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Noninvasive respiratory support delivered through a face mask has become a cornerstone treatment for adults and children with acute or chronic respiratory failure. However, an imperfect mask fit by using commercially available interfaces is frequently encountered, which may result in patient discomfort and treatment inefficiency or failure. To overcome this challenge, over the past decade, increasing attention has been given to the development of personalized face masks, which are custom-made to address the specific facial dimensions of an individual patient. With this scoping review, we aim to provide a comprehensive overview of the current advances and gaps in knowledge with regard to the personalization masks for CPAP and NIV. We performed a systematic search of the literature and identified and summarized a total of 23 studies. Most studies included were involved in the development of nasal masks. Studies that targeted adult respiratory care mainly focused on chronic (home) ventilation and included some clinical testing in a relevant subject population. In contrast, pediatric studies focused mostly on respiratory support in the acute setting, whereas testing was limited to bench or case studies only. Most studies were positive with regard to the performance (ie, comfort, level of air leak, and mask pressure applied to the skin) of personalized masks in bench testing or in human, healthy or patient, subjects. Advances in the field of 3-dimensional scanning and soft material printing were identified, but important gaps in knowledge remain. In particular, more insight into cushion materials, headgear design, clinical feasibility, and cost-effectiveness is needed before definite recommendations can be made with regard to implementation of large-scale clinical programs that personalize noninvasive respiratory support masks for adults and children. [ABSTRACT FROM AUTHOR]

BACKGROUND: The ratio of oxygen saturation index (ROX index; or .../.../breathing frequency) has been shown to predict risk of intubation after high-flow nasal cannula (HFNC) support among adults with acute hypoxemic respiratory failure primarily due to pneumonia. However, its predictive value for other subtypes of respiratory failure is unknown. This study investigated whether the ROX index predicts liberation from HFNC or noninvasive ventilation (NIV), intubation with mechanical ventilation, or death in adults admitted for respiratory failure due to an exacerbation of COPD. METHODS: We performed a retrospective study of 260 adults hospitalized with a COPD exacerbation and treated with HFNC and/or NIV (continuous or bi-level). ROX index scores were collected at treatment initiation and predefined time intervals throughout HFNC and/or NIV treatment or until the subject was intubated or died. A ROX index score of ≥ 4.88 was applied to the cohort to determine if the same score would perform similarly in this different cohort. Accuracy of the ROX index was determined by calculating the area under the receiver operator curve. RESULTS: A total of 47 subjects (18%) required invasive mechanical ventilation or died while on HFNC/NIV. The ROX index at treatment initiation, 1 h, and 6 h demonstrated the best prediction accuracy for avoidance of invasive mechanical ventilation or death (area under the receiver operator curve 0.73 [95% CI 0.66-0.80], 0.72 [95% CI 0.65-0.79], and 0.72 [95% CI 0.63-0.82], respectively). The optimal cutoff value for sensitivity (Sn) and specificity (Sp) was a ROX index score > 6.88 (sensitivity 62%, specificity 57%). CONCLUSIONS: The ROX index applied to adults with COPD exacerbations treated with HFNC and/or NIV required higher scores to achieve similar prediction of low risk of treatment failure when compared to subjects with hypoxemic respiratory failure/pneumonia. ROX scores < 4.88 did not accurately predict intubation or death. [ABSTRACT FROM AUTHOR]

BACKGROUND: When treating acute respiratory failure, both hypoxemia and hyperoxemia should be avoided. ... should be monitored closely and O2 flows adjusted accordingly. Achieving this goal might be easier with automated O2 titration compared with manual titration of fixed-flow O2. We evaluated the feasibility of using an automated O2 titration device in subjects treated for acute hypoxemic respiratory failure in a tertiary care hospital. METHODS: Health-care workers received education and training about oxygen therapy, and were familiarized with an automated O2 titration device (FreeO2,). A coordinator was available from 8:00 AM to 5:00 PM during weekdays to provide technical assistance. The ability of the device to maintain ... within the prescribed therapeutic window was recorded. Basic clinical information was recorded. RESULTS: Subjects were enrolled from November 2020 to August 2022. We trained 508 health-care workers on the use of automated O2 titration, which was finally used on 872 occasions in 763 subjects, distributed on the respiratory, COVID-19, and thoracic surgery wards, and in the emergency department. Clinical information could be retrieved for 609 subjects (80%) who were on the system for a median (interquartile range) of 3 (2-6) d, which represented 2,567 subject-days of clinical experience with the device. In the 82 subjects (14%) for whom this information was available, the system maintained ... within the prescribed targets 89% of the time. Ninety-six subjects experienced clinical deterioration as defined by the need to be transferred to the ICU and/or requirement of high flow nasal oxygen but none of these events were judged to be related to the O2 device. CONCLUSIONS: Automated O2 titration could be successfully implemented in hospitalized subjects with hypoxemic respiratory failure from various causes. This experience should foster further improvement of the device and recommendations for an optimized utilization. [ABSTRACT FROM AUTHOR]

BACKGROUND: Noninvasive ventilation (NIV) is a widely used and well-established treatment modality for respiratory failure. In patients with increased respiratory work of breathing, accessory muscles are commonly activated along with the diaphragm. Whereas diaphragm ultrasound has been utilized to assess outcomes of mechanical ventilation, the data on intercostal muscle ultrasound remain limited. We aimed to investigate the association between intercostal muscle thickening fraction (TF) and NIV failure in critical care patients with hypercapnic respiratory failure. METHODS: Critical care subjects receiving NIV for hypercapnic respiratory failure were enrolled in the study. The intercostal muscle TF was measured on admission day (day 0) and the following day (day 1). NIV failure was defined as the need for invasive mechanical ventilation or death during NIV therapy. RESULTS: A total of 158 subjects were enrolled, and 30 experienced NIV failure. Age, sex, and body mass index (BMI) were similar in the NIV success and failure groups. Acute Physiology And Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment (SOFA) scores were higher in the NIV failure group. In terms of causes of respiratory failure, the COPD exacerbation rate was higher in the NIV success group. TF was higher in the NIV failure group on both day 0 and day 1. The increased TF on the ICU admission day, with a cutoff value of 12%, was associated with NIV failure after adjusting for age, sex, BMI, APACHE II, and SOFA. Persistence of a higher TF value on both day 0 and day 1 was also associated with NIV failure risk. CONCLUSIONS: There was a positive relation between intercostal muscle TF measured by ultrasound and NIV failure, even after adjusting for APACHE II and SOFA scores. [ABSTRACT FROM AUTHOR]

BACKGROUND: The bag-valve-mask (BVM) or manual resuscitator bag is used as a first-line technique to ventilate patients with respiratory failure. Volume-restricted manual resuscitator bags (eg, pediatric bags) have been suggested to minimize overventilation and associated complications. There are studies that both support and caution against the use of a pediatric resuscitator bag to ventilate an adult patient. In this study, we evaluated the ability of pre-hospital clinicians to adequately ventilate an adult manikin with both an adult- and pediatric-size manual resuscitator bag without the assistance of an advanced airway or airway adjunct device. METHODS: This study was conducted at an international conference in 2022. Conference attendees with pre-hospital health care experience were recruited to ventilate an adult manikin using a BVM for 1 min with both an adult and pediatric resuscitator bag, without the use of adjunct airway devices, while 6 ventilatory variables were collected or calculated: tidal volume (VT), breathing frequency, adequate breaths (VT > 150 mL), proportion of adequate breaths, peak inspiratory pressure (PIP), and estimated alveolar ventilation (EAV). RESULTS: A total of 208 participants completed the study. Ventilation with the adult-sized BVM delivered an average VT of 290.4 mL compared to 197.1 mL (P < .001) when using the pediatric BVM. PIP with the adult BVM was higher than with the pediatric BVM (10.6 cm H2O vs 8.6 cm H2O, P < .001). The median EAV with the adult bag (1,138.1 [interquartile range [IQR] 194.0-2,869.9] mL/min) was markedly greater than with the pediatric BVM (67.7 [IQR 0-467.3] mL/min, P < .001). CONCLUSIONS: Both pediatric- and adult-sized BVM provided lower ventilation volumes than those recommended by professional guidelines for an adult. Ventilation with the pediatric BVM was significantly worse than with the adult bag when ventilating a simulated adult subject. [ABSTRACT FROM AUTHOR]

Despite prior publications of clinical practice guidelines related to ventilator liberation, some questions remain unanswered. Many of these questions relate to the details of bedside implementation. We, therefore, formed a guidelines committee of individuals with experience and knowledge of ventilator liberation as well as a medical librarian. Using Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, we make the following recommendations: (1) We suggest that calculation of a rapid shallow breathing index is not needed to determine readiness for a spontaneous breathing trial (SBT) (conditional recommendation; moderate certainty); (2) We suggest that SBTs can be conducted with or without pressure support ventilation (conditional recommendation, moderate certainty); (3) We suggest a standardized approach to assessment and, if appropriate, completion of an SBT before noon each day (conditional recommendation, very low certainty); and (4) We suggest that FIO2 should not be increased during an SBT (conditional recommendation, very low certainty). These recommendations are intended to assist bedside clinicians to liberate adult critically ill patients more rapidly from mechanical ventilation. [ABSTRACT FROM AUTHOR]

Background: Tracheostomies provide many advantages for the care of patients who are critically ill but may also result in complications, including tracheostomy-related pressure injuries. Research efforts into the prevention of these pressure injuries has resulted in specialized clinical care teams and pathways. These solutions are expensive and labor intensive, and fail to target the root cause of these injuries; namely, pressure at the device-skin interface. Here we measure that pressure directly and introduce a novel medical device, the tracheostomy support system, to reduce it. Methods: This was a cross-sectional study of 21 subjects in the ICU, each with a tracheostomy tube connected to a ventilator. A force-sensing resistor was used to measure baseline pressures at the device-skin interface along the inferior flange. This pressure was then measured again with the use of the tracheostomy support system in the inactive and active states. Resultant pressures and demographics were compared. Results: Fifteen male and 6 female subjects, with an average age of 47 ± 14 (mean ± SD) years, were included in this study. Average pressures at the tracheostomy-skin interface at baseline in these 21 ICU subjects were 273 ± 115 (mean ± SD) mm Hg. Average pressures were reduced by 59% (median 62%, maximum 98%) with the active tracheostomy support system to 115 ± 83 mm Hg (P < .001). All the subjects tolerated the tracheostomy support system without issue. Conclusions: Despite best clinical practice, pressure at the tracheostomy-skin interface can remain quite high. Here we provide measures of this pressure directly and show that a tracheostomy support system can be highly effective at minimizing that pressure. There is room for improvement in tracheostomy care, and such improvement does not have to come at a great expense. [ABSTRACT FROM AUTHOR]

The purpose of this article is to identify (by brand name) and then classify the modes available on contemporary portable ventilators used for noninvasive ventilation in the United States. We propose a formal taxonomy that identifies the modes by their control variable, breath sequence, and targeting scheme, therefore describing what the mode does. Use of this taxonomy should be helpful in finding modes with comparable functionality that cater to the specific goal of mechanical ventilation and effective ventilatory strategies for each disease state. [ABSTRACT FROM AUTHOR]

The article discusses research which evaluated real-time physiological effects of clamping the endotracheal tube (ETT) during mechanical ventilator disconnection on regional lung volumes and ventilation distribution. The study recorded pulmonary electric impedance tomography measurements of regional lung volumes and ventilation distribution with and without clamping. It analyzed intrapulmonary shunts using simultaneous arterial and central venous gas sampling.

Background: Tracheostomy in patients who are critically ill is generally performed due to prolonged mechanical ventilation and expected extubation failure. However, tracheostomy criteria and ideal timing are poorly defined, including equivocal data from randomized controlled trials and median intubation to tracheostomy times that range from 7-21 d. However, a consistent finding is that only -50% of late tracheostomy groups actually undergo tracheostomy, with non-performance due to recovery or clinical deterioration. Unlike in many jurisdictions, elective surgical procedures in our institution require a court-appointed guardian, which necessitates an approximately 1-week delay between the decision to perform tracheostomy and surgery. This offers a unique opportunity to observe patients with potential tracheostomy during a delay between the decision and the performance. Methods: ICU patients who were ventilated were identified for inclusion retrospectively by an application for guardianship relating to tracheostomy, the intention-to-treat point. The main outcomes of tracheostomy, extubation, or death/palliative care after inclusion were noted. Demographics, outcomes, and event timing were compared for the 3 outcome groups. Results: Tracheostomy-related guardianship requests were made for 388 subjects. Of these, 195 (50%) underwent tracheostomy, whereas 127 (33%) were extubated and 66 (17%) either died before tracheostomy (46 [12%]) or were transitioned to palliative care (20 [5%]). The median time (interquartile range) from guardianship request until a defining event was the following: 6.2 (4.0-11) d for tracheostomy, 5.0 (2.9-8.2) d for extubation (P < .001 as compared to tracheostomy group), and 6.5 (2.5-11) d for death/palliative care (P = .55 as compared to tracheostomy). Neurological admissions were more common in the tracheostomy group and less common in the palliative group. Other admission demographics and hospitalization characteristics were similar. Hospital mortality was higher for subjects undergoing tracheostomy (58/195 [30%]) versus extubation (24/127 [19%]) (P = .03). Conclusions: Delay in performing tracheostomy due to legal requirements was associated with a 50% decrease in the need for tracheostomy. This suggests that decision-making with regard to ideal tracheostomy timing could be improved, saving unnecessary procedures. [ABSTRACT FROM AUTHOR]

BACKGROUND: Preoperative inspiratory muscle training (IMT) is frequently used in patients waiting for major surgery to improve respiratory muscle function and to reduce the risk of postoperative pulmonary complications (PPCs). Currently, the mechanism of action of IMT in reducing PPCs is still unclear. Therefore, we investigated the associations between preoperative IMT variables and the occurrence of PPCs in patients with esophageal cancer. METHODS: A multi-center cohort study was conducted in subjects scheduled for esophagectomy, who followed IMT as part of a prehabilitation program. IMT variables included maximum inspiratory pressure (PImax) before and after IMT and IMT intensity variables including training load, frequency, and duration. Associations between PImax and IMT intensity variables and PPCs were analyzed using independent samples t tests and logistic regression analyses, corrected for age and pulmonary comorbidities and stratified for the occurrence of anastomotic leakages. RESULTS: Eighty-seven subjects were included (69 males; mean age 66.7 6 7.3 y). A higher PImax (odds ratio 1.016, P 5 .07) or increase in PImax during IMT (odds ratio 1.020, P 5 .066) was not associated with a reduced risk of PPCs after esophagectomy. Intensity variables of IMT were also not associated (P ranging from .16 to .95) with PPCs after esophagectomy. Analyses stratified for the occurrence of anastomotic leakages showed no associations between IMT variables and PPCs. CONCLUSIONS: This study shows that an improvement in preoperative inspiratory muscle strength during IMT and training intensity of IMT were not associated with a reduced risk on PPCs after esophagectomy. Further research is needed to investigate other possible factors explaining the mechanism of action of preoperative IMT in patients undergoing major surgery, such as the awareness of patients related to respiratory muscle function and a diaphragmatic breathing pattern. [ABSTRACT FROM AUTHOR]

Negative-pressure ventilation (NPV) is a form of noninvasive ventilation that has been recently utilized in pediatric acute respiratory failure. Negative-pressure ventilators apply negative pressure onto the chest wall via a cuirass to recruit areas of atelectasis. Continuous negative extrathoracic pressure, the most common mode, is similar to CPAP, where negative pressure is maintained at a constant level throughout the respiratory cycle while patients initiate their own breaths and continue to breathe spontaneously throughout. Control mode, which is similar to bi-level positive airway pressure, alternates negative pressure with positive pressure and controls both phases of breathing at a mandatory frequency set higher than the patient's spontaneous frequency. Supplemental oxygen is provided through a nasal cannula or face mask due of the lack of NPV devices' interface with the mouth or nose. NPV can improve preload to the heart and cardiac output (CO) in patients with restrictive right-ventricular physiology requiring CO augmentation and those with Fontan physiology. The purpose of this article is to review the physiological principles of spontaneous and NPV, examine the evidence supporting the use of NPV, give practical and meaningful guidance on its clinical application in the pediatric ICU, and summarize areas for future studies on its uses. [ABSTRACT FROM AUTHOR]

BACKGROUND: Noninvasive ventilation (NIV) plays an important role in avoiding endotracheal intubation during myasthenic crisis, yet there are few published data concerning long-term home NIV in stable out-patients with myasthenia gravis (MG). The aim of this study was to describe the prevalence of NIV in a cohort of subjects with stable MG and to analyze contributing factors that could predict the need of NIV. METHODS: We performed a cross-sectional study that included subjects diagnosed with MG managed in the respiratory care unit over the previous year. Subjects underwent clinical analysis including demographic, clinical, and functional respiratory data. RESULTS: Of the 50 subjects included, 35 (70%) were positive for nicotinic acetylcholine receptor antibodies, and 68% had a diagnosis of generalized MG. Bulbar symptoms developed in 16 (32%), and 10 (20%) subjects needed long-term home NIV. The only variable predicting the need for longterm NIV was MG severity measured with Myasthenia Gravis Foundation of America (MGFA), mainly grades IIB (odds ratio 0.14 [95% CI 0.02--0.85], P 5 .03) and IIIB (odds ratio 0.02 [95% CI 0.01--0.34], P 5 .01). CONCLUSIONS: Home NIV was needed in a substantial percentage of medically stable subjects with MG, mainly in those with generalized type and with oropharyngeal and/or respiratory muscle involvement (MGFA grades IIB and IIIB). [ABSTRACT FROM AUTHOR]

BACKGROUND: Accuracy of esophageal pressure measured by an air-filled esophageal balloon catheter is dependent on balloon filling volume. However, this has been understudied in mechanically ventilated children. We sought to study the optimal filling volume in children receiving ventilation by using previously reported calibration methods. Secondary objectives included to examine the difference in pressure measurements at individualized optimal filling volume versus a standardized inflation volume and to study if a static hold during calibration is required to identify the optimal filling volume. METHODS: An incremental inflation calibration procedure was performed in children receiving ventilation, <18 y, instrumented with commercially available catheters (6 or 8 French) who were not breathing spontaneously. The balloon was manually inflated by 0.2 to 1.6 mL (6 French) or 2.6 mL (8 French). Esophageal pressure (Pes) and airway pressure tracings were recorded during the procedure. Data were analyzed offline by using 2 methods: visual determination of filling range with the calculation of the highest difference between expiratory and inspiratory Pes and determination of a correctly filled balloon by calculating the esophageal elastance. RESULTS: We enrolled 40 subjects with median (interquartile range [IQR]) age 6.8 (2--25) months. The optimal filling volume ranged from 0.2 to 1.2 mL (median [IQR] 0.6 [0.2--1.0] mL) in the subjects with a 6 French catheter and 0.2--2.0 mL (median [IQR] 0.7 [0.521.2] mL) for 8 French catheters. Inflating the balloon with 0.6 mL (median computed from the whole cohort) gave an absolute difference in transpulmonary pressure that ranged from 24 to 7 cm H2O compared with the personalized volume. Pes calculated over 5 consecutives breaths differed with a maximum of 1 cm H2O compared to Pes calculated during a single inspiratory hold. The esophageal elastance was correlated with weight, age, and sex. CONCLUSIONS: The optimal balloon inflation volume was highly variable, which indicated the need for an individual calibration procedure. Pes was not overestimated when an inspiratory hold was not applied. [ABSTRACT FROM AUTHOR]

BACKGROUND: Infants with a high risk of extubation failure are often treated with noninvasive ventilation (NIV) or CPAP, but data on the role of these support modalities following extubation are sparse. This report describes our experience using NIV or CPAP to support infants following extubation in our pediatric ICUs (PICUs). METHODS: We performed a retrospective study of children < 10 kg receiving postextubation NIV or CPAP in our PICUs. Data on demographics, medical history, type of support, vital signs, pulse oximetry, near-infrared spectroscopy (NIRS), gas exchange, support settings, and re-intubation were extracted from the electronic medical record. Support was classified as prophylactic if planned before extubation and rescue if initiated within 24 h of extubation. We compared successfully extubated and re-intubated subjects using chi-square test for categorical variables and Mann-Whitney test for continuous variables. RESULTS: We studied 51 subjects, median age 44 (interquartile range 0.5-242) d and weight 3.7 (3-4.9) kg. There were no demographic differences between groups, except those re-intubated were more likely to have had cardiac surgery prior to admission (0% vs 14%, P = .040). NIV was used in 31 (61%) and CPAP in 20 (39%) subjects. Prophylactic support was initiated in 25 subjects (49%), whereas rescue support was needed in 26 subjects (51%). Twenty-two subjects (43%) required reintubation. Re-intubation rate was higher for rescue support (58% vs 28%, P = .032). Subjects with a pH < 7.35 (4.3% vs 42.0%, P = .003) and lower somatic NIRS (39 [24-56] vs 62 [46-72], P = .02) were more likely to be re-intubated. The inspiratory positive airway pressure, expiratory positive airway pressure, and ... were higher in subjects who required re-intubation. CONCLUSIONS: NIV or CPAP use was associated with a re-intubation rate of 43% in a heterogeneous sample of high-risk infants. Acidosis, cardiac surgery, higher FIO2, lower somatic NIRS, higher support settings, and application of rescue support were associated with the need for re-intubation. [ABSTRACT FROM AUTHOR]

BACKGROUND: COVID-19 is associated with variable symptoms and clinical sequelae. Studies have examined the clinical course of these patients, finding a prolonged need for invasive ventilation and variable re-intubation rates. However, no research has investigated factors and outcomes related to reintubation secondary to respiratory failure among patients with COVID-19 with ARDS. METHODS: We conducted a single-center, retrospective study on subjects intubated for ARDS secondary to COVID-19. The primary outcome was re-intubation status; secondary outcomes were hospital and ICU stay and mortality. Data were analyzed using between-group comparisons using chisquare testing for categorical information and Student t test for quantitative data. Univariate and multivariate logistic regression was performed to determine factors related to re-intubation and mortality as dependent variables. RESULTS: One hundred and fourteen subjects were included, of which 32% required re-intubation. No between-group differences were detected for most demographic variables or comorbidities. No differences were detected in COVID-19 treatments, noninvasive respiratory support, mechanical circulatory support, or duration of ventilation. Midazolam (odds ratio [OR] 5.55 [95% CI 1.83-16.80], P = .002), fentanyl (OR 3.64 [95% CI 1.26-10.52], P = .02), and APACHE II scores (OR 1.08 [95% CI 1.030-1.147], P = .005) were independently associated with re-intubation (area under the curve 5 0.81). Re-intubated subjects had extended hospital (36.7 6 22.7 d vs 26.1 6 12.1 d, P = .01) and ICU (29.6 ± 22.4 d vs 15.8 ± 10.4 d, P < .001) stays. More subjects died who failed extubation (49% vs 3%, P < .001). Age (OR 1.07 [95% CI 1.02-1.23], P = .005), male sex (OR 4.9 [95% CI 1.08-22.35], P = .041), positive Confusion Assessment Method for the ICU (CAM-ICU) (OR 5.43 [95% CI 1.58-18.62], P = .007), and re-intubation (OR 12.75 [95% CI 2.80-57.10], P < .001) were independently associated with death (area under the curve 5 0.93). CONCLUSIONS: Midazolam, fentanyl, and higher APACHE II scores were independently associated with re-intubation secondary to respiratory failure in subjects with COVID-19--related ARDS. Furthermore, age, male sex, positive CAM-ICU, and re-intubation were independently associated with mortality. Re-intubation also correlated with prolonged hospital and ICU stay. [ABSTRACT FROM AUTHOR]

The authors offer observation on syndrome-based research to improve how hypercapnic respiratory failure patients were treated. Topics discussed include demonstrated benefit of noninvasive ventilation (NIV) in chronic obstructive pulmonary disease (COPD), guidelines pertaining to NIV management for chronic hypercapnic respiratory failure, and indication of the failure to normalize the partial pressure of carbon dioxide (PCO2).

Diaphragm inactivity during invasive mechanical ventilation leads to diaphragm atrophy and weakness, hemodynamic instability, and ventilatory heterogeneity. Absent respiratory drive and effort can, therefore, worsen injury to both lung and diaphragm and is a major cause of failure to wean. Phrenic nerve stimulation (PNS) can maintain controlled levels of diaphragm activity independent of intrinsic drive and as such may offer a promising approach to achieving lung and diaphragm protective ventilatory targets. Whereas PNS has an established role in the management of chronic respiratory failure, there is emerging interest in how its multisystem putative benefits may be temporarily harnessed in the management of invasively ventilated patients with acute respiratory failure. [ABSTRACT FROM AUTHOR]

Mechanical ventilation is ubiquitous in critical care, and duration of ventilator liberation is variable and multifactorial. While ICU survival has increased over the last two decades, positive-pressure ventilation can cause harm to patients. Weaning and discontinuation of ventilatory support is the first step in ventilator liberation. Clinicians have a wealth of evidence-based literature at their disposal; however, more high-quality research is needed to describe outcomes. Additionally, this knowledge must be distilled into evidence-based practice and applied at the bedside. A proliferation of research on the subject of ventilator liberation has been published in the last 12 months. Whereas some authors have reconsidered the value of applying the rapid shallow breathing index in weaning protocols, others have begun to investigate new indices to predict liberation outcomes. New tools such as diaphragmatic ultrasonography have begun to appear in the literature as a tool for outcome prediction. A number of systematic reviews with both meta-analysis and network meta-analysis that synthesize the literature on ventilator liberation have also been published in the last year. This review describes changes in performance, monitoring of spontaneous breathing trials, and evaluations of successful ventilator liberation. [ABSTRACT FROM AUTHOR]

Mechanical ventilation is a lifesaving intervention that may also induce further lung injury by exerting excessive mechanical forces on susceptible lung tissue, a phenomenon termed ventilator-induced lung injury (VILI). The concept of mechanical power (MP) aims to unify in one single variable the contribution of the different ventilatory parameters that could induce VILI by measuring the energy transfer to the lung over time. Despite an increasing amount of evidence demonstrating that high MP values can be associated with VILI development in experimental studies, the evidence regarding the association of MP and clinical outcomes remains controversial. In the present review, we describe the different determinants of VILI, the concept and computation of MP, and discuss the experimental and clinical studies related to MP. Currently, due to different limitations, the clinical application of MP is debatable. Further clinical studies are required to enhance our understanding of the relationship between MP and the development of VILI, as well as its potential impact on clinical outcomes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Aerosol delivery via high-flow nasal cannula (HFNC) has gained popularity due to the increased use of the modality for treating hypoxemic and hypercapnic respiratory failure. Various HFNC devices are available in the United States; however, the effectiveness of aerosol delivery via HFNC devices remains unclear. Thus, this study aimed to investigate the impact of various commercially available devices on transnasal aerosol delivery. METHODS: This was a bench study that used a 2-chamber lung model, in which one chamber was connected to an adult manikin with anatomically correct upper-airway proportions. The other chamber was connected to a critical care ventilator used to simulate spontaneous breathing. A size large nasal cannula was placed at the nasal opening of the manikin. Five different HFNC devices (Hamilton-C1, OptiFlow, Airvo2, V60 Plus, and Vapotherm) were compared. Four flow settings were used on each device, with a vibrating mesh nebulizer placed at the humidifier. Salbutamol (2.5 mg/3 mL) was used during the experiments to quantify inhaled drug doses. A collection filter was placed between the manikin's trachea and the lung model. The drug was eluted from the filter and assayed with ultraviolet spectrophotometry (276 nm). RESULTS: Among the 5 HFNC devices, OptiFlow had the highest inhaled dose at 10 L/min (mean ± SD 18.2% ± 1.2%). At 20 L/min, the Hamilton-C1 (mean ± SD 13.5% ± 0.4%) performed marginally better than the OptiFlow (mean ± SD 12.6% ± 1.9%) and Airvo2 (mean ± SD 12.8% ± 1%). At high flow settings (40--60 L/min), the inhaled dose of Hamilton-C1 was 2--3 times that of the Airvo2 and V60 Plus. When compared with the other devices, the mean inhaled dose with the Vapotherm was lower (0.9-2.5%). In all devices, the inhaled dose decreased as the flow increased. CONCLUSIONS: Transnasal aerosol delivery was significantly impacted by the types of HFNC devices and flow settings. Nominal doses might need to be adjusted if changing HFNC devices or flow is not an option. [ABSTRACT FROM AUTHOR]

BACKGROUND: Chronic hypercapnic respiratory failure is associated with high mortality. Although previous work has demonstrated a mortality improvement with high-intensity noninvasive ventilation in COPD, it is unclear whether a PCO2 reduction strategy is associated with improved out- comes in other populations of chronic hypercapnia. METHODS: The objective of this study was to investigate the association between PCO2 reduction (by using transcutaneous PCO2 as an estimate for PaCO2 and survival in a broad population of individuals treated with noninvasive ventilation for chronic hypercapnia. We hypothesized that reductions in PCO2 would be associated with improved survival. Therefore, we performed a cohort study of all the subjects evaluated from February 2012 to January 2021 for noninvasive ventilation initiation and/or optimization due to chronic hypercapnia at a home ventilation clinic in an academic center. We used multivariable Cox proportional hazard models with time-varying coefficients and PCO2 as a time-varying cova- riate to test the association between PCO2 and all-cause mortality and when adjusting for known cofounders. RESULTS: The mean 6 SD age of 337 subjects was 57 6 16 years, 37% women, and 85% white. In a univariate analysis, survival probability increased with reductions in PCO2 to < 50 mm Hg after 90 d, and these remained significant after adjusting for age, sex, race, body mass index, diagnosis, Charlson comorbidity index, and baseline PCO2 . In the multivariable analysis, the subjects who had a PaCO2 < 50 mm Hg had a reduced mortality risk of 94% between 90 and 179 d (hazard ratio [HR] 0.06, 95% CI 0.01-0.50), 69% between 180 and 364 d (HR 0.31, 95% CI 0.12-0.79), and 73% for 365-730 d (HR 0.27, 95% CI 0.13-0.56). CONCLUSIONS: Reduction in PCO2 from baseline for subjects with chronic hypercapnia treated with noninvasive ventilation was associated with improved survival. Management strategies should target the greatest attainable reductions in PCO2. [ABSTRACT FROM AUTHOR]

BACKGROUND: Timely ventilator liberation can prevent morbidities associated with invasive mechanical ventilation in the pediatric ICU (PICU). There currently exists no standard benchmark for duration of invasive mechanical ventilation in the PICU. This study sought to develop and validate a multi-center prediction model of invasive mechanical ventilation duration to determine a standardized duration of invasive mechanical ventilation ratio. METHODS: This was a retrospective cohort study using registry data from 157 institutions in the Virtual Pediatric Systems database. The study population included encounters in the PICU between 2012-2021 involving endotracheal intubation and invasive mechanical ventilation in the first day of PICU admission who received invasive mechanical ventilation for > 24 h. Subjects were stratified into a training cohort (2012-2017) and 2 validation cohorts (2018-2019/2020-2021). Four models to predict the duration of invasive mechanical ventilation were trained using data from the first 24 h, validated, and compared. RESULTS: The study included 112,353 unique encounters. All models had observed-to-expected (O/E) ratios close to one but low mean squared error and R² values. The random forest model was the best performing model and achieved an O/E ratio of 1.043 (95% CI 1.030-1.056) and 1.004 (95% CI 0.990-1.019) in the validation cohorts and 1.009 (95% CI 1.004-1.016) in the full cohort. There was a high degree of institutional variation, with single- unit O/E ratios ranging between 0.49-1.91. When stratified by time period, there were observ- able changes in O/E ratios at the individual PICU level over time. CONCLUSIONS: We derived and validated a model to predict the duration of invasive mechanical ventilation that performed well in aggregated predictions at the PICU and the cohort level. This model could be beneficial in quality improvement and institutional benchmarking initiatives for use at the PICU level and for tracking of performance over time. [ABSTRACT FROM AUTHOR]

BACKGROUND: Patient-triggered adaptive pressure control (APC) continuous mandatory ventilation (CMV) (APC-CMV) has been widely adopted as an alternative ventilator mode to patient-triggered volume control (VC) CMV (VC-CMV). However, the comparative effectiveness of the 2 ventilator modes remains uncertain. We sought to explore clinical and implementation factors pertinent to a future definitive randomized controlled trial assessing APC-CMV versus VC-CMV as an initial ventilator mode strategy. The research objectives in our pilot trial tested clinician adherence and explored clinical outcomes. METHODS: In a single-center pragmatic sequential cluster crossover pilot trial, we enrolled all eligible adults with acute respiratory failure requiring mechanical ventilation admitted during a 9-week period to the medical ICU. Two-week time epochs were assigned a priori in which subjects received either APC-CMV or VC-CMV The primary outcome of the trial was feasibility, defined as 80% of subjects receiving the assigned mode within 1 h of initiation of ICU ventilation. The secondary outcome was proportion of the first 24 h on the assigned mode. Finally, we surveyed clinician stakeholders to understand potential facilitators and barriers to conducting a definitive randomized trial. RESULTS: We enrolled 137 subjects who received 152 discreet episodes of mechanical ventilation during time epochs assigned to APC-CMV (n 5 61) and VC-CMV (n 5 91). One hundred and thirty-one episodes were included in the prespecified primary outcome. One hundred and twenty-six (96%) received the assigned mode within the first hour of ICU admission (60 of 61 subjects assigned APC-CMV and 66 of 70 assigned VC-CMV). VC-CMV subjects spent a lower proportion of first 24 h (84% [95% CI 78--89]) on the assigned mode than APC-CMV recipients (95% [95% CI 91--100]). Mixed-methods analyses identified preconceived perceptions of subject comfort by clinicians and need for real-time education to address this concern. CONCLUSIONS: In this pilot pragmatic, sequential crossover trial, unit-wide allocation to a ventilator mode was fea- sible and acceptable to clinicians. [ABSTRACT FROM AUTHOR]

Endotracheal intubation for airway management is a common procedure in the ICU. Intubation may be difficult due to anatomic airway abnormalities but also due to physiologic derangements that predispose patients to cardiovascular collapse during the procedure. Results of studies demonstrate a high incidence of morbidity and mortality associated with airway management in the ICU. To reduce the likelihood of complications, medical teams must be well versed in the general principles of intubation and be prepared to manage physiologic derangements while securing the airway. In this review, we present relevant literature on the approach to endotracheal intubation in the ICU and provide pragmatic recommendations relevant to medical teams performing intubations in patients who are physiologically unstable. [ABSTRACT FROM AUTHOR]

Background: Sleep deprivation alters respiratory muscle performance and may precipitate respiratory failure. This study aimed to assess sleep in subjects admitted to ICU for acute hypoxemic respiratory failure and its role in the risk of intubation. Methods: This was a prospective observational single-center cohort study including subjects admitted to ICU for de novo acute hypoxemic respiratory failure defined as breathing frequency ≥ 25 breaths/min or clinical signs of respiratory distress and ... < 300 mm Hg while receiving high-flow nasal oxygen. Subjects with altered consciousness, central nervous or psychiatric disorders, continuous sedation or neuroleptic medication, or were uncooperative were excluded. Sleep was assessed by complete polysomnography (PSG) the night following ICU admission. The main outcome was to assess sleep among subjects with acute hypoxemic respiratory failure and to compare sleep between subjects who eventually required intubation to those who did not. Results: Over a 24-month inclusion period, 34 subjects had complete PSG, among whom 5 (15%) required intubation in the ICU. Total sleep time was 4.2 h in median (interquartile range 2.9-6.8); deep-sleep duration was 70 min (34-127), and rapid eye movement (REM) sleep duration was 9 min (0-28). Among them, 13 subjects (38%) had no REM sleep. Total sleep time and duration of deep and REM sleep stages did not differ between subjects who required intubation and those successfully treated with high-flow nasal oxygen. Conclusions: Whereas total sleep time remained relatively preserved in critically ill subjects with acute hypoxemic respiratory failure, REM sleep time was uncommon or completely absent in a large number of subjects. Sleep did not differ between subjects who required intubation and those who did not. However, given a trend toward an increased risk of intubation in subjects with a complete absence of REM sleep, further studies are needed to better explore the impact of REM sleep on the risk of intubation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Noninvasive respiratory support (NRS) is widely used in pediatric ICUs (PICUs). However, there is limited experience regarding the utilization of NRS in non-PICU settings. We aimed to evaluate the success rate of NRS in pediatric high-dependency units (PHDUs), identify predictors of NRS failure, quantify adverse events, and assess outcomes. METHODS: We included infants and children (> 7 d to < 13 y old) admitted to PHDU in 2 tertiary hospitals for acute respiratory distress over a 19-month period. Collected data included diagnosis, type and duration of NRS, adverse events, and the need for PICU transfer or invasive ventilation. RESULTS: Two hundred and ninety-nine children were included, with a median age of 7 (interquartile range [IQR] 3-25) months and a median weight of 6.1 (IQR 4.3-10.5) kg. Bronchiolitis (37.5%), pneumonia (34.1%), and asthma (12.7%) were the most frequent diagnoses. Median NRS duration was 2 (IQR 1-3) d. At baseline, median SpO2 was 96% (IQR 90-99); median pH was 7.36 (IQR 7.31-7.41), and median PCO was 44 (IQR 36-53) mm Hg. Overall, 234 (78.3%) children were successfully managed in PHDU, whereas 65 (21.7%) required transfer to PICU. Thirty-eight (12.7%) needed invasive ventilation on a median time of 43.5 (IQR 13.5-108.0) h. On multivariable analysis, maximum FIO2 > 0.5 (odds ratio 4.49 [95% CI 1.36-14.9], P = .01) and PEEP > 7 cm H2O (odds ratio 3.37 [95% CI 1.49-7.61], P = .004) were predictors for NRS failure. Significant apnea, cardiopulmonary resuscitation, and air leak syndrome were reported in 0.3, 0.7, and 0.7% children, respectively. CONCLUSIONS: In our cohort, we found NRS in PHDU safe and effective; however, maximum FIO2 > 0.5 post treatment and PEEP > 7 cm H2O were associated with NRS failure. [ABSTRACT FROM AUTHOR]

BACKGROUND: To understand the fate of aerosols delivered by high-flow nasal cannula using continuous nebulization, an open-source anatomical model was developed and validated with a modified real-time gamma ratemeter technique. Mass balance defined circuit losses. Responsiveness to infusion rate and device technology were tested. METHODS: A nasal airway cast derived from a computed tomography scan was converted to a 3-dimensional-- printed head and face structure connected to a piston ventilator (breathing frequency 30 breaths/min, tidal volume 750 mL, duty cycle 0.50). For mass balance experiments, saline mixed with Technetium-99m was infused for 1 h. Aerosol delivery was measured using a gamma ratemeter oriented to an inhaled mass filter at the hypopharynx of the model. Background and dead-space effects were minimized. All components were imaged by scintigraphy. Continuous nebulization was tested at infusion rates of 10-40 mL/h with gas flow of 60 L/min using a breath-enhanced jet nebulizer (BEJN), and a vibrating mesh nebulizer. Drug delivery rates were defined by the slope of ratemeter counts/min (CPM/min) versus time (min). RESULTS: The major source of aerosol loss was at the nasal interface (~25%). Significant differences in deposition on circuit components were seen between nebulizers. The nebulizer residual was higher for BEJN (P = .006), and circuit losses, including the humidifier, were higher for vibrating mesh nebulizer (P = .006). There were no differences in delivery to the filter and head model. For 60 L/min gas flow, as infusion pump flow was increased, the rate of aerosol delivery (CPM/min) increased, for BEJN from 338 to 8,111; for vibrating mesh nebulizer, maximum delivery was 2,828. CONCLUSIONS: The model defined sites of aerosol losses during continuous nebulization and provided a realistic in vitro system for testing aerosol delivery during continuous nebulization. Real-time analysis can quantify effects of multiple changes in variables (nebulizer technology, infusion rate, gas flow, and ventilation) during a given experiment. [ABSTRACT FROM AUTHOR]

BACKGROUND: High-flow nasal cannula (HFNC) oxygen therapy is used to deliver warm and humidified gases to patients in respiratory failure. A purported advantage of HFNC oxygen therapy is that it can allow for oral feeding while on the device, although few data support this practice. The purpose of this study was to identify practices and opinions with regard to feeding practices during HFNC oxygen therapy. METHODS: A survey related to the practice and opinions of feeding practices during HFNC oxygen therapy was developed and sent to respiratory therapists, speech-language pathologists, physicians, advanced practice providers, and registered dietitians. RESULTS: Respondents included 307 professionals from 14 different countries. Most respondents worked in an academic/teaching hospital (n = 174 [56.7%]) with patients ages ≥ 18 years (n = 282 [91.9%]). Most respondents stated that their institution did not have a specific feeding protocol for HFNC oxygen therapy (n = 246 [80.4%]) and felt that patients could have an oral diet during HFNC oxygen therapy if not in imminent danger of being intubated (n = 264 [86.3%]). Fewer than half of the respondents felt that patients should have a bedside/clinical swallow examination before eating and/or drinking during HFNC oxygen therapy (n = 143 [46.7%]). By profession, most physicians/advanced practice providers (n = 67 [59.3%]), respiratory therapists (n = 37 [62.7%]) and half of the registered dietitians (n = 16 [50%]) felt that bedside/clinical swallow examinations were unnecessary before eating and/or drinking with HFNC, but speech-language pathologists were in favor (n = 77 [75.5%]). CONCLUSIONS: Most facilities did not have a protocol to guide feeding practices when HFNC oxygen therapy is used. Most clinicians felt that an oral diet is safe for stable patients not in danger of being intu- bated. In general, speech-language pathologists felt that patients on HFNC oxygen therapy should undergo a bedside/clinical swallow examination before eating and/or drinking. [ABSTRACT FROM AUTHOR]

BACKGROUND: Ineffective effort (IE) is a frequent patient-ventilator asynchrony in invasive mechanical ventilation. This study aimed to investigate the incidence of IE and to explore its relationship with respiratory drive in subjects with acute brain injury undergoing invasive mechanical ventilation. METHODS: We retrospectively analyzed a clinical database that assessed patient-ventilator asynchrony in subjects with acute brain injury. IE was identified based on airway pressure, flow, and esophageal pressure waveforms collected at 15-min intervals 4 times daily. At the end of each data set recording, airway-occlusion pressure (P0.1) was determined by the airway occlusion test. IE index was calculated to indicate the severity of IE. The incidence of IE in different types of brain injuries as well as its relationship with P0.1 was determined. RESULTS: We analyzed 852 data sets of 71 subjects with P0.1 measured and undergoing mechanical ventilation for at least 3 d after enrollment. IE was detected in 688 (80.8%) data sets, with a median index of 2.2% (interquartile range 0.4-13.1). Severe IE (IE index ≥ 10%) was detected in 246 (28.9%) data sets. The post craniotomy for brain tumor and the stroke groups had higher median IE index and lower P0.1 compared with the traumatic brain injury group (2.6% [0.7--9.7] vs 2.7% [0.3-21] vs 1.2% [0.1--8.5], P = .002; 1.4 [1-2] cm H2O vs 1.5 [1-2.2] cm H2O vs 1.8 [1.1-2.8] cm H2O, P = .001). Low respiratory drive (P0.1 < 1.14 cm H2O) was independently associated with severe IE in the expiratory phase (IEE) even after adjusting for confounding factors by logistic regression analysis (odds ratio 5.18 [95% CI 2.69-10], P < .001). CONCLUSIONS: IE was very common in subjects with acute brain injury. Low respiratory drive was independently associated with severe IEE. [ABSTRACT FROM AUTHOR]

The utilization of extracorporeal membrane oxygenation (ECMO) for cardiopulmonary support continues to increase globally, with > 190,000 ECMO cases reported to the international Extracorporeal Life Support Organization Registry. The present review aims to synthesize important contributions to the literature surrounding the management of mechanical ventilation, prone positioning, anticoagulation, bleeding complications, and neurologic outcomes for infants, children, and adults undergoing ECMO in 2022. Additionally, issues related to cardiac ECMO, Harlequin syndrome, and anticoagulation during ECMO will be discussed. [ABSTRACT FROM AUTHOR]

Recent technological advances in respiratory support and monitoring have dramatically enhanced the utility of long-term noninvasive ventilation (NIV). Improved quality of life and prolonged survival have been demonstrated for several common chronic neuromuscular diseases. Many adults with progressive neuromuscular respiratory disease can now comfortably maintain normal ventilation at home to near total respiratory muscle paralysis without needing a tracheostomy. However, current practice in many communities falls short of that potential. Mastery of the new technology calls for detailed awareness of the respiratory cycle; expert knowledge of mechanical devices, facial interfaces, and quantitative monitoring tools for home ventilation; and a willingness to stay current in a rapidly expanding body of clinical research. The depth and breadth of the expertise required to manage home assisted ventilation has given rise to a new focused medical subspecialty in chronic respiratory failure at the interface between pulmonology, critical care, and sleep medicine. For clinicians seeking pragmatic "how to" guidance, this primer presents a comprehensive, physician-directed management approach to long-term NIV of adults with chronic neuromuscular respiratory disease. Bi-level devices, portable ventilators, ventilation modalities, terminology, and monitoring strategies are reviewed in detail. Building on that knowledge base, we present a step-by-step guide to initiation, refinement, and maintenance of home NIV tailored to patient-centered goals of therapy. The quantitative approach recommended incorporates routine monitoring of home ventilation using technologies that have only recently become widely available including cloud-based device telemonitoring and non-invasive measurements of blood gases. Strategies for troubleshooting and problem solving are included. [ABSTRACT FROM AUTHOR]

BACKGROUND: Diaphragm atrophy has been observed in subjects who undergo invasive mechanical ventilation. We propose a new method to assess for respiratory muscle (RM) changes in subjects who undergo invasive mechanical ventilation by assessing for changes in respiratory muscles through computed tomography (CT). METHODS: A retrospective case series study was conducted on subjects who underwent invasive mechanical ventilation and received at least 2 chest CT scans during admission. Exclusion criteria included history of chronic mechanical ventilation dependence and neuromuscular disease. Respiratory muscle cross-sectional area (CSA) was measured at the T6 vertebrae. RESULTS: Fourteen subjects were included: mean (± SD) age, BMI, and admission APACHE II scores were 54.0 y (± 14.9), 32.6 kg/m² (± 10.9), and 23.5 (± 6.0), respectively. Ten (71%) subjects were male. Mean length of time between CT chest scans was 7.5 d (± 3.3). Mean duration of invasive mechanical ventilation was 4.5 d (± 3.4). The percentage change in TM CSA among those who underwent invasive mechanical ventilation was 10.5% (± 6.1). CONCLUSIONS: We demonstrated that serial analysis of respiratory muscle CSA through CT chest scans can be a method to assess for respiratory muscle atrophy in subjects undergoing mechanical ventilation. Future prospective studies involving larger populations are needed to better understand how this method can be used to predict outcomes in mechanically ventilated patients. [ABSTRACT FROM AUTHOR]

Patients with hypercapnic COPD appear to represent a phenotype driven by specific physiology including air trapping and mechanical disadvantage, sleep hypoventilation, and sleep apnea. Such individuals appear to be at high risk for adverse health outcomes. Home noninvasive ventilation (NIV) has been shown to have the potential to help compensate for physiological issues underlying hypercapnia. In contrast to older literature, contemporary clinical trials of home NIV have been shown to improve patient-oriented outcomes including quality of life, hospitalizations, and mortality. Advancements in the use of NIV, including the use of higher inspiratory pressures, may account for recent success. Successful practical application of home NIV thus requires an adequate understanding of patient selection, devices and modes, and strategies for titration. The emergence of telemonitoring holds promise for further improvements in patient care by facilitating titration, promoting adherence, troubleshooting issues, and possibly predicting exacerbations. Given the complexity of home NIV, clinicians and health systems might consider establishment of dedicated home ventilation programs to provide such care. In addition, incorporation of respiratory therapist expertise is likely to improve success. Traditional fee-for-service structures have been a challenge for financing such programs, but ongoing changes toward value-based care are likely to make home NIV programs more feasible. [ABSTRACT FROM AUTHOR]

COPD is a progressive inflammatory process affecting both the airways and alveolar structures of the lungs. Exacerbations of COPD are episodes of acute worsening of this inflammatory process, often triggered by infections. The most severe exacerbations are characterized by substantial air trapping and inspiratory muscle overload, which leads to hypercapnic respiratory failure. Pharmacologic therapies focus on intense bronchodilator administration (usually by aerosol), corticosteroids, and antibiotics. Respiratory life support technologies are often needed for severe exacerbations and range from carefully titrated supplemental O2 administration to positive-pressure ventilation (both invasive and noninvasive). Future life support strategies will likely involve extracorporeal life support technologies. [ABSTRACT FROM AUTHOR]

A COPD exacerbation is characterized by an increase in symptoms such as dyspnea, cough, and sputum production that worsens over a period of 2 weeks. Exacerbations are common. Respiratory therapists and physicians in an acute care setting often treat these patients. Targeted O2 therapy improves outcomes and should be titrated to an SpO2) of 88-92%. Arterial blood gases remain the standard approach to assessing gas exchange in patients with COPD exacerbation. The limitations of arterial blood gas surrogates (pulse oximetry, capnography, transcutaneous monitoring, peripheral venous blood gases) should be appreciated so that they can be used wisely. Inhaled short-acting bronchodilators can be provided by nebulizer (jet or mesh), pressurized metered-dose inhaler (pMDI), pMDI with spacer or valved holding chamber, soft mist inhaler, or dry powder inhaler. The available evidence for the use of heliox for COPD exacerbation is weak. Noninvasive ventilation (NIV) is standard therapy for patients who present with COPD exacerbation and is supported by clinical practice guidelines. Robust high-level evidence with patient important outcomes is lacking for the use of high-flow nasal cannula in patients with COPD exacerbation. Management of auto-PEEP is the priority in mechanically ventilated patients with COPD. This is achieved by reducing airway resistance and decreasing minute ventilation. Trigger asynchrony and cycle asynchrony are addressed to improve patient-ventilator interaction. Patients with COPD should be extubated to NIV. Additional high-level evidence is needed before widespread use of extracorporeal CO2 removal. Care coordination can improve the effectiveness of care for patients with COPD exacerbation. Evidence-based practices improve outcomes in patients with COPD exacerbation. [ABSTRACT FROM AUTHOR]

The article discusses research which aimed to describe the use of the S3-NIV questionnaire to describe comfort of patients receiving home non-invasive ventilation (NIV). Topics covered include an estimation of the minimal clinically importance difference of the S3-NIC score, results which show that the questionnaire is responsive to recovery after hospital admission for an acute respiratory failure, and the strengths and limitations of the study.

BACKGROUND: Acute respiratory failure (ARF) remains the most frequent reason for ICU admission in patients who are immunocompromised. This study reports etiologies and outcomes of ARF in subjects with solid tumors. METHODS: This study was a post hoc analysis of the EFRAIM study, a prospective multinational cohort study that included 1611 subjects who were immunocompromised and with ARF admitted to the ICU. Subjects with solid tumors admitted to the ICU with ARF were included in the analysis. RESULTS: Among the subjects from the EFRAIM cohort, 529 subjects with solid tumors (32.8%) were included in the analysis. At ICU admission, the median (interquartile range) Sequential Organ Failure Assessment score was 5 (3-9). The types of solid tumor were mostly lung cancer (n = 111, 21%), breast cancer (n = 52, 9.8%), and digestive cancer (n = 47, 8.9%). A majority, 379 subjects (71.6%) were full code at ICU admission. The ARF was caused by bacterial or viral infection (n = 220, 41.6%), extrapulmonary sepsis (n = 62, 11.7%), or related to cancer or treatment toxicity (n = 83, 15.7%), or fungal infection (n = 23, 4.3%). For 63 subjects (11.9%), the ARF etiology remained unknown after an extensive diagnostic workup. The hospital mortality rate was 45.7% (n = 232/508). Hospital mortality was independently associated with chronic cardiac failure (odds ratio 1.78, 95% CI 1.09-2.92; P = .02), lung cancer (odds ratio 2.50, 95% CI 1.51-4.19; P < .001), day 1 Sequential Organ Failure Assessment score (odds ratio 1.97, 95% CI 1.32-2.96; P < .001). ARF etiologies other than infectious, related to cancer, or treatment toxicity were associated with better outcomes (odds ratio 0.32, 95% CI 0.16-0.61; P < .001). CONCLUSIONS: Infectious diseases remained the most frequent cause of ARF in subjects with solid tumors admitted to the ICU. Hospital mortality was related to severity at ICU admission, previous comorbidities, and ARF etiologies related to non-malignant causes or pulmonary embolism. Lung tumor was also independently associated with higher mortality. [ABSTRACT FROM AUTHOR]

Introduction: Awake prone positioning (PP) reduces need for intubation for patients with COVID-19 with acute respiratory failure. We investigated the hemodynamic effects of awake PP in non-ventilated subjects with COVID-19 acute respiratory failure. Methods: We conducted a single-center prospective cohort study. Adult hypoxemic subjects with COVID-19 not requiring invasive mechanical ventilation receiving at least one PP session were included. Hemodynamic assessment was done with transthoracic echocardiography before, during, and after a PP session. Results: Twenty-six subjects were included. We observed a significant and reversible increase in cardiac index (CI) during PP compared to supine position (SP): 3.0 ± 0.8 L/min/m2 in PP, 2.5 ± 0.6 L/min/m2 before PP (SP1), and 2.6 ± 0.5 L/min/m2 after PP (SP2, P < .001). A significant improvement in right ventricular (RV) systolic function was also evidenced during PP: The RV fractional area change was 36 ± 10% in SP1, 46 ± 10% during PP, and 35 ± 8% in SP2 (P < .001). There was no significant difference in PaO2 /FIO2 and breathing frequency. Conclusion: CI and RV systolic function are improved by awake PP in non-ventilated subjects with COVID-19 with acute respiratory failure. [ABSTRACT FROM AUTHOR]

BACKGROUND: The optimal spontaneous breathing trial (SBT) duration is not known for children who are critically ill. The study objective was to evaluate extubation outcomes between cohorts exposed to a 1- or 2-h SBT. METHODS: This was a retrospective cohort study of a quality improvement project database in a 24-bed pediatric ICU. The intervention was a respiratory therapist-driven SBT clinical pathway across 2 improvement cycles by using a 2- or 1-h SBT. The primary outcomes were extubation failure and rescue noninvasive ventilation in the first 48 h. Secondary outcomes included SBT results and process measures. RESULTS: There were 218 and 305 encounters in the 2- and 1-h cohorts, respectively. Extubation failure (7.3 vs 8.5%; P = .62) and rescue noninvasive ventilation rates (9.3 vs 8.2%; P = .68) were similar. In logistic regression models, SBT duration was not independently associated with either primary outcome. Extubation after 1-h SBT failure was associated with significantly higher odds of rescue noninvasive ventilation exposure (odds ratio 3.94, 95% CI 1.3-11.9; P = .02). SBT results were not associated with odds of extubation failure. There were 1,072 (2 h) and 1,333 (1 h) SBTs performed. The 1-h SBT pass rate was significantly higher versus the 2-h SBT (71.4 vs 51.1%; P < .001). Among all failed SBTs, the top 3 reported failure modes were tidal volume ≤ 5 mL/kg (23.6%), breathing frequency increase > 30% (21%), and oxygen saturation < 92% (17.3%). When considering all failed SBTs, 75.5% of failures occurred before 45 min. CONCLUSIONS: A 1-h SBT may be a viable alternative to a 2-h version for the average child who is critically ill. Further, a 1-h SBT may better balance extubation outcomes and duration of invasive ventilation for the general pediatric ICU population. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Oxylator is an automatic resuscitator, powered only by an oxygen cylinder with no electricity required, that could be used in acute respiratory failure in situations in which standard mechanical ventilation is not available or feasible. We aimed to assess the feasibility and safety of mechanical ventilation by using this automatic resuscitator in an animal model of ARDS. METHODS: A randomized experimental study in a porcine ARDS model with 12 pigs randomized to the Oxylator group or the control group (6 per group) and ventilated for 4 h. In the Oxylator group, peak pressure was set at 20 cm H2O and PEEP was set at the lowest observed breathing frequency during a decremental PEEP titration. The control pigs were ventilated with a conventional ventilator by using protective settings and PEEP at the crossing point of collapse and overdistention, as indicated by electrical impedance tomography. Our end points were feasibility and safety as well as respiratory mechanics, gas exchange, and hemodynamics. RESULTS: After lung injury, the mean ± SD respiratory system compliance and PaO2 /FIO2 were 13 ± 2 mL/cm H2O and 61 ± 17 mm Hg, respectively. The mean ± SD total PEEP was 10 ± 2 cm H2O and 13 ± 2 cm H2O in the control and Oxylator groups, respectively (P = .046). The mean plateau pressure was kept to < 30 cm H2O in both groups. In the Oxylator group, the tidal volume was transiently > 8 mL/kg but was 6 ± 0.4 mL/kg at 4 h, whereas the breathing frequency increased from 38 ± 4 to 48 ± 3 breaths/min (P < .001). There was no difference in driving pressure, compliance, PaO2/FIO2, and pulmonary shunt between the groups. The mean ± SD PaCO2 was higher in the Oxylator group after 4 h, 74 ± 9 mm Hg versus 58 ± 6 mm Hg (P < .001). There were no differences in hemodynamics between the groups, including blood pressure and cardiac output. CONCLUSIONS: Short-term mechanical ventilation by using an automatic resuscitator and a fixed pressure setting in an ARDS animal model was feasible and safe. [ABSTRACT FROM AUTHOR]

BACKGROUND: In refractory respiratory failure, extracorporeal membrane oxygenation (ECMO) is a rescue therapy to prevent ventilator-induced lung injury. Optimal ventilator parameters during ECMO remain unknown. Our objective was to describe the association between mortality and ventilator parameters during ECMO for neonatal and pediatric respiratory failure. METHODS: We performed a secondary analysis of the Bleeding and Thrombosis on ECMO dataset. Ventilator parameters included breathing frequency, tidal volume, peak inspiratory pressure, PEEP, dynamic driving pressure, pressure support, mean airway pressure, and FIO2. Parameters were evaluated before cannulation, on the calendar day of ECMO initiation (ECMO day 1), and the day before ECMO separation. RESULTS: Of 237 included subjects analyzed, 64% were neonates, of whom 36% had a congenital diaphragmatic hernia. Of all the subjects, 67% were supported on venoarterial ECMO. Overall in-hospital mortality was 35% (n = 83). The median (interquartile range) PEEP on ECMO day 1 was 8 (5.0-10.0) cm H2O for neonates and 10 (8.0-10.0) cm H2O for pediatric subjects. By multivariable analysis, higher PEEP on ECMO day 1 in neonates was associated with lower odds of in-hospital mortality (odds ratio 0.77, 95% CI 0.62-0.92; P = .01), with a further amplified effect in neonates with congenital diaphragmatic hernia (odds ratio 0.59, 95% CI 0.41-0.86; P = .005). No ventilator type or parameter was associated with mortality in pediatric subjects. CONCLUSIONS: Avoiding low PEEP on ECMO day 1 for neonates on ECMO may be beneficial, particularly those with a congenital diaphragmatic hernia. No additional ventilator parameters were associated with mortality in either neonatal or pediatric subjects. PEEP is a modifiable parameter that may improve neonatal survival during ECMO and requires further investigation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Noninvasive respiratory support (NRS) is increasingly used to support patients with acute respiratory failure. However, noninvasive support failure may worsen outcomes compared to primary support with invasive mechanical ventilation. Therefore, there is a need to identify patients where NRS is failing so that treatment can be reassessed and adjusted. The objective of this study was to develop and evaluate 3 recurrent neural network (RNN) models to predict NRS failure. METHODS: This was a cross-sectional observational study to evaluate the ability of deep RNN models (long short-term memory [LSTM], gated recurrent unit [GRU]), and GRU with trainable decay) to predict failure of NRS. Data were extracted from electronic health records from all adult (6 18 y) patient records requiring any type of oxygen therapy or mechanical ventilation between November 1, 2013-September 30, 2020, across 46 ICUs in the Southwest United States in a single health care network. Input variables for each model included serum chloride, creatinine, albumin, breathing frequency, heart rate, SpO2, FIO2, arterial oxygen saturation (SaO2), and 2 measurements each (point-of-care and laboratory measurement) of PaO2 and partial pressure of arterial oxygen from an arterial blood gas. RESULTS: Time series data from electronic health records were available for 22,075 subjects. The highest accuracy and area under the receiver operating characteristic curve were for the LSTM model (94.04% and 0.9636, respectively). Accurate predictions were made 12 h after ICU admission, and performance remained high well in advance of NRS failure. CONCLUSIONS: RNN models using routinely collected time series data can accurately predict NRS failure well before intubation. This lead time may provide an opportunity to intervene to optimize patient outcomes. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pediatric extubation failure is associated with morbidity and mortality. The most common cause is upper-airway obstruction. Subglottic edema is common, but upper-airway obstruction can occur from the oral cavity to the trachea. Dichotomous categorization of extubation failure as airway versus non-airway may help identify risk factors as well as strategies that translate to lower extubation failure rates. METHODS: This was as single-center, retrospective cohort study of invasive mechanical ventilation encounters within a quality improvement database between October 1, 2017-November 30, 2020. Utilizing a 3-physician adjudication process, all extubation failures were categorized as airway versus non-airway. Primary outcome was failure subtype prevalence. Secondary outcome was failure subtype risk factors. Clinical outcomes were explored. RESULTS: The all-cause extubation failure rate was 10% in a cohort of 844 encounters. Airway and non-airway extubation failure represented 60.7% and 39.3%, respectively. Most airway failures were due to upper-airway obstruction (84.3%)--35.3% were supraglottic, 25.5% subglottic, and 23.5% mixed. Other causes of airway failure were airway patency/secretions (11.8%) and aspiration (3.9%). Non-airway failures were attributed to respiratory failure (75.8%), encephalopathy (15.2%), and other (9%). All-cause extubation failure was associated with dysgenetic/syndromic comorbidity (P = .005), ≥ 3 concurrent comorbid conditions (P = .007), indication for invasive ventilation (P < .001), and longer invasive mechanical ventilation duration (P < .001). Airway extubation failure was significantly associated with the presence of a respiratory comorbidity (P = .01) and Glasgow coma scale < 10 (P = .02). No significant non-airway failure risk factors were identified. Longer pediatric ICU (PICU) stay (P < .001) and PICU mortality (P < .001) were associated with all-cause extubation failure. No significant outcome associations with extubation failure subtype were identified. CONCLUSIONS: Airway extubation failure prevalence was 1.5 times higher than non-airway failure. Potential risk factors for airway failure were identified. These findings are hypothesis generating for future study focused on key evidence gaps and pragmatic bedside application. [ABSTRACT FROM AUTHOR]

BACKGROUND: Spinal muscular atrophy (SMA) is a neurodegenerative disease that results in progressive muscular atrophy and weakness. The primary cause of morbidity and mortality in these children is pulmonary disease due to poor airway clearance that leads to acute respiratory failure. There is a paucity of literature on the treatment of children with SMA and acute respiratory failure. METHODS: We performed a retrospective chart review of pediatric patients with SMA type I or II admitted to the PICU in a tertiary-care children's hospital with acute respiratory failure who required mechanical ventilation and/or aggressive airway clearance. RESULTS: The study included 300 unique encounters among 137 unique subjects. All the subjects received airway clearance at home before admission, and 257 encounters (85.7%) were supported with noninvasive ventilation (NIV) before admission. Sixty-eight subjects (49.6%) required endotracheal intubation on admission or at some point during their PICU stay. The median (interquartile range [IQR]) time to intubation was 0 (0-20) h, and the median (IQR) duration of mechanical ventilation was 2 (1-5) d on invasive mechanical ventilation with no statistical difference between type I and type II (P = .89). Of those, 65 (91.1%) were successfully extubated to NIV on the first attempt, whereas 4 subjects (5.8%) required multiple extubation attempts and 3 subjects (4.4%) required subsequent tracheostomy. For the subjects who were intubated, both PICU and hospital length of stay were longer (P < .001) when compared with the subjects managed by NIV alone. The subjects with SMA type I had a longer PICU length of stay, with a median (IQR) of 5 (3-11) d versus 4 (2-7) d (P = .002). The hospital length of stay and duration of invasive mechanical ventilation were not statistically different (P = .055 and P = .068, respectively). CONCLUSIONS: The subjects with SMA types I or II can be treated successfully with NIV and aggressive airway clearance during acute respiratory failure. Similarly, when intubation is required, successful extubation can be achieved with NIV transitional support combined with aggressive airway clearance maneuvers. [ABSTRACT FROM AUTHOR]

BACKGROUND: Patients requiring mechanical ventilation due to COVID-19 have different characteristics of evolution and outcome compared to the general ICU population. Although early weaning from mechanical ventilation is associated with improved outcomes, inadequate identification of patients unable to be weaned may lead to extubation failure and increased days on mechanical ventilation. Outcomes related to mechanical ventilation weaning in this population are scare and inconclusive. Therefore, the objective of this study was to describe the characteristics of mechanical ventilation weaning in subjects with acute respiratory failure induced by COVID-19. METHODS: This was a multi-center, prospective cohort study. We included adult subjects requiring at least 12 h of mechanical ventilation due to COVID-19 infection admitted to any participating ICUs. Characteristics of the mechanical ventilation weaning and extubation process, as well as clinical results, were the primary outcome variables. Weaning types were defined according to previously described and internationally recognized categories. RESULTS: Three hundred twenty-six subjects from 8 ICUs were included. A spontaneous breathing trial (SBT) was not performed in 52.1% of subjects. One hundred twenty-eight subjects were extubated, and 29.7% required re-intubation. All the subjects included could be classified by Weaning according to a New Definition (WIND) classification (group 0 = 52.1%, group 1 = 28.5%, group 2 = 8.0%, and group 3 = 11.3%) with statistically significant differences in duration of mechanical ventilation (P < .001) and ICU length of stay (P < .001) between groups. CONCLUSIONS: The mechanical ventilation weaning process in subjects with COVID-19 was negatively affected by the disease, with many subjects never completing an SBT. Even though temporal variables were modified, the clinical outcomes in each weaning group were similar to those previously reported. [ABSTRACT FROM AUTHOR]

BACKGROUND: Noninvasive ventilation (NIV) is the reference standard treatment for most situations of chronic respiratory failure. NIV settings must be titrated to both preserve upper-airway patency and control hypoventilation. Automatic adjustment of pressure support (PS) and expiratory positive airway pressure (EPAP) may facilitate the initiation and follow-up of domiciliary NIV. However, whether the automatic-adjustment algorithms embedded into current devices accurately detect, respond to, and score common sleep-related respiratory events remains unclear. METHODS: A bench was set up to simulate central hypopnea (CH), central apnea (CA), obstructive hypopnea (OH), and obstructive apnea (OA). Four home ventilators were evaluated, with their dedicated modes for automatic PS and EPAP adjustment. RESULTS: All 4 devices increased PS during CH, CA, and OH. However, PS adjustment varied widely in magnitude, with tidal volumes within 100 6 20% of the target being provided by only 3 devices for CH, one for CA, and one for OH. Two devices increased EPAP for OH and 3 for OA, including one that also increased EPAP for CA. Only 2 devices scored residual hypopnea after simulated CA, and only one scored a residual event after OH. One device scored no event. CONCLUSIONS: Current NIV devices differed markedly in their responses to, and reporting of, standardized sleep-related respiratory events. Further improvements in embedded NIV algorithms are needed to allow more widespread out-of-laboratory initiation and follow- up of NIV. [ABSTRACT FROM AUTHOR]

BACKGROUND: In the midst of the COVID-19 pandemic, noninvasive respiratory support (NRS) therapies such as high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) were central to respiratory care. The extent to which these treatments increase the generation and dispersion of infectious respiratory aerosols is not fully understood. The objective of this study was to characterize SARS-CoV-2 aerosol dispersion from subjects with COVID-19 undergoing NRS therapy. METHODS: Several different aerosol sampling devices were used to collect air samples in the vicinity of 31 subjects with COVID-19, most of whom were receiving NRS therapy, primarily HFNC. Aerosols were collected onto filters and analyzed for the presence of SARS-CoV-2 RNA. Additional measurements were collected in an aerosol chamber with healthy adult subjects using respiratory therapy devices under controlled and reproducible conditions. RESULTS: Fifty aerosol samples were collected from subjects receiving HFNC or NIV therapy, whereas 6 samples were collected from subjects not receiving NRS. Only 4 of the 56 aerosol samples were positive for SARS-CoV-2 RNA, and all positive samples were collected using a high air flow scavenger mask collection device placed in close proximity to the subject. The chamber measurements with healthy subjects did not show any significant increase in aerosol dispersion caused by the respiratory therapy devices compared to baseline. CONCLUSIONS: Our findings demonstrate very limited detection of SARS-CoV-2--containing aerosols in the vicinity of subjects with COVID-19 receiving NRS therapies in the clinical setting. These results, combined with controlled chamber measurements showing that HFNC and NIV device usage was not associated with increased aerosol dispersion, suggest that NRS therapies do not result in increased dispersal of aerosols in the clinical setting. [ABSTRACT FROM AUTHOR]

BACKGROUND: The evidence regarding benefits of high-flow nasal cannula (HFNC) in patients with COVID-19 is controversial. The aim of this study was to evaluate the impact of HFNC in comparison with standard oxygen therapy on the frequency of endotracheal intubation at 28 d in subjects with acute hypoxemic respiratory failure (AHRF) secondary to SARS-CoV-2 infection. METHODS: A retrospective, age- and sex-matched-paired, cohort study was conducted in subjects with moderate-to-severe AHRF. Intervention group was treated with HFNC, and control group was treated with standard oxygen therapy. Baseline characteristics and clinical evolution were analyzed. Mantel-Haenszel test was used for categorical variables. Paired samples Wilcoxon test was used for quantitative variables. Multivariate analysis was performed using conditional multiple logistic regression. RESULTS: Eighty-four subjects were included. The median time from admission to progression of oxygen therapy to FIO2 ≥ 0.5 or HFNC was 1 (interquartile range [IQR] 0-3) d. PaO2/FIO2 at the time of oxygen therapy progression showed a median of 150.5 (IQR 100.0-170.0) for the entire sample and was lower in HFNC group compared with control group (median 135 [IQR 96-162] vs median 158 [IQR 132-174], respectively, P = .02). Endotracheal intubation at 28 d was observed in 54.8% HFNC and 73.8% standard oxygen (unadjusted odds ratio 0.38 [95% CI 0.13-1.07], P = .069). In the multivariate analysis, presence of dyspnea at hospital admission, Sequential Organ Failure Assessment score, and PaO2/FIO2 at time of progression of oxygen therapy to FIO2 ≥ 0.5 was identified as confounding factors for the association between the intervention group and the outcome. Use of HFNC was not an independent predictor of endotracheal intubation frequency after adjusting confounders (odds ratio 0.26 [95% CI 0.04-1.51], P = .13). CONCLUSIONS: In this study, HFNC therapy in subjects with AHRF secondary to COVID-19 was not an independent predictor of endotracheal intubation, compared with standard oxygen therapy, after adjusting for confounders. [ABSTRACT FROM AUTHOR]