Errors in the arterial blood pressure measurement

ntroduction The artefacts affecting arterial wave morphology may compromise recorded values of arterial blood pressure (ABP) and can lead to therapeutic errors. The aim of this study is to evaluate the errors between invasive and noninvasive arterial pressure values, the incidence of artefacts due to an inadequate dynamic response of the transducer-tubing system, and their detection by the ICU staff. Methods Seventy-five consecutive patients (50 male, mean age 55 ± 18) admitted to the ICU for heterogeneous pathologies were enrolled. Inclusion criteria were: the presence of an intra-arterial catheter (IAC) for invasive blood pressure monitoring, and age >18 years. Pregnancy was excluded. At admission and every time the IAC was replaced we acquired invasive systolic, diastolic, and medium arterial pressure values (I-SP, I-DP, I-MP) during hemodynamic stability (variations of mean arterial pressure <10%); at the same time, noninvasive systolic and diastolic arterial pressure values (Ni-SP, Ni-DP) were measured with a sphygmomanometer at the same arm of the IAC. Noninvasive medium arterial pressure (Ni-MP) was calculated as follows: (SP + 2DP) / 3. At every time of the study, before ABP value acquisition, medical and nursing staff answered a questionnaire on the reliability of the arterial waveform. The staff could perform the fast flush test if considered appropriate. However, the fast flush test was executed by the main investigator at the end of questionnaire in all patients. Bland–Altman analysis was performed. Results We compared 130 pairs of Ni-SP, Ni-DP and Ni-MP and I-SP, I-DP and I-MP. The mean bias between Ni-SP and I-SP was –11 mmHg (limit of agreement (LoA) –43.6 to 21.4 mmHg). The mean bias between Ni-DP and I-DP and between Ni-MP and I-MP was 6.1 mmHg (LoA –15.5 to 27.7 mmHg) and 0.37 mmHg (LoA –21.0 to 21.7 mmHg), respectively. We performed the fast flush test 130 times; an inadequate dynamic response of the transducer-tubing system was observed 55 times: in 45 cases the arterial signal was underdumped and in 10 cases was overdumped. The arterial dumping was correctly detected by the medical staff in 95% of cases, by nursing staff and postgraduates in 35% of cases. Conclusion The bias between invasive and noninvasive ABP measure can be relevant and mislead in the therapeutic management. These errors can be avoided by identifying the artefacts that affect arterial signal and so the ICU staff must pay attention to the recognition of arterial dumping in critically ill patients

Environmental surveillance and spatio-temporal analysis of Legionella spp. In a region of northeastern Italy (2002\u20132017)

Legionella spp. are considered an important cause of potentially preventable morbidity and mortality, making environmental surveillance a crucial component of risk assessment plans. In this work, 20,319 water samples were collected in 3,983 environmental surveys during a 16-year period by ARPA, the Regional Agency for Environmental Protection, Friuli Venezia Giulia, and the results were studied to better understand the diffusion mechanisms of Legionella. The data showed a strong seasonal signal, a prevalence of L. pneumophila serogroup 2-15 in most environments (63% of positive samples), a prevalence of L. pneumophila serogroup 1 in swimming pool-associated environments (82% of positive samples), a persistent presence of Legionella in hospitals and a recurrent presence of Legionella in other facilities such as hotels, possibly years after interventions, highlighting the difficulty of eradicating the bacteria. Retrospective spatio-temporal analyses on geocoded historical data were carried out with SaTScan using an ordinal model with risk as a covariate to identify potential clusters with an excess of cases in the higher-risk categories. Although no outbreaks occurred during the period of study, such analyses identified spatially restricted zones with unusual contamination, which sometimes were also areas in which several surveys triggered by notifications of clinical cases were performed. Simulations of periodic prospective analyses permitted the assessment of the efficacy of the method in early detection of such clusters. The proposed method may be a useful tool in environmental surveillance, prevention and control of Legionella

Incoherence between systemic hemodynamic and microcirculatory response to fluid challenge in critically ill patients

Background: The aim of the study was to assess the coherence between systemic hemodynamic and microcirculatory response to a fluid challenge (FC) in critically ill patients. Methods: We prospectively collected data in patients requiring a FC whilst cardiac index (CI) and microcir-culation were monitored. The sublingual microcirculation was assessed using the incident dark field (IDF) CytoCam device (Braedius Medical, Huizen, The Netherlands). The proportion of small perfused vessels (PPV) was calculated. Fluid responders were defined by at least a 10% increase in CI during FC. Responders according to changes in microcirculation were defined by at least 10% increase in PPV at the end of FC. Cohen’s kappa coefficient was measured to assess the agreement to categorize patients as “responders” to FC according to CI and PPV. Results: A total of 41 FC were performed in 38 patients, after a median time of 1 (0–1) days after ICU admission. Most of the fluid challenges (39/41, 95%) were performed using crystalloids and the median total amount of fluid was 500 (500–500) mL. The main reasons for fluid challenge were oliguria (n = 22) and hypotension (n = 10). After FC, CI significantly increased in 24 (58%) cases; a total of 19 (46%) FCs resulted in an increase in PPV. Both CI and PPV increased in 13 responders and neither in 11; the coefficient of agreement was only 0.21. We found no correlation between absolute changes in CI and PPV after fluid challenge. Conclusions: The results of this heterogenous population of critically ill patients suggest incoherence in fluid responsiveness between systemic and microvascular hemodynamics; larger cohort prospective studies with adequate a priori sample size calculations are needed to confirm these findings

Imaging Tests for Predicting the Presence of Difficult Airway in Head and Neck Cancer Patients Undergoing Otorhinolaryngological Surgery

Patients with head and neck cancers represent a challenge for the surgical team from many points of view, but, especially, the surgical moment where greater stress generated corresponds to the perioperative management of the airway, because in many occasions we can face unexpected situations, most of the time, incidental findings can hinder ventilation and endotracheal intubation. Gutierrez et al., in 2018, decided to study four tomography measures and their correlation in anesthesia records with airway management difficulties. Material and methods: A retrospective, observational study was carried out in 104 patients operated by head and neck cancers over a period of 36 months, only in those with access to tomographic records. Four tomographic measurements were considered and were statistically related to the extreme degrees of visualization of the glottis (Cormack III–IV) and the presence of the physical examination of Mallampati III–IV. Results: After performing a multivariate model in the group of extreme degrees of visualization of the glottis, the results were not statistically significant (p > 0.05; 95% CI: 0.030–2.31: EPI/PPW, 0.018–1.37 TB/PPW). In the Mallampati III–IV group, in the multivariate model only the VC/PPW showed clinically significant results (p < 0.05; 95% CI: 0.104–8.53). Conclusions: Tomographic measurements and the physical examination predictors could represent a useful guide in the prediction of the difficult airway in these patients

Identification and antimicrobial activity of most representative secondary metabolites from different plant species

Abstract Background The plant kingdom constitutes an enormous reservoir of bioactive molecules, generally used by plants to prevent or to protect themselves from pathogens' attacks. To date, several primary or secondary plant metabolites have been already proven to exert antibiotic activities; nonetheless, researchers are still continuing to lavish great efforts to identify and characterize new natural molecules one by one. Aiming at the replacement of synthetic chemical products, the bioactivity of plant extracts should be assessed case by case, and active substances should be tested as individuals to obtain accurate information on the real usefulness of plant metabolites. In this work major glycoalkaloids obtained from Solanum nigrum, glucosinolates from Armoracia rusticana, and cannabinoids from Cannabis sativa were identified. The antimicrobial activity of crude extracts and pure components against Gram+ (Bacillus cereus (A1I), Bacillus thuringiensis (B7I2), and Bacillus amyloliquefaciens (A5TI)) and Gram− bacteria (Pseudomonas orientalis (A14-1II), and Stenotrophomonas maltophilia (B9TIII)), employed as model organisms, was tested. Result Major glycoalkaloids, glucosinolates, and cannabinoids were identified in crude plants' extracts using high-resolution LC–ESI-FTICR/MS. From antimicrobial assays useful information towards a few of biological activities of crude extracts and individual components were obtained. Solanum nigrum extracts revealed inhibition activity on all bacteria tested as well as the main active glycoalkaloids, solamargine and solasonine, which were found to be active even when tested individually. At assayed concentrations, A. rusticana extract was active towards a few of the microorganisms tested, confirming that the activity of glucosinolates can be referred only partially to the mother molecules, while biological efficiency of such kind of compounds is mainly due to their enzymatic breaking off, where myrosinase converts them into isothiocyanates and/or thiocyanates. Hemp-type C. sativa extract showed antimicrobial activity only against Gram+ bacteria, but the main individual components tested showed always a limited bioactivity. Conclusion Promising results were obtained, but tests performed in vitro are only the first step of a wider investigation as required for an extensive application. Further research efforts are necessary to demonstrate the efficiency of natural substances in different target environments

Protective effect of hydroxytyrosol and tyrosol metabolites in LPS-induced vascular barrier derangement in vitro

Introduction The maintenance of endothelial barrier function is essential for vasal homeostasis and prevention of cardiovascular diseases. Among the toxic stimuli involved in the initiation of atherosclerotic lesions, Gram negative lipopolysaccharide (LPS) has been reported to be able to trigger endothelial dysfunction, through the alteration of barrier permeability and inflammatory response. Hydroxytyrosol (HT) and tyrosol (Tyr), the major phenolic compounds of extra virgin olive oil (EVOO), as wells as their circulating sulphated and glucuronidated metabolites have been shown to exert anti-inflammatory effects at endothelial level. Methods In this study we investigated the protective effects of HT and Tyr metabolites on LPS-induced alteration of permeability in Human Umbilical Vein Endothelial Cells (HUVEC) monolayers and examined underlying signaling pathways, focusing on tight junction (TJ) proteins, mitogen-activated protein kinase (MAPK) and NOD-, LRR-and pyrin domain-containing protein 3 (NLRP3) inflammasome activation. Results It was shown that LPS-increased permeability in HUVEC cells was due to the alteration of TJ protein level, following the activation of MAPK and NLRP3. HT and Tyr sulphated and glucuronidated metabolites were able to limit the effects exerted by LPS, acting as signaling molecules with an efficacy comparable to that of their precursors HT and Tyr. Discussion The obtained results add a further piece to the understanding of HT and Tyr metabolites mechanisms of action in vascular protection

Axonal Odorant Receptors Mediate Axon Targeting

In mammals, odorant receptors not only detect odors but also define the target in the olfactory bulb, where sensory neurons project to give rise to the sensory map. The odorant receptor is expressed at the cilia, where it binds odorants, and at the axon terminal. The mechanism of activation and function of the odorant receptor at the axon terminal is, however, still unknown. Here, we identify phosphatidylethanolamine- binding protein 1 as a putative ligand that activates the odorant receptor at the axon terminal and affects the turning behavior of sensory axons.Genetic ablation of phosphatidylethanolamine-binding protein 1 in mice results in a strongly disturbed olfactory sensory map. Our data suggest that the odorant receptor at the axon terminal of olfactory neurons acts as an axon guidance cue that responds to molecules originating in the olfactory bulb. The dual function of the odorant receptor links specificity of odor perception and axon targeting

Self-repair ability of evolved self-assembling systems in cellular automata

Self-repairing systems are those that are able to reconfigure themselves following disruptions to bring them back into a defined normal state. In this paper we explore the self-repair ability of some cellular automata-like systems, which differ from classical cellular automata by the introduction of a local diffusion process inspired by chemical signalling processes in biological development. The update rules in these systems are evolved using genetic programming to self-assemble towards a target pattern. In particular, we demonstrate that once the update rules have been evolved for self-assembly, many of those update rules also provide a self-repair ability without any additional evolutionary process aimed specifically at self-repair

Cyto- and genotoxic effects of metallic nanoparticles in untransformed human fibroblast

AbstractMetallic nanoparticles such as silver (Ag), cerium dioxide (CeO2) and titanium dioxide (TiO2) are produced at a large scale and included in many consumer products. It is well known that most metallic NPs are toxic to humans which raise concerns about these engineered particles. Various studies have already been published on the subject, however, almost all of these studies have been conducted in cancer or transformed cell lines. In this work we performed a comparative evaluation of these metallic NPs on normal untransformed human fibroblasts (GM07492) detecting cyto- and geno-toxic responses after exposure to these NPs. Our results showed that all three metallic NPs were able to cross the plasma membrane and were mainly found in endocytic vesicles. The Ag and TiO2 NPs affected mitochondrial enzymatic activity (XTT), increased DNA fragmentation, oxidative damage (Comet assay) and induced cell death mainly by the apoptotic pathway. Ag NPs increased GADD45α transcript levels and the phosphorylation of proteins γH2AX. Transient genotoxicity was also observed from exposure to CeO2 NPs while TiO2 NPs showed no increase in DNA damage at sub-cytotoxic concentrations. In comparison, Ag NPs were found to be the most cyto-genotoxic NPs to fibroblasts. Thus, these results support the use of normal fibroblast as a more informative tool to detect the mechanisms of action induced by metallic NPs