The Antimicrobial Properties of Cannabis and Cannabis-Derived Compounds and Relevance to CB2-Targeted Neurodegenerative Therapeutics.

Cannabinoid receptor 2 (CB2) is of interest as a much-needed target for the treatment or prevention of several neurogenerative diseases. However, CB2 agonists, particularly phytocannabinoids, have been ascribed antimicrobial properties and are associated with the induction of microbiome compositional fluxes. When developing novel CB2 therapeutics, CB2 engagement and antimicrobial functions should both be considered. This review summarizes those cannabinoids and cannabis-informed molecules and preparations (CIMPs) that show promise as microbicidal agents, with a particular focus on the most recent developments. CIMP-microbe interactions and anti-microbial mechanisms are discussed, while the major knowledge gaps and barriers to translation are presented. Further research into CIMPs may proffer novel direct or adjunctive strategies to augment the currently available antimicrobial armory. The clinical promise of CIMPs as antimicrobials, however, remains unrealized. Nevertheless, the microbicidal effects ascribed to several CB2 receptor-agonists should be considered when designing therapeutic approaches for neurocognitive and other disorders, particularly in cases where such regimens are to be long-term. To this end, the potential development of CB2 agonists lacking antimicrobial properties is also discussed.

Proposed delay for safe surgery after COVID-19.

BACKGROUND: Long-term effects after COVID-19 may affect surgical safety. This study aimed to evaluate the literature and produce evidence-based guidance regarding the period of delay necessary for adequate recovery of patients following COVID-19 infection before undergoing surgery. METHODS: A rapid review was combined with advice from a working group of 10 clinical experts across Australia and New Zealand. MEDLINE, medRxiv and grey literature were searched to 4 October 2020. The level of evidence was stratified according to the National Health and Medical Research Council evidence hierarchy. RESULTS: A total of 1020 records were identified, from which 20 studies (12 peer-reviewed) were included. None were randomized trials. The studies comprised one case-control study (level III-2 evidence), one prospective cohort study (level III-2) and 18 case-series studies (level IV). Follow-up periods containing observable clinical characteristics ranged from 3 to 16 weeks. New or excessive fatigue and breathlessness were the most frequently reported symptoms. SARS-CoV-2 may impact the immune system for multiple months after laboratory confirmation of infection. For patients with past COVID-19 undergoing elective curative surgery for cancer, risks of pulmonary complications and mortality may be lowest at 4 weeks or later after a positive swab. CONCLUSION: After laboratory confirmation of SARS-CoV-2 infection, minor surgery should be delayed for at least 4 weeks and major surgery for 8-12 weeks, if patient outcome is not compromised. Comprehensive preoperative and ongoing assessment must be carried out to ensure optimal clinical decision-making.

Aerosolisation in endonasal endoscopic pituitary surgery.

PURPOSE: To determine the particle size, concentration, airborne duration and spread during endoscopic endonasal pituitary surgery in actual patients in a theatre setting. METHODS: This observational study recruited a convenience sample of three patients. Procedures were performed in a positive pressure operating room. Particle image velocimetry and spectrometry with air sampling were used for aerosol detection. RESULTS: Intubation and extubation generated small particles (< 5 µm) in mean concentrations 12 times greater than background noise (p < 0.001). The mean particle concentrations during endonasal access were 4.5 times greater than background (p = 0.01). Particles were typically large (> 75 µm), remained airborne for up to 10 s and travelled up to 1.1 m. Use of a microdebrider generated mean aerosol concentrations 18 times above baseline (p = 0.005). High-speed drilling did not produce aerosols greater than baseline. Pituitary tumour resection generated mean aerosol concentrations less than background (p = 0.18). Surgical drape removal generated small and large particles in mean concentrations 6.4 times greater than background (p < 0.001). CONCLUSION: Intubation and extubation generate large amounts of small particles that remain suspended in air for long durations and disperse through theatre. Endonasal access and pituitary tumour resection generate smaller concentrations of larger particles which are airborne for shorter periods and travel shorter distances.

COVID-19 risk in elective surgery during a second wave: a prospective cohort study.

BACKGROUND: The COVID-19 pandemic has greatly affected access to elective surgery, largely because of concerns for patients and healthcare workers. A return to normal surgery workflow depends on the prevalence and transmission of coronavirus in elective surgical patients. The aim of this study was to determine the prevalence of active SARS-coronavirus-2 infection during a second wave among patients admitted to hospital for elective surgery in Victoria. METHODS: Prospective cohort study across eight hospitals in Victoria during July-August 2020 was conducted enrolling adults and children admitted to hospital for elective surgery or interventional procedure requiring general anaesthesia. Study outcomes included a positive polymerase chain reaction (PCR) test for SARS-CoV-2 in the preoperative period (primary outcome), and for those with a negative test preoperatively, the incidence of a positive PCR test for SARS-CoV-2 in the post-operative period. RESULTS: We enrolled 4965 elective adult and paediatric surgical patients from 15 July to 31 August 2020. Four patients screened negative on questionnaire but had a positive PCR test for coronavirus, resulting in a Bayesian estimated prevalence of 0.12% (95% probability interval 0-0.26%). There were no reports of healthcare worker infections linked to elective surgery during and up to 2 weeks after the study period. CONCLUSION: The prevalence of SARS-CoV-2 in asymptomatic elective surgical patients during a second wave was approximately 1 in 833. Given the very low likelihood of coronavirus transmission, and with existing current hospital capacity, recommencement of elective surgery should be considered. A coronavirus screening checklist should be mandated for surgical patients.