The Effects of Endogenous Cannabinoids on the Mammalian Respiratory System: A Scoping Review of Cyclooxygenase-Dependent Pathways.

Introduction: The endogenous cannabinoid (endocannabinoid) system is an emerging target for the treatment of chronic inflammatory disease with the potential to advance treatment for many respiratory illnesses. The varied effects of endocannabinoids across tissue types makes it imperative that we explore their physiologic impact within unique tissue targets. The aim of this scoping review is to explore the impact of endocannabinoid activity on eicosanoid production as a measure of human airway inflammation. Methods: A scoping literature review was conducted according to PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews) guidelines. Search strategies using MeSH terms related to cannabinoids, eicosanoids, cyclooxygenase (COX), and the respiratory system were used to query Medline, Embase, Cochrane, CINAHL, Web of Science, and Biosis Previews in December 2021. Only studies that investigated the relationship between endocannabinoids and the eicosanoid system in mammalian respiratory tissue after 1992 were included. Results: Sixteen studies were incorporated in the final qualitative review. Endocannabinoid activation increases COX-2 expression, potentially through ceramide-dependent or p38 and p42/44 Mitogen-Activated Protein Kinase pathways and is associated with a concentration-dependent increase in prostaglandin (PG)E2. Inhibitors of endocannabinoid hydrolysis found either an increase or no change in levels of PGE2 and PGD2 and decreased levels of leukotriene (LT)B4, PGI2, and thromboxane A2 (TXA2). Endocannabinoids increase bronchial epithelial cell permeability and have vasorelaxant effects in human pulmonary arteries and cause contraction of bronchi and decreased gas trapping in guinea pigs. Inhibitors of endocannabinoid hydrolysis were found to have anti-inflammatory effects on pulmonary tissue and are primarily mediated by COX-2 and activation of eicosanoid receptors. Direct agonism of endocannabinoid receptors appears to play a minor role. Conclusion: The endocannabinoid system has diverse effects on the mammalian airway. While endocannabinoid-derived PGs can have anti-inflammatory effects, endocannabinoids also produce proinflammatory conditions, such as increased epithelial permeability and bronchial contraction. These conflicting findings suggest that endocannabinoids produce a variety of effects depending on their local metabolism and receptor agonism. Elucidation of the complex interplay between the endocannabinoid and eicosanoid pathways is key to leveraging the endocannabinoid system as a potential therapeutic target for human airway disease.

Understanding abdominal pelvic computerized tomography scan usage amongst adolescent blunt trauma patients treated at adult trauma centers.

INTRODUCTION: The algorithm for evaluating adolescent patients with blunt trauma includes abdominal pelvic CT (APCT). The aim of this study is to evaluate the utility of APCT in this context. METHODS: We performed a retrospective review of adolescent (11 to 18 years of age) blunt trauma patients at an urban adult level 1 trauma center from January 2015 to December 2019. The primary outcome was the prevalence of positive findings on APCT scan.  Additionally, clinical risk factors concerning for intra-abdominal injury were analyzed. RESULTS: There were 546 patients evaluated for blunt trauma and the prevalence of APCT within the population was 59.3% (95% CI 54.2%-64.9%). Of the patients who received APCT, 123 (37.9%) had positive findings on APCT. Only 25 patients (7.7% of those who underwent APCT) required abdominal surgery while 40 patients (12.3%) had intraabdominal injury that did not require surgery. Risk factors were present in 100% of patients with intraabdominal injury and absent in 28.7% of patients without intraabdominal injury. Abnormal abdominal exam, abnormal FAST, positive chest x-ray and elevated transaminases were independently associated with intraabdominal injury. CONCLUSIONS: Our study found that adolescent blunt trauma patients treated at our trauma center had a higher rate of APCT usage, but a comparable rate of positive findings when compared with the most recent literature. Future studies should focus on reducing the number of patients who undergo APCT despite an absence of clinical risk factors.

Cervical Spine Computed Tomography in Adolescent Blunt Trauma Patients: Are They Being Overutilized?

INTRODUCTION: Cervical spine computed tomography (CSCT) scans are used to evaluate cervical spine traumatic injuries; however, recent evidence demonstrates that adult trauma centers (ATCs) overutilize CSCT when evaluating adolescent patients. This leads to unnecessary radiation exposure. The aim of this study is to review a level 1 ATC's use of CSCT in the adolescent blunt trauma population. METHODS: A retrospective chart review was conducted of a level 1 ATC's trauma database. Blunt trauma patients between the ages of 11 and 18 who receive a CSCT between January 2015 to December 2019 were included. The primary outcome was the prevalence of positive findings on CSCT scans. Data were analyzed using Fischer-Exact analysis and multivariate logistic regression where appropriate. RESULTS: Three-hundred thirty-seven of 546 (61.7%) adolescent blunt trauma patients received CSCT. Of those, 68.2% (230) were male; the mean age was 16.6 ± 1.0 y old. Twenty-eight patients (8.3%) had a positive finding on CSCT. All patients with a positive CSCT failed the National Emergency X-Radiography Utilization study (NEXUS) criteria while 123 patients (36.5%) with a negative CSCT met NEXUS criteria. CONCLUSIONS: CSCT was overutilized in our trauma center. There is a low positive CSCT scan rate among adolescent patients, which aligns with the current literature. All patients with positive CSCT passed NEXUS criteria suggesting that a quality improvement project focusing on the use of the NEXUS criteria to assess the risk of cervical spine injury could potentially reduce the use of CSCT scans by nearly 40%.