Tracheal tube obstruction in mechanically ventilated patients assessed by high-resolution computed tomography.

BACKGROUND: Tracheal intubation compromises mucus clearance and secretions accumulate inside the tracheal tube (TT). The aim of this study was to evaluate with a novel methodology TT luminal obstruction in critically ill patients. METHODS: This was a three-phase study: (1) the authors collected 20 TTs at extubation. High-resolution computed tomography (CT) was performed to determine cross-sectional area (CSA) and mucus distribution within the TT; (2) five TTs partially filled with silicone were used to correlate high-resolution CT results and increased airflow resistance; and (3) 20 chest CT scans of intubated patients were reviewed for detection of secretions in ventilated patients' TT. RESULTS: Postextubation TTs showed a maximum CSA reduction of (mean±SD) 24.9±3.9% (range 3.3 to 71.2%) after a median intubation of 4.5 (interquartile range 2.5 to 6.5) days. CSA progressively decreased from oral to lung end of used TTs. The luminal volume of air was different between used and new TTs for all internal diameters (P<0.01 for new vs. used TTs for all studied internal diameters). The relationship between pressure drop and increasing airflow rates was nonlinear and depended on minimum CSA available to ventilation. Weak correlation was found between TT occlusion and days of intubation (R²=0.352, P=0.006). With standard clinical chest CT scans, 6 of 20 TTs showed measurable secretions with a CSA reduction of 24.0±3.9%. CONCLUSIONS: TT luminal narrowing is a common finding and correlates with increased airflow resistance. The authors propose high-resolution CT as a novel technique to visualize and quantify secretions collected within the TT lumen.

Use of flow cytometry to compare the antimicrobial efficacy of silver-containing wound dressings against planktonic Staphylococcus aureus and Pseudomonas aeruginosa.

Silver-impregnated wound dressings continue to be routinely used for the management of infected wounds, or wounds that are at risk of becoming infected. The ability of antimicrobials that have been incorporated into wound dressings to kill microorganisms within the dressing requires appropriate evaluation using in vitro models. In vitro models that have been exploited for this purpose have included the corrected zone of inhibition and the log reduction assay. However, these and other related culturable-based assays are purported to have poor correlation with the overall microbicidal barrier activity of an antimicrobial wound dressing. This is because culturable-based methods only retrospectively indicate bacterial cell death and do not take into account viable but nonculturable states of microorganisms. Consequently, it was the purpose of this study to show that the use of flow cytometry, in conjunction with Syto(®) 9 and propidium iodide, could be used as a method for accurately evaluating and comparing the antimicrobial barrier efficacy of a silver alginate and a silver carboxymethyl cellulose dressing on individual bacterial cells without the need for the use of culturable assays. When a comparison of antimicrobial barrier efficacy on individual planktonic Staphylococcus aureus cells in a simulated wound fluid assay was made between each dressing, enhanced antimicrobial efficacy (as showed by the percentage of dead to alive bacterial cells) of the silver alginate dressing was shown. When Pseudomonas aeruginosa was exposed to both silver-containing dressings, equivalent kill rates were showed for up to 4 days. This result was not significantly different (p<0.05). By utilizing the use of flow cytometric assays, the antimicrobial barrier efficacy of wound dressings can be accurately evaluated enabling differentiation to be achieved between individual dead and live bacteria. The flow cytometric assay is considered a significant advancement to the traditionally used culturable-based methods that are presently used for antimicrobial barrier efficacy testing on planktonic microorganisms.

The efficacy of silver dressings and antibiotics on MRSA and MSSA isolated from burn patients.

In this study our objectives were (1) to investigate whether meticillin-resistant Staphylococcus aureus (MRSA) showed an increased tolerance to silver wound dressings compared with meticillin-sensitive S. aureus (MSSA); and (2) to evaluate the effects of bacterial phenotypic states of MRSA and MSSA, and pH, on the activity of silver wound dressings and two antibiotics, ampicillin and clindamycin. Twenty MRSA strains and 10 MSSA strains isolated from burns patients in South Africa were evaluated for their susceptibility to a silver alginate and a silver carboxymethyl cellulose wound dressing, employing a corrected zone of inhibition assay, conducted on Mueller Hinton agar and a poloxamer-based biofilm model. When exposed to the two silver dressings, all 30 S. aureus strains showed susceptibility. Possible enhanced antimicrobial efficacy of the silver dressings occurred when pH was lowered to 5.5, compared with a pH of 7.0. When all S. aureus were grown in the biofilm phenotypic state and exposed to both silver dressings and antibiotics, enhanced tolerance was noted. Susceptibility to silver was overall higher for MRSA when compared with MSSA. This study showed that the effect of pH and bacterial phenotypic state must be considered when the antimicrobial activity of silver wound dressings is being investigated. It is evident from the data generated that both pH and the bacterial phenotypic state are factors that induce changes that affect both antimicrobial performance and bacterial susceptibility.

Use of 16S ribosomal RNA gene analyses to characterize the bacterial signature associated with poor oral health in West Virginia.

BACKGROUND: West Virginia has the worst oral health in the United States, but the reasons for this are unclear. This pilot study explored the etiology of this disparity using culture-independent analyses to identify bacterial species associated with oral disease. METHODS: Bacteria in subgingival plaque samples from twelve participants in two independent West Virginia dental-related studies were characterized using 16S rRNA gene sequencing and Human Oral Microbe Identification Microarray (HOMIM) analysis. Unifrac analysis was used to characterize phylogenetic differences between bacterial communities obtained from plaque of participants with low or high oral disease, which was further evaluated using clustering and Principal Coordinate Analysis. RESULTS: Statistically different bacterial signatures (P<0.001) were identified in subgingival plaque of individuals with low or high oral disease in West Virginia based on 16S rRNA gene sequencing. Low disease contained a high frequency of Veillonella and Streptococcus, with a moderate number of Capnocytophaga. High disease exhibited substantially increased bacterial diversity and included a large proportion of Clostridiales cluster bacteria (Selenomonas, Eubacterium, Dialister). Phylogenetic trees constructed using 16S rRNA gene sequencing revealed that Clostridiales were repeated colonizers in plaque associated with high oral disease, providing evidence that the oral environment is somehow influencing the bacterial signature linked to disease. CONCLUSIONS: Culture-independent analyses identified an atypical bacterial signature associated with high oral disease in West Virginians and provided evidence that the oral environment influenced this signature. Both findings provide insight into the etiology of the oral disparity in West Virginia.

The antimicrobial efficacy of a silver alginate dressing against a broad spectrum of clinically relevant wound isolates.

Wound dressings impregnated with silver have a role to play in aiding to reduce both the dressing and wound microbial bioburden. It is therefore imperative that antimicrobial wound dressings have efficacy on a broad range of clinical significant microorganisms. Accordingly, this study aimed to determine the antimicrobial efficacy of a silver alginate dressing against 115 wound isolates that had been isolated routinely from patients at West Virginia University Hospital. Standardised corrected zones of inhibition (CZOIs) were performed on all clinical isolates. It was found that the silver alginate dressing was able to inhibit the growth of all microorganisms tested. In particular, the silver alginate dressing inhibited the growth of Candida albicans and yeasts with CZOI of 3-11·5 mm. All meticillin-resistant Staphylococcus aureus (MRSA) strains were found to be sensitive to the silver alginate dressing with a CZOI range calculated at 3-7·8 mm. Sensitivity to the silver alginate dressing was also evident for S. aureus and vancomycin-resistant Enterococci. CZOIs of 4·25 mm were calculated for Enterococcus faecium and 9·8 mm for viridans streptococcus. The bacteria which demonstrated the highest tolerance to ionic silver included Enterobacter cloacae and Acinetobacter baumannii. Contrary to this the most responsive microorganisms to ionic silver included strains of staphylococci, viridans streptococcus and Candida albicans. No antibiotic-resistant isolates, as identified by Kirby Bauer Clinical Laboratory Standards Institute classification system, were found to be resistant to ionic silver. When a selected number of microorganisms were grown in the biofilm phenotypic state enhanced tolerance to silver was observed, compared to their non biofilm counterparts. Overall, this study has demonstrated the broad antimicrobial activity of a silver alginate dressing on wound isolates grown in the non biofilm and biofilm state. This finding is clinically relevant as both the non biofilm and biofilm phenotypic states of microorganisms are evident in wounds and therefore significant to delayed healing. Consequently, it is imperative that antimicrobial wound dressings demonstrate antimicrobial activity against microorganisms in both phenotypic states.

Prospective Associations between Attitudes toward Sweet Foods, Sugar Consumption, and Cravings for Alcohol and Sweets in Early Recovery from Alcohol Use Disorders.

Sweet liking (heightened preference for highly-sweet solutions) is linked to Alcohol Use Disorder (AUD) and relapse, as well as attitudes towards sweet foods - use of sugar to cope with negative affect (sweet-cope), and impaired control over sweets consumption (sweet-control). This prospective analysis of individuals with AUD (N=26) participating in an Alcohol and Drug partial hospitalization program observed increases in self-reported sugar consumption and sweet craving from Time 1 (T1) to Time 2 (T2; 4 weeks later). Sweet-cope (T1) predicted T2 sweet craving. In an exploratory cross-lagged panel model, sweet-cope predicted sugar consumption and sweet craving at T1 and T2, and alcohol craving at T2. This pattern of results suggests the hypothesis that use of sugar to regulate negative affect may prove a novel, modifiable risk mechanism of the association between sweet liking and relapse. Sweet-cope may also prove an intervention target for improving nutrition and weight-related factors in early recovery. Future research in larger sample sizes is needed.

Biofilms and bacterial imbalances in chronic wounds: anti-Koch.

Microbial imbalances and synergistic relationships between bacteria in medically important biofilms are poorly researched. Consequently, little is known about how synergy between bacteria may increase the net pathogenic effect of a biofilm in many diseases and infections, including chronic wounds. Microbial synergy in chronic wounds may increase virulence and pathogenicity, leading to enhanced tissue degradation, malodour and in some cases, an impairment of the host immune response. Microbial synergy and growth within a biofilm provide a competitive advantage to the microorganisms cohabiting in a wound, thereby promoting their survival and tolerance and resistance to antimicrobial agents. The aim of this article was to provide greater insight into microbial imbalances found within wound biofilms and the significance they may have on non healing and infected wounds. We also present two possible hypotheses which could explain the role microorganisms play in non healing chronic wounds and offer possible strategies for combating harmful and detrimental biofilms.

Self-stigma and weight loss: The impact of fear of being stigmatized.

This study sought to examine whether two facets of weight self-stigma (fear of enacted stigma and self-devaluation) were associated with weight change and treatment engagement for 188 individuals participating in a 3-month online weight loss program. Fear of enacted stigma predicted less weight loss 3 months later after controlling for demographics, eating problems, and psychological symptoms. Self-devaluation did not predict weight loss. Neither weight self-stigma variable predicted engagement in the online program. These results add to the literature indicating the negative effects of weight self-stigma while highlighting the central role of fear of being stigmatized by others in this process.

Rationale and protocol for translating basic habituation research into family-based childhood obesity treatment: Families becoming healthy together study.

This publication describes the rationale and protocol, including design, aims, intervention, and measures, of Families Becoming Healthy Together, a randomized clinical trial examining the effect of a limited RED (non-nutrient-dense, energy-dense) food variety prescription delivered within an 18-month family-based behavioral obesity treatment (FBT) on body mass index (BMI) and habituation rate to RED foods. One hundred fifty-six children (ages: 8-12 y; BMI: ≥ 85th percentile-for-age) and a caregiver (BMI: ≥ 25 kg/m2), both with overweight or obesity, will be randomized to one of two, interventions: FBT or FBT + Variety. All participants will receive 29 sessions of FBT and be prescribed the Traffic Light Diet (1000-1500 kcal/day, ≤ 2 RED food servings/day), and a physical activity goal (≥ 60 min/day [child] or 150 min/week [adult] of moderate-vigorous physical activity (MVPA)). FBT + Variety will also identify two RED foods, a dinner entrée and snack food, and develop meal plans that reduce variety of RED foods by regularly consuming these foods and limiting consumption of other RED foods. Measures of anthropometrics, dietary intake, habituation of salivary response to food cues, and physical activity will be assessed at 0, 6, 12, and 18-months. This study translates a line of basic behavioral research examining how dietary variety influences habituation into a dietary prescription that will be tested within an efficacy trial. It is hypothesized that a novel, limited dietary variety prescription within FBT should promote a faster food habituation rate, reducing energy intake and amplifying long-term weight loss in children.

Transmission of Helicobacter pylori and the role of water and biofilms.

Documented evidence relating to the survival of Helicobacter pylori outside the gastric niche is extremely limited. To date the primary transmission routes of H. pylori have yet to be confirmed and when this is achieved preventive infection control measures can be implemented to reduce and ultimately prevent human infection from this pathogen. There is mounting evidence which suggests that the prevalence of H. pylori infection has a strong correlation with access to clean water, suggesting a transmission route to the host. However, there are no established culture methods for the detection of viable H. pylori in the environment, in particular drinking water supplies, preventing the development of true epidemiological and risk assessments. The aim of this review is to highlight the available data to date that suggests drinking water and possible survival in biofilms as a probable transmission mode for H. pylori.

Silver-Coated Endotracheal Tubes Cleaned With a Mechanism for Secretion Removal.

BACKGROUND: Biofilm on the surface of endotracheal tubes (ETTs) is associated with ventilator-associated pneumonia. The use of silver-coated ETTs has been suggested to reduce the occurrence of ventilator-associated pneumonia by preventing biofilm formation. However, mucus accumulation can reduce the antibacterial activity of silver-coated ETTs by isolating bacterial colonies from the silver surface. We hypothesized that, in mechanically ventilated subjects, periodic removal of secretions through the use of a cleaning device would enhance the antimicrobial properties of silver-coated ETTs and thus reduce bacterial colonization. METHODS: Subjects were randomized to either standard suctioning (blind tracheal suctioning, control group) or blind tracheal suctioning plus cleaning maneuver every 8 h (treatment group). Tracheal aspirates were collected immediately before extubation for microbiological culture. After extubation, ETTs were collected for both cultural and non-cultural microbiological analysis and biofilm isolation. RESULTS: 39 subjects expected to be ventilated for > 48 h were enrolled; 36 ETTs (18 control, 18 treatment) and 29 tracheal samples (15 control, 14 treatment) were collected. Among the ETTs positive for bacterial colonization (15 vs 9, P = .18), cleaning maneuvers did not reduce microbial load, shown as the decimal logarithm of colony-forming units (CFU) per mL (1.6 ± 1.2 vs 0.9 ± 1.2 logCFU/mL, P = .15). There was a trend toward decreased biofilm deposition (439.5 ± 29.0 vs 288.9 ± 157.7 mg, P = .09) in the treated ETTs. No significant differences were observed in the number of positive tracheal aspirates (13 vs 10, P = .39) or in the microbial load (4.8 ± 4.0 vs 4.2 ± 3.8 logCFU/mL, P = .70) of tracheal secretions. Finally, no differences in the microbial load of Gram-positive organisms, Gram-negative organisms, or yeasts were found between the ETTs and tracheal aspirates of the 2 groups. CONCLUSIONS: In 39 critically-ill subjects intubated with silver-coated ETTs, periodic cleaning maneuvers did not decrease bacterial colonization of the ETTs and did not lower respiratory tract colonization compared to the standard suctioning. (Clinicaltrials.gov registration NCT02120001.).

Study protocol of the Center for Oral Health Research in Appalachia (COHRA) etiology study.

BACKGROUND: People in Appalachia experience some of the worst oral health in the United States. To develop effective intervention and prevention strategies in Appalachia, we must understand the complex relationships among the contributing factors and how they affect the etiology of oral diseases. To date, no such comprehensive analysis has been conducted. This report summarizes the characteristics of the sample and describes the protocol of a study determining contributions of individual, family, and community factors to oral diseases in Appalachian children and their relatives. METHODS/DESIGN: Families participated in a comprehensive assessment protocol involving interviews, questionnaires, a clinical oral health assessment, a microbiological assessment, and collection of DNA. The design of the study is cross-sectional. CONCLUSION: Due to its multilevel design and large, family-based sample, this study has the potential to greatly advance our understanding of factors that contribute to oral health in Appalachian children.

Application of Machine Learning to Predict Dietary Lapses During Weight Loss.

BACKGROUND: Individuals who adhere to dietary guidelines provided during weight loss interventions tend to be more successful with weight control. Any deviation from dietary guidelines can be referred to as a "lapse." There is a growing body of research showing that lapses are predictable using a variety of physiological, environmental, and psychological indicators. With recent technological advancements, it may be possible to assess these triggers and predict dietary lapses in real time. The current study sought to use machine learning techniques to predict lapses and evaluate the utility of combining both group- and individual-level data to enhance lapse prediction. METHODS: The current study trained and tested a machine learning algorithm capable of predicting dietary lapses from a behavioral weight loss program among adults with overweight/obesity (n = 12). Participants were asked to follow a weight control diet for 6 weeks and complete ecological momentary assessment (EMA; repeated brief surveys delivered via smartphone) regarding dietary lapses and relevant triggers. RESULTS: WEKA decision trees were used to predict lapses with an accuracy of 0.72 for the group of participants. However, generalization of the group algorithm to each individual was poor, and as such, group- and individual-level data were combined to improve prediction. The findings suggest that 4 weeks of individual data collection is recommended to attain optimal model performance. CONCLUSIONS: The predictive algorithm could be utilized to provide in-the-moment interventions to prevent dietary lapses and therefore enhance weight losses. Furthermore, methods in the current study could be translated to other types of health behavior lapses.

Effect of ototopical medications on tympanostomy tube biofilms.

OBJECTIVE: Examine how ototopical medications affect biofilms on fluoroplastic tympanostomy tubes. STUDY DESIGN: In vitro comparison of different ototopical medications against a clinical isolate of Pseudomonas aeruginosa biofilm on tympanostomy tubes treated for 5, 10, 14, and 21 days. METHODS: Under sterile conditions 21 tympanostomy tubes were cut in half. These were attached to pegs of two Calgary Biofilm Devices via rubber cement. Device 1 evaluated microbial growth as colony forming units (CFUs). Device 2 evaluated presence of biofilms. Tubes were prepped for biofilm growth, incubated, and stressed for 72 hours. Afterward, one tube per device was removed and forcefully washed. One was sonificated for 5 minutes, serially diluted, and plated for CFUs. Formalin preserved the other for biofilm evaluation by scanning electron microscopy. Next, tubes were exposed to five drops of Ciprofloxacin, Ciprofloxacin/Dexamethasone, Dexamethasone, Ofloxacin, or saline for 1 hour. Afterward, the ototopicals were removed and sterile broth was placed in the wells as a nutrient. This was repeated every 12 hours for 5, 10, 14, and 21 days of treatment. Prior to the last dose of treatment intervals, a streak plate was performed to evaluate for microbial growth in the wells. The tubes were evaluated for CFUs and biofilms at each interval as previously described. RESULTS: Microbial activity in CFUs decreased by day 5 and continued through day 21 for the antibiotic containing drops. Despite treatment, the biofilm was never eradicated and continued to progress. CONCLUSIONS: Infectivity of the biofilm is neutralized by antibiotic ototopicals; however, the biofilm will progress despite treatment.

The impact of a cation channel blocker (furosemide) on Pseudomonas aeruginosa PAO1 biofilm architecture.

OBJECTIVE: To determine if furosemide could have a role in inhibition of biofilm formation. STUDY DESIGN: A prospective study of 72-hour biofilms grown in the Calgary Biofilm Device (CBD) treated with furosemide and controls. METHODS: Bacteria were treated with furosemide and controls to determine its antiplanktonic properties. PA01 biofilms were treated with serial 2-fold dilutions of furosemide and controls over a 48-hour period at pH concentrations of 7.0, 8.0, and 9.0. RESULTS: Furosemide had no effect on planktonic PA01. It had minimal effect at pH below 8.0. A pH of 8.0 and 9.0 reduced biofilms 25%. Furosemide 10 mg/mL reduced biofilms 50% at pH 8.0 and 9.0. It inhibited biofilms to < 30% at concentrations of 0.6 to 0.16 mg/mL at pH 8.0 and < 10% at concentrations of 1.25 to 0.3 mg/mL at pH 9.0. CONCLUSION: Furosemide was found to be nonantiplanktonic, but does appear to destabilize preformed PA01 biofilms at pH-dependent concentrations.

Managing the complexity of a dynamic biofilm.

BACKGROUND: This article provides an overview of the history of oral microbiology, a discussion of dental plaque as both a microbial community and a biofilm, and a review of the measures available to control the oral microflora. TYPES OF STUDIES REVIEWED: The authors reviewed the literature related to oral microbiology and associated infectious diseases. They also examined articles that detailed the structure and physiology of biofilms, including dental plaque biofilms. CONCLUSIONS: Biofilms cannot be eliminated. The pathogenic nature of the dental plaque biofilm can be diminished in the oral cavity by reducing the bioburden and effectively maintaining a normal oral flora via oral hygiene procedures that include daily toothbrushing, flossing and rinsing with an antimicrobial mouthrinse. An oral hygiene regimen that includes rinsing with an antimicrobial mouthrinse is a practical approach to the prevention and management of periodontal diseases. This strategy may have wider benefits when the link between periodontal disease and certain systemic diseases is considered. CLINICAL IMPLICATIONS: An effective oral hygiene regimen can help control dental plaque biofilm and associated periodontal diseases.

Current status and future prospects of using advanced computer-based methods to study bacterial colonial morphology.

Despite the advancement of recent molecular technologies, culturing is still considered the gold standard for microbial sample analysis. Here we review three different bacterial colony-based screening modalities that provide significant information beyond the simple shape and color of the colony. The plate imaging technique provides numeration and quantitative spectral reflectance information for each colony, while Raman spectroscopic analysis of bacteria colonies relates the Raman-shifted peaks to specific chemical bonding. Finally, the elastic-light-scatter technique provides a volumetric interaction of the whole colony through laser-bacteria interactions, instantly capturing the morphological traits of the colony and allowing quantitative classifications.

Endotracheal Tubes Cleaned With a Novel Mechanism for Secretion Removal: A Randomized Controlled Clinical Study.

INTRODUCTION: Intubation compromises mucus clearance, allowing secretions to accumulate inside the endotracheal tube (ETT). The purpose of this trial was to evaluate a novel device for ETT cleaning. We hypothesized that its routine use would reduce tube occlusion due to mucus accumulation, while decreasing airway bacterial colonization. METHODS: Subjects were randomized to either the use of the device every 8 h, or the institutional standard of care (blind tracheal suction) only. ETTs were collected at extubation and analyzed with high-resolution computed tomography (HRCT) for quantification of mucus volume. Microbiological testing was performed on biofilm samples. Vital signs and ventilatory settings were collected at the bedside. In-hospital follow-up was conducted, and a final evaluation survey was completed by respiratory therapists. RESULTS: Seventy-four subjects expected to remain intubated for longer than 48 h were enrolled (77 ETTs, 37 treatment vs 40 controls). Treated tubes showed reduced mucus accumulation (0.56 ± 0.12 vs 0.71 ± 0.28 mL; P = .004) and reduced occlusion (6.3 ± 1.7 vs 8.9 ± 7.6%; P = .039). The HRCT slice showing the narrowest lumen within each ETT exhibited less occlusion in cleaned tubes (10.6 ± 8.0 vs 17.7 ± 13.4%, 95% CI: 2-12.1; P = .007). Data on microbial colonization showed a trend in the treatment group toward a reduced ETT-based biomass of bacteria known to cause ventilator-associated pneumonia. No adverse events were reported. The staff was satisfied by the overall safety and feasibility of the device. CONCLUSION: The endOclear is a safe and effective device. It prevents luminal occlusion, thereby better preserving ETT nominal function.

Micropatterned Endotracheal Tubes Reduce Secretion-Related Lumen Occlusion.

Tracheal intubation disrupts physiological homeostasis of secretion production and clearance, resulting in secretion accumulation within endotracheal tubes (ETTs). Novel in vitro and in vivo models were developed to specifically recapitulate the clinical manifestations of ETT occlusion. The novel Sharklet™ micropatterned ETT was evaluated, using these models, for the ability to reduce the accumulation of both bacterial biofilm and airway mucus compared to a standard care ETT. Novel ETTs with micropattern on the inner and outer surfaces were placed adjacent to standard care ETTs in in vitro biofilm and airway patency (AP) models. The primary outcome for the biofilm model was to compare commercially-available ETTs (standard care and silver-coated) to micropatterned for quantity of biofilm accumulation. The AP model's primary outcome was to evaluate accumulation of artificial airway mucus. A 24-h ovine mechanical ventilation model evaluated the primary outcome of relative quantity of airway secretion accumulation in the ETTs tested. The secondary outcome was measuring the effect of secretion accumulation in the ETTs on airway resistance. Micropatterned ETTs significantly reduced biofilm by 71% (p = 0.016) compared to smooth ETTs. Moreover, micropatterned ETTs reduced lumen occlusion, in the AP model, as measured by cross-sectional area, in distal (85%, p = 0.005), middle (84%, p = 0.001) and proximal (81%, p = 0.002) sections compared to standard care ETTs. Micropatterned ETTs reduced the volume of secretion accumulation in a sheep model of occlusion by 61% (p < 0.001) after 24 h of mechanical ventilation. Importantly, micropatterned ETTs reduced the rise in ventilation peak inspiratory pressures over time by as much as 49% (p = 0.005) compared to standard care ETTs. Micropatterned ETTs, demonstrated here to reduce bacterial contamination and mucus occlusion, will have the capacity to limit complications occurring during mechanical ventilation and ultimately improve patient care.

Chronic rhinosinusitis and biofilms.

BACKGROUND AND HYPOTHESIS: Biofilms have been implicated in several head and neck infectious processes such as the following: dental and periodontal disease, otitis media, tympanostomy tube otorrhea, and chronic tonsillitis. We believe that biofilms also are associated with chronic rhinosinusitis. No information is known regarding the presence of biofilms in chronic rhinosinusitis. STUDY DESIGN AND SETTING: With institutional review board approval, tissue was obtained from consenting chronic rhinosinusitis patients who were undergoing functional endoscopic sinus surgery. Specimens were taken bilaterally from the ethmoid and maxillary sinuses. Inclusion criteria consisted of a positive diagnosis with pathologic tissue confirmation of chronic inflammation. Diagnosis was based on patient history, physical exam, and coronal sinus CT findings. Once collected, the specimens were labeled and fixed in formalin. The specimens were subsequently dehydrated, with successive immersions in increasing concentrations of diluted ethanol. The specimens were allowed to air dry and then were affixed to aluminum stubs with colloidal carbon. The sample surface was coated with a gold and palladium layer. The specimens were examined under an electron microscope. Areas of interest were photographed. RESULTS: Specimens from 5 patients were examined. All revealed bacterial biofilms. Invariably, biofilms were seen in the ethmoid, as well as in other samples. Denudation of ciliated and goblet cells was noted in all specimens. Biofilms resembled that of Staphylococcus species. Unidentified biofilms were also seen. CONCLUSIONS: This is the first documentation of biofilms in association with chronic rhinosinusitis. Further investigation is warranted, especially with control research subjects.