Reduced Resistance to Air Flow from Nanomodified Endotracheal Tubes

2011 ◽  
Vol 1316 ◽  
Author(s):  
Mary C. Machado ◽  
Keiko M. Tarquinio ◽  
Thomas J. Webster
Keyword(s):  
Biofilm Formation ◽  
Cost Effective ◽  
Clinical Problem ◽  
Flow Chamber ◽  
High Morbidity ◽  
Ventilator Associated Pneumonia ◽  
Pressure Gradients ◽  
Dynamic Flow ◽  
Endotracheal Tubes ◽  
Significant Evidence

AbstractVentilator associated pneumonia (VAP) is a serious and costly clinical problem. Specifically, receiving mechanical ventilation over 24 hours increases the risk of VAP and is associated with high morbidity, mortality and medical costs. Cost effective endotracheal tubes (ETTs) that are resistant to bacterial infection would help to prevent this problem. The objective of this study was to determine differences in bacterial growth on nanomodified and unmodified ETTs under dynamic airway conditions, a bench top model based upon the general design of Hartmann et al. (1999) was constructed to test of the effectiveness of nanomodified ETTs under the airflow conditions present in the airway. Twenty-four hour studies performed in a dynamic flow chamber showed a marked difference in the biofilm formation on different areas of unmodified tubes. Areas where tubes were curved, such as at the entrance to the mouth and the connection between the oropharynx and the larynx, seemed to collect the largest amount of biofilm. On the nanomodified tubes biofilm formation was markedly different occurring on smaller pieces.The biofilm formation on ETTs in the airflow system after 24 hours showed a large difference depending upon where tubes were oriented within the apparatus. This illustrates the importance of dynamic flow on biofilm formation in pediatric ETTs. It is of particular interest that increased biofilm density on both unmodified and nanomodified tubes appeared to occur at curves in the tube where changes in flow pattern occured. This emphasizes the need for more accurate models of airflow within pediatric ETTs, suggesting that not only does flow affect pressure gradients along the tube, but in fact, determines the composition of the film itself. More testing is needed to determine the effects of biofilm formation on the efficiency of ETT under airflow, however this study provides significant evidence for nanomodification alone (without the use of antibiotics) to decrease bacteria function.

Bacterial Adhesion to Nanomodified Surfaces: Dynamic Flow Effects onS. aureusandP. aeruginosa

2013 ◽  
Vol 1498 ◽  
pp. 79-84
Author(s):  
Mary C. Machado ◽  
Keiko M. Tarquinio ◽  
Thomas J. Webster
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Cost Effective ◽  
Clinical Problem ◽  
Flow Chamber ◽  
High Morbidity ◽  
Pressure Gradients ◽  
Dynamic Flow ◽  
Endotracheal Tubes ◽  
Flow Effects

AbstractVentilator associated pneumonia (VAP) is a serious and costly clinical problem. Specifically, receiving mechanical ventilation over 24 hours increases the risk of VAP and is associated with high morbidity, mortality and medical costs. Cost effective endotracheal tubes (ETTs) that are resistant to bacterial infection would help to prevent this problem. The objective of this study was to determine differences in bacterial growth on nanomodified and unmodified ETTs under dynamic airway conditions. A bench top model based upon the general design of Hartmann et al. (1999) was constructed to test of the effectiveness of nanomodified ETTs under the airflow conditions present in the airway. Twenty-four hour studies performed in a dynamic flow chamber showed a marked difference in the biofilm formation on different areas of unmodified tubes. Areas where tubes were curved, such as at the entrance to the mouth and the connection between the oropharynx and the larynx, seemed to collect the largest amount of biofilm.The biofilm formation on ETTs in the airflow system after 24 hours showed a large difference depending upon where tubes were oriented within the apparatus. This illustrates the importance of dynamic flow on biofilm formation in pediatric ETTs. It is of particular interest that increased biofilm density on both unmodified and nanomodified tubes appeared to occur at curves in the tube where changes in flow pattern occurred. This emphasizes the need for more accurate models of airflow within pediatric ETTs, suggesting that not only does flow affect pressure gradients along the tube, but in fact, determines the composition of the film itself. More testing is needed to determine the effects of biofilm formation on the efficiency of ETT under airflow, however this study provides significant evidence for nanomodification alone (without the use of antibiotics) to decrease bacteria function.

Nanomodified Endotracheal Tubes: Spatial Analysis of Reduced Bacterial Colonization in a Bench Top Airway Model

2012 ◽  
Vol 1418 ◽  
Author(s):  
Mary C. Machado ◽  
Keiko M. Tarquinio ◽  
Thomas J. Webster
Keyword(s):  
Computational Models ◽  
Bacterial Colonization ◽  
Air Flow ◽  
Cost Effective ◽  
Clinical Problem ◽  
High Morbidity ◽  
The Novel ◽  
Endotracheal Tubes ◽  
Surface Features ◽  
Log Reduction

ABSTRACTVentilator associated pneumonia (VAP) is a serious and costly clinical problem. Specifically, receiving mechanical ventilation for over 24 hours increases the risk of VAP and is associated with high morbidity, mortality and medical costs. Cost effective endotracheal tubes (ETTs) that are resistant to bacterial infection could help prevent this problem. The objective of this study was to determine differences in the growth ofStaphylococcus aureus(S. aureus) on nanomodified and unmodified polyvinyl chloride (PVC) ETTs under dynamic airway conditions. PVC ETTs were modified to have nanometer surface features by soaking them inRhizopus arrhisus,a fungal lipase. Twenty-four hour experiments (supported by computational models) showed that air flow conditions within the ETT influenced both the location and concentration of bacterial growth on the ETTs especially within areas of tube curvature. More importantly, experiments revealed a 1.5 log reduction in the total number ofS. aureuson the novel nanomodified ETTs compared to the conventional ETTs after 24 hours of air flow. This dynamic study showed that lipase etching can create nano-rough surface features on PVC ETTs that suppressS. aureusgrowth and, thus, may provide clinicians with an effective and inexpensive tool to combat VAP.

Reducing Infections Using Nanotechnology

2014 ◽  
Vol 1621 ◽  
pp. 25-32
Author(s):  
Thomas J. Webster
Keyword(s):  
Computational Models ◽  
Air Flow ◽  
Cost Effective ◽  
Clinical Problem ◽  
High Morbidity ◽  
The Novel ◽  
Flow Conditions ◽  
Endotracheal Tubes ◽  
Surface Features ◽  
Log Reduction

ABSTRACTVentilator associated pneumonia (VAP) is a serious and costly clinical problem. Specifically, receiving mechanical ventilation for over 24 hours increases the risk of VAP and is associated with high morbidity, mortality and medical costs. Cost effective endotracheal tubes (ETTs) that are resistant to bacterial infection could help prevent this problem. The objective of this study was to determine differences in the growth ofStaphylococcus aureus(S. aureus) on nanomodified and unmodified polyvinyl chloride (PVC) ETTs under dynamic airway conditions. PVC ETTs were modified to have nanometer surface features by soaking them inRhizopus arrhisus,a fungal lipase. Twenty-four hour experiments (supported by computational models) showed that air flow conditions within the ETT influenced both the location and concentration of bacterial growth on the ETTs especially within areas of tube curvature. More importantly, experiments revealed a 1.5 log reduction in the total number ofS. aureuson the novel nanomodified ETTs compared to the conventional ETTs after 24 hours of air flow. This dynamic study showed that lipase etching can create nano-rough surface features on PVC ETTs that suppressS. aureusgrowth and, thus, may provide clinicians with an effective and inexpensive tool to combat VAP.

scholarly journals Advanced understanding of prokaryotic biofilm formation using a cost-effective and versatile multi-panel adhesion (mPAD) mount

2022 ◽  
Author(s):  
Stefan Schulze ◽  
Heather Schiller ◽  
Jordan Solomonic ◽  
Orkan Telhan ◽  
Kyle Costa ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Cost Effective ◽  
Flow Chamber ◽  
Culture Conditions ◽  
Multiple Time ◽  
Wild Type ◽  
Surface Attachment ◽  
Flowing Liquid ◽  
Multiple Time Points ◽  
Static Conditions

Most microorganisms exist in biofilms, which comprise aggregates of cells surrounded by an extracellular matrix that provides protection from external stresses. Based on the conditions under which they form, biofilm structures vary in significant ways. For instance, biofilms that develop when microbes are incubated under static conditions differ from those formed when microbes encounter the shear forces of a flowing liquid. Moreover, biofilms develop dynamically over time. Here, we describe a cost-effective, 3D-printed coverslip holder that facilitates surface adhesion assays under a broad range of standing and shaking culture conditions. This multi-panel adhesion (mPAD) mount further allows cultures to be sampled at multiple time points, ensuring consistency and comparability between samples and enabling analyses of the dynamics of biofilm formation. As a proof of principle, using the mPAD mount for shaking, oxic cultures, we confirm previous flow chamber experiments showing that Pseudomonas aeruginosa wild type and a phenazine deletion mutant (Δ phz ) form biofilms with similar structure but reduced density in the mutant strain. Extending this analysis to anoxic conditions, we reveal that microcolony and biofilm formation can only be observed under shaking conditions and are decreased in the Δ phz mutant compared to wild-type cultures, indicating that phenazines are crucial for the formation of biofilms if oxygen as an electron acceptor is unavailable. Furthermore, while the model archaeon Haloferax volcanii does not require archaella for surface attachment under static conditions, we demonstrate that H. volcanii mutants that lack archaella are impaired in early stages of biofilm formation under shaking conditions. Importance: Due to the versatility of the mPAD mount, we anticipate that it will aid the analysis of biofilm formation in a broad range of bacteria and archaea. Thereby, it contributes to answering critical biological questions about the regulatory and structural components of biofilm formation and understanding this process in a wide array of environmental, biotechnological, and medical contexts.

scholarly journals Biofilm formation on three different endotracheal tubes: A prospective clinical trial

2020 ◽  
Author(s):  
Hulda Rosa Thorarinsdottir ◽  
Thomas Kander ◽  
Anna Holmberg ◽  
Sarunas Petronis ◽  
Bengt Klarin
Keyword(s):  
Noble Metal ◽  
Biofilm Formation ◽  
Noble Metals ◽  
Ventilator Associated Pneumonia ◽  
High Grade ◽  
Invasive Ventilation ◽  
Mechanically Ventilated ◽  
Endotracheal Tubes ◽  
Frequent Event ◽  
Significant Difference

Abstract Background: Biofilm formation on endotracheal tubes (ETTs) is an early and frequent event in mechanically ventilated patients. The biofilm is believed to act as a reservoir for infecting microorganisms and thereby contribute to development and relapses of ventilator-associated pneumonia (VAP). Once a biofilm has formed on an ETT surface, it is difficult to eradicate. This clinical study aimed to compare biofilm formation on three widely used ETTs with different surface properties and to explore factors potentially predictive of biofilm formation.Methods: We compared the grade of biofilm formation on ETTs made of uncoated polyvinyl chloride (PVC), silicone-coated PVC, and PVC coated with noble metals after > 24 hours of mechanical ventilation in critically ill patients. The comparison was based on scanning electron microscopy of ETT surfaces, biofilm grading, surveillance and biofilm cultures, and occurrence of VAP.Results: High-grade (score ≥ 7) biofilm formation on the ETTs was associated with development of VAP (OR 4.17 [95% CI 1.14–15.3], p = 0.031). Compared to uncoated PVC ETTs, the silicone-coated and noble-metal-coated PVC ETTs were independently associated with reduced high-grade biofilm formation (OR 0.18 [95% CI 0.06–0.59], p = 0.005, and OR 0.34 [95% CI 0.13–0.93], p = 0.036, respectively). No significant difference was observed between silicon-coated ETTs and noble-metal-coated ETTs (OR 0.54 [95% CI 0.17–1.65], p = 0.278). In 60% of the oropharyngeal cultures and 58% of the endotracheal cultures collected at intubation, the same microorganism was found in the ETT biofilm at extubation. In patients who developed VAP, the causative microbe remained in the biofilm in 56% of cases, despite appropriate antibiotic therapy. High-grade biofilm formation on ETTs was not predicted by either colonization with common VAP pathogens in surveillance cultures or duration of invasive ventilation.Conclusion: High-grade biofilm formation on ETTs was associated with development of VAP. Compared to the uncoated PVC ETTs, the silicone-coated and noble-metal-coated PVC ETTs were independently associated with reduced high-grade biofilm formation. Further research on methods to prevent, monitor, and manage biofilm occurrence is needed.Trial registration: ClinicalTrials.gov, NCT02284438. Retrospectively registered on 21 October 2014, URL: https://clinicaltrials.gov/ct2/show/NCT02284438.

scholarly journals Advanced understanding of prokaryotic biofilm formation using a cost-effective and versatile multi-panel adhesion (mPAD) mount

2021 ◽  
Author(s):  
Stefan Schulze ◽  
Heather Schiller ◽  
Jordan Solomonic ◽  
Orkan Telhan ◽  
Kyle Costa ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Cost Effective ◽  
Flow Chamber ◽  
Culture Conditions ◽  
Multiple Time ◽  
Wild Type ◽  
Flowing Liquid ◽  
External Stresses ◽  
Multiple Time Points ◽  
Static Conditions

AbstractMost microorganisms exist in biofilms, which comprise aggregates of cells surrounded by an extracellular matrix that provides protection from external stresses. Based on the conditions under which they form, biofilm structures vary in significant ways. For instance, biofilms that develop when microbes are incubated under static conditions differ from those formed when microbes encounter the shear forces of a flowing liquid. Moreover, biofilms develop dynamically over time. Here, we describe a cost-effective, 3D-printed coverslip holder that facilitates surface adhesion assays under a broad range of standing and shaking culture conditions. This multi-panel adhesion (mPAD) mount further allows cultures to be sampled at multiple time points, ensuring consistency and comparability between samples and enabling analyses of the dynamics of biofilm formation. As a proof of principle, using the mPAD mount for shaking, oxic cultures, we confirm previous flow chamber experiments showing that Pseudomonas aeruginosa wild type and a phenazine deletion mutant (Δphz) form similar biofilms. Extending this analysis to anoxic conditions, we reveal that microcolony and biofilm formation can only be observed under shaking conditions and are decreased in the Δphz mutant compared to wild-type cultures, indicating that phenazines are crucial for the formation of biofilms if oxygen as an electron acceptor is not available. Furthermore, while the model archaeon Haloferax volcanii does not require archaella for attachment to surfaces under static conditions, we demonstrate that H. volcanii mutants that lack archaella are negatively affected in their early stages of biofilm formation under shaking conditions.ImportanceDue to the versatility of the mPAD mount, we anticipate that it will aid the analysis of biofilm formation in a broad range of bacteria and archaea. Thereby, it contributes to answering critical biological questions about the regulatory and structural components of biofilm formation and understanding this process in a wide array of environmental, biotechnological, and medical contexts.

scholarly journals Biofilm formation on three different endotracheal tubes: a prospective clinical trial

2020 ◽  
Author(s):  
Hulda Rosa Thorarinsdottir ◽  
Thomas Kander ◽  
Anna Holmberg ◽  
Sarunas Petronis ◽  
Bengt Klarin
Keyword(s):  
Noble Metal ◽  
Biofilm Formation ◽  
Noble Metals ◽  
Ventilator Associated Pneumonia ◽  
High Grade ◽  
Invasive Ventilation ◽  
Mechanically Ventilated ◽  
Endotracheal Tubes ◽  
Frequent Event ◽  
Significant Difference

Abstract Background: Biofilm formation on endotracheal tubes (ETTs) is an early and frequent event in mechanically ventilated patients. The biofilm is believed to act as a reservoir for infecting microorganisms and thereby contribute to development and relapses of ventilator-associated pneumonia (VAP). Once a biofilm has formed on an ETT surface, it is difficult to eradicate. This clinical study aimed to compare biofilm formation on three widely used ETTs with different surface properties and to explore factors potentially predictive of biofilm formation.Methods: We compared the grade of biofilm formation on ETTs made of uncoated polyvinyl chloride (PVC), silicone-coated PVC, and PVC coated with noble metals after > 24 hours of mechanical ventilation in critically ill patients. The comparison was based on scanning electron microscopy of ETT surfaces, biofilm grading, surveillance and biofilm cultures, and occurrence of VAP.Results: High-grade (score ≥ 7) biofilm formation on the ETTs was associated with development of VAP (OR 4.17 [95% CI 1.14–15.3], p = 0.031). Compared to uncoated PVC ETTs, the silicone-coated and noble-metal-coated PVC ETTs were independently associated with reduced high-grade biofilm formation (OR 0.18 [95% CI 0.06–0.59], p = 0.005, and OR 0.34 [95% CI 0.13–0.93], p = 0.036, respectively). No significant difference was observed between silicon-coated ETTs and noble-metal-coated ETTs (OR 0.54 [95% CI 0.17–1.65], p = 0.278). In 60% of the oropharyngeal cultures and 58% of the endotracheal cultures collected at intubation, the same microorganism was found in the ETT biofilm at extubation. In patients who developed VAP, the causative microbe remained in the biofilm in 56% of cases, despite appropriate antibiotic therapy. High-grade biofilm formation on ETTs was not predicted by either colonization with common VAP pathogens in surveillance cultures or duration of invasive ventilation.Conclusion: High-grade biofilm formation on ETTs was associated with development of VAP. Compared to the uncoated PVC ETTs, the silicone-coated and noble-metal-coated PVC ETTs were independently associated with reduced high-grade biofilm formation. Further research on methods to prevent, monitor, and manage biofilm occurrence is needed.Trial registration: ClinicalTrials.gov, NCT02284438. Retrospectively registered on 21 October 2014, URL: https://clinicaltrials.gov/ct2/show/NCT02284438.

Malignant Pleural Effusion: Still a Long Way to Go

2019 ◽  
Vol 14 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Fausto Meriggi
Keyword(s):  
Pleural Effusion ◽  
Malignant Pleural Effusion ◽  
English Language ◽  
Metastatic Cancer ◽  
Primary Tumour ◽  
Clinical Problem ◽  
Therapeutic Options ◽  
High Morbidity ◽  
Sclerosing Agents ◽  
Pubmed Database

Background:Malignant pleural effusion, which is a common clinical problem in patients with cancer, may be due to both primary thoracic tumours or to a metastatic spread in the chest and constitutes the first sign of disease in approximately 10% of patients. Almost all cancers can potentially produce a pleural effusion. The presence of malignant tumour cells in the pleural fluid is generally indicative of advanced disease and is associated with high morbidity and mortality with reduced therapeutic options. Dyspnoea during mild physical activity or at rest is generally the typical sign of restrictive respiratory failure. </P><P> Methods: This is a systematic review of all the main articles in the English language on the topic of malignant pleural effusion and reported by the Pubmed database from 1959 to 2018. I reviewed the literature and guidelines with the aims to focus on what is known and on future pathways to follow the diagnosis and treatment of malignant pleural effusions.Results:The main goal of palliation of a malignant pleural effusion is a quick improvement in dyspnoea, while thoracentesis under ultrasound guidance is the treatment of choice for patients with a limited life expectancy or who are not candidates for more invasive procedures such as drainage using an indwelling small pleural catheter, chemical pleurodesis with sclerosing agents, pleurectomy or pleuro-peritoneal shunt.Conclusion:Despite progress in therapeutic options, the prognosis remains severe, and the average survival is 4-9 months from the diagnosis of malignant pleural effusion. Moreover, mortality is higher for patients with malignant pleural effusion compared with those with metastatic cancer but no malignant pleural effusion. Therefore, the prognosis of these patients primarily depends on the underlying disease and the extension of a primary tumour. This review focuses on the most relevant updates in the management of malignant pleural effusion.

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