Auto-adjusted versus fixed positive airway pressure in patients with severe OSA: A large randomized controlled trial.

BACKGROUND AND OBJECTIVE: Continuous positive airway pressure (CPAP) in the treatment of severe obstructive sleep apnoea (OSA) can be used in fixed CPAP or auto-adjusted (APAP) mode. The aim of this prospective randomized controlled clinical study was to evaluate the 3 month-efficacy of CPAP used either in fixed CPAP or APAP mode. METHODS: Eight hundred one patients with severe OSA were included in twenty-two French centres. After 7 days during which all patients were treated with APAP to determine the effective pressure level and its variability, 353 and 351 patients were respectively randomized in the fixed CPAP group and APAP group. After 3 months of treatment, 308 patients in each group were analysed. RESULTS: There was no difference between the two groups in terms of efficacy whatever the level of efficient pressure and pressure variability (p = 0.41). Exactly, 219 of 308 patients (71.1%) in the fixed CPAP group and 212 of 308 (68.8%) in the APAP group (p = 0.49) demonstrated residual apnoea hypopnoea index (AHI) <10/h and Epworth Score <11. Tolerance and adherence were also identical with a similar effect on quality of life and blood pressure evaluation. CONCLUSION: The two CPAP modes, fixed CPAP and APAP, were equally effective and tolerated in severe OSA patients.

Long-Term Noninvasive Ventilation in Chronic Obstructive Pulmonary Disease: Association between Clinical Phenotypes and Survival.

BACKGROUND: Long-term noninvasive ventilation (LTNIV) is widely used in patients with chronic hypercapnic respiratory failure (CHRF) related to COPD. Prognosis of these patients is however poor and heterogenous. RESEARCH QUESTION: In COPD patients under LTNIV for CHRF, is it possible to identify specific phenotypes which are predictive of probability of pursuing NIV and survival? STUDY DESIGN AND METHODS: A latent class analysis was performed in a COPD population under LTNIV included in a comprehensive database of patients in the Geneva Lake area, to determine clinically relevant phenotypes. The observation period of this subgroup of COPD was extended to allow assessment of survival and/or pursuit of NIV for at least 2 years after inclusion. A logistic regression was conducted to generate an equation accurately attributing an individual patient to a defined phenotype. The identified phenotypes were compared on a series of relevant variables, as well as for probability of pursuing NIV or survival. A competitive risk analysis allowed to distinguish death from other causes of cessation of NIV. RESULTS: Two phenotypes were identified: a "respiratory COPD" profile with very severe airway obstruction, a low or normal body mass index, and a low prevalence of comorbidities and a "systemic COPD" profile of obese COPDs with moderate airway obstruction and a high rate of cardiovascular and metabolic comorbidities. The logistic regression correctly classified 95.7% of patients studied. Probability of pursuing NIV and survival were significantly related to these phenotypes, with a poorer prognosis for "respiratory COPD." Probability of death 5 years after implementing NIV was 22.3% (95% CI: 15.4-32.2) for "systemic COPD" versus 47.2% (37.4-59.6) for "respiratory COPD" (p = 0.001). CONCLUSION: The two distinct phenotypes of COPD under LTNIV for CHRF identified appear to be strongly related to prognosis and require further validation in other cohort studies.

Mask side-effects in long-term CPAP-patients impact adherence and sleepiness: the InterfaceVent real-life study.

BACKGROUND: For some patients, Continuous Positive Airway Pressure (CPAP) remains an uncomfortable therapy despite the constant development of technological innovations. To date, no real life study has investigated the relationship between mask related side-effects (MRSEs) and CPAP-non-adherence (defined as < 4 h/day) or residual-excessive-sleepiness (RES, Epworth-Sleepiness-Scale (ESS) score ≥ 11) in the long-term. METHODS: The InterfaceVent-CPAP study is a prospective real-life cross-sectional study conducted in an apneic adult cohort undergoing at least 3 months of CPAP with unrestricted mask-access (34 different masks). MRSEs were evaluated using visual-analogue-scales, CPAP-data using CPAP-software, sleepiness using ESS. RESULTS: 1484 patients were included in the analysis (72.2% male, median age 67 years (IQ25-75: 60-74), initial Apnea-Hypopnea-Index (AHI) of 39 (31-56)/h, residual AHIflow was 1.9 (0.9-4) events/h), CPAP-treatment lasted 4.4 (2.0-9.7) years, CPAP-usage was 6.8 (5.5-7.8) h/day, the prevalence of CPAP-non-adherence was 8.6%, and the prevalence of RES was 16.17%. Leak-related side-effects were the most prevalent side-effects (patient-reported leaks concerned 75.4% of responders and had no correlation with CPAP-reported-leaks). Multivariable logistic regression analyses evaluating explanatory-variable (demographic data, device/mask data and MRSEs) effects on variables-of-interest (CPAP-non-adherence and RES), indicated for patient-MRSEs significant associations between: (i) CPAP-non-adherence and dry-mouth (p = 0.004); (ii) RES and patient-reported leaks (p = 0.007), noisy mask (p < 0.001), dry nose (p < 0.001) and harness pain (p = 0.043). CONCLUSION: In long-term CPAP-treated patients, leak-related side-effects remain the most prevalent side-effects, but patient-reported leaks cannot be predicted by CPAP-reported-leaks. Patient-MRSEs can be independently associated with CPAP-non-adherence and RES, thus implying a complementary role for MRSE questionnaires alongside CPAP-device-reported-data for patient monitoring. Trial registration InterfaceVent is registered with ClinicalTrials.gov (NCT03013283).

Results of the home mechanical ventilation national program among adults in Chile between 2008 and 2017.

BACKGROUND: Home mechanical ventilation (HMV) is a viable and effective strategy for patients with chronic respiratory failure (CRF). The Chilean Ministry of Health started a program for adults in 2008. METHODS: This study examined the following data from a prospective cohort of patients with CRF admitted to the national HMV program: characteristics, mode of admission, quality of life, time in the program and survival. RESULTS: A total of 1105 patients were included. The median age was 59 years (44-58). Women accounted for 58.1% of the sample. The average body mass index (BMI) was 34.9 (26-46) kg/m2. A total of 76.2% of patients started HMV in the stable chronic mode, while 23.8% initiated HMV in the acute mode. A total of 99 patients were transferred from the children's program. There were 1047 patients on non-invasive ventilation and 58 patients on invasive ventilation. The median baseline PaCO2 level was 58.2 (52-65) mmHg. The device usage time was 7.3 h/d (5.8-8.8), and the time in HMV was 21.6 (12.2-49.5) months. The diagnoses were COPD (35%), obesity hypoventilation syndrome (OHS; 23.9%), neuromuscular disease (NMD; 16.3%), non-cystic fibrosis bronchiectasis or tuberculosis (non-CF BC or TBC; 8.3%), scoliosis (5.9%) and amyotrophic lateral sclerosis (ALS; 5.24%). The baseline score on the Severe Respiratory Insufficiency questionnaire (SRI) was 47 (± 17.9) points and significantly improved over time. The lowest 1- and 3-year survival rates were observed in the ALS group, and the lowest 9-year survival rate was observed in the non-CF BC or TB and COPD groups. The best survival rates at 9 years were OHS, scoliosis and NMD. In 2017, there were 701 patients in the children's program and 722 in the adult´s program, with a prevalence of 10.4 per 100,000 inhabitants. CONCLUSION: The most common diagnoses were COPD and OHS. The best survival was observed in patients with OHS, scoliosis and NMD. The SRI score improved significantly in the follow-up of patients with HMV. The prevalence of HMV was 10.4 per 100,000 inhabitants. Trial registration This study was approved by and registered at the ethics committee of North Metropolitan Health Service of Santiago, Chile (N° 018/2021).

Monitoring of noninvasive ventilation: comparative analysis of different strategies.

BACKGROUND: Noninvasive ventilation (NIV) represents an effective treatment for chronic respiratory failure. However, empirically determined NIV settings may not achieve optimal ventilatory support. Therefore, the efficacy of NIV should be systematically monitored. The minimal recommended monitoring strategy includes clinical assessment, arterial blood gases (ABG) and nocturnal transcutaneous pulsed oxygen saturation (SpO2). Polysomnography is a theoretical gold standard but is not routinely available in many centers. Simple tools such as transcutaneous capnography (TcPCO2) or ventilator built-in software provide reliable informations but their role in NIV monitoring has yet to be defined. The aim of our work was to compare the accuracy of different combinations of tests to assess NIV efficacy. METHODS: This retrospective comparative study evaluated the efficacy of NIV in consecutive patients through four strategies (A, B, C and D) using four different tools in various combinations. These tools included morning ABG, nocturnal SpO2, TcPCO2 and data provided by built-in software via a dedicated module. Strategy A (ABG + nocturnal SpO2), B (nocturnal SpO2 + TcPCO2) and C (TcPCO2 + builtin software) were compared to strategy D, which combined all four tools (NIV was appropriate if all four tools were normal). RESULTS: NIV was appropriate in only 29 of the 100 included patients. Strategy A considered 53 patients as appropriately ventilated. Strategy B considered 48 patients as appropriately ventilated. Strategy C misclassified only 6 patients with daytime hypercapnia. CONCLUSION: Monitoring ABG and nocturnal SpO2 is not enough to assess NIV efficacy. Combining data from ventilator built-in software and TcPCO2 seems to represent the best strategy to detect poor NIV efficacy. Trial registration Institutional Review Board of the Société de Pneumologie de Langue Française (CEPRO 2016 Georges).

Patterns of adaptive servo-ventilation settings in a real-life multicenter study: pay attention to volume! : Adaptive servo-ventilation settings in real-life conditions.

BACKGROUNDS: To explain the excess cardiovascular mortality observed in the SERVE-HF study, it was hypothesized that the high-pressure ASV default settings used lead to inappropriate ventilation, cascading negative consequences (i.e. not only pro-arrythmogenic effects through metabolic/electrolyte abnormalities, but also lower cardiac output). The aims of this study are: i) to describe ASV-settings for long-term ASV-populations in real-life conditions; ii) to describe the associated minute-ventilations (MV) and therapeutic pressures for servo-controlled-flow versus servo-controlled-volume devices (ASV-F Philips®-devices versus ASV-V ResMed®-devices). METHODS: The OTRLASV-study is a cross-sectional, 5-centre study including patients who underwent ASV-treatment for at least 1 year. The eight participating clinicians were free to adjust ASV settings, which were compared among i) initial diagnosed sleep-disordered-breathing (SBD) groups (Obstructive-Sleep-Apnea (OSA), Central-Sleep-Apnea (CSA), Treatment-Emergent-Central-Sleep-Apnea (TECSA)), and ii) unsupervised groups (k-means clusters). To generate these clusters, baseline and follow-up variables were used (age, sex, body mass index (BMI), initial diagnosed Obstructive-Apnea-Index, initial diagnosed Central-Apnea-Index, Continuous-Positive-Airway-Pressure used before ASV treatment, presence of cardiopathy, and presence of a reduced left-ventricular-ejection-fraction (LVEF)). ASV-data were collected using the manufacturer's software for 6 months. RESULTS: One hundred seventy-seven patients (87.57% male) were analysed with a median (IQ25-75) initial Apnea-Hypopnea-Index of 50 (38-62)/h, an ASV-treatment duration of 2.88 (1.76-4.96) years, 61.58% treated with an ASV-V. SDB groups did not differ in ASV settings, MV or therapeutic pressures. In contrast, the five generated k-means clusters did (generally described as follows: (C1) male-TECSA-cardiopathy, (C2) male-mostly-CSA-cardiopathy, (C3) male-mostly-TECSA-no cardiopathy, (C4) female-mostly-elevated BMI-TECSA-cardiopathy, (C5) male-mostly-OSA-low-LVEF). Of note, the male-mostly-OSA-low-LVEF-cluster-5 had significantly lower fixed end-expiratory-airway-pressure (EPAP) settings versus C1 (p = 0.029) and C4 (p = 0.007). Auto-EPAP usage was higher in the male-mostly-TECSA-no cardiopathy-cluster-3 versus C1 (p = 0.006) and C2 (p < 0.001). MV differences between ASV-F (p = 0.002) and ASV-V (p < 0.001) were not homogenously distributed across clusters, suggesting specific cluster and ASV-algorithm interactions. Individual ASV-data suggest that the hyperventilation risk is not related to the cluster nor the ASV-monitoring type. CONCLUSIONS: Real-life ASV settings are associated with combinations of baseline and follow-up variables wherein cardiological variables remain clinically meaningful. At the patient level, a hyperventilation risk exists regardless of cluster or ASV-monitoring type, spotlighting a future role of MV-telemonitoring in the interest of patient-safety. TRIAL REGISTRATION: The OTRLASV study was registered on ClinicalTrials.gov (Identifier: NCT02429986 ). 1 April 2015.

AVAPS-AE versus ST mode: A randomized controlled trial in patients with obesity hypoventilation syndrome.

BACKGROUND AND OBJECTIVE: Average volume-assured pressure support-automated expiratory positive airway pressure (AVAPS-AE) combines an automated positive expiratory pressure to maintain upper airway patency to an automated pressure support with a targeted tidal volume. The aim of this study was to compare the effects of 2-month AVAPS-AE ventilation versus pressure support (ST) ventilation on objective sleep quality in stable patients with OHS. Secondary outcomes included arterial blood gases, health-related quality of life, daytime sleepiness, subjective sleep quality and compliance to NIV. METHODS: This is a prospective multicentric randomized controlled trial. Consecutive OHS patients included had daytime Pa CO2 > 6 kPa, BMI ≥ 30 kg/m2 , clinical stability for more than 2 weeks and were naive from home NIV. PSG were analysed centrally by two independent experts. Primary endpoint was sleep quality improvement at 2 months. RESULTS: Among 69 trial patients, 60 patients had successful NIV setup. Baseline and follow-up PSG were available for 26 patients randomized in the ST group and 30 in the AVAPS-AE group. At baseline, Pa CO2 was 6.94 ± 0.71 kPa in the ST group and 6.61 ± 0.71 in the AVAPS-AE group (P = 0.032). No significant between-group difference was observed for objective sleep quality indices. Improvement in Pa CO2 was similar between groups with a mean reduction of -0.87 kPa (95% CI: -1.12 to -0.46) in the ST group versus -0.87 kPa (95% CI: -1.14 to -0.50) in the AVAPS-AE group (P = 0.984). Mean NIV use was 6.2 h per night in both groups (P = 0.93). NIV setup duration was shorter in the AVAPS-AE group (P = 0.012). CONCLUSION: AVAPS-AE and ST ventilation for 2 months had similar impact on sleep quality and gas exchange.

Framework for patient-ventilator asynchrony during long-term non-invasive ventilation.

Episodes of patient-ventilator asynchrony (PVA) occur during acute and chronic non-invasive positive pressure ventilation (NIV). In long-term NIV, description and quantification of PVA is not standardised, thus limiting assessment of its clinical impact. The present report provides a framework for a systematic analysis of polygraphic recordings of patients under NIV for the detection and classification of PVA validated by bench testing. The algorithm described uses two different time windows: rate asynchrony and intracycle asynchrony. This approach should facilitate further studies on prevalence and clinical impact of PVA in long-term NIV.

What is the remaining status of adaptive servo-ventilation? The results of a real-life multicenter study (OTRLASV-study) : Adaptive servo-ventilation in real-life conditions.

BACKGROUNDS: As a consequence of the increased mortality observed in the SERVE-HF study, many questions concerning the safety and rational use of ASV in other indications emerged. The aim of this study was to describe the clinical characteristics of ASV-treated patients in real-life conditions. METHODS: The OTRLASV-study is a prospective, 5-centre study including patients who underwent ASV-treatment for at least 1 year. Patients were consecutively included in the study during the annual visit imposed for ASV-reimbursement renewal. RESULTS: 177/214 patients were analysed (87.57% male) with a median (IQ25-75) age of 71 (65-77) years, an ASV-treatment duration of 2.88 (1.76-4.96) years, an ASV-usage of 6.52 (5.13-7.65) hours/day, and 54.8% were previously treated via continuous positive airway pressure (CPAP). The median Epworth Scale Score decreased from 10 (6-13.5) to 6 (3-9) (p < 0.001) with ASV-therapy, the apnea-hypopnea-index decreased from 50 (38-62)/h to a residual device index of 1.9 (0.7-3.8)/h (p < 0.001). The majority of patients were classified in a Central-Sleep-Apnea group (CSA; 59.3%), whereas the remaining are divided into an Obstructive-Sleep-Apnea group (OSA; 20.3%) and a Treatment-Emergent-Central-Sleep-Apnea group (TECSA; 20.3%). The Left Ventricular Ejection Fraction (LVEF) was > 45% in 92.7% of patients. Associated comorbidities/etiologies were cardiac in nature for 75.7% of patients (neurological for 12.4%, renal for 4.5%, opioid-treatment for 3.4%). 9.6% had idiopathic central-sleep-apnea. 6.2% of the patients were hospitalized the year preceding the study for cardiological reasons. In the 6 months preceding inclusion, night monitoring (i.e. polygraphy or oximetry during ASV usage) was performed in 34.4% of patients, 25.9% of whom required a subsequent setting change. According to multivariable, logistic regression, the variables that were independently associated with poor adherence (ASV-usage ≤4 h in duration) were TECSA group versus CSA group (p = 0.010), a higher Epworth score (p = 0.019) and lack of a night monitoring in the last 6 months (p < 0.05). CONCLUSIONS: In real-life conditions, ASV-treatment is often associated with high cardiac comorbidities and high compliance. Future research should assess how regular night monitoring may optimize devices settings and patient management. TRIAL REGISTRATION: The OTRLASV study is registered on ClinicalTrials.gov (Identifier: NCT02429986 ) on 1 April 2015.

Is the 2013 American Thoracic Society CPAP-tracking system algorithm useful for managing non-adherence in long-term CPAP-treated patients?

BACKGROUND: Whereas telemedicine usage is growing, the only clinical algorithm for Continuous Positive Airway Pressure (CPAP) adherence management is that stipulated by the 2013 American Thoracic Society (ATS). The capacity of the latter to predict non-adherence in long-term CPAP-treated patients has not been validated. METHODS: Patients from the prospective real-life InterfaceVent study (NCT03013283, study conducted in an adult cohort undergoing at least 3 months of CPAP) and eligible for ATS algorithm usage were analysed. The residual device Apnea-Hypopnea-Index (AHIflow) and High Large Leak (HLL) thresholds proposed in the ATS algorithm were evaluated for predicting adherence (i.e. AHIflow > 10/h, HLLs 95th > 24 L/min for ResMed® devices and ResMed® nasal mask, HLLs 95th > 36 l/min for ResMed® devices and ResMed® oronasal masks, HLLs > 1 h for Philips® devices and HHLs > 60 l/min for Fisher & Paykel® devices). Adherence was defined according to the 2013 ATS algorithm (i.e. CPAP use > 4 h/j for at least 70% of days). RESULTS: 650/1484 patients eligible for ATS algorithm usage were analysed (15.38% non-adherent, 74% male with a median (IQ25-75) age of 68 (61-77) years, a body mass index of 30.8 (27.7-34.5) kg/m2, an initial AHI of 39 (31-55) events/h, and CPAP-treatment-duration of 5.1 (2.2-7.8) years). Logistic regression analysis demonstrated no significant relationship between the ATS proposed AHIflow or HLL thresholds and non-adherence. Complementary ROC curve analysis failed to determine satisfactory AHIflow and HLL thresholds. CONCLUSION: When managing non-adherence in long-term CPAP-treated patients, our data do not validate absolute AHIflow or HLL thresholds in general. TRIAL REGISTRATION: The INTERFACE-VENT study is registered on ClinicalTrials.gov (Identifier: study ( NCT03013283 ).

Monitoring Noninvasive Ventilation in Patients with Obesity Hypoventilation Syndrome: Comparison between Ventilator Built-in Software and Respiratory Polygraphy.

BACKGROUND: Polygraphy (PG) remains the standard method of assessing noninvasive ventilation (NIV) effectiveness. Built-in software (BIS) of recent NIV equipment provides estimates of some ventilator parameters, but their usefulness is unclear. OBJECTIVES: To assess the reliability of BIS compared with PG in a cohort of obesity hypoventilation syndrome (OHS) patients on NIV. METHODS: Thirty stable OHS patients on NIV were evaluated in an outpatient setting with simultaneous PG and BIS recordings. The automated apnea-hypopnea event index (EIAUT) provided by Rescan and manual scoring based on available traces obtained from the software (EIBIS) were compared with manual PG scoring (EIPG). Each manual scoring was separately performed by 2 trained operators. Agreement between the 2 operators was assessed using the kappa coefficient. Pearson correlation and Bland-Altman plots were used to evaluate agreement between EIAUT, EIBIS, and EIPG. RESULTS: Twenty-six cases were valid for analysis (age ±61 years, 17 men). All patients were ventilated in the spontaneous/timed mode (mean inspiratory positive airway pressure 17 ± 3 cm H2O, mean expiratory positive airway pressure 10 ± 3 cm H2O). Cohen's kappa agreement between the operators was 0.7 for EIBIS and 0.84 for EIPG. EIBIS showed good correlation with EIPG (r2 = 0.79 p < 0.001), better than scoring provided by the automated analysis (r2 = 0.71, p < 0.006 for EIAUT vs. EIPG). CONCLUSIONS: In stable OHS patients on NIV, unattended home-based monitoring using Rescan is reproducible and reliable to assess quality of ventilation when compared with PG. In addition, manual scoring of events using data obtained with this device is more consistent than software-based automated analysis.

Combined effects of leaks, respiratory system properties and upper airway patency on the performance of home ventilators: a bench study.

BACKGROUND: Combined effects of leaks, mechanical property of respiratory system and upper airway (UA) patency on patient-ventilator synchrony (PVA) and the level of clinically "tolerable" leaks are not well established in home ventilators. METHODS: We comparatively assessed on a bench model, the highest leak level tolerated without inducing significant asynchrony ("critical leak") in three home ventilators (Astral 150, Trilogy 100 and Vivo 60; noted as A150, T100 and V60 respectively) subjected to three simulated diseased respiratory conditions: chronic obstructive pulmonary disease (COPD), obesity hypoventilation (OHS) and neuromuscular disorders (NMD), with both open and closed UA. Also, total leak values in the device reports were compared to the bench-measured values. RESULTS: With open UA, all ventilators were able to avoid asynchrony up to a 30 L/min leak and even to 55 L/min in some cases. UA closure and respiratory diseases especially OHS influenced PVA. With closed UA, the critical leak of A150 and T100 remained higher than 55 L/min in COPD and OHS, while for V60 decreased to 41 and 33 L/min respectively. In NMD with closed UA, only T100 reached a high critical leak of 69 L/min. Besides, inspiratory trigger sensitivity change was often necessary to avoid PVA. CONCLUSIONS: Home ventilators were able to avoid PVA in high-level leak conditions. However, asynchrony appeared in cases of abnormal mechanical properties of respiratory system or closed UA. In case of closed UA, the EPAP should be adjusted prior to the inspiratory trigger. TRIAL REGISTRATION: Not applicable.

New modes in non-invasive ventilation.

Non-invasive ventilation is useful to treat some forms of respiratory failure. Hence, the number of patients receiving this treatment is steadily increasing. Considerable conceptual and technical progress has been made in the last years by manufacturers concerning this technique. This includes new features committed to improve its effectiveness as well as patient-ventilator interactions. The goal of this review is to deal with latest advances in ventilatory modes and features available for non-invasive ventilation. We present a comprehensive analysis of new modes of ventilator assistance committed to treat respiratory failure (hybrid modes) and central and complex sleep apnea (adaptive servo ventilation), and of new modes of triggering and cycling (neurally adjusted ventilatory assist). Technical aspects, modes of operation and settings of these new features as well as an exhaustive review of published data, their benefits and limits, and the potential place of these devices in clinical practice, are discussed.

Usefulness of transcutaneous PCO2 to assess nocturnal hypoventilation in restrictive lung disorders.

BACKGROUND AND OBJECTIVE: Nocturnal hypoventilation is now an accepted indication for the initiation of non-invasive ventilation. Nocturnal hypoventilation may be an under diagnosed condition in chronic respiratory failure. The most appropriate strategy to identify sleep hypoventilation is not yet clearly defined. In clinical practice, it is indirectly assessed using nocturnal pulse oximetry (NPO) and morning arterial blood gases (mABG). Even though continuous transcutaneous carbon dioxide partial pressure (TcPCO2 ) monitoring is theoretically superior to NPO plus mABG, it is not routinely used. We aimed to prospectively compare NPO plus mABG with nocturnal TcPCO2 for the detection of alveolar hypoventilation in a cohort of patients with chronic restrictive respiratory dysfunction. METHODS: We assessed 80 recordings of mABG, nocturnal TcPCO2 and NPO in 72 consecutive patients with neuromuscular disease or thoracic cage disorders. Nocturnal hypoventilation was defined as a mean nightime TcPCO2 ≥50 mm Hg, and nocturnal hypoxaemia as ≥30% of the night with transcutaneous pulse oxygen saturation ≤90% and/or >5 consecutive minutes with transcutaneous pulse oxygen saturation ≤88%. RESULTS: Amongst the 80 recordings, 25 of 76 (32.9%) without nocturnal hypoxaemia and 16 of 59 (27.1%) without hypercapnia on mABG showed nocturnal hypoventilation on TcPCO2 . Amongst recordings showing both normal NPO and mABG, 16 of 52 (30.8%) had a mean TcPCO2 ≥50 mm Hg. Nocturnal hypoxaemia was associated with nocturnal hypoventilation in all recordings. However, 5 of 21 (23.8%) recordings that showed an absence of nocturnal hypoventilation at the chosen threshold showed hypercapnia on mABG. CONCLUSION: Morning arterial blood gases and NPO alone or in combination underestimate nocturnal hypoventilation in patients with chronic restrictive respiratory dysfunction of extrapulmonary origin.

Residual upper airway obstruction during nocturnal noninvasive ventilation despite high positive expiratory pressure. Impact of oronasal mask to nasal mask switch.

BACKGROUND: Nasal mask (NM) and oronasal masks (OM) can be used to provide noninvasive ventilation (NIV). Recent studies suggested that OM is the most used interface and that there is no difference in efficacy or in tolerance between OM and NM for chronic use. However, studies focusing on video laryngoscopy underlined the impact of OM in residual upper airway obstruction (UAO) under NIV. We sought to assess the real-life practice of switching from OM to NM when UAO events persist despite high EPAP levels. METHODS: In an open-label single center prospective cohort study, data from files and full night polysomnography on NM and OM were collected for patients wearing OM and presenting an UAO index ≥15/h despite an EPAP level ≥ 10 cmH20. RESULTS: Forty-four patients were included in the study. In 31 patients (74 %), switching to a NM reduced UAOi to ≥10/h. Interestingly, 92 % of these patients still had NM at 3 to 12 months of follow-up. Switching to a NM was also associated with a trend in paCO2 reduction and significant improvements in Epworth, sleep quality and NIV compliance. Successful interface switching was significantly associated with female gender, and a trend was observed in non-smokers. CONCLUSION: As for CPAP, switching to a NM improved NIV efficacy in a selected group of patients presenting residual UAO events despite high EPAP levels. Additionally, this switch has an impact on compliance and subjective sleepiness. Thus, in patients with persisting UAO on OM, switching to a NM could be a first-line intervention before considering further investigation such as polygraphy or video laryngoscopy. We also derive an algorithm for mask allocation and adaptation in acute and chronic NIV use.

Is COVID-19 Infection a Multiorganic Disease? Focus on Extrapulmonary Involvement of SARS-CoV-2.

First described in December 2019 in Wuhan (China), COVID-19 disease rapidly spread worldwide, constituting the biggest pandemic in the last 100 years. Even if SARS-CoV-2, the agent responsible for COVID-19, is mainly associated with pulmonary injury, evidence is growing that this virus can affect many organs, including the heart and vascular endothelial cells, and cause haemostasis, CNS, and kidney and gastrointestinal tract abnormalities that can impact in the disease course and prognosis. In fact, COVID-19 may affect almost all the organs. Hence, SARS-CoV-2 is essentially a systemic infection that can present a large number of clinical manifestations, and it is variable in distribution and severity, which means it is potentially life-threatening. The goal of this comprehensive review paper in the series is to give an overview of non-pulmonary involvement in COVID-19, with a special focus on underlying pathophysiological mechanisms and clinical presentation.

Real-life evaluation of NIV to CPAP switch in patients with chronic respiratory failure. A case control study.

BACKGROUND: Non-invasive ventilation (NIV) is a standard of care for hypercapnic chronic respiratory failure (CRF). Obstructive sleep apnea syndrome (OSA) frequently contributes to hypoventilation in CRF patients. CPAP improves hypercapnia in selected COPD and obese patients, like NIV. We aimed to describe the profile of patients switching from NIV to CPAP in a cohort of patients on long-term ventilation and to identify the factors associated with a successful switch. METHODS: In this case-control study, 88 consecutive patients who were candidates for a NIV-CPAP switch were compared with 266 controls among 394 ventilated patients treated at the Dijon University Hospital between 2015 and 2020. They followed a standardized protocol including a poly(somno)graphy recorded after NIV withdrawal for three nights. CPAP trial was performed if severe OSA was confirmed. Patients were checked for recurrent hypoventilation after 1 and 23[14-46] nights under CPAP. RESULTS: Patients were 53% males, median age 65 [56-74] years, and median BMI 34 [25-38.5] kg/m2. Sixty four percent of patients were safely switched and remained on long-term CPAP. In multivariate analysis, the probability of a NIV-CPAP switch was correlated to older age (OR: 1.3 [1.01-1.06]), BMI (OR: 1.7 [1.03-1.12]), CRF etiology (OR for COPD: 20.37 [4.2-98,72], OR for obesity: 7.31 [1.58-33.74]), circumstances of NIV initiation (OR for acute exacerbation: 11.64 [2.03-66.62]), lower pressure support (OR: 0.90 [0.73-0.92]), lower baseline PaCO2 (OR: 0.85 [0.80-0.91]) and lower compliance (OR: 0.76 [0.64-0.90]). Among 72 patients who went home under CPAP, pressure support level was the only factor associated with the outcome of the NIV-CPAP switch, even after adjustment for BMI and age (p=0.01) with a non-linear correlation. Etiology of chronic respiratory failure, age, BMI, baseline PaCO2, circumstances of NIV initiation, time under home NIV or NIV compliance were not predictive of the outcome of the NIV-CPAP switch. CONCLUSIONS: A NIV-CPAP switch is possible in real life conditions in stable obese and COPD patients with underlying OSA.

Measurement of thoraco-abdominal synchrony using respiratory inductance plethysmography: technical aspects and a proposal to overcome its limitations.

BACKGROUND: Thoraco-abdominal asynchrony (TAA) is usually assessed by respiratory inductance plethysmography. The main parameter used for its assessment is the calculation of the phase angle based on Lissajous plots. However, there are some mathematical limitations to its use. RESEARCH DESIGN AND METHODS: Sequences of five breaths were selected from a) normal subjects, b) COPD patients, both at rest and during exercise, and c) patients with obstructive apnea syndrome. Automated analysis was performed calculating phase angle, loop rotation (clockwise or counterclockwise), global phase delay and loop area. TAA severity was estimated quantitatively and in subgroups. RESULTS: 2290 cycles were analyzed (55% clockwise rotation). Phase angle ranged from -86.90 to + 88.4 degrees, while global phase delay ranged from -179.75 to + 178.54. Despite a good correlation with global phase delay (p < 0.01, ANOVA test), phase angle and loop area were not able to correctly classify breaths with severe deviation and paradoxical movements (p=ns, Bonferroni post hoc test). CONCLUSIONS: Global phase delay covers the whole spectrum of TAA situations in a single value. It may be a relevant parameter for diagnosis and follow-up of clinical conditions leading to TAA. CLINICAL TRIAL REGISTRATION: The trial from which the traces were obtained was registered at ClinicalTrials.gov ;(identifier: NCT04597606).