Mask pressure effects on the nasal bridge during short-term noninvasive ventilation

Development of personalized non-invasive ventilation masks for critically ill children: a bench study

BACKGROUND

Obtaining a properly fitting non-invasive ventilation (NIV) mask to treat acute respiratory failure is a major challenge, especially in young children and patients with craniofacial abnormalities. Personalization of NIV masks holds promise to improve pediatric NIV efficiency. As current customization methods are relatively time consuming, this study aimed to test the air leak and surface pressure performance of personalized oronasal face masks using 3D printed soft materials. Personalized masks of three different biocompatible materials (silicone and photopolymer resin) were developed and tested on three head models of young children with abnormal facial features during preclinical bench simulation of pediatric NIV. Air leak percentages and facial surface pressures were measured and compared for each mask.

RESULTS

Personalized NIV masks could be successfully produced in under 12 h in a semi-automated 3D production process. During NIV simulation, overall air leak performance and applied surface pressures were acceptable, with leak percentages under 30% and average surface pressure values mostly remaining under normal capillary pressure. There was a small advantage of the masks produced with soft photopolymer resin material.

CONCLUSION

This first, proof-of-concept bench study simulating NIV in children with abnormal facial features, showed that it is possible to obtain biocompatible, personalized oronasal masks with acceptable air leak and facial surface pressure performance using a relatively short, and semi-automated production process. Further research into the clinical value and possibilities for application of personalized NIV masks in critically ill children is needed.

Feasibility, acceptability, and usability of implementing a medical device-related pressure injury algorithm for critically ill patients using non-invasive ventilation

OBJECTIVES

Describe the feasibility, acceptability, and usability of implementing a nurse-led intervention to prevent medical device-related pressure injury in critical care patients using non-invasive ventilation during hospitalization.

STUDY DESIGN

A quality improvement project, using a descriptive single-arm study design with convenience sampling.

SETTING AND PARTICIPANTS

This study was conducted at a Midwestern medical center with 640 beds (two hospital campuses). After an educational session, the nurse-led algorithm for non-invasive ventilation medical device-related pressure injury prevention was implemented in two critical care nursing units (cardiac medical progressive care and neurotrauma intensive care unit). Nursing staff were full or part-time critical care nurses.

MAIN OUTCOME MEASURES

Feasibility, acceptability, and usability of the non-invasive ventilation medical device-related pressure injury algorithm were measured (bedside rounding and pre/post System Usability Scale).

RESULTS

Thirty-five nurses (52.2 %) completed a pre-educational survey; 8 (11.2 %) completed a post-survey. The total mean pre-survey score was 70.7 (SD ± 13.6) and the post-survey mean score was 71.3(SD ± 19.6). There was a statistically significant increase in the post-survey mean score {Χ2 (1, N = 43) = 43.5, p <.05}, however, the 0.06 increase was not clinically meaningful. Bedside rounding interviews (n = 22) indicated 82 % (n = 18) of the nurses used the algorithm. The SUS tool mean score was 83.3 (10.73) pre-implementation (n = 21); and 85.63 (8.26) post-implementation (n = 5), indicating clinical usability of the algorithm pre- and post-implementation.

CONCLUSION

The feasibility, acceptability, and usability of implementing a medical device-related pressure injury algorithm for critically ill patients using non-invasive ventilation were demonstrated during this study. More nursing research is needed to develop scalable interdisciplinary clinical algorithms to reduce medical device-related pressure injuries in patients using non-invasive ventilation.

IMPLICATIONS FOR CLINICAL PRACTICE

This study focused on the bedside usability of the algorithm in a clinical setting. Implementing this nursing-developed algorithm created an interdisciplinary framework in which nursing assessment may guide clinical care.

Non-invasive Ventilation Interventions for Skin Injury Prevention: Scoping Review

BACKGROUND

Pressure ulcers associated with the non-invasive ventilation mask can significantly reduce the quality of life of the patient who needs this therapy. This study aims to identify clinical interventions to prevent skin lesions associated with the use of non-invasive ventilation medical devices.

METHODS

The Scoping Review followed the methodology of the Joanna Briggs Institute. For this study the research was carried out, during the month of January 2022, in several databases, such as PubMed, Web of Science, Scopus, EBSCOhost, RCAAP and OpenGrey, and studies published between 2010 and 2022 were included.

RESULTS

Of the 33 articles identified, 11 articles were included in this review, in which we identified several interventions for the prevention of skin lesions associated with the use of medical devices for non-invasive ventilation. The interventions identified include skin assessment, optimal fixation of the device, and the use of interfaces, namely, hydrocolloid or foam dressing under the NIV mask, among others Conclusion: This scoping review demonstrates that there is some scientific evidence for prevention, however the methodological approaches are very different, which makes it difficult to clearly describe the referenced interventions. This study was not registered.

Under-The-Nose Versus Over-The-Nose Face Mask to Prevent Facial Pressure Sores During Face Mask-Delivered Noninvasive Ventilation for Acute Hypercapnic Respiratory Failure: A Randomized Controlled Trial

OBJECTIVES

To determine whether an under-the-nose face mask (FM) as the first-line interface strategy reduces the incidence of facial pressure sores with the same clinical improvement as the one obtained by standard over-the-nose face mask-noninvasive ventilation (FM-NIV) in patients with acute hypercapnic respiratory failure (AHRF).

DESIGN

A multicenter, prospective randomized controlled study.

SETTING

Two ICUs from two French tertiary hospitals.

PATIENTS

A total of 108 patients needed NIV for AHRF.

INTERVENTIONS

participants were randomized (1/1) to receive either the under-the-nose FM (intervention group) or the over-the-nose FM (control group). The primary endpoint was the reduction of facial pressure sores. Secondary endpoints included patients outcome, NIV failure (intubation or death), arterial blood gas improvement, and interface failure (the need to switch to a total face mask).

MEASUREMENTS AND MAIN RESULTS

Despite less protective dressings in the intervention group ( n = 4, 5% vs n = 27, 51%; p < 0.001), pressure sores developed less frequently than in the control group ( n = 3, 5% vs n = 39, 74%; p < 0.001). Similar mortality, NIV failure, and arterial blood gas improvement occurred in the two groups. However, under-the-nose FM resulted in a higher interface failure rate than conventional FM ( n = 18, 33% vs n = 5, 9%; p = 0.004), mainly because of excessive unintentional air leaks ( n = 15, 83% vs n = 0, 0%; p < 0.001).

CONCLUSIONS

In patients with AHRF, under-the-nose FM significantly reduced the incidence of facial pressure sores compared to the most commonly used first-line interface, the standard FM. However, with this new mask, excessive unintentional air leaks more often compelled the attending clinician to switch to another interface to pursue NIV.

Feasibility of nasal bridge pressure injury prevention using a protective dressing and the Halyard Fluidshield® N95 mask in a COVID-positive environment

The purpose of this study was to prevent nasal bridge pressure injury among fit-tested employees, secondary to long-term wear of the N95 mask during working hours. A prospective, single-blinded, experimental cohort design. Participants were enrolled using the convenience sampling methods and randomisation was utilised for group assignment. Eligibility was determined by a COVID Anxiety Scale score and non-COVID clinical assignment. Participants with a history of previous skin injury or related condition were excluded. The experimental group was assigned Mepilex Lite® and the control group used Band- Aid®. Formal skin evaluations were done by Nurse Specialists who are certified in wound and ostomy care by the Wound, Ostomy, Continence, Nursing Certification Board (WOCNCB®). Fit test logs were provided to participants to measure subjective user feedback regarding mask fit and level of comfort. The results of this feasibility trial are promising in supporting the use of a thin polyurethane foam dressing as a safe and effective dressing to apply beneath the N95 mask. Additional research is needed to validate results due to limited data on efficacy and safety of the various barrier dressings as a potential intervention to prevent skin breakdown to the nasal bridge.

Biomechanical and Physiological Evaluation of Respiratory Protective Equipment Application

Purpose

Respiratory protective equipment is widely used in healthcare settings to protect clinicians whilst treating patients with COVID-19. However, their generic designs do not accommodate the variability in face shape across genders and ethnicities. Accordingly, they are regularly overtightened to compensate for a poor fit. The present study aims at investigating the biomechanical and thermal loads during respirator application and the associated changes in local skin physiology at the skin–device interface.

Materials and Methods

Sixteen healthy volunteers were recruited and reflected a range of gender, ethnicities and facial anthropometrics. Four single-use respirators were evaluated representing different geometries, size and material interfaces. Participants were asked to wear each respirator in a random order while a series of measurements were recorded, including interface pressure, temperature and relative humidity. Measures of transepidermal water loss and skin hydration were assessed pre- and post-respirator application, and after 20 minutes of recovery. Statistical analysis assessed differences between respirator designs and associations between demographics, interface conditions and parameters of skin health.

Results

Results showed a statistically significant negative correlation (p < 0.05) between the alar width and interface pressures at the nasal bridge, for three of the respirator designs. The nasal bridge site also corresponded to the highest pressures for all respirator designs. Temperature and humidity significantly increased (p < 0.05) during each respirator application. Significant increases in transepidermal water loss values (p < 0.05) were observed after the application of the respirators in females, which were most apparent at the nasal bridge.

Conclusion

The results revealed that specific facial features affected the distribution of interface pressures and depending on the respirator design and material, changes in skin barrier function were evident. The development of respirator designs that accommodate a diverse range of face shapes and protect the end users from skin damage are required to support the long-term use of these devices.

Quantitative Fit Test of a 3D Printed Frame Fitted Over a Surgical Mask: An Alternative Option to N95 Respirator

Background

COVID-19 has spread worldwide and caused severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to numerous dead cases. However, with the new COVID-19 outbreaks, there is a shortage of personal protective equipment (PPE) especially N95 masks worldwide including Thailand. This issue had placed the health professional in great need of an alternative mask.

Aim

This study aimed to measure the fit factor of 3D printed frames by quantitative fit testing (QNFT) to find an alternative facemask by using a mask fitter together with 2 different kinds of the American Society for Testing and Materials (ASTM) level 1 surgical mask.

Materials and Methods

Two commonly used surgical masks (Sultan Com-Fit Super Sensitive Ear Loop Mask or “White Mask Group,” not water-resistant, and Sultan Blue Com-Fit Super High Filtration Ear Loop Mask or “Blue Mask Group,” water-resistant) with and without 3D printed frame covering. The fit performance was measured by a quantitative fit test (QNFT) device (PortaCount, model 8048, TSI Incorporated, Minnesota, USA) accepted by the Occupational Safety and Health Administration (OSHA). The PortaCount device, which is based on a miniature continuous flow condensation nucleus counter (CNC), assesses the respiratory fit by comparing the concentration of ambient dust particles outside the surgical mask to the concentration that has leaked into the surgical mask. The ratio of these two concentrations (C_out/C_in) is called the fit factor. A fit factor of a 3D printed frame of at least 100 is required and considered as a pass level.

Results

We found that the mask fitter improves the overall performance of surgical masks significantly. The improved performance is comparable to that of N95.

Conclusion

The mask fitter improves the performance of surgical masks. The authors suggested that further study on frame material, shape, and expanded sample size would be beneficial to society.

Reduced Air Leakage During Non-Invasive Ventilation Using a Simple Anesthetic Mask With 3D-Printed Adaptor in an Anthropometric Based Pediatric Head-Lung Model

Non-invasive ventilation (NIV) is increasingly used in the support of acute respiratory failure in critically ill children admitted to the pediatric intensive care unit (PICU). One of the major challenges in pediatric NIV is finding an optimal fitting mask that limits air leakage, in particular for young children and those with specific facial features. Here, we describe the development of a pediatric head-lung model, based on 3D anthropometric data, to simulate pediatric NIV in a 1-year-old child, which can serve as a tool to investigate the effectiveness of NIV masks. Using this model, the primary aim of this study was to determine the extent of air leakage during NIV with our recently described simple anesthetic mask with a 3D-printed quick-release adaptor, as compared with a commercially available pediatric NIV mask. The simple anesthetic mask provided a better seal resulting in lower air leakage at various positive pressure levels as compared with the commercial mask. These data further support the use of the simple anesthetic mask as a reasonable alternative during pediatric NIV in the acute setting. Moreover, the pediatric head-lung model provides a promising tool to study the applicability and effectiveness of customized pediatric NIV masks in the future.

The biomechanical efficacy of a hydrogel-based dressing in preventing facial medical device-related pressure ulcers

Continuous positive airway pressure masks for breathing assistance are used widely during the coronavirus pandemic. Nonetheless, these masks endanger the viability of facial tissues even after a few hours because of the sustained tissue deformations and extreme microclimate conditions. The risk of developing such device-related pressure ulcers/injuries can be reduced through suitable cushioning materials at the mask-skin interface, to alleviate localised contact forces. Here, we determined the facial tissue loading state under an oral-nasal mask while using hydrogel-based dressing cuts (Paul Hartmann AG, Heidenheim, Germany) for prophylaxis, which is a new concept in prevention of device-related injuries. For this purpose, we measured the compressive mask-skin contact forces at the nasal bridge, cheeks, and chin with vs without these dressing cuts and fed these data to a finite element, adult head model. Model variants were developed to compare strain energy densities and effective stresses in skin and through the facial tissue depth, with vs without the dressing cuts. We found that the dry (new) dressing cuts reduced tissue exposures to loads (above the median loading level) by at least 30% at the nasal bridge and by up to 99% at the cheeks, across the tissue depth. These dressing cuts were further able to maintain at least 65% and 89% of their protective capacity under moisture at the nasal bridge and cheeks, respectively. The hydrogel-based dressings demonstrated protective efficacy at all the tested facial sites but performed the best at the nasal bridge and cheeks, which are at the greatest injury risk.

Validation of a numerical model for the mechanical behavior of a continuous positive airway pressure mask

Finite Element models (FEM) are developed for the analysis of the contact pressures exerted by a Continuous Positive Airway Pressure (CPAP) mask applied to a dummy head. This is seen as a preliminary step in the analysis of the mechanical effects of CPAP masks applied to human faces, such as recently employed for the care of COVID-19 patients, or other purposes. These mechanical effects can range from negligible, in the case of correct positioning, sufficiently light tension in the headgear, correct mask design, etc., to the possible development of device-related pressure ulcers and/or dentofacial deformations, especially in children. The results of Finite Element analyses are compared, for their validation, with experimental ones. The numerical analysis tool appears able to predict, at an acceptable cost, both the intensity and the area distribution of the contact pressures, as well as the force-displacement relationship occurring in the headgear. This might help the design and the production of more effective and tolerable CPAP masks.

In Vitro Evaluation of Facial Pressure and Air Leak with a Newly Designed Cushion for Non-Invasive Ventilation Masks

Background: The aim of this study was to evaluate the effect of a newly designed foam cushion on the air leakage and pressure when applied to the face. Methods: A teaching manikin connected to a bilevel positive airway pressure ventilator attached to four different brands of oronasal masks (Amara, Mirage, Forma, and Wizard) was used. The foam cushions of 5-mm and 10-mm-thickness were attached to the masks, and each mask was tested without a cushion. Six pressure sensors were placed on the manikin’s face, and data were recorded. Inspiratory volume and air leak flow from the ventilator were observed. Results: Air leakage was influenced by both the mask brand and the presence of a cushion. The presence of a cushion did not affect the Wizard mask in terms of leakage (p = 0.317) or inspiratory volume (p = 0.726). The Wizard and Amara masks generated the lowest contact pressure on the frontal forehead (p < 0.001) compared to the other five points. Conclusions: Utilisation of a cushion reduces air leakage and maintains greater inspiratory volume regardless of its thickness. The contact pressure varies depending on the brand of the mask, which would require a difference in the thickness of the cushion for pressure reduction.

A 3D registration methodology to evaluate the goodness of fit at the individual-respiratory mask interface

Respiratory masks are used to deliver non-invasive ventilation for cardiorespiratory pathologies. Masks must minimize skin tissue compression while maintaining a seal at the interface. Ill-fitting masks or those applied too tightly are implicated in pressure ulcer formation. This study aimed to analyse respiratory mask goodness of fit in a cohort of face shapes. A number of parameters were identified and analysed with a novel registration protocol. In the majority of cases, mask indentation exceeded the thickness of the interface material and significant gapping was observed. The size range was most appropriate for males, with only one size suitable for females.

Material and Technology: Back to the Future for the Choice of Interface for Non-Invasive Ventilation - A Concise Review

Non-invasive ventilation (NIV) has dramatically changed the treatment of both acute and chronic respiratory failure in the last 2 decades. The success of NIV is correlated to the application of the "best ingredients" of a patient's "tailored recipe," including the appropriate choice of the selected candidate, the ventilator setting, the interface, the expertise of the team, and the education of the caregiver. The choice of the interface is crucial for the success of NIV. Type (oral, nasal, nasal pillows, oronasal, hybrid mask, helmet), size, design, material and headgears may affect the patient's comfort with respect to many aspects, such as air leaks, claustrophobia, skin erythema, eye irritation, skin breakdown, and facial deformity in children. Companies are paying great attention to mask development, in terms of shape, materials, comfort, and leak reduction. Although the continuous development of new products has increased the availability of interfaces and the chance to meet different requirements, in patients necessitating several daily hours of NIV, both in acute and in chronic home setting, the rotational use of different interfaces may remain an excellent strategy to decrease the risk of skin breakdown and to improve patient's tolerance. The aim of the present review was to give the readers a background on mask technology and materials in order to enhance their "knowledge" in making the right choice for the interface to apply during NIV in the different clinical scenarios.

Injection Molded Autoclavable, Scalable, Conformable (iMASC) system for aerosol-based protection: a prospective single-arm feasibility study

OBJECTIVE

To develop and test a new reusable, sterilisable N95 filtering facepiece respirator (FFR)-comparable face mask, known as the Injection Molded Autoclavable, Scalable, Conformable (iMASC) system, given the dire need for personal protective equipment within healthcare settings during the COVID-19 pandemic.

DESIGN

Single-arm feasibility study.

SETTING

Emergency department and outpatient oncology clinic.

PARTICIPANTS

Healthcare workers who have previously undergone N95 fit testing.

INTERVENTIONS

Fit testing of new iMASC system.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome is success of fit testing using an Occupational Safety and Health Administration (OSHA)-approved testing method, and secondary outcomes are user experience with fit, breathability and filter replacement.

RESULTS

Twenty-four subjects were recruited to undergo fit testing, and the average age of subjects was 41 years (range of 21-65 years) with an average body mass index of 26.5 kg/m². The breakdown of participants by profession was 46% nurses (n=11), 21% attending physicians (n=5), 21% resident physicians (n=5) and 12% technicians (n=3). Of these participants, four did not perform the fit testing due to the inability to detect saccharin solution on premask placement sensitivity test, lack of time and inability to place mask over hair. All participants (n=20) who performed the fit test were successfully fitted for the iMASC system using an OSHA-approved testing method. User experience with the iMASC system, as evaluated using a Likert scale with a score of 1 indicating excellent and a score of 5 indicating very poor, demonstrated an average fit score of 1.75, breathability of 1.6, and ease of replacing the filter on the mask was scored on average as 2.05.

CONCLUSIONS

The iMASC system was shown to successfully fit multiple different face sizes and shapes using an OSHA-approved testing method. These data support further certification testing needed for use in the healthcare setting.

Injection Molded Autoclavable, Scalable, Conformable (iMASC) system for aerosol-based protection: a prospective single-arm feasibility study

OBJECTIVE

To develop and test a new reusable, sterilisable N95 filtering facepiece respirator (FFR)-comparable face mask, known as the Injection Molded Autoclavable, Scalable, Conformable (iMASC) system, given the dire need for personal protective equipment within healthcare settings during the COVID-19 pandemic.

DESIGN

Single-arm feasibility study.

SETTING

Emergency department and outpatient oncology clinic.

PARTICIPANTS

Healthcare workers who have previously undergone N95 fit testing.

INTERVENTIONS

Fit testing of new iMASC system.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome is success of fit testing using an Occupational Safety and Health Administration (OSHA)-approved testing method, and secondary outcomes are user experience with fit, breathability and filter replacement.

RESULTS

Twenty-four subjects were recruited to undergo fit testing, and the average age of subjects was 41 years (range of 21-65 years) with an average body mass index of 26.5 kg/m². The breakdown of participants by profession was 46% nurses (n=11), 21% attending physicians (n=5), 21% resident physicians (n=5) and 12% technicians (n=3). Of these participants, four did not perform the fit testing due to the inability to detect saccharin solution on premask placement sensitivity test, lack of time and inability to place mask over hair. All participants (n=20) who performed the fit test were successfully fitted for the iMASC system using an OSHA-approved testing method. User experience with the iMASC system, as evaluated using a Likert scale with a score of 1 indicating excellent and a score of 5 indicating very poor, demonstrated an average fit score of 1.75, breathability of 1.6, and ease of replacing the filter on the mask was scored on average as 2.05.

CONCLUSIONS

The iMASC system was shown to successfully fit multiple different face sizes and shapes using an OSHA-approved testing method. These data support further certification testing needed for use in the healthcare setting.

Interpersonal differences in the friction response of skin relate to FTIR measures for skin lipids and hydration

Understanding the mechanical response of skin to contact is of importance when developing products that interact with the skin. The shear forces that arise due to friction in the interface are a key aspect of skin interactions, because shear is known to contribute to discomfort and tissue injury. However, the frictional response of skin shows large variations between people. It has been hypothesised that these variations relate to differences between people in the physiological properties of their skin, but the underlying mechanisms are not well understood. In order to gain new insights into these interpersonal differences in friction behaviour, in vivo FTIR measurements and in vivo friction measurements were performed on the same patch of skin. Quantitative analysis of the various peaks in the FTIR spectra provided information on the moisture content of the stratum corneum and the amount and mechanical properties of the lipids on the skin. The lipid viscosity, as characterised by the width of the 2920 cm^-1 peak, correlates with the friction, whilst, interestingly, no relationship was found between the quantity of lipids on the skin surface and the coefficient of friction. Additionally, and as expected, a fairly strong correlation was obtained between the moisture content, as characterised by the height of the Amide I peak and the coefficient of friction. The presented results show that spectroscopy techniques can be used in as a non-invasive method to identify people who may show elevated levels of friction and thus are at increased risk of developing shear induced tissue injury.

Bioengineering considerations in the prevention of medical device-related pressure ulcers

BACKGROUND

In recent years, it has become increasingly apparent that medical device-related pressure ulcers represent a significant burden to both patients and healthcare providers. Medical devices can cause damage in a variety of patients from neonates to community based adults. To date, devices have typically incorporated generic designs with stiff polymer materials, which impinge on vulnerable soft tissues. As a result, medical devices that interact with the skin and underlying soft tissues can cause significant deformations due to high interface pressures caused by strapping or body weight.

METHODS

This review provides a detailed analysis of the latest bioengineering tools to assess device related skin and soft tissue damage and future perspectives on the prevention of these chronic wounds. This includes measurement at the device-skin interface, imaging deformed tissues, and the early detection of damage through biochemical and biophysical marker detection. In addition, we assess the potential of computational modelling to provide a means for device design optimisation and material selection.

INTERPRETATION

Future collaboration between academics, industrialists and clinicians should provide the basis to improve medical device design and prevent the formation of these potentially life altering wounds. Ensuring clinicians report devices that cause pressure ulcers to regulatory agencies will provide the opportunity to identify and improve devices, which are not fit for purpose.