Interventional Study of Nonpharmaceutical Measures to Prevent COVID-19 Aboard Cruise Ships.

Cruise ships carrying COVID-19-vaccinated populations applied near-identical nonpharmaceutical measures during July-November 2021; passenger masking was not applied on 2 ships. Infection risk for masked passengers was 14.58 times lower than for unmasked passengers and 19.61 times lower than in the community. Unmasked passengers' risk was slightly lower than community risk.

Utilizing Carbon Dots Derived from Waste Face Masks for Pentachlorophenol Detection.

Pentachlorophenol is a very toxic chemical that is used as a pesticide, fungicide, herbicide, wood preservative, etc., and it should be monitored in terms of human health and environmental production. Another environmental problem is the increase in the use of facemasks, especially during the COVID-19 pandemic. This study provides a value added chemicals to sustainability of recycling process. Fluorescent carbon dots (CDs) were synthesized from waste facemasks and investigated their fluorescence sensor performances. UV-Vis and fluorescence spectra of the synthesized carbon dots were recorded in different organic solvents. The sensor properties of these carbon dots against pesticides were investigated, and a 'turn-off' response was observed toward pentachlorophenol. The limit of detection was found 8.5 µM in the linear range from 43.3 µM to 375 µM. This study showed that waste plastics such as facemasks can be recycled to obtain carbon dots, which are used in different technological areas such as photocatalysis, bioimaging, etc., as well as in sensors.

Effectiveness of preoxygenation strategies: a systematic review and network meta-analysis.

BACKGROUND: Preoxygenation is universally recommended before induction of general anaesthesia to prolong safe apnoea time. The optimal technique for preoxygenation is unclear. We conducted a systematic review to determine the preoxygenation technique associated with the greatest effectiveness in adult patients having general anaesthesia. METHODS: We searched six databases for randomised controlled trials of patients aged ≥16 yr, receiving general anaesthesia in any setting and comparing different preoxygenation techniques and methods. Our primary effectiveness outcome was safe apnoea time, and secondary outcomes included incidence of arterial oxygen desaturation; lowest SpO2 during airway management; time to end-tidal oxygen concentration of 90%; and [Formula: see text] and [Formula: see text] at the end of preoxygenation. We assessed the quality of evidence according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) recommendations. RESULTS: We included 52 studies of 3914 patients. High-flow nasal oxygen with patients in a head-up position was most likely to be associated with a prolonged safe apnoea time when compared with other strategies, with a mean difference (95% credible interval) of 291 (138-456) s and 203 (79-343) s compared with preoxygenation with a facemask in the supine and head-up positions, respectively. Subgroup analysis of studies without apnoeic oxygenation also showed high-flow nasal oxygen in the head-up position as the highest ranked technique, with a statistically significantly delayed mean difference (95% credible interval) safe apnoea time compared with facemask in supine and head-up positions of 222 (63-378) s and 139 (15-262) s, respectively. High-flow nasal oxygen was also the highest ranked technique for increased [Formula: see text] at the end of preoxygenation. However, the incidence of arterial desaturation was less likely to occur when a facemask with pressure support was used compared with other techniques, and [Formula: see text] was most likely to be lowest when preoxygenation took place with patients deep breathing in a supine position. CONCLUSIONS: Preoxygenation of adults before induction of general anaesthesia was most effective in terms of safe apnoea time when performed with high-flow nasal oxygen with patients in the head-up position in comparison with facemask alone. Also, high-flow nasal oxygen in the head-up position is likely to be the most effective technique to prolong safe apnoea time among those evaluated. Clinicians should consider this technique and patient position in routine practice. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42022326046.

Exploring the impact of parents' face-mask wearing on dyadic interactions in infants at higher likelihood for autism compared with general population.

Since the COVID-19 pandemic, both the public and researchers have raised questions regarding the potential impact of protective face-mask wearing on infants' development. Nevertheless, limited research has tested infants' response to protective face-mask wearing adults in real-life interactions and in neurodiverse populations. In addition, scarce attention was given to changes in interactive behavior of adults wearing a protective face-mask. The aims of the current study were (1) to examine differences in 12-month-old infants' behavioral response to an interactive parent wearing a protective face-mask during face-to-face interaction, (2) to investigate potential differences in infants at higher likelihood for autism (HL-ASD) as compared with general population (GP) counterparts, and (3) to explore significant differences in parents' behaviors while wearing or not wearing a protective face-mask. A total of 50 mother-infant dyads, consisting of 20 HL-ASD infants (siblings of individuals with autism) and 30 GP infants, participated in a 6-min face-to-face interaction. The interaction was videotaped through teleconferencing and comprised three 2-min episodes: (a) no mask, (b) mask, and (c) post-mask. Infants' emotionality and gaze direction, as well as mothers' vocal production and touching behaviors, were coded micro-analytically. Globally, GP infants exhibited more positive emotionality compared with their HL-ASD counterparts. Infants' negative emotionality and gaze avoidance did not differ statistically across episodes. Both groups of infants displayed a significant increase in looking time toward the caregiver during the mask episode. No statistically significant differences emerged in mothers' behaviors. These findings suggest that the use of protective face-masks might not negatively affect core dimensions of caregiver-infant interactions in GP and HL-ASD 12-month-old infants.

Facial growth dynamics dictate optimal facemask fitting during the first year of life.

AIM: The aim of this study is to prevent mask leak during ventilation in infant emergencies, appropriate facemask fitting is essential. Therefore, we investigated facial profiles during the first year of life and their correlation with the correct sizing of masks. METHODS: This is a post hoc subgroup analysis of 32 healthy term infants, based on a prospective observational study performed from September 2018 to December 2019 in Tuebingen, Germany. In 3-monthly intervals, facial aspects were measured based on anatomical landmarks in three-dimensional frontal photographs to describe their changes across the first year of life. All infants were awake and breathing spontaneously; none required any anaesthesia. RESULTS: In 130 3D images, mean distance between nasion and gnathion was 54 mm (3.3) measured at birth and 70 mm (3.5) at age 12 months. Gompertz models showed relevant growth-related changes in the facial profile in vertical but not horizontal direction. Vertical growth occurred mainly in the first 6 months. Boys and girls differed by an average of about 2 mm (boys >girls). CONCLUSION: Based on our findings, it should now be verified whether the 50 mm facemasks are suitable for infants from birth to 2 months of age, respectively, the 60 mm version for infants aged three to 12 months.

Cephalometric changes of pushing splints 3 compared to rapid maxillary expansion and facemask therapy on the airway space in class III growing patients: A randomized clinical trial.

BACKGROUND: Early orthopaedic treatment with rapid maxillary expansion (RME) associated with facemask (FM) has been shown to be effective in correcting Class III malocclusions in children. Treatment with pushing splints 3 (PS3) has shown to correct skeletal discrepancies in Class III growing patients. However, the effects of orthopaedic treatment on the upper airways in children with Class III malocclusion is controversial. OBJECTIVES: The aim of this study was to evaluate the cephalometric changes in the airways of PS3 compared to the RME/FM protocol. MATERIALS AND METHODS: In this study, 48 patients with Class III malocclusion (age range 5.5-8.5 years old) were selected for this study, and 24 were treated with PS3 appliance and 24 with RME/FM therapy. Lateral cephalograms before (T0) and at the end of the treatment (T1) were analysed to compare pharyngeal spaces. Paired and unpaired t tests were used for data analysis (P < .05). RESULTS: A total of 41 patients (21 patients for the PS3 group, 11 males and 10 females, mean age 7.0 ± 1.2 years; 20 patients for the RME/FM group, 10 males and 10 females, mean age 7.2 ± 1.3 years) were included. The results showed a statistically significant (P < .05) increase in the nasopharyngeal space after both therapies. However, the effects were similar considering that there were no differences between groups for the assessed variables at T0-T1. CONCLUSIONS: Early treatment of Class III malocclusion with PS3 does not induce a statistically significant increase in the sagittal airway space compared to RME/FM. The absence of untreated group could not define the role of growth in the increase of space.

A comparison of maxillary posterior changes following facemask therapy: Skeletal anchorage versus tooth-borne anchorage.

OBJECTIVE: To compare changes in the maxillary posterior structure as seen in cone-beam computed tomography (CBCT) images resulting from facemask therapy using skeletal (miniplate/FM) anchorage versus tooth-borne anchorage (RME/FM). MATERIALS AND METHODS: A retrospective study was conducted on 20 patients divided into the miniplate/FM group (nine patients aged 9.5 ± 1.4 years) and the RME/FM group (11 patients aged 9.2 ± 1.4 years). CBCT images before and after facemask therapy were evaluated to assess changes in the maxillary posterior structure. RESULTS: The miniplate/FM group had greater advancement of the maxilla and midface compared to the RME/FM group (p < .05). Specifically, there was about three times more advancement of the pterygomaxillary suture in the miniplate/FM group than in the RME/FM group (p < .05). Moreover, the advancement of the pterygomaxillary suture was about half the advancement of A point in the miniplate/FM group, while only about 25% in the RME/FM group. Finally, the miniplate/FM group showed an increase in the transverse dimension of the posterior and superior parts of the maxilla (p < .05). CONCLUSION: There was greater forward movement of the pterygomaxillary suture with facemask therapy using the skeletal anchorage compared to tooth-borne anchorage, leading to a more significant advancement of the maxilla and midface.

Does the use of surgical face masks reduce postoperative infections in traumatic wounds sutured outside hospital? A randomized study at a Norwegian casualty center.

OBJECTIVE: To investigate if wearing surgical face mask by doctors and nurses during suturing of traumatic wounds has any impact on postoperative infection rate. DESIGN: Randomized controlled study with masked or unmasked health personnel groups. SETTING: A Norwegian Minor Injury Department. SUBJECTS: Adult patients with traumatic wounds sutured at the clinic between 7 October 2019 and 28 May 2020. MAIN OUTCOME MEASURES: Postoperative infections of sutured wounds. RESULTS: One hundred and sixty-five patients with 176 wounds were included in the study. Nine out of 88 wounds (10.2%) in the masked group and 11 out of 88 wounds in the unmasked group (12.5%) had a wound infection. CONCLUSIONS: Despite a higher percentage of postoperative infections in the unmasked than in the masked group (12.5% versus 10.2%), the difference was not statistically significant (p = .6). This might imply that the use of facemasks during suture of traumatic wounds in an outpatient setting does not significantly reduce the number of infections. However, due to the covid pandemic, the study had to be prematurely stopped before the planned number of participants had been recruited (n = 594). This increases the risk of type II error.

Few studies from hospital setting have found significant difference in postoperative wound infections if surgical face masks were worn or not during surgery.High quality studies about face masks and wound infections from primary care are lacking.This randomized study at a minor injury department outside hospital found no significant difference in frequency of postoperative wound infection if health personnel had worn surgical face masks or not while suturing traumatic wounds.

Towards the Instrumentation of Facemasks Used as Personal Protective Equipment for Unobtrusive Breathing Monitoring of Workers.

This study focuses on the integration and validation of a filtering face piece 3 (FFP3) facemask module for monitoring breathing activity in industrial environments. The key objective is to ensure accurate, real-time respiratory rate (RR) monitoring while maintaining workers' comfort. RR monitoring is conducted through temperature variations detected using temperature sensors tested in two configurations: sensor t1, integrated inside the exhalation valve and necessitating structural mask modifications, and sensor t2, mounted externally in a 3D-printed structure, thus preserving its certification as a piece of personal protective equipment (PPE). Ten healthy volunteers participated in static and dynamic tests, simulating typical daily life and industrial occupational activities while wearing the breathing activity monitoring module and a chest strap as a reference instrument. These tests were carried out in both indoor and outdoor settings. The results demonstrate comparable mean absolute error (MAE) for t1 and t2 in both indoor (i.e., 0.31 bpm and 0.34 bpm) and outdoor conditions (i.e., 0.43 bpm and 0.83 bpm). During simulated working activities, both sensors showed consistency with MAE values in static tests and were not influenced by motion artifacts, with more than 97% of RR estimated errors within ±2 bpm. These findings demonstrate the effectiveness of integrating a smart module into protective masks, enhancing occupational health monitoring by providing continuous and precise RR data without requiring additional wearable devices.

Oral Health Assessment in Cleft Lip & Palate Patients During Orthodontic Treatment for Maxillary Protraction: A Periodontal & Microbiological Study.

OBJECTIVE: To assess the oral health status and microbiota of subgingival plaque in patients with surgically repaired cleft lip and palate (CLP) during orthodontic treatment for maxillary protraction with two different orthodontic appliances. DESIGN: Randomized controlled trial. SETTING: Institutional. PARTICIPANTS: A total of 90 patients with surgically repaired Unilateral Cleft Lip and Palate, out of initially enrolled 120 patients, were divided into 3 groups: experimental group I, experimental group II and control group, with 30 subjects each. Patients with a history of oral prophylaxis in last 6 months or antibiotic therapy within 3 months were excluded from the study. INTERVENTIONS: Bone Anchored Maxillary Protraction was done in experimental group I, while facemask with acrylic occlusal splint was used for maxillary protraction in experimental group II and no orthodontic intervention in control group. MEAN OUTCOME MEASURES: Plaque Index (PI), Gingival Index (GI), Gingival Bleeding Index (GBI), Probing Depth (PD), and microbiota of subgingival plaque (P. gingivalis, P. intermedia, Veillonella and Capnocytophaga) were compared at baseline (T0) and after 8 months (T1). RESULTS: The PI, GI, GBI and PD were observed to be significantly higher in experimental group II followed by experimental group I as compared to control group at 8 months interval (P < .001). The microbiota counts increased significantly in experimental group II and experimental group I (P < .001), as compared to control group. CONCLUSION: Maxillary protraction with facemask and bone plates was found to be a better alternative than facemask with occlusal splint, considering the overall oral health of patients with CLP.

Design of customizable personal protective equipment for 3-D printing: Performance evaluation of N95 respirators using computational fluid dynamics.

3-D printing the structural components of facemasks and personal protective equipment (PPE) based on 3-D facial scans creates a high degree of customizability. As a result, the facemask fits more comfortably with its user's specific facial characteristics, filters contaminants more effectively with its increased sealing effect, and minimizes waste with its cleanable and reusable plastic structure compared to other baseline models. In this work, 3-D renditions of the user's face taken with smartphone laser scanning techniques were used to generate customized computer-aided design (CAD) models for the several components of an N95 respirator, which are each designed with considerations for assembly and 3-D printing constraints. Thorough analyses with computational fluid dynamics (CFD) simulations were carried out to verify the respirator's efficiency in filtering airborne contaminants to comply with industry safety guidelines and generate data to showcase the relationships between various input and output design parameters. This involved a comparative study to identify the ideal cross-sectional geometry of exposed filter fabric, a sensitivity study to evaluate the respirator's ability to protect the user in various scenarios, and the 3-D printing of several prototypes to estimate printing time, cost of materials, and comfort level at the user's face. Results showed that the combination of different digital tools can increase efficiency in the design, performance assessment, and production of customized N95-rated respirators.

Impact of Concurrent Use of N95 and Surgical Masks on Peripheral Oxygen Saturation and Heart Rate Frequency-A Prospective Study during the COVID-19 Outbreak.

Background and Objectives: The COVID-19 outbreak has necessitated the prolonged use of N95 facemasks in addition to traditional surgical facemasks by healthcare workers. The aim of this study was to investigate the effect of wearing N95 facemasks in addition to surgical facemasks on peripheral oxygen saturation (SpO2) and heart rate (HR) among dental professionals during routine care. Materials and Methods: This prospective study compared SpO2 and HR between dental providers wearing N95 + surgical facemasks vs. wearing a surgical facemask only. SpO2 and HR were recorded using a portable pulse oximeter before wearing the facemask (T0); at 30 min (T1); at 1 h (T2); and at the end of clinical activity (T3). Inter-group and intra-group differences were assessed with independent t tests and repeated measures ANOVA, respectively. Results: A total of 88 participants (57 wearing N95 + surgical facemasks, and 31 wearing a surgical facemask only) completed the study. The two groups did not statistically differ in SpO2 at different timepoints nor showed any intra-group differences. The participants wearing N95 + surgical facemasks exhibited a statistically higher HR at T0 (p = 0.007), T2 (p = 0.010), and T3 (p = 0.014) compared to those wearing a surgical facemask only. A statistically significant decrease was observed in HR between T0 and T3 in those wearing N95 + surgical facemasks (p = 0.012). No intra-group differences were seen in HR over time in those wearing a surgical facemask only. Conclusions: The continuous use of an N95 in addition to a surgical facemask did not show any significant effects in SpO2 during routine care; however, the concurrent use of an N95 and a surgical facemask seemed to be accompanied by a decrease in HR, although the values remained within the normal range.

Comparative effectiveness of N95, surgical or medical, and non-medical facemasks in protection against respiratory virus infection: A systematic review and network meta-analysis.

The aim of this systematic review and network meta-analysis is to evaluate the comparative effectiveness of N95, surgical/medical and non-medical facemasks as personal protective equipment against respiratory virus infection. The study incorporated 35 published and unpublished randomized controlled trials and observational studies investigating specific mask effectiveness against influenza virus, SARS-CoV, MERS-CoV and SARS-CoV-2. We searched PubMed, Google Scholar and medRxiv databases for studies published up to 5 February 2021 (PROSPERO registration: CRD42020214729). The primary outcome of interest was the rate of respiratory viral infection. The quality of evidence was estimated using the GRADE approach. High compliance to mask-wearing conferred a significantly better protection (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.23-0.82) than low compliance. N95 or equivalent masks were the most effective in providing protection against coronavirus infections (OR, 0.30; CI, 0.20-0.44) consistently across subgroup analyses of causative viruses and clinical settings. Evidence supporting the use of medical or surgical masks against influenza or coronavirus infections (SARS, MERS and COVID-19) was weak. Our study confirmed that the use of facemasks provides protection against respiratory viral infections in general; however, the effectiveness may vary according to the type of facemask used. Our findings encourage the use of N95 respirators or their equivalents (e.g., P2) for best personal protection in healthcare settings until more evidence on surgical and medical masks is accrued. This study highlights a substantial lack of evidence on the comparative effectiveness of mask types in community settings.

Difficult or impossible facemask ventilation in children with difficult tracheal intubation: a retrospective analysis of the PeDI registry.

BACKGROUND: Difficult facemask ventilation is perilous in children whose tracheas are difficult to intubate. We hypothesised that certain physical characteristics and anaesthetic factors are associated with difficult mask ventilation in paediatric patients who also had difficult tracheal intubation. METHODS: We queried a multicentre registry for children who experienced "difficult" or "impossible" facemask ventilation. Patient and case factors known before mask ventilation attempt were included for consideration in this regularised multivariable regression analysis. Incidence of complications, and frequency and efficacy of rescue placement of a supraglottic airway device were also tabulated. Changes in quality of mask ventilation after injection of a neuromuscular blocking agent were assessed. RESULTS: The incidence of difficult mask ventilation was 9% (483 of 5453 patients). Infants and patients having increased weight, being less than 5th percentile in weight for age, or having Treacher-Collins syndrome, glossoptosis, or limited mouth opening were more likely to have difficult mask ventilation. Anaesthetic induction using facemask and opioids was associated with decreased risk of difficult mask ventilation. The incidence of complications was significantly higher in patients with "difficult" mask ventilation than in patients without. Rescue placement of a supraglottic airway improved ventilation in 71% (96 of 135) of cases. Administration of neuromuscular blocking agents was more frequently associated with improvement or no change in quality of ventilation than with worsening. CONCLUSIONS: Certain abnormalities on physical examination should increase suspicion of possible difficult facemask ventilation. Rescue use of a supraglottic airway device in children with difficult or impossible mask ventilation should be strongly considered.

Preventing difficult facemask ventilation in children: all is well that starts well.

Difficult facemask ventilation at induction of general anaesthesia can trigger hypoxaemia and inadequate ventilation if not immediately identified and adequately treated. For this reason, identification of predisposing conditions before induction of anaesthesia and causes of poor facemask ventilation are critical to avoid the subsequent complications. In a recently published secondary analysis of the Paediatric Difficult Intubation (PeDI) registry, the incidence and risk factors for difficult facemask ventilation in children with difficult tracheal intubation was described, as highlighted in the editorial.

Pressure-controlled versus manual facemask ventilation for anaesthetic induction in adults: A randomised controlled non-inferiority trial.

BACKGROUND: Pressure-controlled face mask ventilation (PC-FMV) with positive end-expiratory pressure (PEEP) after apnoea following induction of general anaesthesia prolongs safe apnoea time and reduces atelectasis formation. However, depending on the set inspiratory pressure, a delayed confirmation of a patent airway might occur. We hypothesised that by lowering the peak inspiratory pressure (PIP) when using PC-FMV with PEEP, confirmation of a patent airway would not be delayed as studied by the first return of CO2 , compared with manual face mask ventilation (Manual FMV). METHODS: This was a single-centre, randomised controlled non-inferiority trial. Seventy adult patients scheduled for elective day-case surgery under general anaesthesia with body mass index between 18.5 and 29.9 kg m-2 , American Society of Anesthesiologists (ASA) classes I-III, and without anticipated difficult FMV, were included. Before the start of pre-oxygenation and induction of general anaesthesia, participants were randomly allocated to receive ventilation with either PC-FMV with PEEP, at a PIP of 11 and a PEEP of 6 cmH2 O or Manual FMV, with the adjustable pressure-limiting valve set at 11 cmH2 O. The primary outcome variable was the number of ventilatory attempts needed until confirmation of a patent airway, defined as the return of at least 1.3 kPa CO2 . RESULTS: The return of ≥1.3 kPa CO2 on the capnography curve was observed after mean ± SD, 3.6 ± 4.2 and 2.5 ± 1.9 ventilatory attempts/breaths with PC-FMV with PEEP and Manual FMV, respectively. The difference in means (1.1 ventilatory attempts/breaths) had a 99% CI of -1.0 to 3.1, within the accepted upper margin of four breaths for non-inferiority. CONCLUSION: Following induction of general anaesthesia, PC-FMV with PEEP was used without delaying a patent airway as confirmed with capnography, if moderate pressures were used.

Effect of Facemask in Congenital Central Hypoventilation Syndrome.

INTRODUCTION: Congenital central hypoventilation syndrome (CCHS) is a rare genetic disorder with a mutation in the PHOX2B gene. Patients need ventilatory support by noninvasive ventilation or tracheostomy to treat alveolar hypoventilation. Patients with CCHS have a defect in chemosensitivity signal integration. Recently, due to the COVID-19 pandemic, the entire world has had to get used to wearing medical masks (MM). OBJECTIVES: The aim of the study was to evaluate the effect of an MM on gas exchange and to determine the role of central and peripheral chemoresponsiveness on the partial pressure of transcutaneous carbon dioxide (PtcCO2) in patients with CCHS wearing an MM. METHODS: This study was based on the analysis of recordings obtained without and with an MM during hospitalization and was conducted to assess the impact of MM on PtcCO2 and SpO2 recordings with the SenTec Digital Monitor and their relationships with peripheral CO2 chemosensitivity obtained during tidal breathing measurement and with the hypercapnic hyperoxic ventilatory response. RESULTS: Sixteen patients were included (13 boys) and were 10.2 (7.5; 18.5) years old. The use of an MM had a negative impact on gas exchange in patients with CCHS. The median PtcCO2 increased significantly. Peripheral chemosensitivity correlated with MM-induced PtcCO2 changes (R = -0.72, p = 0.005), but central chemosensitivity (the hypercapnic ventilator response slope) did not (R = -0.22, p = 0.510). CONCLUSION: The use of an MM had a negative impact on gas exchange in patients with CCHS.

Determining the filtration effectiveness of non-standard respiratory protective devices by an ad-hoc laboratory methodology.

The recent pandemic caused by COVID-19 profoundly changed people's habits. Wearing a face mask has become usual in everyday life to reduce the risk of infection from airborne diseases. At the beginning of the pandemic, the massive request of surgical or filtering face piece (FFP) masks resulted in a global shortage of these devices for the most exposed people, such as healthcare workers. Due to this high demand for respiratory protective devices, many industrial plants have partly converted to the production of face masks using adapted materials and not complying with any specific regulation (non-standard respiratory protective devices or community masks). In this work, an ad-hoc laboratory methodology has been developed to evaluate the filtration efficiency of the materials that compose the community masks using specific instrumentation. The instrumentation consists of three main tools: an aerosol generator, a specifically designed measuring chamber, and an optical particle sizer (OPS) for the measurement of aerosol concentration. The generated aerosol was sent into the measuring chamber, divided into two separate sections by the respiratory mask. The OPS measured the aerosol mass concentration upstream and downstream of the respiratory mask, and from the concentration difference the filtration efficiency was evaluated. The proposed methodology has been validated by evaluating the particle filtration efficiency (PFE) of certified respiratory masks and was then applied for the evaluation of the filtration efficiency of different types of non-standard or community masks to analyze their effectiveness in protecting from the risk of infection of airborne diseases.

Comparison of preoxygenation efficiency measured by the oxygen reserve index between high-flow nasal oxygenation and facemask ventilation: a randomised controlled trial.

BACKGROUND: High-flow nasal oxygenation and the oxygen reserve index (ORI), which is a non-invasive and innovative modality that reflects the arterial oxygen content, are used in general anaesthesia. This study compares the preoxygenation efficiency (measured by the ORI) of high-flow nasal oxygenation and facemask ventilation during the induction process. METHODS: This single-centre, two-group, randomised controlled trial included 197 patients aged ≥ 20 years who underwent orotracheal intubation for general anaesthesia for elective surgery. The patients were randomly allocated to receive preoxygenation via facemask ventilation or high-flow nasal oxygenation. The ORI was measured and compared between both groups. RESULTS: The ORI increased during preoxygenation in all patients. At 1 min of preoxygenation, the ORI was significantly higher in the high-flow nasal oxygenation group (0.34 ± 0.33) than in the facemask ventilation group (0.21 ± 0.28; P = 0.003). The highest ORI was not significantly different between the two groups (0.68 ± 0.25 in the high-flow nasal oxygenation group vs. 0.70 ± 0.28 in the facemask ventilation group; P = 0.505). CONCLUSIONS: High-flow nasal oxygenation results in an oxygenation status similar to that provided by facemask ventilation during the induction process of general anaesthesia; therefore, high-flow nasal oxygenation is a feasible preoxygenation method. TRIAL REGISTRATION: Clinicaltrials.gov (NCT04291339).

Comparison of the skeletodental effects of miniscrew-anchored and tooth-anchored facemask treatment in growing patients with skeletal class III malocclusions.

INTRODUCTION: This retrospective study aimed to evaluate the skeletal and dental effects of the miniscrew-anchored facemask in skeletal Class III growing patients and compare them with those of conventional tooth-anchored facemasks. METHODS: Retrospectively a total of 50 patients with skeletal Class III (mean ANB: -1.12°) were investigated and divided into two groups according to the treatment modality. Twenty-five patients were treated using the conventional tooth-anchored facemask (T group: mean age 9.3 ± 1.1 years, mean ANB: -0.93°) whereas the other 25 were treated using a miniscrew-anchored facemask (M group: mean age 9.7 ± 1.3 years. mean ANB: -1.61°). Two miniscrews were placed on the palate for bone anchorage. In both T and M groups, facemasks applied a force of 20-30° down on the occlusal plane, and the force increased from 200 g to 300-350 g per side throughout the treatments. The patients were instructed to wear facemasks for at least 14 h per day. A total of 16 angular and 11 linear cephalometric measurements were analysed to determine the skeletal and dental changes before and after facemask treatment. A paired t-test was used to verify the effects before and after treatment in each group. RESULTS: All miniscrews were well maintained during treatment. The values of SNA, SN-ANS, ANB and A to N-Perp, which indicate anterior protraction of the maxilla, were significantly higher in the M group compared with the T group (P < .05). Proclination of the maxillary incisors, extrusion and mesialization of the maxillary molars were significantly greater in the T group (P < .05). CONCLUSIONS: Miniscrew-anchored facemask treatment increased the amount of maxillary protraction and reduced the dental side effects compared with conventional tooth-anchored facemask treatment in growing patients with skeletal Class III malocclusion.