-in mouse model expressing a FLAG-tagged Cnr2 gene, we discovered that CNR2 binds to JAK1 and inhibits the downstream STAT signaling in T cells. Taken together, our results unveiled a novel mechanism of the ECS-mediated suppression on T-cell immunity against cancer, and suggest that cannabis and cannabinoid drugs should be avoided during immunotherapy.

Chronic cough and weight loss in an adolescent marijuana smoker

Marijuana is the most widely used illicit drug in the United States. As marijuana becomes legalized in more states and its use increases among adolescents, pediatricians must be aware of the impact of marijuana on pediatric health. Marijuana smoking as well as cigarette smoking has been associated with numerous lung diseases, including chronic bronchitis and bullous lung diseases. This case report postulates that regular marijuana smoking may be associated with pulmonary Langerhans cell histiocytosis, a severe lung disease that lacks definitive treatment and can cause respiratory failure. Given the potential risk of life-threatening lung diseases, pediatricians must screen adolescents with respiratory symptoms for marijuana use. In addition, this case underscores the need for further research and improved understanding of the relationship between marijuana smoking and lung disease.

Septic arthritis due to Nocardia brasiliensis and a review of nocardiosis as a cause of arthritis

Bacteria of the genus Nocardia are implicated in several disease processes but are a rare cause of septic arthritis. Typically, the cause of Nocardia septic arthritis is dissemination from a pulmonary infection in an immunocompromised host. Herein we present a case of a 64-year-old male who had received a long course of prednisone for membranous nephropathy and developed a septic arthritis due to Nocardia brasiliensis. He was treated sequentially with trimethoprim-sulfamethoxazole and amoxicillin-clavulanate, linezolid and amoxicillin-clavulanate, tigecycline and amoxicillin-clavulanate, and omadacycline and amoxicillin-clavulanate. To our knowledge, only two prior cases of Nocardia brasiliensis septic arthritis without antecedent trauma to the joint or local skin breakdown have been reported. A review of the literature identified 19 other cases of Nocardia septic arthritis. This case reinforces the need to consider Nocardia infection in the differential diagnosis in the immunocompromised patient with concurrent pulmonary infection and septic arthritis.

Clinical Approaches to Cannabis: A Narrative Review

Cannabis use in the United States is growing at an unprecedented pace. Most states in the United States have legalized medical cannabis use, and many have legalized nonmedical cannabis use. In this setting, health care professionals will increasingly see more patients who have questions about cannabis use, its utility for medical conditions, and the risks of its use. This narrative review provides an overview of the background, pharmacology, therapeutic use, and potential complications of cannabis.

Wonder or evil?: Multifaceted health hazards and health benefits of Cannabis sativa and its phytochemicals

Cannabis sativa, widely known as 'Marijuana' poses a dilemma for being a blend of both good and bad medicinal effects. The historical use of Cannabis for both medicinal and recreational purposes suggests it to be a friendly plant. However, whether the misuse of Cannabis and the cannabinoids derived from it can hamper normal body physiology is a focus of ongoing research. On the one hand, there is enough evidence to suggest that misuse of marijuana can cause deleterious effects on various organs like the lungs, immune system, cardiovascular system, etc. and also influence fertility and cause teratogenic effects. However, on the other hand, marijuana has been found to offer a magical cure for anorexia, chronic pain, muscle spasticity, nausea, and disturbed sleep. Indeed, most recently, the United Nations has given its verdict in favour of Cannabis declaring it as a non-dangerous narcotic. This review provides insights into the various health effects of Cannabis and its specialized metabolites and indicates how wise steps can be taken to promote good use and prevent misuse of the metabolites derived from this plant.

Cannabis and the Cancer Patient

Session 2 of the National Cancer Institute's Cannabis, Cannabinoids, and Cancer Research Workshop opened with testimony from a lymphoma survivor who detailed medicinal cannabis-related improvements in nausea, low appetite, insomnia, and mental health and the limited clinical counsel she received regarding cannabis use. Discussion next turned to the evolution of the legal landscape of cannabis in the United States, one in which state and federal laws frequently conflict and the Controlled Substance Act renders cannabis Schedule I. This legal climate creates conundrums for US medicinal cannabis researchers who contend with limited funding opportunities, avenues to source trial drug, and procedural red tape and for oncology clinicians who recommend medicinal cannabis to patients with some frequency while perceiving themselves as ill equipped to make such clinical recommendations. Ultimately, it creates challenges for cancer patients who find themselves turning to nonmedical and anecdotal information sources. The risks of cannabis use by the cancer patient were discussed next. These include infection, pharmacodynamic and pharmacokinetic drug-botanical interactions, cyclic nausea and vomiting, e-cigarette or vaping product use-associated illness, legal issues, and high cost. The session concluded with a broad survey of the research supporting oncologic cannabinoid use, conclusive evidence for chemotherapy-induced nausea and vomiting, and suggestive evidence for cancer-related pain.

Driving under the influence: a multi-center evaluation of vehicular crashes in the era of cannabis legalization

Background

Eleven states have instituted laws allowing recreational cannabis use leading to growing public health concerns surrounding the effects of cannabis intoxication on driving safety. We hypothesized that after the 2016 legalization of cannabis in California, the use among vehicular injury patients would increase and be associated with increased injury severity.

Methods

San Diego County’s five adult trauma center registries in were queried from January 2010 to June 2018 for motor vehicle or motorcycle crash patients with completed toxicology screens. Patients were stratified as toxicology negative (TOX−), positive for only THC (THC+), only blood alcohol >0.08% (ETOH+), THC+ETOH, or THC+ with any combination with methamphetamine or cocaine (M/C). County medical examiner data were reviewed to characterize THC use in those with deaths at the scene of injury.

Results

Of the 11,491 patients identified, there were 61.6% TOX−, 11.7% THC+, 13.7% ETOH+, 5.0% THC+ETOH, and 7.9% M/C. THC+ increased from 7.3% to 14.8% over the study period and peaked at 14.9% post-legalization in 2017. Compared with TOX− patients, THC+ patients were more likely to be male and younger. THC+ patients were also less likely to wear seatbelts (8.5% vs 14.3%, p<0.001) and had increased mean Injury Severity Score (8.4±9.4 vs 9.0±9.9, p<0.001) when compared with TOX− patients. There was no difference in in-hospital mortality between groups. From the medical examiner data of the 777 deaths on scene, 27% were THC+.

Discussion

THC+ toxicology screens in vehicular injury patients peaked after the 2016 legalization of cannabis. Public education on the risks of driving under the influence of cannabis should be a component of injury prevention initiatives.

Level of evidence

III, Prognostic

Development and validation of a mouse model of contemporary cannabis smoke exposure

Cannabis is widely used for both recreational and medicinal purposes. Inhalation of combusted cannabis smoke is the most common mode of drug consumption, exposing the lungs to the pharmacologically active ingredients, including tetrahydrocannabinol (THC) and cannabidiol (CBD). While the relationship between cannabis smoke exposure and compromised respiratory health has yet to be sufficiently defined, previous investigations suggest that cannabis smoke may dysregulate pulmonary immunity. Presently, there exist few preclinical animal models that have been extensively validated for contemporary cannabis smoke exposure.

 To address this need, we developed a mouse model with readouts of total particulate matter, serum cannabinoid and carboxyhaemoglobin levels, lung cellular responses, and immune-mediator production.

 Using a commercially available smoke exposure system and a cannabis source material of documented THC/CBD composition, we exposed mice to a mean±sd total particulate matter of 698.89±66.09 µg·L⁻¹ and demonstrate increases in serum cannabinoids and carboxyhaemoglobin. We demonstrate that cannabis smoke modulates immune cell populations and mediators in both male and female BALB/c mice. This modulation is highlighted by increases in airway and lung tissue macrophage populations, including tissue-resident alveolar macrophages, monocyte-derived alveolar macrophages, and interstitial macrophage subpopulations. No changes in airway or lung tissue infiltration of neutrophils were observed. Immune-mediator analysis indicated significant upregulation of macrophage-derived chemokine, thymus and activation-regulated chemokine, and vascular endothelial growth factor within the lung tissue of cannabis smoke-exposed mice.

 This accessible and reproducible smoke-exposure model provides a foundation to explore the impact of chronic cannabis exposures and/or co-exposures with pathogens of clinical relevance, such as influenza.

Validation of the use of contemporary cannabis available on the legal market of known THC/CBD composition in a mouse model of smoke exposure with readouts of lung inflammationhttps://bit.ly/3okHWS4

Marijuana induced spontaneous pneumomediastinum

Spontaneous pneumomediastinum (SPM), a rare occurrence, is defined by the presence of extraluminal gas in the mediastinum in the absence of trauma or underlying parenchymal disease. It is usually benign and has been associated with the inhalation of marijuana, cocaine, and amphetamines. The breathing maneuvers along with cyclical vomiting have been postulated as the underlying etiology. We present a case of a 27-year-old previously healthy male who presented with sudden onset chest pain and was found to have marijuana-induced pneumomediastinum.

Cannabis Abuse and Perioperative Complications Following Inpatient Spine Surgery in the United States

MINI

Due to its complicated legal status, the effects of cannabis on elective spine surgery patients have not been well studied. In this nationwide analysis, we find that cannabis abuse is associated with higher perioperative thromboembolism and neurologic complications, respiratory complications, sepsis, length of stay, hospital charges, and rates of unfavorable discharge disposition.

Gender differences in the associations of early onset poly tobacco and drug use prior to age 18 with the prevalence of adult bronchitis in the United States

PURPOSE

We investigated the associations of early onset polysubstance use prior to age 18 with the prevalence of bronchitis among U.S. adults and tested whether the associations differ by gender.

METHODS

A total of 77,950 adults, of them 2,653 with bronchitis in the past year, were from the combined 2013 and 2014 National Survey on Drug Use and Health data. The variable cluster analysis was used to classify nine variables about substance use prior to age 18 (cigarettes, cigars, smokeless tobacco, marijuana, cocaine, heroin, methamphetamines, ecstasy, and phencyclidine). Weighted multivariate logistic regression analysis (MLR) was used to examine the associations with bronchitis.

RESULTS

Nine variables were divided into two clusters: early onset poly tobacco use (three tobacco use variables) and early onset poly drug use (six drug use variables). The overall prevalence of bronchitis was 3.8% (5.1% for females and 2.3% for males). MLR analysis showed that being female, elderly (ages 65 and above), obese, and early onset poly tobacco use were associated with increased odds of bronchitis (p < 0.05). Gender-stratified analyses showed that early-onset poly tobacco use was significantly associated with bronchitis only in males, whereas early onset poly drug use was associated with bronchitis only in females. Moreover, obesity and tobacco use in the past year revealed associations with bronchitis regardless of gender.

CONCLUSIONS

Obesity, early onset poly tobacco use prior to age 18, and tobacco use in the past year were positively associated with bronchitis; furthermore, the associations of early onset polysubstance use with bronchitis differed by gender, which indicated that gender differences should be considered in developing effective prevention strategies.

The Effects of Cannabis: Implications for the Surgical Patient

Background:

Cannabis use is increasingly prevalent. Cannabinoid receptors regulate pro-inflammatory cytokines, and compounds in marijuana exert diverse physiologic effects. As more patients use cannabis, clinicians should recognize implications of perioperative cannabis use. Although the role of cannabis use in perioperative pain control has been explored, little is known about its effect on perioperative wound healing or on hematologic, pulmonary, and cardiovascular physiology.

Methods:

We searched PubMed for English-language articles related to cannabis (ie, marijuana, cannabidiol oil, and tetrahydrocannabinol) and wound healing, cardiovascular, pulmonary, or hematologic outcomes, and surgery. Titles and abstracts were reviewed, and relevant articles were analyzed. Human, animal, and pathology studies were included. Editorials, case reports, and review articles were excluded.

Results:

In total, 2549 wound healing articles were identified; 5 human studies and 8 animal/pathology studies were included. Results were conflicting. An estimated 2900 articles related to cardiovascular effects were identified, of which 2 human studies were included, which showed tetrahydrocannabinol and marijuana caused tachycardia. A total of 142 studies regarding pulmonary effects were identified. Three human studies were included, which found no difference in respiratory complications. In total, 114 studies regarding hematologic effects were identified. The 3 included human studies found conflicting venous thromboembolism risks. The overall study quality was poor. Information about dose/duration, administration route, and follow-up was reported with variable completeness.

Conclusions:

Surgeons should consider effects of cannabis in the perioperative setting. Little is known about its perioperative effects on wound healing, or on cardiovascular, pulmonary, and hematologic physiology. Further research should elucidate the effects of administration route, dose, and timing of cannabis use among surgical patients.

Multiple clinical risks for cannabis users during the COVID-19 pandemic

The pandemic caused by Sars-CoV-2 (COVID-19) has been a great concern for public and mental health systems worldwide. The identification of risk groups is essential for the establishment of preventive and therapeutic strategies, as for substance users. During COVID-19 pandemic, there was an increase in the use of psychoactive substances during the lockdown, including cannabis. This commentary reviews relevant findings and discusses scientific evidence on the risks of worse clinical and psychiatric complications due to coronavirus disease COVID-19 in subjects who use cannabis. Although they are not included as a risk group in the health recommendations for that disease, they may have a more vulnerable respiratory system to viral diseases. There are certain similarities between the harmful cardiovascular and respiratory effects of cannabis use and those of smoking. Due to the different modes of smoking, cannabis chemicals are retained in the body for longe and may also contain other toxic substances such as tar, a substance found in tobacco and which has been associated with the development of lung cancer, bronchitis and pulmonary emphysema. Therefore, we discuss if individuals who use cannabis regularly might be more vulnerable to COVID-19 infection. This population deserves more clinical attention worldwide and this manuscript can help clinicians become more aware of cannabis risks during pandemics and develop specific intervention strategies.

Cannabis use disorder and the lungs

Cannabis is one of the world's most widely used recreational drugs and the second most commonly smoked substance. Research on cannabis and the lungs has been limited by its illegal status, the variability in strength and size of cannabis cigarettes (joints), and the fact that most cannabis users also smoke tobacco, making the effects difficult to separate. Despite these difficulties, the available evidence indicates that smoking cannabis causes bronchitis and is associated with changes in lung function. The pattern of effects is surprisingly different from that of tobacco. Whereas smoking cannabis appears to increase the risk of severe bronchitis at quite low exposure, there is no convincing evidence that this leads to chronic obstructive pulmonary disease. Instead, cannabis use is associated with increased central airway resistance, lung hyperinflation and higher vital capacity with little evidence of airflow obstruction or impairment of gas transfer. There are numerous reports of severe bullous lung disease and pneumothorax among heavy cannabis users, but convincing epidemiological data of an increased risk of emphysema or alveolar destruction are lacking. An association between cannabis and lung cancer remains unproven, with studies providing conflicting findings.

Atteintes pulmonaires liées au cannabis inhalé

La relation entre cannabis et pathologies pulmonaires est difficile à établir : le cannabis est souvent fumé-mélangé à du tabac (« joint ») et les fumeurs de cannabis fument souvent aussi des cigarettes de tabac.

L’usage régulier de cannabis est un facteur de risque de bronchite chronique.

Il n’y a pas d’association significative entre inhalation de fumée de cannabis et obstruction bronchique, typique de la BPCO.

L’usage de cannabis peut augmenter le risque de sifflements thoraciques et/ou de développement d’un asthme.

L’usage régulier de cannabis est un facteur de risque de pneumopathies infectieuses, avec un risque plus élevé chez les sujets immunodéprimés et notamment les patients infectés par le VIH.

Les résultats des études épidémiologiques sur le risque de cancer bronchique chez les fumeurs de cannabis sont discordants.

Des cas de pneumothorax, pneumomédiastin, pneumopéricarde et pneumorachis ont été décrits chez les fumeurs de cannabis.

Les études épidémiologiques ne montrent pas d’association entre usage de cannabis et emphysème pulmonaire.

Les cannabinoïdes de synthèse, plus récemment introduits sur le marché, ont une toxicité importante. Ils peuvent provoquer des pneumopathies sévères et/ou une dépression respiratoire sévère.

Acute neuroradiological, behavioral, and physiological effects of nose-only exposure to vaporized cannabis in C57BL/6 mice

Objective: The rapid increase of cannabis consumption reinforces the need to elucidate the health hazards of this practice. The presence of fine particulate matter in cannabis smoke and vapor poses a major concern, as it may contribute to cardiopulmonary disease. To facilitate the assessment of risks associated with cannabis inhalation, we developed and characterized a method for exposing mice to cannabis in a way that mimics the delivery of the drug to the airways of smokers. Materials and Methods: Cannabis (10.3% THC, 0.05% CBD) was vaporized to generate aerosols with a reproducible particle profile. Aerosols were acutely delivered to male, adult C57BL/6 mice via a nose-only exposure system. Serum THC levels were measured for increasing cannabis doses. Blood pressure and heart rate were recorded at baseline and following exposure. Behavioral response to cannabis inhalation in the open field was documented. Awake neurological activity upon cannabis exposure was monitored using BOLD fMRI.Results and Discussion: Cannabis aerosols contained particles with count median diameter of 243 ± 39 nm and geometric standard deviation of 1.56 ± 0.06. Blood serum THC levels increased linearly with aerosolized mass and peaked at 136 ± 5 ng/mL. Cannabis inhalation decreased heart rate and blood pressure but promoted anxiety-like behavior. Observed differences in BOLD activation volumes linked cannabis to increased awareness to sensory stimuli and reduced behavioral arousal.Conclusions: Quantified physiological, behavioral, and neurological responses served as validation for our mouse model of cannabis inhalation. Animal models of aerosol exposure will be instrumental for uncovering the health outcomes of chronic cannabis use.

The effects of marijuana smoking on lung function in older people

BACKGROUND

Previous studies have associated marijuana exposure with increased respiratory symptoms and chronic bronchitis among long-term cannabis smokers. The long-term effects of smoked marijuana on lung function remain unclear.

METHODS

We determined the association of marijuana smoking with the risk of spirometrically defined chronic obstructive pulmonary disease (COPD) (post-bronchodilator forced expiratory volume in 1 s (FEV₁)/forced vital capacity ratio <0.7) in 5291 population-based individuals and the rate of decline in FEV₁ in a subset of 1285 males and females, aged ≥40 years, who self-reported use (or non-use) of marijuana and tobacco cigarettes and performed spirometry before and after inhaled bronchodilator on multiple occasions. Analysis for the decline in FEV₁ was performed using random mixed effects regression models adjusted for age, sex and body mass index. Heavy tobacco smoking and marijunana smoking was defined as >20 pack-years and >20 joint-years, respectively.

RESULTS

∼20% of participants had been or were current marijuana smokers with most having smoked tobacco cigarettes in addition (83%). Among heavy marijuana users, the risk of COPD was significantly increased (adjusted OR 2.45, 95% CI 1.55-3.88). Compared to never-smokers of marijuana and tobacco, heavy marijuana smokers and heavy tobacco smokers experienced a faster decline in FEV₁ by 29.5 mL·year^-1 (p=0.0007) and 21.1 mL·year^-1 (p<0.0001), respectively. Those who smoked both substances experienced a decline of 32.31 mL·year^-1 (p<0.0001).

INTERPRETATION

Heavy marijuana smoking increases the risk of COPD and accelerates FEV₁ decline in concomitant tobacco smokers beyond that observed with tobacco alone.

The Impact of Perioperative Cannabis Use: A Narrative Scoping Review

As countries progressively embrace the legalization of both medicinal and recreational cannabis, there remains a significant knowledge gap when it comes to the perioperative uses of cannabis, as well as the management of cannabis users. This review summarizes the information available on the subject based on existing published studies. Articles outlining the physiological changes occurring in the human body during acute and chronic use of cannabis (outside the context of anesthesia) are also taken into consideration as understanding these changes allows a more calculated approach to better anticipate patients' needs in the perioperative setting. Common questions facing the anesthesiologist at each phase of the perioperative period will be addressed and a systematic approach to the effect of cannabinoids on various organ systems will also be presented. Issues unique to cannabis use such as cannabis withdrawal syndrome and alterations in post-operative pain processing will also be discussed. To date, the number of studies available for guidance is small and study designs are markedly heterogenous, if not limited, making conclusions challenging. While the currently available information can assist in making decisions, further studies of larger scale are eagerly anticipated to help guide future patient care.

Medical Cannabis for the Primary Care Physician

Medical cannabis use is common in the United States and increasingly more socially acceptable. As more patients seek out and acquire medical cannabis, primary care physicians will be faced with a growing number of patients seeking information on the indications, efficacy, and safety of medical cannabis. We present a case of a patient with several chronic health conditions who asks her primary care provider whether she should try medical cannabis. We provide a review of the pharmacology of medical cannabis, the state of evidence regarding the efficacy of medical cannabis, variations in the types of medical cannabis, and safety monitoring considerations for the primary care physician.

Microbiomic differences at cancer-prone oral mucosa sites with marijuana usage

Marijuana smoke contains cannabinoids, immunosuppressants, and a mixture of potentially-mutagenic chemicals. In addition to systemic disease, it is thought to contribute to oral disease, such as tooth loss, tissue changes in the gums and throat, and possibly oral pharyngeal cancer. We used a cross-sectional study of 20 marijuana users and 19 control non-users, to determine if chronic inhalation-based exposure to marijuana was associated with a distinct oral microbiota at the two most common sites of head and neck squamous cell carcinoma (HNSCC), the lateral border of the tongue and the oral pharynx. At the tongue site, genera earlier shown to be enriched on HNSCC mucosa, Capnocytophaga, Fusobacterium, and Porphyromonas, were at low levels in marijuana users, while Rothia, which is found at depressed levels on HNSCC mucosa, was high. At the oral pharynx site, differences in bacteria were distinct, with higher levels of Selenomonas and lower levels of Streptococcus which is what is seen in HNSCC. No evidence was seen for a contribution of marijuana product contaminating bacteria to these differences. This study revealed differences in the surface oral mucosal microbiota with frequent smoking of marijuana.

Pulmonary effects of inhaled cannabis smoke

Background: The smoke generated from cannabis delivers biologically active cannabinoids and a number of combustion-derived toxins, both of which raise questions regarding the impact of cannabis smoking on lung function, airway inflammation and smoking-related lung disease.Objectives: Review the potential effects of cannabis smoking on respiratory symptoms, lung function, histologic/molecular alterations in the bronchial mucosa, smoking-related changes in alveolar macrophage function and the potential clinical impact of cannabis smoking on chronic obstructive pulmonary disease, lung cancer and pulmonary infections.Methods: Focused literature review.Results: The carcinogens and respiratory toxins in cannabis and tobacco smoke are similar but the smoking topography for cannabis results in higher per-puff exposures to inhaled tar and gases. The frequency of chronic cough, sputum and wheeze and the presence of airway mucosal inflammation, goblet cell and vascular hyperplasia, metaplasia and cellular disorganization are similar between cannabis smokers and tobacco smokers. Cannabis smoke has modest airway bronchodilator properties but of unclear clinical significance. While clear evidence exists for progression to obstructive lung disease and emphysema in chronic tobacco smokers, the effects from habitual cannabis use are less clear. Evidence suggests that alveolar macrophages from cannabis smokers have deficits in cytokine production and antimicrobial activity not present in cells from tobacco smokers.Conclusions: Solid conclusions regarding the respiratory consequences of regular cannabis smoking are difficult to make due to a relative paucity of literature, confounding by concurrent tobacco smoking and reports of conflicting outcomes. Additional well-controlled clinical studies on the pulmonary consequences of habitual cannabis use are needed.

[Cannabis and cannabinoids in palliative care]

Cannabis and cannabinoids are discussed as a potential treatment for a broad spectrum of diseases and symptoms. This article presents current evidence for the use of cannabis and cannabinoids in palliative care and delivers background information. For this purpose recent literature was examined and evaluated. The authors focused on a systematic review and meta-analysis of cannabinoids in palliative care by Mücke et al.Overall, there is no high-quality evidence for the use of cannabis and cannabinoids in palliative care. Cannabinoids may be considered as a therapeutic attempt in the treatment of cancer pain and weight gain in patients with HIV as well as other symptoms (such as nausea and loss of appetite) if established treatments fail.Further studies involving more patients are needed to evaluate the therapeutic potential of cannabis and cannabinoids. However, special conditions in the field of palliative care make it difficult to carry out high-quality studies.

Position Statement: A Pragmatic Approach for Medical Cannabis and Patients with Rheumatic Diseases

Objective.

Pain is one reason some rheumatology patients may consider use of medical cannabis, a product increasingly perceived as a safe and neglected natural treatment option for many conditions. Legalization of recreational cannabis in Canada will promote access to cannabis. Physicians must therefore provide patients with the best evidence-based information regarding the medicinal effects and harm of cannabis.

Methods.

The Canadian Rheumatology Association (CRA) mandated the development of a position statement for medical cannabis and the rheumatology patient. The current literature regarding the effects of medical cannabis for rheumatology patients was assessed, and a pragmatic position statement to facilitate patient care was developed by the Therapeutics Committee of the CRA and approved by the CRA board.

Results.

There are no clinical trials of medical cannabis in rheumatology patients. Evidence is insufficient about the benefit of pharmaceutical cannabinoids in fibromyalgia, osteoarthritis, rheumatoid arthritis, and back pain, but there is evidence of a high risk of harm. Extrapolating from other conditions, medical cannabis may provide some symptom relief for some patients. Short-term risks of psychomotor effects can be anticipated, but longterm risks have not been determined and are of concern.

Conclusion.

Despite lack of evidence for use of medical cannabis in rheumatology patients, we acknowledge the need to provide empathetic and pragmatic guidance for patient care. This position statement aims to facilitate the dialogue between patients and healthcare professionals in a mutually respectful manner to ensure harm reduction for patients and society.

Effect of marijuana smoking on pulmonary disease in HIV-infected and uninfected men: a longitudinal cohort study

BACKGROUND

Lung disease is a common comorbidity in people with HIV/AIDS, independent of smoking status. The effects of marijuana smoking on risk of lung disease in HIV-infected individuals are unclear.

METHODS

In this prospective cohort study, we quantified lung disease risk among men enrolled in the Multicenter AIDS Cohort Study (MACS), a long-term observational cohort of HIV-infected and uninfected men who have sex with men. Eligible participants were aged ≥30 years with self-reported marijuana and tobacco smoking data from biannual study visits between 1996 and 2014. Pulmonary diagnoses were obtained from self-report and medical records. Analyses were performed using Cox models and Generalized Estimating Equations adjusted for tobacco smoking, CD4 T cell count, and other risk factors.

FINDINGS

1,630 incident pulmonary diagnoses were reported among 1,352 HIV-seropositive and 1,352 HIV-seronegative eligible participants matched for race and baseline age (53,794 total person-visits, median follow-up 10.5 years). 27% of HIV-infected participants reported daily or weekly marijuana smoking for one or more years in follow-up, compared to 18% of uninfected participants (median 4·0 and 4·5 years daily/weekly use, respectively). HIV-infected participants had an increased likelihood of infectious or non-infectious pulmonary diagnoses compared to uninfected participants (33·2% vs. 21·5%, and 20·6% vs. 17·2%, respectively). Among HIV-infected participants, recent marijuana smoking was associated with increased risk of infectious pulmonary diagnoses and chronic bronchitis independent of tobacco smoking and other risk factors for lung disease (hazard ratio [95% confidence interval] 1·43 [1·09-1·86], and 1·54 [1·11-2·13], respectively); these risks were additive in participants smoking both substances. There was no association between marijuana smoking and pulmonary diagnoses in HIV-uninfected participants.

INTERPRETATION

In this longitudinal study, long-term marijuana smoking was associated with lung disease independent of tobacco smoking and other risk factors in HIV-infected individuals. These findings could be used to reduce modifiable risks of lung disease in high-risk populations.

European Pain Federation (EFIC) position paper on appropriate use of cannabis-based medicines and medical cannabis for chronic pain management

Cannabis-based medicines are being approved for pain management in an increasing number of European countries. There are uncertainties and controversies on the role and appropriate use of cannabis-based medicines for the management of chronic pain. EFIC convened a European group of experts, drawn from a diverse range of basic science and relevant clinical disciplines, to prepare a position paper to empower and inform specialist and nonspecialist prescribers on appropriate use of cannabis-based medicines for chronic pain. The expert panel reviewed the available literature and harnessed the clinical experience to produce these series of recommendations. Therapy with cannabis-based medicines should only be considered by experienced clinicians as part of a multidisciplinary treatment and preferably as adjunctive medication if guideline-recommended first- and second-line therapies have not provided sufficient efficacy or tolerability. The quantity and quality of evidence are such that cannabis-based medicines may be reasonably considered for chronic neuropathic pain. For all other chronic pain conditions (cancer, non-neuropathic noncancer pain), the use of cannabis-based medicines should be regarded as an individual therapeutic trial. Realistic goals of therapy have to be defined. All patients must be kept under close clinical surveillance. As with any other medical therapy, if the treatment fails to reach the predefined goals and/or the patient is additionally burdened by an unacceptable level of adverse effects and/or there are signs of abuse and misuse of the drug by the patient, therapy with cannabis-based medicines should be terminated.

SIGNIFICANCE

This position paper provides expert recommendations for nonspecialist and specialist healthcare professionals in Europe, on the importance and the appropriate use of cannabis-based medicines as part of a multidisciplinary approach to pain management, in properly selected and supervised patients.