Impacts of a fraction of inspired oxygen adjustment protocol in COVID-19 patients under mechanical ventilation: A prospective cohort study

OBJECTIVE

We examined weather a protocol for fraction of inspired oxygen (FiO₂) adjustment can reduce hyperoxemia and excess oxygen use in COVID-19 patients mechanically ventilated.

DESIGN

Prospective cohort study.

SETTING

Two intensive care units (ICUs) dedicated to COVID-19 patients in Brazil.

PATIENTS

Consecutive patients with COVID-19 mechanically ventilated.

INTERVENTIONS

One ICU followed a FiO₂ adjustment protocol based on SpO₂ (conservative-oxygen ICU) and the other, which did not follow the protocol, constituted the control ICU.

MAIN VARIABLES OF INTEREST

Prevalence of hyperoxemia (PaO₂>100mmHg) on day 1, sustained hyperoxemia (present on days 1 and 2), and excess oxygen use (FiO₂>0.6 in patients with hyperoxemia) were compared between the two ICUs.

RESULTS

Eighty two patients from the conservative-oxygen ICU and 145 from the control ICU were included. The conservative-oxygen ICU presented lower prevalence of hyperoxemia on day 1 (40.2% vs. 75.9%, p<0.001) and of sustained hyperoxemia (12.2% vs. 49.6%, p<0.001). Excess oxygen use was less frequent in the conservative-oxygen ICU on day 1 (18.3% vs. 52.4%, p<0.001). Being admitted in the control ICU was independently associated with hyperoxemia and excess oxygen use. Multivariable analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FiO₂ use and adverse clinical outcomes.

CONCLUSIONS

Following FiO₂ protocol was associated with lower hyperoxemia and less excess oxygen use. Although those results were not associated with better clinical outcomes, adopting FiO₂ protocol may be useful in a scenario of depleted oxygen resources, as was seen during the COVID-19 pandemic.

"Vaccinate your child for best protection": attitude towards vaccination in a group of pregnant women

BACKGROUND

Although the benefits and importance of vaccination before and right after pregnancy, are well known, vaccination coverage among pregnant women remains very low. The aim of our study was to evaluate pregnant women's knowledge and attitude towards vaccination.

STUDY DESIGN

A cross sectional study was performed from October 2018 to June 2019 at the University of Messina.

METHODS

We gave pregnant women >18 years old a non-self-compiling paper questionnaire. We stratified the sample according to age (<30 and >30 years old), marital status (single/divorced, in a relationship and married) and level of education (<8 and >8 years of school attendance). All possible correlations between collected data were analysed using software R.

RESULTS

The sample included 156 women (mean age 32±0.49 years old). Only 1.4% of the subjects were aware of all the vaccines indicated for children. Luckily, 86.7% of the sample had a positive attitude, believing in the effectiveness and safety of immunization, despite a limited lack of confidence and a belief in false myths was expressed by some of the subjects. Interestingly, results showed that information about vaccination were more frequently obtained from family/friends (52.6%), mass media (49.1%), blogs/forums (19.3%), rather than from medical institutions (only 17.5%) or the family physician (only 35.0%), reflecting the quality of the information obtained.

CONCLUSIONS

Our results proved that a general positive attitude emerged among our sample towards vaccination, however, correct information was not always provided to women, making it a crucial issue for public health in the future.

The role of water distribution system in HCAIs

Introduction

The water distribution system in hospitals may constitute a source of healthcare-associated infections. Understanding the means of acquisition, sources and reservoirs of nosocomial pathogens is crucial for developing methods to reduce the incidence of nosocomial infections. The aim of our study was to evaluate the microbiological contamination by Pseudomonas aeruginosa in the water system of the University Hospital “G. Martino” in Messina over a period of nine years, in order to a) clarify possible relationship between the presence of aerators and contamination, b) to highlight the presence of a yearly variation and c) to verify the statistical difference between microbiological contamination of taps with and without filters.

Materials and

Methods

We carried out a retrospective study for nine year through the collection of water samples that were analysed for total bacteria count and Pseudomonas aeruginosa. The differences between the results recorded over the nine-year study period were evaluated using variance analysis. P values of &lt; 0.05 were considered statistically significant. Software R was used for statistical assessment.

Results

We analysed a total of 6168 samples with a positive rate of 9.31% and a decreasing trend over the nine years to a value of 2.44% (p &lt; 0.001), due to the elimination of the aerators of taps without filters and also to the introduction of filters in taps of high-risk wards and surgical rooms. We found statistical difference between taps with or without filter (p &lt; 0.001) and a higher positive rate during the summer season compared to the other months. Also, an increase of the positivity rate was detected in some year due to the lack of monthly replacement of the filter.

Conclusions

These results reveal a high level of contamination of taps by opportunistic bacteria with severe implications especially for high-risk settings and therefore, the need to improve the management of these devices.

Key messages

Particular attention must be reserved to the water distribution systems in hospitals in order to prevent the spread of healthcare associated infections. The continued application and strengthening of guidelines and procedures is essential to limit the spread of multidrug resistant pathogens.

Effects of aerators, filters and chlorination on contamination of water samples: a nine years study in a Southern University Hospital

OBJECTIVES

The aim of our study was to evaluate the microbiological contamination by Pseudomonas aeruginosa in the water system of the University Hospital "G. Martino" in Messina over a period of nine years, in order to a) clarify possible relationship between the presence of aerators and contamination, b) to highlight the presence of a yearly variation and c) to verify the statistical difference between microbiological contamination of taps with and without filters.

MATERIAL AND METHODS

We carried out our study between January 2010 and December 2018 through the collection of water samples that were analysed for total bacteria count and Pseudomonas aeruginosa. The differences between the results recorded over the nine-year study period were evaluated using variance analysis. P values of <0.05 were considered statistically significant. Software R was used for statistical assessment.

RESULTS

We analysed a total of 6168 samples with a positive rate of 9.31% and a decreasing trend over the years to a value of 2.44% (p<0.001), due to the elimination of the aerators of taps without filters and also to the introduction of filters in taps of high-risk wards and surgical rooms. We found statistical difference between taps with or without filter (p<0.001) and a higher positive rate during the summer season compared to the other months.

CONCLUSIONS

These results reveal a high level of contamination of taps by opportunistic bacteria with severe implications especially for high-risk settings and therefore, the need to improve the management of these devices.

Drug-resistant bacteria on hands of healthcare workers and in the patient area: an environmental survey in Southern Italy's hospital

OBJECTIVE

Drug-resistant bacteria on hands of healthcare workers and in the patient area: an environmental survey in Southern Italy's hospital.

METHODS

The study was conducted from June 2017 to May 2018 using contact slides for surfaces and active sampling for air. We used automated biochemical methods to identify microorganisms; antibiograms were performed in compliance with the EUCAST expert rules.

RESULTS

We analyzed 3,760 samples, 16.17% were found positive and 34 % of these were antimicrobial-resistant. On analyzing the isolated Staphylococci, 39% were multidrug-resistant and 5% extensively drug-resistant. A 30% of the Enterococcus faecalis isolates were resistant to gentamycin and vancomycin. We found Klebsiella pneumoniae isolates resistant to ceftriaxone, cefoxitin, mecillinam and imipenem. A 7% and 8% of the Acinetobacter baumannii and Pseudomonas aeruginosa isolates, respectively, were resistant to gentamicin, imipenem, and ceftazidime.

CONCLUSIONS

These findings are in line with the international literature, confirming that antimicrobial resistance is also steadily growing in Italy with rates varied for the different pathogens.

Surface enhanced Raman scattering, electronic spectrum and Mulliken charge distribution in the normal modes of bis(diethyldithiocarbamate)zinc(II) complex

Surface-enhanced Raman scattering (SERS) was used to study the interactions of the normal modes of the bis(diethyldithiocarbamate)zinc(II) complex, [Zn(DDTC)2], on nano-structured silver surfaces. The electronic spectrum of this complex was measured and the charge transfer bands were assigned through the TD-PBE1PBE procedure. To see the electronic dispersion, the Mulliken electronic charges were calculated for each normal mode and correlated with the SERS effect. Full assignment of the SERS spectra was also supported by carefully analysis of the distorted geometries generated by the normal modes.

In vitro treatment with killed Helicobacter pylori downregulates the production of RANTES by peripheral blood mononuclear cells

The mechanisms by which Helicobacter pylori colonizes and persists within the gastric mucosa are poorly understood. The gastric immune response observed in vivo during H. pylori infection, is characterized by a polarization of Th1 cell type that seems to be responsible for gastric pathology. The purpose of this study was to test the direct effect of H. pylori cagA(+)/vacA(+ )(live and/or gentamicin-killed) on human peripheral blood mononuclear cells (PBMCs) in order to evaluate the production of regulated activation normal T cell expressed and secreted (RANTES) in vitro. We also evaluated the possible relationship between RANTES release and the presence of IL-12 and IFN-gamma in supernatants of the same cells. In the present study, we show for the first time that the low amount of RANTES in supernatants of PBMC incubated with killed H. pylori is linked, at least in part, to the inhibition of IL-12 and IFN-gamma release.

Echocardiographic characteristics of patients with sickle cell anaemia in Sergipe, Brazil

This study describes the cardiac size and function of patients with sickle cell anaemia, in Segipe, Brazil, and its association to the clinical severity, duration of illness and haemoglobin levels. Heart measurements were obtained by echocardiography from 38 children and adolescents and compared to international reference values. Sickle cell patients had increased left atrial and ventricular dimensions in systole and an increased end diastolic septal and left ventricular free wall thickness. These findings correlated with age. There were no abnormalities in the ejection or shortening fractions. These results suggest early haemodynamic changes with progressive cardiac chamber dilation and diastolic dysfunction that become increasingly abnormal with growth.

Comparative effect of gentamicin and pefloxacin treatment on the late stages of mouse typhoid

The present study compares the ability of gentamicin and pefloxacin to eradicate a Salmonella infection in BALB/c mice when the treatment is instituted in the late stages of the infection. The results indicate that pefloxacin is highly effective in the treatment of mouse typhoid even when the therapy is instituted after the suppression of bacterial growth in the reticuloendothelial system (RES). Conversely, gentamicin treatment only reduced the bacterial load in the RES of infected mice, but neither induced the clearance of the organisms from the RES, nor prevented the resurgence of bacterial growth. Even when using gentamicin at a high dosage, bacterial clearance could not be accomplished.

Immunobiological activities of mould products: functional impairment of human monocytes exposed to aflatoxin B1

In order to elucidate the effects upon the human immune system of aflatoxin B1 produced by the food-contaminating mould Aspergillus flavus, phagocytosis, microbicidal activity, superoxide production and intrinsic antiviral activity were studied in monocytes exposed to aflatoxin B1 for different times at concentrations ranging from 0.1 to 1 pg/ml. Phagocytosis and microbicidal activity were significantly impaired (p < 0.05) by aflatoxin B1 at doses as low as 0.1 pg/ml. However, pretreatment of monocytes with aflatoxin B1 did not modify intrinsic antiviral activity or superoxide production. These results confirmed data obtained from animals fed with mycotoxin-contaminated foods. The potential danger to human health of exposure to mycotoxins demonstrates the necessity for careful microbiological control of food.

Functional impairment of rat Kupffer cells induced by aflatoxin B1 and its metabolites

Contamination of food with mycotoxins is a major health problem. Impairment of several immune functions has been repeatedly reported in animals fed with contaminated fodder. Since the liver is a major target of toxicity by aflatoxins, the effects of aflatoxins B1, and its hepatic metabolites Q1 and M1 on Kupffer cell function was investigated in vitro. Aflatoxin B1 induced significant (P < 0.05) inhibition of phagocytosis, intracellular killing of Candida albicans, and intrinsic anti-Herpes virus activity at concentrations as low as 0.01 pg ml-1. Aflatoxin Q1 and M1 had similar effects on phagocytosis and microbicidal activity, but were two- to ten-fold less potent than aflatoxin B1.

Cellular uptake and activity of rufloxacin in different cell types and professional phagocytic cells

The penetration of the new quinolene rufloxacin into human professional phagocytic cells and different cell types was determined. The intracellular distribution was demonstrated in all cells studied. At 4 degrees C the transport of rufloxacin was reduced. An intracellular dose-dependent activity was demonstrated for rufloxacin in monocytes and granulocytes infected with E. coli and S. aureus. In all the experiments rufloxacin was able to eliminate all intracellular bacteria.

Effects of rufloxacin in Salmonella typhimurium infection in mice

This study was undertaken to investigate the efficacy of rufloxacin, a new quinolone which is interesting due to its pharmacokinetics characterized by a long plasma half-life, in the treatment of systemic salmonella infections in the mouse typhoid model. Innately susceptible BALB/c and resistant CBA mice were used to investigate the efficacy of rufloxacin in controlling systemic salmonella infections when given for brief or prolonged periods. The present study shows that rufloxacin is not only very effective on both mouse strains, but can completely eradicate the salmonellae from livers and spleens when given early in the infection of CBA resistant mice.

Serum TNF alpha in mouse typhoid and enhancement of a Salmonella infection by anti-TNF alpha antibodies

Tumour necrosis factor alpha (TNF alpha) was detected by the L929 cell assay in the sera of mice 1 h after large i.v. inocula of virulent Salmonella typhimurium C5. TNF alpha was not detectable in sera from innately susceptible BALB/c mice during the course of a lethal infection commencing from a low inoculum, or from resistant A/J mice during the course of a lethal or sublethal infection, but only 1 h after i.v. challenge with large numbers of organisms. Administration of a single dose of rabbit polyclonal anti-TNF alpha antiserum on day 1 had no effect on the early course of a lethal infection in A/J mice. However, the same treatment exacerbated a sublethal infection in A/J mice. Anti-TNF alpha treatment did not accelerate the early bacterial net growth rate in the RES. Instead, the cfu count in treated mice continued to increase past the point at which the host response suppressed a further increase in bacterial numbers (the plateau phase) in normal controls. A second dose of anti-TNF alpha antiserum on day 4 together with a higher but still sublethal challenge caused a lethal infection in A/J mice. The results indicate that TNF alpha is important in mediating the plateau phase in a salmonella infection, and its effect may be local.

Effect of aflatoxins on rat peritoneal macrophages

Phagocytosis, intracellular killing of Candida albicans, and superoxide production by rat peritoneal macrophages exposed to aflatoxins B1, B2, G1, G2, B2a, and M1 at several times and concentrations were analyzed to evaluate the intensity of a depressive effect for each mycotoxin. All aflatoxins used at very low concentrations had a depressive effect on the functions of macrophages. The biggest impairment of phagocytosis, intracellular killing, and spontaneous superoxide production was observed in macrophages exposed to aflatoxins B1 and M1.

[Endomyocardial fibrosis: surgical treatment]

The authors analyse the experience acquired for surgical treatment of endomyocardiofibrosis. Among the 15 patients submitted to the operation, nine had the biventricular form, four had the disease in the right ventricle and two only in the left ventricle. The surgery consisted of endocardioectomy of the ventricles (RV--04,LV--02, bilateral--08) and replacement of the diseased atrioventricular valves (mitral--02, tricuspid--06, mitral and tricuspid--07). In one patient there was severe obstruction of the anterior descending artery and a bypass was done. Three patients had associated rheumatic mitral stenosis. There was one early operative death and three late deaths (respectively 13.34 and 37 months later). Two patients required re-operation. The first one, 33 months later, to replace the mitral valve which had been preserved in the first procedure, and the second, 12 months later, who presented ventricular septal defect secondary to rupture of the weak septum. Of all the patients who underwent surgery, 11 survived and all, except one, have had a good course. The detailed analysis of this series permitted us to conclude that: 1st--the general use of the bidimensional echocardiography in high risk patients, allows early diagnosis in a greater number of them; 2nd, the surgery must be early to avoid cardiac and extracardiac injury due to the disease; 3rd--a low profile valve must be used; 4th--to this moment there have been no signs of recurrence; 5th--surgical treatment appears to improve the course of this terrible disease.

Impairment of macrophage antiviral activity by soluble tumor products. Effects of bacterial immunomodulators

The antiviral activities of normal rat peritoneal macrophages versus Herpes Simplex Virus type 1 were inhibited by sera from tumor-bearing rats and 3M KCl extracts of tumor mass. The inhibitory activity was demonstrated on the extrinsic as well as on the intrinsic macrophage functions. Sera from Corynebacterium parvum and Listeria monocytogenes treated tumor bearing rats did not inhibit these macrophages functions. Furthermore the 3 M KCl extracts from the tumor mass of the above treated TBR show a decrease in the capability to impair these macrophage functions. On the other hand, the treatment with the oral polyvalent adjuvant "Buccalin" was not able to restore the compromised antiviral activity in tumor bearing rats.