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Background: Standard high-flow nasal cannula (HFNC) is a respiratory support device widely used to manage post-extubation hypoxemic acute respiratory failure (hARF) due to greater comfort, oxygenation, alveolar recruitment, humidification, and reduction of dead space, as compared to conventional oxygen therapy. On the contrary, the effects of the new asymmetrical HFNC interface (Optiflow® Duet system (Fisher & Paykel, Healthcare, Auckland, New Zealand) is still under discussion. Our aim is investigating whether the use of asymmetrical HFNC interface presents any relevant difference, compared with the standard configuration, on lung aeration (as assessed by end-expiratory lung impedance (EELI) measured by electrical impedance tomography (EIT)), diaphragm ultrasound thickening fraction (TFdi) and excursion (DE), ventilatory efficiency (estimated by corrected minute ventilation (MV)), gas exchange, dyspnea, and comfort., Methods: Pilot physiological crossover randomized controlled study enrolling 20 adults admitted to the Intensive Care unit, invasively ventilated for at least 24 h, and developing post-extubation hARF, i.e., PaO 2 /set FiO 2  < 300 mmHg during Venturi mask (VM) within 120 min after extubation. Each HFNC configuration was applied in a randomized 60 min sequence at a flow rate of 60 L/min., Results: Global EELI, TFdi, DE, ventilatory efficiency, gas exchange and dyspnea were not significantly different, while comfort was greater during asymmetrical HFNC support, as compared to standard interface (10 [7-10] and 8 [7-9], p-value 0.044)., Conclusions: In post-extubation hARF, the use of the asymmetrical HFNC, as compared to standard HFNC interface, slightly improved patient comfort without affecting lung aeration, diaphragm activity, ventilatory efficiency, dyspnea and gas exchange., Clinical Trial Number: ClinicalTrial.gov., Registration Number: NCT05838326 (01/05/2023)., New & Noteworthy: The asymmetrical high-flow nasal cannula oxygen therapy (Optiflow® Duet system (Fisher & Paykel, Healthcare, Auckland, New Zealand) provides greater comfort as compared to standard interface; while their performance in term of lung aeration, diaphragm activity, ventilatory efficiency, dyspnea, and gas exchange is similar., (© 2024. The Author(s).)

Background: In the last decades, noninvasive ventilation (NIV) has been increasingly used to support patients with hypercapnic and hypoxemic acute respiratory failure. Pressure ulcers are a frequently observed NIV-related adverse effect, directly related to interface type and exposure time. Switching to a different interface has been proposed as a solution to improve patient comfort. However, large studies investigating the benefit of this strategy are not available. Thus, the aim of the ROTAtional-USE of interface STUDY (ROTA-USE STUDY) is to investigate whether a protocolized rotational use of interfaces during NIV is effective in reducing the incidence of pressure ulcers., Methods: The ROTA-USE STUDY is a pragmatic, parallel arm, open-label, multicenter, spontaneous, non-profit, randomized controlled trial requiring non-significant risk medical devices, with the aim to determine whether a rotational strategy of NIV interfaces is associated with a lower incidence of pressure ulcers compared to the standard of care. In the intervention group, NIV mask will be randomly chosen and rotated every 6 h. In the control group, mask will be chosen according to the standard of care of the participating centers and changed in case of discomfort or in the presence of new pressure sores. In both groups, the skin underneath the mask will be inspected every 12 h for any possible damage by blinded assessors. The primary outcome is the proportion of patients developing new pressure sores at 36 h from randomization. The secondary outcomes are (i) onset of pressure sores measured at different time points, i.e., 12, 24, 36, 48, 60, 72, 84, and 96 h; (ii) number and stage of pressure sores and comfort measured at 12, 24, 36, 48, 60, 72, 84, and 96 h; and (iii) the economic impact of the protocolized rotational use of interfaces. A sample size of 239 subjects per group (intervention and control) is estimated to detect a 10% absolute difference in the proportion of patients developing pressure sores at 36 h., Discussion: The development of pressure ulcers is a common side effect of NIV that negatively affects the patients' comfort and tolerance, often leading to NIV failure and adverse outcomes. The ROTA-USE STUDY will determine whether a protocolized rotational approach can reduce the incidence, number, and severity of pressure ulcers in NIV-treated patients., Trial Registration: ClinicalTrials.gov NCT05513508. Registered on August 24, 2022., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: The effect of noninvasive respiratory support (NRS), including high-flow nasal oxygen, bi-level positive airway pressure and continuous positive airway pressure (noninvasive ventilation (NIV)), for preventing and treating post-extubation respiratory failure is still unclear. Our objective was to assess the effects of NRS on post-extubation respiratory failure, defined as re-intubation secondary to post-extubation respiratory failure (primary outcome). Secondary outcomes included the incidence of ventilator-associated pneumonia (VAP), discomfort, intensive care unit (ICU) and hospital mortality, ICU and hospital length of stay (LOS), and time to re-intubation. Subgroup analyses considered "prophylactic" versus "therapeutic" NRS application and subpopulations (high-risk, low-risk, post-surgical and hypoxaemic patients)., Methods: We undertook a systematic review and network meta-analysis (Research Registry: reviewregistry1435). PubMed, Embase, CENTRAL, Scopus and Web of Science were searched (from inception until 22 June 2022). Randomised controlled trials (RCTs) investigating the use of NRS after extubation in ICU adult patients were included., Results: 32 RCTs entered the quantitative analysis (5063 patients). Compared with conventional oxygen therapy, NRS overall reduced re-intubations and VAP (moderate certainty). NIV decreased hospital mortality (moderate certainty), and hospital and ICU LOS (low and very low certainty, respectively), and increased discomfort (moderate certainty). Prophylactic NRS did not prevent extubation failure in low-risk or hypoxaemic patients., Conclusion: Prophylactic NRS may reduce the rate of post-extubation respiratory failure in ICU patients., Competing Interests: Conflict of interest: None related to the present work. P. Navalesi's research lab has received grants/research equipment from Draeger, Intersurgical SPA and Gilead. P. Navalesi receives royalties from Intersurgical SPA for the Helmet Next invention. He has also received speaking fees from Getinge, Intersurgical SPA, Mindray, Gilead, MSD, Draeger and Medicair. The other authors have no other competing interests to declare., (Copyright ©The authors 2023.)

Rationale: When compared with VenturiMask after extubation, high-flow nasal oxygen provides physiological advantages. Objectives: To establish whether high-flow oxygen prevents endotracheal reintubation in hypoxemic patients after extubation, compared with VenturiMask. Methods: In this multicenter randomized trial, 494 patients exhibiting Pa O 2 :Fi O 2 ratio ⩽ 300 mm Hg after extubation were randomly assigned to receive high-flow or VenturiMask oxygen, with the possibility to apply rescue noninvasive ventilation before reintubation. High-flow use in the VenturiMask group was not permitted. Measurements and Main Results: The primary outcome was the rate of reintubation within 72 hours according to predefined criteria, which were validated a posteriori by an independent adjudication committee. Main secondary outcomes included reintubation rate at 28 days and the need for rescue noninvasive ventilation according to predefined criteria. After intubation criteria validation ( n  = 492 patients), 32 patients (13%) in the high-flow group and 27 patients (11%) in the VenturiMask group required reintubation at 72 hours (unadjusted odds ratio, 1.26 [95% confidence interval (CI), 0.70-2.26]; P  = 0.49). At 28 days, the rate of reintubation was 21% in the high-flow group and 23% in the VenturiMask group (adjusted hazard ratio, 0.89 [95% CI, 0.60-1.31]; P  = 0.55). The need for rescue noninvasive ventilation was significantly lower in the high-flow group than in the VenturiMask group: at 72 hours, 8% versus 17% (adjusted hazard ratio, 0.39 [95% CI, 0.22-0.71]; P  = 0.002) and at 28 days, 12% versus 21% (adjusted hazard ratio, 0.52 [95% CI, 0.32-0.83]; P  = 0.007). Conclusions: Reintubation rate did not significantly differ between patients treated with VenturiMask or high-flow oxygen after extubation. High-flow oxygen yielded less frequent use of rescue noninvasive ventilation. Clinical trial registered with www.clinicaltrials.gov (NCT02107183).

Objectives: To investigate the rate of hypoxaemic acute respiratory failure (hARF) on patients undergoing surgery for non-small-cell lung cancer (NSCLC) after neoadjuvant chemotherapy, to describe clinical and radiological findings and to explore potential risk factors for this complication., Methods: Retrospective review of medical records of all patients who underwent surgery for NSCLC after neoadjuvant chemotherapy at a single centre between 2014 and 2021. Computed tomography scans of patients who developed hARF were reviewed by an experienced radiologist to provide a quantitative assessment of radiologic alterations., Results: The final cohort consisted of 211 patients. Major morbidity was 13.3% (28/211) and hARF was the most common major complication (n = 11, 5.2%). Postoperative mortality was 1.9% (4/211) and occurred only in patients who experienced hARF. Most patients who experienced hARF underwent major procedures, including pneumonectomy (n = 3), lobectomy with chest wall resection (n = 3), bronchial or vascular reconstructions (n = 3) and extended or bilateral resections (n = 2). Analysis of computed tomography findings revealed that crazy paving and ground glass were the most common alterations and were more represented in the non-operated lung. Male gender, current smoking status, pathologic stage III-IV and operative time resulted significant risk factors for hARF at univariable analysis (P < 0.05)., Conclusions: hARF is the main cause of major morbidity and mortality after neoadjuvant therapy and surgery for NSCLC and occurs more frequently after complex and lengthier surgical procedures. Overall, our findings suggest that operative time may represent the most important risk factor for hARF., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Introduction: Patient self-inflicted lung injury (P-SILI) has been proposed as a form of lung injury caused by strong inspiratory efforts consequent to a high respiratory drive in patients with hypoxemic acute respiratory failure (hARF). Increased respiratory drive and effort may lead to variable combinations of deleterious phenomena, such as excessive transpulmonary pressure, pendelluft , intra-tidal recruitment, local lung volutrauma, and pulmonary edema. Gas exchange and respiratory mechanics derangements further increase respiratory drive and effort, thus inducing a vicious circle. Forms of partial ventilatory support may further add to the detrimental effects of P-SILI. Since P-SILI may worsen patient outcome, strategies aimed at identifying and preventing P-SILI would be of great importance., Areas Covered: We systematically searched Pubmed since inception until 15 April 2022 to review the patho-physiological mechanisms of P-SILI and the strategies to identify those patients at risk of P-SILI., Expert Opinion: Although the concept of P-SILI has been increasingly supported by experimental and clinical data, no study has insofar demonstrated the efficacy of any strategy to identify it in the clinical setting. Further research is thus needed to ascertain the detrimental effects of spontaneous breathing and identify patients with hARF at high risk of developing P-SILI.

Background: High-flow nasal cannula (HFNC) has become a frequently used noninvasive form of respiratory support in acute settings; however, evidence supporting its use has only recently emerged. These guidelines provide evidence-based recommendations for the use of HFNC alongside other noninvasive forms of respiratory support in adults with acute respiratory failure (ARF)., Materials and Methodology: The European Respiratory Society task force panel included expert clinicians and methodologists in pulmonology and intensive care medicine. The task force used the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) methods to summarise evidence and develop clinical recommendations for the use of HFNC alongside conventional oxygen therapy (COT) and noninvasive ventilation (NIV) for the management of adults in acute settings with ARF., Results: The task force developed eight conditional recommendations, suggesting the use of 1) HFNC over COT in hypoxaemic ARF; 2) HFNC over NIV in hypoxaemic ARF; 3) HFNC over COT during breaks from NIV; 4) either HFNC or COT in post-operative patients at low risk of pulmonary complications; 5) either HFNC or NIV in post-operative patients at high risk of pulmonary complications; 6) HFNC over COT in nonsurgical patients at low risk of extubation failure; 7) NIV over HFNC for patients at high risk of extubation failure unless there are relative or absolute contraindications to NIV; and 8) trialling NIV prior to use of HFNC in patients with COPD and hypercapnic ARF., Conclusions: HFNC is a valuable intervention in adults with ARF. These conditional recommendations can assist clinicians in choosing the most appropriate form of noninvasive respiratory support to provide to patients in different acute settings., Competing Interests: Conflict of interest: S. Oczkowski reports support for the current manuscript from librarian support services; support for attending meetings and/or travel from ERS, European Society of Intensive Care Medicine and Society of Critical Care Medicine, outside the submitted work. Conflict of interest: B. Ergan has nothing to disclose. Conflict of interest: L. Bos reports grants from the Dutch Lung Foundation (young investigator grant), the Dutch Lung Foundation and Health Holland (public-private partnership grant), the Dutch Lung Foundation (Dirkje Postma Award), IMI COVID19 initiative and Amsterdam UMC fellowship, outside the submitted work. Conflict of interest: M. Chatwin reports lecture fees from ResMed UK, Breas Medical UK, MPR Italy; and since December 2020 has worked part time for Breas Medical as their global clinical specialist, including CAB membership and support for attending meetings and/or travel. Conflict of interest: M. Ferrer has nothing to disclose. Conflict of interest: C. Gregoretti reports consulting fees from Mindray and Air Liquide; lecture fees from Vivisol, Philips and Air Liquide; support for attending meetings and/or travel from Fisher & Paykel; outside the submitted work. Conflict of interest: L. Heunks reports grants from InflaRx; consulting fees from Liberate Medical, USA; speaker fees from Fisher & Paykel and Maquet; outside the submitted work. Conflict of interest: J-P. Frat reports funding, provision of study materials, personal fees for lectures, travels and accommodations expenses reimbursement from Fisher and Paykel Healthcare; personal fees as a member of a scientific board from SOS Oxygene; grants from French Ministry of health; outside the submitted work. Conflict of interest: F. Longhini reports honoraria for a lecture from Draeger; issued patent for a new device for noninvasive ventilation (European patent number 3320941) from Intersurgical SPA; outside the submitted work. Conflict of interest: S. Nava has nothing to disclose. Conflict of interest: P. Navalesi has nothing to disclose. Conflict of interest: A. Ozsancak Uğurlu has nothing to disclose. Conflict of interest: L. Pisani has nothing to disclose. Conflict of interest: T. Renda has nothing to disclose. Conflict of interest: A.W. Thille reports payments for lectures and support for attending meetings and/or travel from Fisher & Paykel; Fisher & Paykel provided the high-flow nasal oxygen equipment and masks for NIV in several randomised clinical trials coordinated by our center. Conflict of interest: J.C. Winck reports webinar fees from Armstrong Medical, Breas, Philips and Nippon Gases; outside the submitted work. Conflict of interest: W. Windisch reports grants from Philips/Respironics/USA, Löwenstein Medical/Germany, VitalAire/Germany and Vivisol/Germany; speaking fees from Philips/Respironics/USA, Löwenstein Medical/Germany and VitalAire/Germany; outside the submitted work. Conflict of interest: T. Tonia acts as ERS Methodologist. Conflict of interest: J. Boyd is an employee of the European Lung Foundation. Conflict of interest: G. Sotgiu has nothing to disclose. Conflict of interest: R. Scala has nothing to disclose., (Copyright ©The authors 2022. 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Background: Driving pressure can be readily measured during assisted modes of ventilation such as pressure support ventilation (PSV) and neurally adjusted ventilatory assist (NAVA). The present prospective randomized crossover study aimed to assess the changes in driving pressure in response to variations in the level of assistance delivered by PSV vs NAVA., Methods: 16 intubated adult patients, recovering from hypoxemic acute respiratory failure (ARF) and undergoing assisted ventilation, were randomly subjected to six 30-min-lasting trials. At baseline, PSV (PSV100) was set with the same regulation present at patient enrollment. The corresponding level of NAVA (NAVA100) was set to match the same inspiratory peak of airway pressure obtained in PSV100. Therefore, the level of assistance was reduced and increased by 50% in both ventilatory modes (PSV50, NAVA50; PSV150, NAVA150). At the end of each trial, driving pressure obtained in response to four short (2-3 s) end-expiratory and end-inspiratory occlusions was analyzed., Results: Driving pressure at PSV50 (6.6 [6.1-7.8] cmH 2 O) was lower than that recorded at PSV100 (7.9 [7.2-9.1] cmH 2 O, P = 0.005) and PSV150 (9.9 [9.1-13.2] cmH 2 O, P < 0.0001). In NAVA, driving pressure at NAVA50 was reduced compared to NAVA150 (7.7 [5.1-8.1] cmH 2 O vs 8.3 [6.4-11.4] cmH 2 O, P = 0.013), whereas there were no changes between baseline and NAVA150 (8.5 [6.3-9.8] cmH 2 O vs 8.3 [6.4-11.4] cmH 2 O, P = 0.331, respectively). Driving pressure at PSV150 was higher than that observed in NAVA150 (P = 0.011)., Conclusions: NAVA delivers better lung-protective ventilation compared to PSV in hypoxemic ARF patients., Trial Registration Number and Date of Registration: The present trial was prospectively registered at www.clinicatrials.gov (NCT03719365) on 24 October 2018., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature.)

Introduction: High-flow nasal cannula (HFNC) provides benefits to patients undergoing flexible bronchoscopy (FOB). We compared the effects of HFNC versus standard therapy (ST) on gas exchange, lung volume and diaphragm function in patients undergoing FOB for bronchoalveolar lavage (BAL)., Methods: 36 outpatients were randomised to ST or HFNC. Arterial blood gases, episodes of severe desaturation, changes of end-expiratory lung impedance (ΔEELI), diaphragm ultrasound were recorded. Measurements were done at baseline (T0), after bronchoscope insertion (T1), at the end of the procedure (T2) and 10 min afterwards (T3)., Results: Arterial partial oxygen pressure (PaO 2 ) was not different between T0 (10.8 (95% CI 8.7 to 12.0) kPa and T2 (11.1 (95% CI 10.4 to 12.0) kPa) with HFNC, while decreased from 11.1 (95% CI 10.5 to 12.1) to 9.1 (95% CI 8.4 to 9.8) kPa with ST. At T2, PaO 2 was significantly higher with HFNC than with ST (p<0.001). Also, with HFNC, compared with ST, fewer desaturations occurred (11% vs 56%; p<0.01). ΔEELI was no different at the different time points with HFNC, while with ST there was a significant decrease at T1 (-170 (95% CI -382 to -32) mL, p=0.003), T2 (-211 (95% CI -425 to -148) mL, p<0.001) and T3 (-213 (95% CI -398 to -81) mL, p<0.001), as opposed to T0. EELI was lower with ST than HFNC at T1 (p=0.006), T2 (p=0.001) and T3 (p=0.002). Diaphragm displacement was no different between groups (p=0.748), while the thickening fraction significantly increased at T1 and T2 with ST only (p<0.01)., Conclusions: During FOB for BAL, HFNC improves gas exchange, avoiding loss of end-expiratory lung volume and preventing increase of diaphragm activation., Trial Registration Number: NCT04016480., Competing Interests: Competing interests: PN’s research laboratory has received equipment and grants from Draeger and Intersurgical. He also received honoraria/speaking fees from Philips, Resmed, MSD and Novartis. PN contributed to the development of the helmet Next, whose licence for patent belongs to Intersurgical and receives royalties for that invention. FL and PN contributed to the development of a new device (not discussed in the present study), whose patent is in progress (European Patent application number EP20170199831)., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: An increasing number of reports have described the COVID-19-associated pulmonary aspergillosis (CAPA) as being a further contributing factor to mortality. Based on a recent consensus statement supported by international medical mycology societies, it has been proposed to define CAPA as possible, probable, or proven on the basis of sample validity and thus diagnostic certainty. Considering current challenges associated with proven diagnoses, there is pressing need to study the epidemiology of proven CAPA., Methods: We report the incidence of histologically diagnosed CAPA in a series of 45 consecutive COVID-19 laboratory-confirmed autopsies, performed at Padova University Hospital during the first and second wave of the pandemic. Clinical data, laboratory data and radiological features were also collected for each case., Results: Proven CAPA was detected in 9 (20%) cases, mainly in the second wave of the pandemic (7/17 vs. 2/28 of the first wave). The population of CAPA patients consisted of seven males and two females, with a median age of 74 years. Seven patients were admitted to the intensive care unit. All patients had at least two comorbidities, and concomitant lung diseases were detected in three cases., Conclusion: We found a high frequency of proven CAPA among patients with severe COVID-19 thus confirming at least in part the alarming epidemiological data of this important complication recently reported as probable CAPA., (© 2021 The Authors. Mycoses published by Wiley-VCH GmbH.)

The efficacy of non-invasive ventilation (NIV) in acute respiratory failure secondary to SARS-CoV-2 infection remains controversial. Current literature mainly examined efficacy, safety and potential predictors of NIV failure provided out of the intensive care unit (ICU). On the contrary, the outcomes of ICU patients, intubated after NIV failure, remain to be explored. The aims of the present study are: (1) investigating in-hospital mortality in coronavirus disease 2019 (COVID-19) ICU patients receiving endotracheal intubation after NIV failure and (2) assessing whether the length of NIV application affects patient survival. This observational multicenter study included all consecutive COVID-19 adult patients, admitted into the twenty-five ICUs of the COVID-19 VENETO ICU network (February-April 2020), who underwent endotracheal intubation after NIV failure. Among the 704 patients admitted to ICU during the study period, 280 (40%) presented the inclusion criteria and were enrolled. The median age was 69 [60-76] years; 219 patients (78%) were male. In-hospital mortality was 43%. Only the length of NIV application before ICU admission (OR 2.03 (95% CI 1.06-4.98), p = 0.03) and age (OR 1.18 (95% CI 1.04-1.33), p < 0.01) were identified as independent risk factors of in-hospital mortality; whilst the length of NIV after ICU admission did not affect patient outcome. In-hospital mortality of ICU patients intubated after NIV failure was 43%. Days on NIV before ICU admission and age were assessed to be potential risk factors of greater in-hospital mortality., (© 2021. The Author(s).)

Background: Sigh is a cyclic brief recruitment maneuver: previous physiologic studies showed that its use could be an interesting addition to pressure support ventilation to improve lung elastance, decrease regional heterogeneity, and increase release of surfactant., Research Question: Is the clinical application of sigh during pressure support ventilation (PSV) feasible?, Study Design and Methods: We conducted a multicenter noninferiority randomized clinical trial on adult intubated patients with acute hypoxemic respiratory failure or ARDS undergoing PSV. Patients were randomized to the no-sigh group and treated by PSV alone, or to the sigh group, treated by PSV plus sigh (increase in airway pressure to 30 cm H 2 O for 3 s once per minute) until day 28 or death or successful spontaneous breathing trial. The primary end point of the study was feasibility, assessed as noninferiority (5% tolerance) in the proportion of patients failing assisted ventilation. Secondary outcomes included safety, physiologic parameters in the first week from randomization, 28-day mortality, and ventilator-free days., Results: Two-hundred and fifty-eight patients (31% women; median age, 65 [54-75] years) were enrolled. In the sigh group, 23% of patients failed to remain on assisted ventilation vs 30% in the no-sigh group (absolute difference, -7%; 95% CI, -18% to 4%; P = .015 for noninferiority). Adverse events occurred in 12% vs 13% in the sigh vs no-sigh group (P = .852). Oxygenation was improved whereas tidal volume, respiratory rate, and corrected minute ventilation were lower over the first 7 days from randomization in the sigh vs no-sigh group. There was no significant difference in terms of mortality (16% vs 21%; P = .337) and ventilator-free days (22 [7-26] vs 22 [3-25] days; P = .300) for the sigh vs no-sigh group., Interpretation: Among hypoxemic intubated ICU patients, application of sigh was feasible and without increased risk., Trial Registry: ClinicalTrials.gov; No.: NCT03201263; URL: www.clinicaltrials.gov., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

This observational study aims to assess the outcome and safety of O 2 -therapy by high-flow nasal cannula (HFNC) in 28 consecutive patients with severe hypoxemic acute respiratory failure (hARF) consequent to SARS-CoV-2 infection, unresponsive to conventional O 2 -therapy. Nineteen patients had a positive response. Nine patients required escalation of treatment to non-invasive ventilation (five subsequently intubated). None of the staff had a positive swab testing during the study period and the following 14 days. Severity of hypoxemia and C reactive protein level were correlated with HFNC failure. These data suggest HFNC to be a safe treatment for less severe patients with SARS-CoV-2 hARF and efficacy will need to be assessed as part of a clinical trial., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Besides airway suctioning, patients undergoing invasive mechanical ventilation (iMV) benefit of different combinations of chest physiotherapy techniques, to improve mucus removal. To date, little is known about the clearance effects of oscillating devices on patients with acute respiratory failure undergoing iMV. This study aimed to assess (1) the effects of high-frequency chest wall oscillation (HFCWO) on lung aeration and ventilation distribution, as assessed by electrical impedance tomography (EIT), and (2) the effect of the association of HFCWO with recruitment manoeuvres (RM)., Methods: Sixty critically ill patients, 30 classified as normosecretive and 30 as hypersecretive, who received ≥ 48 h of iMV, underwent HFCWO; patients from both subgroups were randomized to receive RM or not, according to two separated randomization sequences. We therefore obtained four arms of 15 patients each. After baseline record (T0), HFCWO was applied for 10 min. At the end of the treatment (T1) or after 1 (T2) and 3 h (T3), EIT data were recorded. At the beginning of each step, closed tracheobronchial suctioning was performed. In the RM subgroup, tracheobronchial suctioning was followed by application of 30 cmH 2 O to the patient's airway for 30 s. At each step, we assessed the change in end-expiratory lung impedance (ΔEELI) and in tidal impedance variation (ΔTIV), and the center of gravity (COG) through EIT. We also analysed arterial blood gases (ABGs)., Results: ΔTIV and COG did not differ between normosecretive and hypersecretive patients. Compared to T0, ΔEELI significantly increased in hypersecretive patients at T2 and T3, irrespective of the RM; on the contrary, no differences were observed in normosecretive patients. No differences of ABGs were recorded., Conclusions: In hypersecretive patients, HFCWO significantly improved aeration of the dorsal lung region, without affecting ABGs. The application of RM did not provide any further improvements., Trial Registration: Prospectively registered at the Australian New Zealand Clinical Trial Registry ( www.anzctr.org.au ; number of registration: ACTRN12615001257550; date of registration: 17th November 2015).

Background: Early identification of noninvasive ventilation (NIV) outcome predictors in patients with COPD who are experiencing acute hypercapnic respiratory failure consequent to exacerbation or pneumonia is a critical issue. The primary aim of this study was to investigate the feasibility of performing diaphragmatic ultrasound for excursion, thickness, and thickening fraction in highly dyspneic subjects with COPD admitted to the emergency department for exacerbation or pneumonia, before starting NIV (T0) and after the first (T1) and second hour (T2) of treatment. Secondarily, we determined whether these variables predicted early NIV failure., Methods: Adult subjects with COPD admitted to the emergency department for exacerbation or pneumonia requiring NIV were eligible. Right-sided diaphragmatic excursion, bilateral thickness, thickening fraction, and arterial blood gas analyses were performed at T0, T1, and T2. Feasibility was estimated by considering the number of subjects whose diaphragmatic function could be evaluated at each time point. At T2, subjects were classified in 2 subgroups according to early NIV failure, which was defined as the inability to achieve a pH ≥ 7.35; the ability to achieve pH ≥ 7.35 indicated NIV success., Results: Of the 22 subjects enrolled, 21 underwent complete diaphragm ultrasound evaluation (ie, right excursion and bilateral thickness at T0, T1, and T2) for a total of 63 excursion and 126 thickness assessments. At T2, 12 NIV successes and 9 NIV failures were recorded. Diaphragmatic excursion was greater in NIV successes than in NIV failures at T0 (1.92 [1.22-2.54] cm versus 1.00 [0.60-1.41] cm, P = .02), at T1 (2.14 [1.76-2.77] cm versus 0.93 [0.82-1.27] cm, P = .007), and at T2 (1.99 [1.63-2.54] cm versus 1.20 [0.79-1.41] cm, P = .008), respectively. Diaphragmatic thickness and thickening fraction were similar in both groups., Conclusions: In our emergency department setting, diaphragm ultrasound was a feasible and reliable tool to monitor highly dyspneic acute hypercapnic respiratory failure subjects with COPD undergoing NIV. (ClinicalTrials.gov registration NCT03314883.)., Competing Interests: The authors have disclosed no conflicts of interest., (Copyright © 2019 by Daedalus Enterprises.)

Chest imaging in patients with acute respiratory failure plays an important role in diagnosing, monitoring and assessing the underlying disease. The available modalities range from plain chest X-ray to computed tomography, lung ultrasound, electrical impedance tomography and positron emission tomography. Surprisingly, there are presently no clear-cut recommendations for critical care physicians regarding indications for and limitations of these different techniques.The purpose of the present European Respiratory Society (ERS) statement is to provide physicians with a comprehensive clinical review of chest imaging techniques for the assessment of patients with acute respiratory failure, based on the scientific evidence as identified by systematic searches. For each of these imaging techniques, the panel evaluated the following items: possible indications, technical aspects, qualitative and quantitative analysis of lung morphology and the potential interplay with mechanical ventilation. A systematic search of the literature was performed from inception to September 2018. A first search provided 1833 references. After evaluating the full text and discussion among the committee, 135 references were used to prepare the current statement.These chest imaging techniques allow a better assessment and understanding of the pathogenesis and pathophysiology of patients with acute respiratory failure, but have different indications and can provide additional information to each other., Competing Interests: Conflict of interest: D. Chiumello has nothing to disclose. Conflict of interest: G.F. Sferrazza Papa has nothing to disclose. Conflict of interest: A. Artigas reports grants from Grifols, Fisher & Paykel, Fundacion Areces and Instituto Carlos III, outside the submitted work. Conflict of interest: B. Bouhemad has nothing to disclose. Conflict of interest: A. Grgic reports personal fees from MSD, Boehringer Ingelheim, Roche and Bayer Vital, outside the submitted work. Conflict of interest: L. Heunks reports personal fees for travel and lecturing from Maquet critical care, and grants from Ventfree and Orionpharma, outside the submitted work. Conflict of interest: K. Markstaller has nothing to disclose. Conflict of interest: G.M. Pellegrino has nothing to disclose. Conflict of interest: L. Pisani has nothing to disclose. Conflict of interest: D. Rigau works as a methodologist for the ERS. Conflict of interest: M.J. Schultz has nothing to disclose. Conflict of interest: G. Sotgiu has nothing to disclose. Conflict of interest: P. Spieth has nothing to disclose. Conflict of interest: M. Zompatori has nothing to disclose. Conflict of interest: P. Navalesi has nothing to disclose., (Copyright ©ERS 2019.)

Background: Noninvasive ventilation (NIV) is indicated to treat respiratory acidosis due to exacerbation of chronic obstructive pulmonary disease (COPD). Recent nonrandomized studies also demonstrated some physiological effects of high-flow nasal therapy (HFNT) in COPD patients. We designed a prospective, unblinded, multicenter, randomized controlled trial to assess the noninferiority of HFNT compared to NIV with respect to the reduction of arterial partial pressure of carbon dioxide (PaCO 2 ) in patients with hypercapnic acute respiratory failure with mild-to-moderate respiratory acidosis., Methods: We will enroll adult patients with acute hypercapnic respiratory failure, as defined by arterial pH between 7.25 and 7.35 and PaCO 2  ≥ 55 mmHg. Patients will be randomly assigned 1:1 to receive NIV or HFNT. NIV will be applied through a mask with a dedicated ventilator in pressure support mode. Positive end-expiratory pressure will be set at 3-5 cmH 2 O with inspiratory support to obtain a tidal volume between 6 and 8 ml/kg of ideal body weight. HFNT will be initially set at a temperature of 37 °C and a flow of 60 L/min. At 2 and 6 h we will assess arterial blood gases, vital parameters, respiratory rate, treatment intolerance and failure, need for endotracheal intubation, time spent under mechanical ventilation (both invasive and NIV), intensive care unit and hospital length of stay, and hospital mortality. Based on an α error of 5% and a β error of 80%, with a standard deviation for PaCO 2 equal to 15 mmHg and a noninferiority limit of 10 mmHg, we computed a sample size of 56 patients. Considering potential drop-outs and nonparametric analysis, the final computed sample size was 80 patients (40 per group)., Discussion: HFNT is more comfortable than NIV in COPD patients recovering from an episode of exacerbation. If HFNT would not be inferior to NIV, HFNT could be considered as an alternative to NIV to treat COPD patients with mild-to-moderate respiratory acidosis., Trial Registration: ClinicalTrials.gov, NCT03370666 . Registered on December 12, 2017.

Objectives: Assessing gas exchange, diaphragm function, respiratory rate, and patient comfort during high-flow oxygen therapy and standard oxygen at the time of noninvasive ventilation discontinuation., Design: Randomized crossover physiologic study., Setting: Two ICUs., Patients: Thirty chronic obstructive pulmonary disease patients with hypercapnic acute respiratory failure receiving noninvasive ventilation greater than 24 hours., Interventions: All patients underwent five 30-minute trials, the first, third, and fifth trial in noninvasive ventilation, whereas the second and fourth were randomly conducted with either standard oxygen and high-flow oxygen therapy., Measurements and Main Results: Diaphragm displacement and thickening fraction were determined by sonographic evaluation at the end of each trial. Arterial blood gases, respiratory rate, and patient comfort were also assessed. PaCO2 (p = 0.153) and pH (p = 0.114) were not different among trials, while PaO2 was greater in noninvasive ventilation than with both standard oxygen (p ≤ 0.005) and high-flow oxygen therapy (p ≤ 0.001). The diaphragm displacement was no different among trials (p = 0.875), while its thickening fraction was greater with standard oxygen, compared with high-flow oxygen therapy and all noninvasive ventilation trials (p < 0.001 for all comparisons), without differences between high-flow oxygen therapy and noninvasive ventilation. Respiratory rate also increased with standard oxygen, compared with both high-flow oxygen therapy (p < 0.001) and noninvasive ventilation (p < 0.01). High-flow oxygen therapy improved comfort, compared with standard oxygen (p = 0.004) and noninvasive ventilation (p < 0.001)., Conclusions: At the time of noninvasive ventilation interruption, PaCO2 and diaphragm displacement remained unchanged regardless of the modality of oxygen administration. However, although standard oxygen resulted in a remarkable increase in diaphragm thickening fraction, high-flow oxygen therapy allowed maintaining it unchanged, while improving patient comfort.

Introduction: Patient-ventilator asynchrony is considered a major clinical problem for mechanically ventilated patients. It occurs during partial ventilatory support, when the respiratory muscles and the ventilator interact to contribute generating the volume output. In this review article, we consider all studies published on patient-ventilator asynchrony in the last 25 years., Evidence Acquisition: We selected 62 studies. The different forms of asynchrony are first defined and classified. We also describe the methods used for detecting and quantifying asynchronies. We then outline the outcome variables considered for evaluating the clinical consequences of asynchronies. The methodology for detection and quantification of patient-ventilator asynchrony are quite heterogeneous. In particular, the Asynchrony Index is calculated differently among studies., Evidence Synthesis: Sixteen studies established some relationship between asynchronies and one or more clinical outcomes, such as duration of mechanical ventilation (seven studies), mortality (five studies), length of intensive care and hospital stay (four studies), patient comfort (four studies), quality of sleep (three studies), and rate of tracheotomy (three studies). In patients with severe patient-ventilator asynchrony, four of seven studies (57%) report prolonged duration of mechanical ventilation, one of five (20%) increased mortality, one of four (25%) longer intensive care and hospital lengths of stay, four of four (100%) worsened comfort, three of four (75%) deteriorated quality of sleep, and one of three (33%) increased rate of tracheotomy., Conclusions: Given the varying outcomes considered and the erratic results, it remains unclear whether asynchronies really affects patient outcome, and the relationship between asynchronies and outcome is causative or associative.

Background: Adding cyclic short sustained inflations (sigh) to assisted ventilation yields optimizes lung recruitment, decreases heterogeneity and reduces inspiratory effort in patients with acute hypoxemic respiratory failure (AHRF). These findings suggest that adding sigh to pressure support ventilation (PSV) might decrease the risk of lung injury, shorten weaning and improve clinical outcomes. Thus, we conceived a pilot trial to test the feasibility of adding sigh to PSV (the PROTECTION study)., Methods: PROTECTION is an international randomized controlled trial that will be conducted in 23 intensive care units (ICUs). Patients with AHRF who have been intubated from 24 h to 7 days and undergoing PSV from 4 to 24 h will be enrolled. All patients will first undergo a 30-min sigh test by adding sigh to clinical PSV for 30 min to identify early oxygenation responders. Then, patients will be randomized to PSV or PSV + sigh until extubation, ICU discharge, death or day 28. Sigh will be delivered as a 3-s pressure control breath delivered once per minute at 30 cmH 2 O. Standardized protocols will guide ventilation settings, switch back to controlled ventilation, use of rescue treatments, performance of spontaneous breathing trial, extubation and reintubation. The primary endpoint of the study will be to verify the feasibility of PSV + sigh evaluated through reduction of failure to remain on assisted ventilation during the first 28 days in the PSV + sigh group versus standard PSV (15 vs. 22%). Failure will be defined by switch back to controlled ventilation for more than 24 h or use of rescue treatments or reintubation within 48 h from elective extubation. Setting the power to 80% and first-risk order to 5%, the computed size of the trial is 129 patients per arm., Discussion: PROTECTION is a pilot randomized controlled trial testing the feasibility of adding sigh to PSV. If positive, it will provide physicians with an effective addition to standard PSV for lung protection, able to reduce failure of assisted ventilation. PROTECTION will provide the basis for a future larger trial aimed at verifying the impact of PSV + sigh on 28-day survival and ventilator-free days., Trial Registration: ClinicalTrials.gov, NCT03201263 . Registered on 28 June 2017.

In an important sense, support of the respiratory system has been a defining characteristic of intensive care since its inception. The pace of basic and clinical research in this field has escalated over the past two decades, resulting in palpable improvement at the bedside as measured by both efficacy and outcome. As in all medical research, however, novel ideas built upon observations are continually proposed, tested, and either retained or discarded on the basis of the persuasiveness of the evidence. What follows are concise descriptions of the current standards of management practice in respiratory support, the areas of present-day uncertainty, and our suggested agenda for the near future of research aimed at testing current assumptions, probing uncertainties, and solidifying the foundation on which to base our progress to the next level.

Noninvasive mechanical ventilation (NIV) is widely used in the acute care setting for acute respiratory failure (ARF) across a variety of aetiologies. This document provides European Respiratory Society/American Thoracic Society recommendations for the clinical application of NIV based on the most current literature.The guideline committee was composed of clinicians, methodologists and experts in the field of NIV. The committee developed recommendations based on the GRADE (Grading, Recommendation, Assessment, Development and Evaluation) methodology for each actionable question. The GRADE Evidence to Decision framework in the guideline development tool was used to generate recommendations. A number of topics were addressed using technical summaries without recommendations and these are discussed in the supplementary material.This guideline committee developed recommendations for 11 actionable questions in a PICO (population-intervention-comparison-outcome) format, all addressing the use of NIV for various aetiologies of ARF. The specific conditions where recommendations were made include exacerbation of chronic obstructive pulmonary disease, cardiogenic pulmonary oedema, de novo hypoxaemic respiratory failure, immunocompromised patients, chest trauma, palliation, post-operative care, weaning and post-extubation.This document summarises the current state of knowledge regarding the role of NIV in ARF. Evidence-based recommendations provide guidance to relevant stakeholders., Competing Interests: Conflict of interest: Disclosures can be found alongside this article at erj.ersjournals.com, (Copyright ©ERS 2017.)

The choice of the interface for noninvasive ventilation (NIV) is a key factor in NIV success. We hypothesised that a new helmet specifically design to improve performance in hypercapnic patients would be clinically equivalent to a standard oronasal mask. In a multicentre, short-term, physiological, randomised trial in chronic obstructive pulmonary disease patients facing an acute hypercapnic respiratory failure episode, we compared the changes in arterial blood gases (ABGs) and tolerance score obtained using the helmet or mask, and, as secondary end-points, dyspnoea, vital signs, early NIV discontinuation and rate of intubation. 80 patients were randomly assigned to receive NIV either with the helmet (n=39) or mask (n=41), using an intensive care unit ventilator. Compared with baseline, in the first 6 h, NIV improved ABGs, dyspnoea and respiratory rate (p<0.05) in both groups. Changes in ABGs and discomfort were similar with the two groups, while dyspnoea decreased more (p<0.005) using the mask. The rate of intubation and the need for interface change during the whole period of NIV were very low and not different between groups. The new helmet may be a valid alternative to a mask in improving ABGs and achieving a good tolerance during an episode of acute hypercapnic respiratory failure., (Copyright ©ERS 2015.)

Background: Although noninvasive ventilation (NIV) is increasingly used in general wards, limited information exists about its ability to provide effective ventilation in this setting. We aim to evaluate NIV delivered in the ward by assessing (1) overall time of application and occurrence of adverse events and (2) differences between daytime and nighttime NIV application., Methods: We studied subjects with hypercapnic acute hypercapnic respiratory failure not fulfilling strict criteria for ICU admission, and excluded those who interrupted NIV prior to 48 h. Time spent on NIV, presence and extent of air leaks, and occurrence of desaturations were assessed for the overall study period, and compared between daytime and nighttime., Results: We enrolled 42 subjects, 25 of whom received NIV for at least 48 h and were included in the data analysis. NIV was successful for 20 subjects, who did not reach criteria for ICU admission. Both PaCO2 and pH significantly improved on average after 2 h and at the end of the study period. NIV was applied for 64.5% of the overall study period and had absent or compensated air leaks for 62.3% of the overall 48-h period. NIV was applied for 55.8% of daytime and for 79.3% of nighttime (P < .01). Effective NIV application was significantly longer overnight (76.9%) than during daytime (53.2%) (P < .01)., Conclusions: In selected subjects with hypercapnic acute respiratory failure not fulfilling criteria for ICU admission, the application of NIV in the ward is feasible; in addition, NIV can be safely administered overnight., (Copyright © 2015 by Daedalus Enterprises.)

Purpose: The use of noninvasive ventilation (NIV) to facilitate discontinuation of mechanical ventilation in patients with acute hypoxemic respiratory failure (hypoxemic ARF) has never been explored. This pilot study aims to assess the feasibility of early extubation followed by immediate NIV, compared conventional weaning, in patients with resolving hypoxemic ARF., Methods: Twenty consecutive hypoxemic patients were randomly assigned to receive either conventional weaning or NIV. The changes in arterial blood gases and respiratory rate were compared between the two groups at 1, 12, 24 and 48 h. Differences in the rate of extubation failure, ICU and hospital mortality, number of invasive-ventilation-free-days at day 28, septic complications, number of tracheotomies, days and rates of continuous intravenous sedation, and ICU length of stay were also determined., Results: No patient interrupted the study protocol. Arterial blood gases were similar during invasive mechanical ventilation, 1 h after NIV application following extubation, and after 12, 24 and 48 h. Respiratory rate was higher after 1 h in the NIV group, but no different after 12, 24 and 48 h. The number of invasive-ventilation-free-days at day 28 was 20 ± 8 (min = 0, max = 25) days in the treatment group and 10 ± 9 (min = 0, max = 25) days in the control group (p = 0.014). The rate of extubation failure, ICU and hospital mortality, tracheotomies, septic complications, days and rates of continuous sedation, and ICU length of stay were not significantly different between the two groups., Conclusions: In a highly experienced centre NIV may be used to facilitate discontinuation of mechanical ventilation in selected patients with resolving hypoxemic ARF.

Purpose: Noninvasive continuous positive airway pressure (n-CPAP) has been proposed for the treatment of hypoxemic acute respiratory failure (h-ARF). Recruitment maneuvers were shown to improve oxygenation, i.e., the ratio of arterial oxygen tension to inspiratory oxygen fraction (PaO2/FiO2), during either invasive mechanical ventilation, and n-CPAP, with a response depending on the distribution of lung collapse. We hypothesized that, during n-CPAP, early h-ARF patients with bilateral (B(L)) distribution of lung involvement would benefit from recruitment maneuvers more than those with unilateral (U(L)) involvement., Methods: To perform a recruitment maneuver, once a minute we increased the pressure applied to the airway from 10 cmH2O to 25 cmH2O for 8 s (SIGH). We enrolled 24 patients with h-ARF (12 B(L) and 12 U(L)) who underwent four consecutive trials: (1) 30 min breathing through a Venturi mask (V(MASK)), (2) 1 h n-CPAP (n-CPAP1), (3) 1 h n-CPAP plus SIGH (n-CPAP(SIGH)), and (4) 1 h n-CPAP (n-CPAP2)., Results: Compared to V(MASK), n-CPAP at 10 cmH2O delivered via a helmet, increased PaO2/FiO2 and decreased dyspnea in both B(L) and U(L); furthermore, it reduced the respiratory rate and brought PaCO2 up to normal in B(L) only. Compared to n-CPAP, n-CPAP(SIGH) significantly improved PaO2/FiO2 in B(L) (225 ± 88 vs. 308 ± 105, respectively), whereas it produced no further improvement in PaO2/FiO2 in U(L) (232 ± 72 vs. 231 ± 77, respectively). SIGH did not affect hemodynamics in both groups., Conclusions: Compared to n-CPAP, n-CPAP(SIGH) further improved arterial oxygenation in B(L) patients, whereas it produced no additional benefit in those with U(L).

Rationale: Patients who fail noninvasive ventilation are generally intubated and are then subjected to complications of invasive mechanical ventilation. With transtracheal open ventilation, ventilator support is delivered through an uncuffed small bore minitracheostomy tube, which eliminates pooling of secretions above the cuff and thus reduces the risk of tracheobronchial microbial colonization., Objective: To compare transtracheal open ventilation (treatment group) with conventional invasive ventilation (control group) in patients with exacerbation of chronic obstructive pulmonary disease who initially failed noninvasive ventilation., Methods: Patients were randomized to receive trans-tracheal open ventilation (n=19) or conventional invasive ventilation (n=20)., Measurements and Main Results: There was no difference in arterial blood gases after 1 and 30 h between the two groups. Two patients receiving transtracheal open ventilation and 13 undergoing conventional ventilation had complications (p<0.0001). Compared with conventional ventilation, transtracheal open ventilation significantly decreased both the duration of mechanical ventilation (7.6+/-4.7 vs. 18.6+/-10.6 d, p<0.0001) and length of stay in the intensive care unit (10.2+/-4.5 vs. 21.3+/-9.7 d, p<0.0001)., Conclusions: Transtracheal open ventilation was as effective as conventional ventilation in maintaining adequate gas exchange and reducing complications, duration of mechanical ventilation, and intensive care unit length of stay.

Objective: Compared with standard medical therapy (SMT), noninvasive ventilation (NIV) does not reduce the need for reintubation in unselected patients who develop respiratory failure after extubation. The goal of this study was to assess whether early application of NIV, immediately after extubation, is effective in preventing postextubation respiratory failure in an at-risk population., Design: Multiple-center, randomized controlled study., Setting: Multiple hospitals., Patients: Ninety-seven consecutive patients with similar baseline characteristics, requiring >48 hrs of mechanical ventilation and considered at risk of developing postextubation respiratory failure (i.e., patients who had hypercapnia, congestive heart failure, ineffective cough and excessive tracheobronchial secretions, more than one failure of a weaning trial, more than one comorbid condition, and upper airway obstruction)., Interventions: After a successful weaning trial, the patients were randomized to receive NIV for > or = 8 hrs a day in the first 48 hrs or SMT. Primary outcome was the need for reintubation according to standardized criteria. Secondary outcomes were intensive care unit and hospital mortality, as well as time spent in the intensive care unit and in hospital., Measurements and Main Results: Compared with the SMT group, the NIV group had a lower rate of reintubation (four of 48 vs. 12 of 49; p = .027). The need for reintubation was associated with a higher risk of mortality (p < .01). The use of NIV resulted in a reduction of risk of intensive care unit mortality (-10%, p < .01), mediated by the reduction for the need of reintubation., Conclusions: NIV was more effective than SMT in preventing postextubation respiratory failure in a population considered at risk of developing this complication.

Objective: To determine whether non-invasive ventilation (NIV) may be an effective and safe alternative to invasive mechanical ventilation in chronic obstructive pulmonary disease (COPD) patients with acute respiratory failure (ARF) meeting criteria for mechanical ventilation., Design and Setting: Matched case-control study conducted in ICU., Patients and Intervention: NIV was prospectively applied to 64 COPD patients with advanced ARF. Their outcomes were compared with those of a control group of 64 COPD patients matched on age, FEV(1), Simplified Acute Physiology Score II, and pH at ICU admission, previously treated in the same ICU with conventional invasive mechanical ventilation., Methods and Results: NIV failed in 40 patients who required intubation. Mortality rate, duration of mechanical ventilation, and lengths of ICU and post-ICU stay were not different between the two groups. The NIV group had fewer complications ( P = 0.01) and showed a trend toward a lower proportion of patients remaining on mechanical ventilation after 30 days ( P = 0.056). Compared to the control group, the outcomes of the patients who failed NIV were no different. Compared to the patients who received intubation, those who succeeded NIV had reduced mortality rate and lengths of ICU and post-ICU stay., Conclusions: In COPD patients with advanced hypercapnic acute respiratory failure, NIV had a high rate of failure, but, nevertheless, provided some advantages, compared to conventional invasive ventilation. Subgroup analysis suggested that the delay in intubation was not deleterious in the patients who failed NIV, whereas a better outcome was confirmed for the patients who avoided intubation.

Objective: We conducted a randomized prospective study comparing noninvasive positive pressure ventilation (NPPV) with conventional mechanical ventilation via endotracheal intubation (ETI) in a group of patients with chronic obstructive pulmonary disease who failed standard medical treatment in the emergency ward after initial improvement and met predetermined criteria for ventilatory support., Design and Setting: Prospective randomized study in a university hospital 13-bed general ICU., Patients: Forty-nine patients were randomly assigned to receive NPPV (n=23) or conventional ventilation (n=26)., Results: both NPPV and conventional ventilation significantly improved gas exchanges. The two groups had similar length of ICU stay, number of days on mechanical ventilation, overall complications, ICU mortality, and hospital mortality. In the NPPV group 11 (48%) patients avoided intubation, survived, and had a shorter duration of ICU stay than intubated patients. One year following hospital discharge the NPPV group had fewer patients readmitted to the hospital (65% vs. 100%) or requiring de novo permanent oxygen supplementation (0% vs. 36%)., Conclusions: The use of NPPV in patients with chronic obstructive pulmonary disease and acute respiratory failure requiring ventilatory support after failure of medical treatment avoided ETI in 48% of the patients, had the same ICU mortality as conventional treatment and, at 1-year follow-up was associated with fewer patients readmitted to the hospital or requiring for long-term oxygen supplementation. An editorial regarding this article can be found in the same issue (http://dx.doi.org/10.1007/s00134-002-1503-3).

We compared crural diaphragm electrical activity (EAdi) with transdiaphragmatic pressure (Pdi) during varying levels of pressure support ventilation (PS) in 13 intubated patients. With changing PS, we found no evidence for changes in neuromechanical coupling of the diaphragm. From lowest to highest PS (2 cm H(2)O +/- 4 to 20 cm H(2)O +/- 7), tidal volume increased from 430 ml +/- 180 to 527 ml +/- 180 (p < 0.001). The inspiratory volume calculated during the period when EAdi increased to its peak did not change from 276 +/- 147 to 277 +/- 162 ml, p = 0.976. Respiratory rate decreased from 23.9 (+/- 7) to 21.3 (+/- 7) breaths/min (p = 0.015). EAdi and Pdi decreased proportionally by adding PS (r = 0.84 and r = 0.90, for mean and peak values, respectively). Mean and peak EAdi decreased (p < 0.001) by 33 +/- 21% (mean +/- SD) and 37 +/- 23% with the addition of 10 cm H(2)O of PS, similar to the decrease in the mean and peak Pdi (p < 0.001) observed (34 +/- 36 and 35 +/- 23%). We also found that ventilator assist continued during the diaphragm deactivation period, a phenomenon that was further exaggerated at higher PS levels. We conclude that EAdi is a valid measurement of neural drive to the diaphragm in acute respiratory failure.

Objective: The efficacy of noninvasive mechanical ventilation (NIMV) in improving breathing pattern and arterial blood gases (ABG) in hypercapnic patients has been well documented; however, little attention has been given to the choice of the interface and the ventilatory mode. We evaluated the effects of three types of masks and two modes of ventilation on patients' ABG, breathing pattern, and tolerance to ventilation., Design: Prospective randomized study., Setting: Two respiratory weaning centers., Patients: A total of 26 stable hypercapnic patients (pH, 7.38 +/- 0.04; PaCO2, 59.2. +/- 10.9 torr) had not received NIMV and were affected by restrictive thoracic disease or obstructive pulmonary disease., Interventions: Three 30-min runs of NIMV, delivered using volume-assisted (n = 13) or pressure-assisted modes of partial mechanical support (n = 13), were performed in random order with a full-face mask, a nasal mask, and nasal plugs., Measurements: ABG, breathing pattern, and patients' tolerance to ventilation., Main Results: Compared with spontaneous breathing, the application of NIMV significantly improved ABG and minute ventilation, irrespective of the ventilatory mode, the underlying pathology or the type of mask. Overall, a nasal mask was better tolerated than the other two interfaces (p < .005 vs. nasal plugs and full-face mask). PaCO2 was significantly lower (p < .01) with a full-face mask or nasal plugs than with a nasal mask (49.5 +/- 9.4 torr, 49.7 +/- 8 torr, and 52.4 +/- 11 torr, respectively). Minute ventilation was significantly higher with a full-face mask than with a nasal mask because of an increase in tidal volume. No differences were observed in tolerance to ventilation, ABG, or breathing pattern, using assist control or pressure-assisted modes., Conclusions: In this physiologic study, we have shown that in patients with hypercapnic respiratory failure, irrespective of the underlying pathology, the type of interface affects the NIMV outcome more than the ventilatory mode.

Proportional assist ventilation (PAV) is a new mode of assisted ventilation which, by applying pressure in proportion to volume (volume assist, VA) and flow (flow assist, FA), should specifically reduce the inspiratory effort needed to overcome respiratory system elastance (Ers) and resistance (Rrs), respectively. The aims of this study were to determine (1) the effects of varying the level of VA on breathing pattern, inspiratory effort, and work of breathing, and (2) the interaction between VA and FA. In eight intubated patients with acute respiratory failure, four levels of VA (20 to 80% Ers) with and without a fixed amount of FA (approximately 50% Rrs) were evaluated. Compared with spontaneous breathing, VA increased tidal volume (VT) while respiratory rate (RR) was unchanged or fell slightly. The increase in minute ventilation (VE) was small and not significant. The addition of FA further increased VT while RR was significantly reduced so that VE remained unchanged. Increasing VA produced a graded reduction in inspiratory effort, reflected by decreases in the pressure-time integral of the diaphragm and the inspiratory muscles. These were further reduced when FA was added. VA decreased the elastic work of breathing (Wel) whereas resistive work (Wres) tended to increase so that the fall in total work (W/tot) was less than expected. At each VA setting, the addition of FA significantly reduced Wres and, as a result, Wtot. These results demonstrate that PAV can improve breathing pattern while reducing inspiratory effort by specifically decreasing Wel and Wres, and that VA and FA should be used together to optimize reductions in Wtot and the efficacy of assistance provided.

BACKGROUND: Noninvasive respiratory support (NRS) has been used to treat acute respiratory failure outside the ICU, but existing data have left many knowledge gaps for managing NRS in general wards. The primary objective of this study was to describe indications, duration of treatment, and outcomes of subjects treated with NRS outside the ICU. The secondary objective was to compare outcomes based on age < 80 or ≥ 80 y. METHODS: This retrospective observational study was conducted at Maggiore della Carita University Hospital in Novara, Italy, and included all patients treated with noninvasive ventilation (NIV) or CPAP outside the ICU from November 2017 to October 2018, with 1 year of follow-up. RESULTS: Of the 570 treatments performed, 383 subjects were analyzed, 136 NIV and 247 CPAP. Subjects' median (interquartile range [IQR]) age was 79 (72-85) y, and the main diagnoses of respiratory failure were cardiogenic pulmonary edema in 128 subjects (33%), pneumonia in 99 (26%), and COPD exacerbation in 52 (14%), with a median (IQR) treatment duration of 38 (16-74) h. Rapid response team visits lasted a median (IQR) 3 (2-6) d. Interface-related pressure lesions occurred in 13% of the subjects, in no case leading to definitive treatment discontinuation. Compared with the subjects ≥ 80 y old, the younger subjects had a median (IQR) longer hospitalization (16 [10-24] d vs 13 [9-20] d; P = .003) but slightly decreased in-hospital mortality (21% vs 30%; P = .061) and a decreased post-discharged 1-year mortality in hospital survivors (25% vs 41%; P = .002), differences observed only in the subjects treated with NIV. CONCLUSIONS: In a real-life setting outside the ICU, NIV and CPAP managed by a rapid response team with a daily visit in collaboration with ward staff highly experienced in NRS allowed us to treat the subjects without major complications. Post-discharge 1-year mortality was higher in the subjects ≥ 80 y old treated with NIV for acute hypercapnic respiratory failure. [ABSTRACT FROM AUTHOR]