Impact of Previous Continuous Positive Airway Pressure Use on Noninvasive Ventilation Adherence and Quality in Obesity Hypoventilation Syndrome: A Pragmatic Single-Center Cross-Sectional Study in Martinique.

There is a strong relationship between obstructive sleep apnea (OSA) and obesity hypoventilation syndrome (OHS). When OHS is combined with severe OSA, treatment consists of continuous positive airway pressure (CPAP), followed by noninvasive ventilation (NIV) in the case of CPAP failure. Currently, the impact of a previous use of CPAP on the quality of NIV is unknown. We conducted a cross-sectional study with OHS patients, to assess the quality of NIV according to previous CPAP use. We included 75 patients with OHS on NIV (65 women, 87%). Among these, 40 patients (53.3%) who had had prior CPAP (CPAP+ group) were compared to the remaining 35 patients (46.7%) (CPAP- group). Key characteristics were comparable between the CPAP+ and the CPAP- groups: age at diagnosis of OHS was 67 ± 3 vs. 66 ± 4 years (p = 0.8), age at inclusion was 73 ± 15 vs. 69 ± 15 years (p = 0.29), number of comorbidities was 3.7 ± 1.2 vs. 3.3 ± 1.5, the Charlson index was 5.1 ± 2 vs. 4.6 ± 1.8, and BMI was 41.6 ± 7.6 kg/m2 vs. 41.2 ± 8.2, respectively, all p > 0.05. Follow-up length was greater in CPAP+ vs. CPAP- patients (5.6 ± 4.2 vs. 2.9 ± 2.9 years, p = 0.001). The quality of NIV based on daily adherence, pressure support, apnea-hypopnea index (AHI) and leaks was similar in both groups. Reduced adherence (less than 4 h daily) was found in 10 CPAP+ patients (25%) versus 7 CPAP- patients (20%), p = 0.80. NIV efficacy was also similar. This study found no difference in the quality of NIV or in adherence between patients who had had prior CPAP and those who had not. Previous CPAP does not appear to improve the quality of NIV.

Factors Associated with the Efficiency of Home Non-Invasive Ventilation in Patients with Obesity-Hypoventilation Syndrome in Martinique.

Obesity-hypoventilation syndrome (OHS) is a respiratory complication of obesity characterized by chronic hypercapnic respiratory failure. It is often associated with several comorbidities and is treated by positive airway pressure (PAP) therapy. This study aimed to identify factors associated with persistent hypercapnia in patients receiving home non-invasive ventilation (NIV). We performed a retrospective study including patients with documented OHS. In total, 143 patients were included (79.7% women, age 67 ± 15.5 years, body mass index 41.6 ± 8.3 kg/m2). After 4.6 ± 4.0 years of follow-up, 72 patients (50.3%) remained hypercapnic. In bivariable analysis, clinical data showed no difference in follow-up duration, number of comorbidities, comorbidities, or circumstance of discovery. Patients with persistent hypercapnia on NIV were generally older, with lower BMI and more comorbidities. (5.5 ± 1.8 versus 4.4 ± 2.1, p = 0.001), female sex (87.5% versus 71.8%), was treated by NIV (100% versus 90.1%, p < 0.01), had lower FVC (56.7 ± 17.2 versus 63.6 ± 18% of theoretical value, p = 0.04), lower TLC (69.1 ± 15.3 versus 74.5 ± 14.6% of theoretical value, p = 0.07), lower RV (88.4 ± 27.1 versus 102.5 ± 29.4% of theoretical value, p = 0.02), higher pCO2 at diagnosis (59.7 ± 11.7 versus 54.6 ± 10.1 mmHg, p = 0.01) and lower pH (7.38 ± 0.03 versus 7.40 ± 0.04, p = 0.007), higher pressure support (12.6 ± 2.6 versus 11.5 ± 2.4 cmH2O, p = 0.04) and lower EPAP (8.2 ± 1.9 versus 9 ± 2.0 cmH2O, p = 0.06). There was no difference in non-intentional leaks and daily use between patients between both groups. By multivariable analysis, sex, BMI, pCO2 at diagnosis, and TLC were independent risk factors for persistent hypercapnia on home NIV. In individuals with OHS, persistent hypercapnia on home NIV therapy is frequent. Sex, BMI, pCO2 at diagnosis, and TLC were all associated with an increased risk of persistent hypercapnia in persons treated with home NIV.

Association between Previous CPAP and Comorbidities at Diagnosis of Obesity-Hypoventilation Syndrome Associated with Obstructive Sleep Apnea: A Comparative Retrospective Observational Study.

Obesity-hypoventilation syndrome (OHS) is associated with many comorbidities. The aim of this study was to evaluate the association between previous continuous positive airway pressure (CPAP) and the prevalence of comorbidities in OHS associated with obstructive sleep apnea (OSA). We performed a retrospective, single-center study at the University Hospital of Martinique, the referral hospital for the island of Martinique. A total of 97 patients with OHS associated with severe OSA on non-invasive ventilation (NIV) were included; 54 patients (56%) had previous treatment of OSA with a positive airway pressure (PAP) device before shifting to NIV (PAP group) and 43 (44%) had no previous treatment of OSA with a PAP device before initiating NIV PAP (no PAP group). Sociodemographic characteristics were similar between groups; there were 40 women (74%) in the PAP group versus 34 (79%) in the no PAP group, mean age at OHS diagnosis was 66 ± 15 versus 67 ± 16 years, respectively, and the mean age at inclusion 72 ± 14 versus 71 ± 15 years, respectively. The average number of comorbidities was 4 ± 1 in the PAP group versus 4 ± 2 in the no PAP group; the mean Charlson index was 5 ± 2 in both groups. The mean BMI was 42 ± 8 kg/m2 in both groups. The mean follow-up duration was 5.8 ± 4.4 years in the PAP group versus 4.7 ± 3.5 years in the no PAP group. Chronic heart failure was less common in patients who had a previous PAP 30% versus 53% (p = 0.02). It is also noted that these patients were diagnosed less often in the context of acute respiratory failure in patients with previous PAP: 56% versus 93% (p < 0.0001). In contrast, asthma patients were more frequent in patients with previous treatment of OSA with a PAP device at the time of OHS diagnosis but not significantly: 37% versus 19% (p = 0.07). Early treatment of severe OSA with a PAP device prior to diagnosis of OHS seems to be associated with a reduced prevalence of cardiac diseases, notably chronic heart failure, in patients diagnosed with OHS associated with severe OSA.

Monitoring Systems in Home Ventilation.

Non-invasive ventilation (NIV) is commonly used at home for patient with nocturnal hypoventilation caused by a chronic respiratory failure. Monitoring NIV is required to optimize the ventilator settings when the lung condition changes over time, and to detect common problems such as unintentional leaks, upper airway obstructions, and patient-ventilator asynchronies. This review describes the accuracy and limitations of the data recorded by the ventilator. To efficiently interpret this huge amount of data, clinician assess the daily use and regularity of NIV utilization, the unintentional leaks and their repartition along the NIV session, the apnea-hypopnea index and the flow waveform, and the patient-ventilator synchrony. Nocturnal recordings of gas exchanges are also required to detect nocturnal alveolar hypoventilation. This review describes the indication, validity criteria, and interpretation of nocturnal oximetry and transcutaneous capnography. Polygraphy and polysomnography are indicated in specific cases to characterize upper airway obstruction. Telemonitoring of the ventilator is a useful tool that should be integrated in the monitoring strategy. The technical solution, information, and limitations are discussed. In conclusion, a basic monitoring package is recommended for all patients complemented by advanced monitoring for specific cases.

Comparison of high-flow nasal therapy, noninvasive ventilation, and continuous positive airway pressure on outcomes in critically ill patients admitted for COVID-19 with acute respiratory failure.

BACKGROUND: The optimal first-line noninvasive respiratory support (NIRS) to improve outcome in patients affected by COVID-19 pneumonia admitted to ICU is still debated. METHODS: We conducted a retrospective study in seven French ICUs, including all adults admitted between July and December 2020 with documented SARS-CoV-2 acute respiratory failure (PaO2/FiO2<300 mmHg), and treated with either high-flow nasal therapy (HFNT) alone, noninvasive ventilation alone or in combination with HFNT (NIV), or continuous positive airway pressure alone or in combination with HFNT (CPAP). The primary outcome was NIRS failure at day 28, defined as the need for endotracheal intubation (ETI) or death without ETI. RESULTS: Among the 355 patients included, 160 (45%) were treated with HFNT alone, 115 (32%) with NIV and 80 (23%) with CPAP. The primary outcome occurred in 65 (41%), 69 (60%), and 25 (31%) patients among those treated with HFNT alone, NIV, and CPAP, respectively (P<0.001). After univariate analysis, patients treated with CPAP had a trend for a lower incidence of the primary outcome, whereas patients treated with NIV had a significant higher incidence of the primary outcome, both compared to those treated with HFNT alone (unadjusted Hazard ratio 0.67; 95% CI [0.42-1.06], and 1.58; 95% CI [1.12-2.22]; P=0.09 and 0.008, respectively). CONCLUSIONS: Among ICU patients admitted for severe COVID-19 pneumonia and managed with NIRS, the outcome seems to differ according to the initial chosen strategy. Prospective randomized controlled studies are warranted to identify the optimal strategy.

Closed-loop ventilation.

PURPOSE OF REVIEW: The last 25 years have seen considerable development in modes of closed-loop ventilation and there are now several of them commercially available. They not only offer potential benefits for the individual patient, but may also improve the organization within the intensive care unit (ICU). Clinicians are showing both greater interest and willingness to address the issues of a caregiver shortage and overload of bedside work in the ICU. This article reviews the clinical benefits of using closed-loop ventilation modes, with a focus on control of oxygenation, lung protection, and weaning. RECENT FINDINGS: Closed-loop ventilation modes are able to maintain important physiological variables, such as oxygen saturation measured by pulse oximetry, tidal volume (VT), driving pressure (ΔP), and mechanical power (MP), within target ranges aimed at ensuring continuous lung protection. In addition, these modes adapt the ventilator support to the patient's needs, promoting diaphragm activity and preventing over-assistance. Some studies have shown the potential of these modes to reduce the duration of both weaning and mechanical ventilation. SUMMARY: Recent studies have primarily demonstrated the safety, efficacy, and feasibility of using closed-loop ventilation modes in the ICU and postsurgery patients. Large, multicenter randomized controlled trials are needed to assess their impact on important short- and long-term clinical outcomes, the organization of the ICU, and cost-effectiveness.

Physiologic Effects of the Awake Prone Position Combined With High-Flow Nasal Oxygen on Gas Exchange and Work of Breathing in Patients With Severe COVID-19 Pneumonia: A Randomized Crossover Trial.

To determine the effect of the awake prone position (APP) on gas exchange and the work of breathing in spontaneously breathing patients with COVID-19-associated acute hypoxemic respiratory failure (AHRF) supported by high-flow nasal oxygen. DESIGN: Prospective randomized physiologic crossover multicenter trial. SETTINGS: Four ICUs in Marseille, France. PATIENTS: Seventeen patients with laboratory-confirmed COVID-19 pneumonia and Pao2/Fio2 less than or equal to 300 mm Hg while treated with high-flow nasal cannula oxygen therapy. INTERVENTIONS: Periods of APP and semirecumbent position (SRP) were randomly applied for 2 hours and separated by a 2-hour washout period. MEASUREMENTS AND MAIN RESULTS: Arterial blood gases, end-tidal CO2. and esophageal pressure were recorded prior to and at the end of each period. Inspiratory muscle effort was assessed by measuring the esophageal pressure swing (∆PES) and the simplified esophageal pressure-time product (sPTPES). The other endpoints included physiologic dead space to tidal volume ratio (VD/VT) and the transpulmonary pressure swing. The APP increased the Pao2/Fio2 from 84 Torr (61-137 Torr) to 208 Torr (114-226 Torr) (p = 0.0007) and decreased both the VD/VT and the respiratory rate from 0.54 (0.47-0.57) to 0.49 (0.45-0.53) (p = 0.012) and from 26 breaths/min (21-30 breaths/min) to 21 breaths/min (19-22 breaths/min), respectively (p = 0.002). These variables remained unchanged during the SRP. The ∆PES and sPTPES per breath were unaffected by the position. However, the APP reduced the sPTPES per minute from 225 cm H2O.s.m-1 (176-332 cm H2O.s.m-1) to 174 cm H2O.s.m-1 (161-254 cm H2O.s.m-1) (p = 0.049). CONCLUSIONS: In spontaneously breathing patients with COVID-19-associated AHRF supported by high-flow nasal oxygen, the APP improves oxygenation and reduces the physiologic dead space, respiratory rate, and work of breathing per minute.

Patient-Ventilator Synchronization During Non-invasive Ventilation: A Pilot Study of an Automated Analysis System.

Background: Patient-ventilator synchronization during non-invasive ventilation (NIV) can be assessed by visual inspection of flow and pressure waveforms but it remains time consuming and there is a large inter-rater variability, even among expert physicians. SyncSmart™ software developed by Breas Medical (Mölnycke, Sweden) provides an automatic detection and scoring of patient-ventilator asynchrony to help physicians in their daily clinical practice. This study was designed to assess performance of the automatic scoring by the SyncSmart software using expert clinicians as a reference in patient with chronic respiratory failure receiving NIV. Methods: From nine patients, 20 min data sets were analyzed automatically by SyncSmart software and reviewed by nine expert physicians who were asked to score auto-triggering (AT), double-triggering (DT), and ineffective efforts (IE). The study procedure was similar to the one commonly used for validating the automatic sleep scoring technique. For each patient, the asynchrony index was computed by automatic scoring and each expert, respectively. Considering successively each expert scoring as a reference, sensitivity, specificity, positive predictive value (PPV), κ-coefficients, and agreement were calculated. Results: The asynchrony index assessed by SynSmart was not significantly different from the one assessed by the experts (18.9 ± 17.7 vs. 12.8 ± 9.4, p = 0.19). When compared to an expert, the sensitivity and specificity provided by SyncSmart for DT, AT, and IE were significantly greater than those provided by an expert when compared to another expert. Conclusions: SyncSmart software is able to score asynchrony events within the inter-rater variability. When the breathing frequency is not too high (<24), it therefore provides a reliable assessment of patient-ventilator asynchrony; AT is over detected otherwise.

Hysteresis and Lung Recruitment in Acute Respiratory Distress Syndrome Patients: A CT Scan Study.

OBJECTIVES: Hysteresis of the respiratory system pressure-volume curve is related to alveolar surface forces, lung stress relaxation, and tidal reexpansion/collapse. Hysteresis has been suggested as a means of assessing lung recruitment. The objective of this study was to determine the relationship between hysteresis, mechanical characteristics of the respiratory system, and lung recruitment assessed by a CT scan in mechanically ventilated acute respiratory distress syndrome patients. DESIGN: Prospective observational study. SETTING: General ICU of a university hospital. PATIENTS: Twenty-five consecutive sedated and paralyzed patients with acute respiratory distress syndrome (age 64 ± 15 yr, body mass index 26 ± 6 kg/m, PaO2/FIO2 147 ± 42, and positive end-expiratory pressure 9.3 ± 1.4 cm H2O) were enrolled. INTERVENTIONS: A low-flow inflation and deflation pressure-volume curve (5-45 cm H2O) and a sustained inflation recruitment maneuver (45 cm H2O for 30 s) were performed. A lung CT scan was performed during breath-holding pressure at 5 cm H2O and during the recruitment maneuver at 45 cm H2O. MEASUREMENTS AND MAIN RESULTS: Lung recruitment was computed as the difference in noninflated tissue and in gas volume measured at 5 and at 45 cm H2O. Hysteresis was calculated as the ratio of the area enclosed by the pressure-volume curve and expressed as the hysteresis ratio. Hysteresis was correlated with respiratory system compliance computed at 5 cm H2O and the lung gas volume entering the lung during inflation of the pressure-volume curve (R = 0.749, p < 0.001 and R = 0.851, p < 0.001). The hysteresis ratio was related to both lung tissue and gas recruitment (R = 0.266, p = 0.008, R = 0.357, p = 0.002, respectively). Receiver operating characteristic analysis showed that the optimal cutoff value to predict lung tissue recruitment for the hysteresis ratio was 28% (area under the receiver operating characteristic curve, 0.80; 95% CI, 0.62-0.98), with sensitivity and specificity of 0.75 and 0.77, respectively. CONCLUSIONS: Hysteresis of the respiratory system computed by low-flow pressure-volume curve is related to the anatomical lung characteristics and has an acceptable accuracy to predict lung recruitment.

In COPD, Nocturnal Noninvasive Ventilation Reduces the FIO2 Delivered Compared With Long-Term Oxygen Therapy at the Same Flow.

BACKGROUND: Nocturnal noninvasive ventilation is recommended for patients with hypercapnic COPD. Long-term oxygen therapy improves survival in patients with hypoxemic disease. However, leaks during noninvasive ventilation are likely to reduce the fraction of inspired oxygen. OBJECTIVES: To compare nocturnal inspired O2 fractions during noninvasive ventilation with daytime pharyngeal inspired O2 fractions during nasal cannula oxygen therapy (with the same O2 flow) in patients with COPD at home (ie, real-life conditions). METHODS: This single-center prospective observational study included 14 subjects with COPD who received long-term O2 therapy. We analyzed pharyngeal inspired O2 fractions in the evening, with a nasopharyngeal probe (sidestream gas analyzer). The O2 flow was measured with a precision flow meter, at the usual flow. Then, the same O2 flow was implemented for noninvasive ventilation with a study's home ventilator. The all-night noninvasive ventilation parameters were delivered in pressure mode with a single-limb leaking circuit. Daytime and nighttime inspired O2 fractions were compared. RESULTS: The mean ± SD daytime pharyngeal inspired O2 fraction, measured with normobaric basal O2 flow, 0.308 ± 0.026%, was significantly higher than the mean ± SD nighttime inspired O2 fraction, measured during noninvasive ventilation (0.251 ± 0.011; P < .001). CONCLUSIONS: The nighttime inspired O2 fraction decreased with a modern noninvasive ventilation pattern, pressure target, and intentional leaks. This partial lack of O2 therapy is likely to be harmful. It might explain the poor results in all but 2 randomized controlled trials on long-term noninvasive ventilation in COPD. (ClinicalTrials.gov registration NCT02599246.).

Airway and transpulmonary driving pressures and mechanical powers selected by INTELLiVENT-ASV in passive, mechanically ventilated ICU patients.

BACKGROUND: Driving pressure (ΔP) and mechanical power (MP) are predictors of the risk of ventilation- induced lung injuries (VILI) in mechanically ventilated patients. INTELLiVENT-ASV® is a closed-loop ventilation mode that automatically adjusts respiratory rate and tidal volume, according to the patient's respiratory mechanics. OBJECTIVES: This prospective observational study investigated ΔP and MP (and also transpulmonary ΔP (ΔPL) and MP (MPL) for a subgroup of patients) delivered by INTELLiVENT-ASV. METHODS: Adult patients admitted to the ICU were included if they were sedated and met the criteria for a single lung condition (normal lungs, COPD, or ARDS). INTELLiVENT-ASV was used with default target settings. If PEEP was above 16 cmH2O, the recruitment strategy used transpulmonary pressure as a reference, and ΔPL and MPL were computed. Measurements were made once for each patient. RESULTS: Of the 255 patients included, 98 patients were classified as normal-lungs, 28 as COPD, and 129 as ARDS patients. The median ΔP was 8 (7 - 10), 10 (8 - 12), and 9 (8 - 11) cmH2O for normal-lungs, COPD, and ARDS patients, respectively. The median MP was 9.1 (4.9 - 13.5), 11.8 (8.6 - 16.5), and 8.8 (5.6 - 13.8) J/min for normal-lungs, COPD, and ARDS patients, respectively. For the 19 patients managed with transpulmonary pressure ΔPL was 6 (4 - 7) cmH2O and MPL was 3.6 (3.1 - 4.4) J/min. CONCLUSIONS: In this short term observation study, INTELLiVENT-ASV selected ΔP and MP considered in safe ranges for lung protection. In a subgroup of ARDS patients, the combination of a recruitment strategy and INTELLiVENT-ASV resulted in an apparently safe ΔPL and MPL.

Setting up home noninvasive ventilation.

Home noninvasive ventilation (NIV) is widely used to correct nocturnal alveolar hypoventilation in patients with chronic respiratory failure of various etiologies. The most commonly used ventilation mode is pressure support with a backup respiratory rate. This mode requires six main settings, as well as some additional settings that should be adjusted according to the individual patient. This review details the effect of each setting, how the settings should be adjusted according to each patient, and the risks if they are not adjusted correctly. The examples described here are based on real patient cases and bench simulations. Optimizing the settings for home NIV may improve the quality and tolerance of the treatment.

X-linked myotubular myopathy: A prospective international natural history study.

OBJECTIVES: Because X-linked myotubular myopathy (XLMTM) is a rare neuromuscular disease caused by mutations in the MTM1 gene with a large phenotypic heterogeneity, to ensure clinical trial readiness, it was mandatory to better quantify disease burden and determine best outcome measures. METHODS: We designed an international prospective and longitudinal natural history study in patients with XLMTM and assessed muscle strength and motor and respiratory functions over the first year of follow-up. The humoral immunity against adeno-associated virus serotype 8 was also monitored. RESULTS: Forty-five male patients aged 3.5 months to 56.8 years were enrolled between May 2014 and May 2017. Thirteen patients had a mild phenotype (no ventilation support), 7 had an intermediate phenotype (ventilation support less than 12 hours a day), and 25 had a severe phenotype (ventilation support 12 or more hours a day). Most strength and motor function assessments could be performed even in very weak patients. Motor Function Measure 32 total score, grip and pinch strengths, and forced vital capacity, forced expiratory volume in the first second of exhalation, and peak cough flow measures discriminated the 3 groups of patients. Disease history revealed motor milestone loss in several patients. Longitudinal data on 37 patients showed that the Motor Function Measure 32 total score significantly decreased by 2%. Of the 38 patients evaluated, anti-adeno-associated virus type 8 neutralizing activity was detected in 26% with 2 patients having an inhibitory titer >1:10. CONCLUSIONS: Our data confirm that XLMTM is slowly progressive for male survivors regardless of their phenotype and provide outcome validation and natural history data that can support clinical development in this population. CLINICALTRIALSGOV IDENTIFIER: NCT02057705.

Noninvasive ventilation: education and training. A narrative analysis and an international consensus document.

Noninvasive ventilation (NIV) is an increasingly used method of respiratory support. The use of NIV is expanding over the time and if properly applied, it can save patients' lives and improve long-term prognosis. However, both knowledge and skills of its proper use as life support are paramount. This systematic review aimed to assess the importance of NIV education and training. Literature search was conducted (MEDLINE: 1990 to June, 2018) to identify randomized controlled studies and systematic reviews with the results analyzed by a team of experts across the world through e-mail based communications. Clinical trials examining the impact of education and training in NIV as the primary objective was not found. A few studies with indirect evidence, a simulation-based training study, and narrative reviews were identified. Currently organized training in NIV is implemented only in a few developed countries. Due to a lack of high-grade experimental evidence, an international consensus on NIV education and training based on opinions from 64 experts across the twenty-one different countries of the world was formulated. Education and training have the potential to increase knowledge and skills of the clinical staff who deliver medical care using NIV. There is a genuine need to develop structured, organized NIV education and training programs, especially for the developing countries.

Risk factors and outcomes for airway failure versus non-airway failure in the intensive care unit: a multicenter observational study of 1514 extubation procedures.

BACKGROUND: Patients liberated from invasive mechanical ventilation are at risk of extubation failure, including inability to breathe without a tracheal tube (airway failure) or without mechanical ventilation (non-airway failure). We sought to identify respective risk factors for airway failure and non-airway failure following extubation. METHODS: The primary endpoint of this prospective, observational, multicenter study in 26 intensive care units was extubation failure, defined as need for reintubation within 48 h following extubation. A multinomial logistic regression model was used to identify risk factors for airway failure and non-airway failure. RESULTS: Between 1 December 2013 and 1 May 2015, 1514 patients undergoing extubation were enrolled. The extubation-failure rate was 10.4% (157/1514), including 70/157 (45%) airway failures, 78/157 (50%) non-airway failures, and 9/157 (5%) mixed airway and non-airway failures. By multivariable analysis, risk factors for extubation failure were either common to airway failure and non-airway failure: intubation for coma (OR 4.979 (2.797-8.864), P < 0.0001 and OR 2.067 (1.217-3.510), P = 0.003, respectively, intubation for acute respiratory failure (OR 3.395 (1.877-6.138), P < 0.0001 and OR 2.067 (1.217-3.510), P = 0.007, respectively, absence of strong cough (OR 1.876 (1.047-3.362), P = 0.03 and OR 3.240 (1.786-5.879), P = 0.0001, respectively, or specific to each specific mechanism: female gender (OR 2.024 (1.187-3.450), P = 0.01), length of ventilation > 8 days (OR 1.956 (1.087-3.518), P = 0.025), copious secretions (OR 4.066 (2.268-7.292), P < 0.0001) were specific to airway failure, whereas non-obese status (OR 2.153 (1.052-4.408), P = 0.036) and sequential organ failure assessment (SOFA) score ≥ 8 (OR 1.848 (1.100-3.105), P = 0.02) were specific to non-airway failure. Both airway failure and non-airway failure were associated with ICU mortality (20% and 22%, respectively, as compared to 6% in patients with extubation success, P < 0.0001). CONCLUSIONS: Specific risk factors have been identified, allowing us to distinguish between risk of airway failure and non-airway failure. The two conditions will be managed differently, both for prevention and curative strategies. TRIAL REGISTRATION: ClinicalTrials.gov, NCT 02450669 . Registered on 21 May 2015.

COMET: a multicomponent home-based disease-management programme versus routine care in severe COPD.

The COPD Patient Management European Trial (COMET) investigated the efficacy and safety of a home-based COPD disease management intervention for severe COPD patients.The study was an international open-design clinical trial in COPD patients (forced expiratory volume in 1 s <50% of predicted value) randomised 1:1 to the disease management intervention or to the usual management practices at the study centre. The disease management intervention included a self-management programme, home telemonitoring, care coordination and medical management. The primary end-point was the number of unplanned all-cause hospitalisation days in the intention-to-treat (ITT) population. Secondary end-points included acute care hospitalisation days, BODE (body mass index, airflow obstruction, dyspnoea and exercise) index and exacerbations. Safety end-points included adverse events and deaths.For the 157 (disease management) and 162 (usual management) patients eligible for ITT analyses, all-cause hospitalisation days per year (mean±sd) were 17.4±35.4 and 22.6±41.8, respectively (mean difference -5.3, 95% CI -13.7 to -3.1; p=0.16). The disease management group had fewer per-protocol acute care hospitalisation days per year (p=0.047), a lower BODE index (p=0.01) and a lower mortality rate (1.9% versus 14.2%; p<0.001), with no difference in exacerbation frequency. Patient profiles and hospitalisation practices varied substantially across countries.The COMET disease management intervention did not significantly reduce unplanned all-cause hospitalisation days, but reduced acute care hospitalisation days and mortality in severe COPD patients.

Parameters for Simulation of Adult Subjects During Mechanical Ventilation.

BACKGROUND: Simulation studies are often used to examine ventilator performance. However, there are no standards for selecting simulation parameters. This study collected data in passively-ventilated adult human subjects and summarized the results as a set of parameters that can be used for simulation studies of intubated, passive, adult subjects with normal lungs, COPD, or ARDS. METHODS: Consecutive adult patients admitted to the ICU were included if they were deeply sedated and mechanically ventilated for <48 h without any spontaneous breathing activity. Subjects were classified as having normal lungs, COPD, or ARDS. Respiratory mechanics variables were collected once per subject. Static compliance was calculated as the ratio between tidal volume and driving pressure. Inspiratory resistance was measured by the least-squares fitting method. The expiratory time constant was estimated by the tidal volume/flow ratio. RESULTS: Of the 359 subjects included, 138 were classified as having normal lungs, 181 as ARDS, and 40 as COPD. Median (interquartile range) static compliance was significantly lower in ARDS subjects as compared with normal lung and COPD subjects (39 [32-50] mL/cm H2O vs 54 [44-64] and 59 [43-75] mL/cm H2O, respectively, P < .001). Inspiratory resistance was significantly higher in COPD subjects as compared with normal lung and ARDS subjects (22 [16-33] cm H2O/L/s vs 13 [10-15] and 12 [9-14] cm H2O/L/s, respectively, P < .001). The expiratory time constant was significantly different for each lung condition (0.60 [0.51-0.71], 1.07 [0.68-2.14], and 0.46 [0.40-0.55] s for normal lung, COPD, and ARDS subjects, respectively, P < .001). In the subgroup of subjects with ARDS, there were no significant differences in respiratory mechanics variables among mild, moderate, and severe ARDS. CONCLUSIONS: This study provides educators, researchers, and manufacturers with a standard set of practical parameters for simulating the respiratory system's mechanical properties in passive conditions.

Closed loop ventilation mode in Intensive Care Unit: a randomized controlled clinical trial comparing the numbers of manual ventilator setting changes.

BACKGROUND: There is an equipoise regarding closed-loop ventilation modes and the ability to reduce workload for providers. On one hand some settings are managed by the ventilator but on another hand the automatic mode introduces new settings for the user. METHODS: This randomized controlled trial compared the number of manual ventilator setting changes between a full closed loop ventilation and oxygenation mode (INTELLiVENT-ASV®) and conventional ventilation modes (volume assist control and pressure support) in Intensive Care Unit (ICU) patients. The secondary endpoints were to compare the number of arterial blood gas analysis, the sedation dose and the user acceptance. Sixty subjects with an expected duration of mechanical ventilation of at least 48 hours were randomized to be ventilated using INTELLiVENT-ASV® or conventional modes with a protocolized weaning. All manual ventilator setting changes were recorded continuously from inclusion to successful extubation or death. Arterial blood gases were performed upon decision of the clinician in charge. User acceptance score was assessed for nurses and physicians once daily using a Likert Scale. RESULTS: The number of manual ventilator setting changes per 24 h-period per subject was lower in INTELLiVENT-ASV® as compared to conventional ventilation group (5 [4-7] versus 10 [7-17]) manuals settings per subject per day [P<0.001]). The number of arterial blood gas analysis and the sedation doses were not significantly different between the groups. Nurses and physicians reported that INTELLiVENT-ASV® was significantly easier to use as compared to conventional ventilation (P<0.001 for nurses and P<0.01 for physicians). CONCLUSIONS: For mechanically ventilated ICU patients, INTELLiVENT-ASV® significantly reduces the number of manual ventilator setting changes with the same number of arterial blood gas analysis and sedation dose, and is easier to use for the caregivers as compared to conventional ventilation modes.