The Substitution of Fifty Percent of Combustible Tobacco Smoke Exposure With Either Electronic Cigarettes or Heated tobacco Products Did Not Attenuate Acute Lung Injury in an Animal Model.

BACKGROUND: To reduce the harmful health effects of combustible cigarette smoke (CS), some (CS) users attempt to substitute CS with electronic cigarettes (ECIG) and/or heated tobacco products (HTP). In this animal study, we evaluated the acute effects of substituting CS consumption with ECIG or HTP thus mimicking the dual users' approach, on the lungs of a mouse model. METHODS: C57BL/6 mice were divided into Control, ECIG, HTP, CS, ECIG + CS, HTP + CS, and HTP + ECIG groups. Animals were exposed for 3 hours in AM and PM sessions to either air, CS, ECIG, or HTP for seven days. Lung injury was assessed by: wet to dry (W/D) ratio, albumin concentration in bronchoalveolar lavage fluid, expression of IL-1ß, IL-6, and TNF-α, histopathology examination, reactive oxygen species (ROS) production, and assessment of cellular apoptosis. RESULTS: W/D ratio was significantly increased in mice exposed to CS only. Albumin leak and expression of IL-1ß, IL-6, and TNF-a were elevated in CS, ECIG + CS, and HTP + CS. Histological examination revealed significant inflammatory cells infiltration, as well as collagen deposit in CS, ECIG + CS, HTP + CS. ROS production was significantly increased in CS, ECIG + CS, HTP + CS. Finally, cell death was also significantly increased in CS, ECIG + CS, and HTP + CS. CONCLUSION: In this animal model, substituting 50% of daily CS exposure by either ECIG or HTP exposure did not result in significant attenuation of acute lung injury.

Increased incidence of massive hemorrhage at uncommon sites after initiation of systemic anticoagulation in critically ill patients with coronavirus disease 2019 (COVID-19) infection.

BACKGROUND: The management of the Coronavirus disease 2019 (COVID-19) infected patients continues to be challenging. Critically ill COVID patients are at increased risk of serious thrombotic events and hence increased mortality. On the other side, COVID-19 patients are also showing major life-threatening bleeds, especially when systemic anticoagulation is used. Pro-coagulant propensity in critically ill COVID-19 patients have been published, but very few have described the incidence of major bleeding and its characteristics. METHODS: In this study, we retrospectively observed the incidence of major bleed in 25 critically ill COVID-19 patients admitted to the Intensive Care Unit at the American University of Beirut Medical Center. Six cases were identified and described together with their outcome. RESULTS: Major bleeding occurred in six of the 25 studied patients. Four patients were on therapeutic anticoagulation at the onset of the bleed, two required embolization for bleeding control and one died from hemorrhagic shock. Half of the described cases had unusual sites of bleeding including gluteal and abdominal wall muscles. CONCLUSIONS: A high rate of major bleeding was witnessed in our sample of critically ill patients with COVID-19 infection, with the majority being on therapeutic anticoagulation. This rate may be higher than previously reported, necessitating additional attention from the treating physician when considering empiric therapeutic anticoagulation. Moreover, the uncommon sites of bleeding shed the light on the need for additional studies in our population to identify the predisposing risk factors and mechanisms behind it.

Role of diabetes in lung injury from acute exposure to electronic cigarette, heated tobacco product, and combustible cigarette aerosols in an animal model.

BACKGROUND: Patients with diabetes are more vulnerable to the detrimental respiratory effects of combustible cigarette smoke (CS) when compared to the general population. Electronic cigarettes (ECIG) and heated tobacco products (HTP) are marketed as less harmful alternatives to CS. In this study, we compared the effects of acute ECIG, HTP and CS exposure on the lungs of type II diabetes versus non-diabetic mice in an animal model. METHODS: Type II Diabetic (Diab) and Non-Diabetic (Non-Diab) mice were divided into Control, ECIG, HTP and CS groups. Animals were exposed for 6 hrs./day to either air, ECIG, HTP or CS for seven days. Lung injury was determined by a) histopathology, b) wet to dry ratio, c) albumin concentration in bronchoalveolar lavage fluid, d) expression of TNF-α, IL-6, and IL-1 ß, e) reactive oxygen species production (ROS), and f) assessment of cellular apoptosis. RESULTS: Lung histology revealed increased edema and inflammatory cells in diabetic mice exposed to ECIG, HTP and CS. The expression of Inflammatory mediators was, in general, more significant in the Diabetic groups as well. TNF-α expression, for example, was upregulated in Diab + ECIG but not in Non-Diab + ECIG. ROS was significantly increased in Diab + CS, less in Non-Diab + CS and weakly noted in ECIG + Diab. Significant albumin leak was observed in Diab and Non-Diab HTP-exposed animals. CS exposure worsened lung injury in Diab when compared to Non-Diab mice. CONCLUSION: Comorbid medical conditions like diabetes may amplify ill effects of CS, ECIG or HTP exposure.