Lactulose Works in the Large Bowel: But How Does It Improve Hepatic Encephalopathy in a Patient Without a Large Bowel?

Introduction: Lactulose is a non-absorbable disaccharide which acts in the large bowel, and is commonly used in the treatment of hepatic encephalopathy. We present an interesting case of altered mental status due to hepatic encephalopathy successfully managed with lactulose in a patient with history of total colectomy. Case Description/Methods: A 67-year-old male with non-alcoholic cirrhosis and inflammatory bowel disease (IBD) post total proctocolectomy with a continent ileostomy known as a Kock-pouch (K-pouch) presented to the hospital with flu like symptoms and altered mental status. He was subsequently found to be positive for COVID-19. At the time of initial evaluation, the patient was obtunded with an elevated ammonia level of 91 umol/L. Colorectal surgery was consulted as the patient was not able to empty his K-pouch. Recently, he complained of inability to catheterize and with bleeding from the stoma. Initial catheterization with a Water's tube yielded 400 cc of effluent. Nasogastric tube was placed through which he was receiving lactulose 30 mg q8 hours. The patient's mental status improved within 24 hours. The patient ultimately underwent flexible pouchoscopy with endoscopic dilation and placement of a 22 French mushroom catheter for decompression of the K-pouch. Discussion(s): Lactulose is a non-absorbable disaccharide composed of galactose and fructose. The small intestine does not have the enzymes required to breakdown lactulose so it reaches the large bowel in its original form. In the large bowel, it is metabolized by colonic bacteria into monosaccharides and then to volatile fatty acids, hydrogen and methane. Lactulose decreases both the production and absorption of ammonia mainly through the presence of gut bacteria. The question arises as to how lactulose decreased ammonia levels in this patient without a large bowel. One proposed mechanism is the translocation of bacteria normally found in the large bowel to the small intestine. Small Intestinal Bacterial Overgrowth (SIBO), is a condition causing an increased number of bacteria in the small intestine. Patients with IBD and structural abnormalities are at increased risk of developing SIBO. Lactulose is commonly used in the diagnosis through the administration of lactulose and subsequent measurements of hydrogen and methane gas in expired air. This condition, in our patient with history of ulcerative colitis and colectomy, is a proposed mechanism of the efficacy of lactulose in the treatment of hepatic encephalopathy.

Aerosol Medication Use in COVID-19 Pandemic

Administration of aerolized drugs to patients diagnosed with COVID-19 leads to the risk of transmission of patient-generated infectious aerosols to healthcare providers.While the COVID-19 pandemic is ongoing, in order to provide the best treatment for patients and at the same time to protect healthcare providers at the highest level, it is necessary to increase access to information and pay maximum attention to preventive measures.Copyright © 2020 Bilimsel Tip Yayinevi. All rights reserved.

The Relationship between Wearing Protective Masks and Poor Oral Health

Since the beginning of the COVID-19 pandemic, the number of people wearing masks in everyday life has increased. At the same time, there has been a noticeable rise in the amount of patients with bad breath (foe-tor ex ore), gingivitis, caries, and xerostomia. The appearance of these symptoms and diseases caused by wearing a mask is designated by the term mask mouth. The aim of this article is to establish the link between wearing protective masks and deteriorating oral health. From the conducted research, it has been es-tablished that wearing a surgical mask over a long period of time leads to reduced air exchange in the mask and "recycling" of exhaled air. This leads to inhalation of air with increased CO2 content and increase in pCO2 in the blood, which is subsequently compensated by rapid and deep breathing in most cases through the mouth. The goal is to exhale the accumulated CO2. As the mask reduces air exchange, the level of CO2 in the mask remains relatively high. Prolonged breathing through the mouth often leads to xerostomia. Saliva is known to have protective functions against the development of bacteria in the oral cavity through its an-tibacterial properties. Xerostomia can be a prerequisite for the development of various diseases of bacterial origin, such as gingivitis. Furthermore, oral respiration leads to an increase in temperature and CO2 in the air in the mask and a decrease in pH in the oral cavity, which are optimal conditions for biofilm formation, plaque buildup, development of most bacteria, e.g., S. mutans, which is the main cause of caries.Copyright © 2022, Bulgarian-American Center. All rights reserved.

SAVES US: Suppression of Airborne Viral Epidemic Spread by Ultraviolet light barriers

Despite the gradual return to pre-pandemic conditions, the spreading of COVID-19 (SARS-CoV-2) left several open issues. Nowadays it is know that airborne infections, including COVID-19, are conveyed by particles having the size of >5 mum (droplets) and <5 mum (droplets nuclei), ejected by coughing and sneezing [1]. While droplets undergo to dehydration and precipitation, droplet nuclei persist in air for long time after their ejection, contributing to infection spreading. Actual prevention strategies are based on non-pharmaceutical interventions act to reduce droplets diffusion and spacing from Personal Protective Equipment, such as facial masks, and social distancing measure. Nevertheless, for the new endemic phase of COVID-19 the development of new strategies for airborne infections' containment becomes unavoidable. In this project, we propose a new device for the suppression of Airborne Viral Aerosols designed to work in situations with constrained geometries (e.g. public transportation, offices, waiting rooms etc.) not allowing social distancing. The device, devised to perform photokilling of viral aerosols in air in presence of humans, has its core in an UV illumination system operating at 222 nm. It is know from literature that UV radiation alters the genetic material of viruses and bacteria whose maximum absorption wavelengths are in the far-UV range (UVC, 100-280 nm), the most effective for sterilization [2]. Differently from the operative wavelength of most commercial systems (254 nm), the higher tissue absorption prevents the 222 nm radiation to travel over the very first epidermal layers [3] constituting a minor health risk for applications in presence of people. The device combines the UV illumination system with a vertical flux of air that conveys exhaled particles to the light source and controls humidity and temperature, crucial parameters for virus diffusion. After its development, the device prototype will be tested in model experiments. Initially, its safety will be verified by monitoring in particular the UVC-induced ozone production. Then, in vitro photokilling experiments will be performed in two steps: (i) on a layer of immobilized SARS-Cov-2 virus act to obtain optimal UV doses for an effective sterilization;(ii) on SARS-Cov-2 aerosol models. For this last experiment, a model viral aerosol miming the characteristics of cough and sneeze particles will be preliminary studied and supported by synthetic data to characterize the optical properties of the reference scenario. The resulting information will be crucial for the final design of the device itself. As a last step, we will test the device in in vivo experiments. An air flux, harvesting exhaled air by infected mice, will be illuminated by the device and will be sent to healthy mice. Finally, the infectiveness of exhaled air after the UV treatment will be evaluated, providing more information for further applications in the presence of humans.Copyright © 2023

SARS-CoV-2 RNA in exhaled air of hospitalized COVID-19 patients

Knowledge about contagiousness is key to accurate management of hospitalized COVID-19 patients. Epidemiological studies suggest that in addition to transmission through droplets, aerogenic SARS-CoV-2 transmission contributes to the spread of infection. However, the presence of virus in exhaled air has not yet been sufficiently demonstrated. In pandemic situations low-tech disposable and user-friendly bedside devices are required, while commercially available samplers are unsuitable for application in patients with respiratory distress. We included 49 hospitalized COVID-19 patients and used a disposable modular breath sampler to measure SARS-CoV-2 RNA load in exhaled air samples and compared these SARS-CoV-2 RNA load of combined nasopharyngeal throat swabs and saliva. Exhaled air sampling using the modular breath sampler has proven to be feasible in a clinical COVID-19 setting and demonstrated viral detection in 25% of the patients (Figure 1).

The role of surfactant lipid composition in the aftermath of covid-19 infection among patients treated in intensive care

Background: SARS-CoV-2 displays high affinity for ACE2 receptors, expressed on type 2 alveolar cells. These cells produce pulmonary surfactant - a crucial thin layer of surface-active lipid rich fluid - fundamental for proper gas exchange. Aims and objectives: To investigate changes in surfactant lipid composition and the relationship to prolonged symptoms of post covid-19 among patients treated in intensive care unit for covid-19 infection. Method(s): Patients (n=43, 17 female, aged 44-80 years) treated in an intensive care unit with covid-19 infection in average six months prior to enrollment were recruited. Particles in exhaled air were collected with PExA-instrument (PExA AB) and we also conducted body plethysmograph and diffusion capacity of the lungs for carbon monoxide. Twenty-two healthy, non-infected, age- and gender-matched controls were also enrolled. Lipids were analysed using liquid chromatography with a triple quadrupole mass spectrometer. Statistical analyses were performed with Qlucore. Result(s): Preliminary results suggest a significant change in the composition of surfactant lipids. Analysis show significant reductions of all measured phosphatidyl-glycerols (PG, n=14) an increase of all measured phosphatidyl- inositols (PI, n=4), e.g. PG 18:1-18:1 22 % lower (p<0.001, q=0.04) and PI:16:0:18:1 67% higher (p<0.001, q=0.0003) among the post-covid patients compared to controls. Conclusion(s): Our findings suggest that surfactant composition is altered also in the recovery phase after covid-19 infection which could be a key component in the post-covid syndrome with lingering effects on the respiratory system.

Expiratory filter sets substantially reduce exhaled small bioaerosol particles and potential COVID-19 virus load

Aim/Introduction: Airborne infections are particularly challenging for in-patient care units. In general, hospitals take more precautions to prevent airborne spread of diseases and several guidelines recommend expiratory filters during nebulizer therapies to reduce exhaled bioaerosols. However, a substantial reduction of virusloaded aerosols depend on a high filter performance for particles 100 -500nm in size. This study aimed to test the effectiveness of filter pads in the reduction of exhaled aerosols by applying 99mTclabeled graphite aerosol. Material(s) and Method(s): In 37 patients with suspected pulmonary embolism or CTEPH an inhalation scintigraphy was performed with 99mTc-labeled graphite aerosol (Technegas ©, particle size 30 -60nm ). The exhalate was filtered by a PARI filter/valve set equipped with a PARI filter pad and then collected in a plastic bag reservoir. Count rates of the filter pads and reservoirs were estimated by planar imaging within a SPECT/ CT. In addition, the individual volumes of the exhaled air were determined. The percentage filter efficacy of the filter pads was calculated. Finally, correlational statistics (Spearman's correlation) addressing the following interactions were performed: (1) exhalate volume and count rates of the filter pads, (2) filter pads' count rates and filter retention efficacy, and (3) exhaled breath volume and filter retention efficacy. Result(s): Mean count rates of the filter pads and the reservoirs containing the filtered exhalate were 26023 +/- 8327 cts/s and 169 +/- 153 cts/s, respectively. The efficacy of the PARI filter/ valve set with PARI filter pad was 98.5 +/- 0.9% (range 96.2 -99.7%). The mean exhaled volume was 9.5 +/- 4.6 l (range 2.4 -21.0 l). The exhalate volumes positively correlate with the filter pad count rates (p=0.006) which, in turn, negatively correlate with the filter pad efficacy (p=0.04). However, an inter-relation of exhaled breath volume and filter pad efficacy failed to reach significance (p=0.07). Conclusion(s): The filter pad of the PARI filter/valve set demonstrated a high retention rate of aerosol particles < 100nm in size. Therefore, in patients suffering from respiratory infections these filter pads used in expiratory filters are suitable to substantially reduce airborne virus load, e.g. COVID-19 SARS CoV2, in their exhalates. Additionally, we found evidence that the filter retention efficacy decreased with increased filter particle load indicating a need for regular filter changes.

Changes in surfactant lipid composition 6 months after severe Covid-19

Background: SARS-CoV-2 displays high affinity for ACE2 receptors as a vector of pathogenesis. ACE2 receptors are highly expressed on surfactant producing type 2 alveolar cells. These cells produce pulmonary surfactant - a crucial thin layer of surface-active fluid mainly composed of lipids, lining the alveolar epithelial surface. The main function, to reduce the surface tension, is fundamental for proper gas exchange. Aims and Objectives: To investigate changes in surfactant lipid composition and the relationship to longstanding symptoms of post Covid-19 among patients treated in intensive care for Covid-19 infection. Methods: We recruited 43 patients (17 women, aged 44-80 years) who had previously been treated in ICU in a major Swedish hospital, in average 6 months before inclusion. The participants answered a questionnaire regarding symptoms, we collected particles in exhaled air with PExA-instrument (PExA AB) and conducted pulmonary function tests, body plethysmography, and diffusion capacity of the lungs for carbon monoxide. Twenty-two healthy, non-infected, ageand gender-matched controls were enrolled. Lipids were analysed using liquid chromatography with a triple quadrupole mass spectrometer. Statistical analyses were performed with Qlucore. Results: Early results suggest a significant change in the composition of surfactant lipids among post-Covid -19 patients treated in intensive care compared to controls. Early analysis show significant reductions of all measured phosphatidyl-glycerols (PG, n = 14) an increase of all measured phosphatidyl-inositols (PI, n = 4), for example were PG 18:1-18:1 22% lower (p < 0.001, q = 0.04) and PI:16:0:18:1 67% higher (p < 0.001, q = 0.0003) in subjects post-Covid compared to controls. Conclusions: Our findings suggest that surfactant composition is altered also in the recovery after Covid-19 infection, which could be a key component in the post-Covid syndrome and the lingering effects on the respiratory system.