BTS/ICS guideline for the ventilatory management of acute hypercapnic respiratory failure in adults

Automated oxygen titration with non-invasive ventilation in hypoxaemic adults with cardiorespiratory disease: a randomised cross-over trial

BACKGROUND

Closed-loop oxygen control systems automatically adjust the fraction of inspired oxygen (FiO2) to maintain oxygen saturation (SpO2) within a predetermined target range. Their performance with low and high-flow oxygen therapies, but not with non-invasive ventilation, has been established. We compared the effect of automated oxygen on achieving and maintaining a target SpO2 range with nasal high flow (NHF), bilevel positive airway pressure (bilevel) and continuous positive airway pressure (CPAP), in stable hypoxaemic patients with chronic cardiorespiratory disease.

METHODS

In this open-label, three-way cross-over trial, participants with resting hypoxaemia (n=12) received each of NHF, bilevel and CPAP treatments, in random order, with automated oxygen titrated for 10 min, followed by 36 min of standardised manual oxygen adjustments. The primary outcome was the time taken to reach target SpO2 range (92%-96%). Secondary outcomes included time spent within target range and physiological responses to automated and manual oxygen adjustments.

RESULTS

Two participants were randomised to each of six possible treatment orders. During automated oxygen control (n=12), the mean (±SD) time to reach target range was 114.8 (±87.9), 56.6 (±47.7) and 67.3 (±61) seconds for NHF, bilevel and CPAP, respectively, mean difference 58.3 (95% CI 25.0 to 91.5; p=0.002) and 47.5 (95% CI 14.3 to 80.7; p=0.007) seconds for bilevel and CPAP versus NHF, respectively. Proportions of time spent within target range were 68.5% (±16.3), 65.6% (±28.7) and 74.7% (±22.6) for NHF, bilevel and CPAP, respectively.Manually increasing, then decreasing, the FiO2 resulted in similar increases and then decreases in SpO2 and transcutaneous carbon dioxide (PtCO2) with NHF, bilevel and CPAP.

CONCLUSION

The target SpO2 range was achieved more quickly when automated oxygen control was initiated with bilevel and CPAP compared with NHF while time spent within the range across the three therapies was similar. Manually changing the FiO2 had similar effects on SpO2 and PtCO2 across each of the three therapies.

TRIAL REGISTRATION NUMBER

ACTRN12622000433707.

Applying Noninvasive Ventilation in Treatment of Acute Exacerbation of COPD Using Evidence-Based Interprofessional Clinical Practice

When administered as first-line intervention to patients admitted with acute hypercapnic respiratory failure secondary to COPD exacerbation in conjunction with guideline-recommended therapies, noninvasive ventilation (NIV) has been shown to reduce mortality and endotracheal intubation. Opportunities to increase uptake of NIV continue to exist despite inclusion of this therapy in clinical guidelines. Identifying patients appropriate for NIV, and subsequently providing close monitoring to determine an improvement in clinical condition involves a team consisting of physician, nurse, and respiratory therapist in institutions that successfully implement NIV. We describe to our knowledge the first known evidence-based algorithm speaking to initiation, titration, monitoring, and weaning of NIV in treatment of acute exacerbation of COPD that incorporates the necessary interprofessional collaboration among physicians, nurses, and respiratory therapists caring for these patients.

A Diagnostic Nomogram for Predicting Hypercapnic Respiratory Failure in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

To develop and validate a nomogram for assessing the risk of developing hypercapnic respiratory failure (HRF) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Patients and Methods

From January 2019 to August 2023, a total of 334 AECOPD patients were enrolled in this research. We employed the Least Absolute Shrinkage and Selection Operator (LASSO) regression and multivariate logistic regression to determine independent predictors and develop a nomogram. This nomogram was appraised by the area under the receiver operating characteristic curve (AUC), calibration curve, Hosmer-Lemeshow goodness-of-fit test (HL test), decision curve analysis (DCA), and clinical impact curve (CIC). The enhanced bootstrap method was used for internal validation.

Results

Sex, prognostic nutritional index (PNI), hematocrit (HCT), and activities of daily living (ADL) were independent predictors of HRF in AECOPD patients. The developed nomogram based on the above predictors showed good performance. The AUCs for the training, internal, and external validation cohorts were 0.841, 0.884, and 0.852, respectively. The calibration curves and HL test showed excellent concordance. The DCA and CIC showed excellent clinical usefulness. Finally, a dynamic nomogram was developed (https://a18895635453.shinyapps.io/dynnomapp/).

Conclusion

This nomogram based on sex, PNI, HCT, and ADL demonstrated high accuracy and clinical value in predicting HRF. It is a less expensive and more accessible approach to assess the risk of developing HRF in AECOPD patients, which is more suitable for primary hospitals, especially in developing countries with high COPD-related morbidity and mortality.

Long-term outcomes in patients with COPD treated with non-invasive ventilation for acute hypercapnic respiratory failure

PURPOSE

Chronic Obstructive Lung Disease (COPD) remains a major cause of morbidity and mortality across the world. We evaluated survival over 9 years in a cohort of patients with COPD requiring acute inpatient non-invasive ventilation (NIV). We analyzed prognostic indices to evaluate if they were associated with mortality.

PATIENTS AND METHODS

We performed a retrospective chart review of all patients who were admitted to St. James's Hospital respiratory ward with COPD and acute hypercapnic respiratory failure who required NIV over a 12-month period and followed their outcomes over 9 years. We investigated the association between survival and potential prognostic variables using univariate analysis and multivariate Cox proportional hazards model. We evaluated the association between survival and the following parameters: age, gender, multiple admissions requiring NIV (> 1 admission in within 12 months of index presentation), home NIV use preadmission, initial arterial blood gas pH, days spent on NIV, serum albumin and serum albumin to serum CRP ratio at admission.

RESULTS

Ninety-nine patients with COPD and acute hypercapnic respiratory failure were identified over a 12-month period from January to December 2011. Survival at 1, 2, 5 and 9 years was 65% (n = 64), 42% (n = 42), 25% (n = 25) and 21% (n = 21), respectively. Increasing age (p value < 0.001) and a lower serum albumin (p value < 0.005) were associated with a higher mortality. There was a trend towards improved survival in the group who were treated with home NIV prior to admission compared to no NIV therapy at home but this did not reach statistical significance (Fig. 3, p value = 0.088).

CONCLUSION

This study highlights the long-term mortality in patients with COPD admitted with hypercapnic respiratory failure requiring NIV and correlates with prior studies. Increasing age and lower serum albumin were associated with increased mortality. Home NIV may have a protective long-term survival benefit in patients with COPD who have been admitted for acute NIV.

Obstructive Sleep Apnea and Risk of Postoperative Complications after Non-Cardiac Surgery

Obstructive sleep apnea (OSA), a common sleep disorder, poses significant challenges in perioperative management due to its complexity and multifactorial nature. With a global prevalence of approximately 22.6%, OSA often remains undiagnosed, and increases the risk of cardiac and respiratory postoperative complications. Preoperative screening has become essential in many institutions to identify patients at increased risk, and experts recommend proceeding with surgery in the absence of severe symptoms, albeit with heightened postoperative monitoring. Anesthetic and sedative agents exacerbate upper airway collapsibility and depress central respiratory activity, complicating intraoperative management, especially with neuromuscular blockade use. Additionally, OSA patients are particularly prone to opioid-induced respiratory depression, given their increased sensitivity to opioids and heightened pain perception. Thus, regional anesthesia and multimodal analgesia are strongly advocated to reduce perioperative complication risks. Postoperative care for OSA patients necessitates vigilant monitoring and tailored management strategies, such as supplemental oxygen and Positive Airway Pressure therapy, to minimize cardiorespiratory complications. Health care institutions are increasingly focusing on enhanced monitoring and resource allocation for patient safety. However, the rising prevalence of OSA, heterogeneity in disease severity, and lack of evidence for the efficacy of costly perioperative measures pose challenges. The development of effective screening and monitoring algorithms, alongside reliable risk predictors, is crucial for identifying OSA patients needing extended postoperative care. This review emphasizes a multidimensional approach in managing OSA patients throughout the perioperative period, aiming to optimize patient outcomes and minimize adverse outcomes.

Development of respiratory care guidelines for Duchenne muscular dystrophy in the UK: key recommendations for clinical practice

Significant inconsistencies in respiratory care provision for Duchenne muscular dystrophy (DMD) are reported across different specialist neuromuscular centres in the UK. The absence of robust clinical evidence and expert consensus is a barrier to the implementation of care recommendations in public healthcare systems as is the need to increase awareness of key aspects of care for those living with DMD. Here, we provide evidenced-based and/or consensus-based best practice for the respiratory care of children and adults living with DMD in the UK, both as part of routine care and in an emergency.

METHODOLOGY

Initiated by an expert working group of UK-based respiratory physicians (including British Thoracic Society (BTS) representatives), neuromuscular clinicians, physiotherapist and patient representatives, draft guidelines were created based on published evidence, current practice and expert opinion. After wider consultation with UK respiratory teams and neuromuscular services, consensus was achieved on these best practice recommendations for respiratory care in DMD.

RESULT

The resulting recommendations are presented in the form of a flow chart for assessment and monitoring, with additional guidance and a separate chart setting out key considerations for emergency management. The recommendations have been endorsed by the BTS.

CONCLUSIONS

These guidelines provide practical, reasoned recommendations for all those managing day-to-day and acute respiratory care in children and adults with DMD. The hope is that this will support patients and healthcare professionals in accessing high standards of care across the UK.

Severe Community-Acquired Pneumonia: Noninvasive Mechanical Ventilation, Intubation, and HFNT

Severe acute respiratory failure (ARF) is a major issue in patients with severe community-acquired pneumonia (CAP). Standard oxygen therapy is the first-line therapy for ARF in the less severe cases. However, respiratory supports may be delivered in more severe clinical condition. In cases with life-threatening ARF, invasive mechanical ventilation (IMV) will be required. Noninvasive strategies such as high-flow nasal therapy (HFNT) or noninvasive ventilation (NIV) by either face mask or helmet might cover the gap between standard oxygen and IMV. The objective of all the supporting measures for ARF is to gain time for the antimicrobial treatment to cure the pneumonia. There is uncertainty regarding which patients with severe CAP are most likely to benefit from each noninvasive support strategy. HFNT may be the first-line approach in the majority of patients. While NIV may be relatively contraindicated in patients with excessive secretions, facial hair/structure resulting in air leaks or poor compliance, NIV may be preferable in those with increased work of breathing, respiratory muscle fatigue, and congestive heart failure, in which the positive pressure of NIV may positively impact hemodynamics. A trial of NIV might be considered for select patients with hypoxemic ARF if there are no contraindications, with close monitoring by an experienced clinical team who can intubate patients promptly if they deteriorate. In such cases, individual clinician judgement is key to choose NIV, interface, and settings. Due to the paucity of studies addressing IMV in this population, the protective mechanical ventilation strategies recommended by guidelines for acute respiratory distress syndrome can be reasonably applied in patients with severe CAP.

Diagnosis and Management of Acute Respiratory Failure

Acute hypoxemic respiratory failure is defined by Pao2 less than 60 mm Hg or SaO2 less than 88% and may result from V/Q mismatch, shunt, hypoventilation, diffusion limitation, or low inspired oxygen tension. Acute hypercapnic respiratory failure is defined by Paco2 ≥ 45 mm Hg and pH less than 7.35 and may result from alveolar hypoventilation, increased fraction of dead space, or increased production of carbon dioxide. Early diagnostic maneuvers, such as measurement of SpO2 and arterial blood gas, can differentiate the type of respiratory failure and guide next steps in evaluation and management.

Switches in non-invasive respiratory support strategies during acute hypoxemic respiratory failure: Need to monitoring from a retrospective observational study

OBJECTIVE

To explore combined non-invasive-respiratory-support (NIRS) patterns, reasons for NIRS switching, and their potential impact on clinical outcomes in acute-hypoxemic-respiratory-failure (AHRF) patients.

DESIGN

Retrospective, single-center observational study.

SETTING

Intensive Care Medicine.

PATIENTS

AHRF patients (cardiac origin and respiratory acidosis excluded) underwent combined NIRS therapies such as non-invasive-ventilation (NIV) and High-Flow-Nasal-Cannula (HFNC).

INTERVENTIONS

Patients were classified based on the first NIRS switch performed (HFNC-to-NIV or NIV-to-HFNC), and further specific NIRS switching strategies (NIV trial-like vs. Non-NIV trial-like and single vs. multiples switches) were independently evaluated.

MAIN VARIABLES OF INTEREST

Reasons for switching, NIRS failure and mortality rates.

RESULTS

A total of 63 patients with AHRF were included, receiving combined NIRS, 58.7% classified in the HFNC-to-NIV group and 41.3% in the NIV-to-HFNC group. Reason for switching from HFNC to NIV was AHRF worsening (100%), while from NIV to HFNC was respiratory improvement (76.9%). NIRS failure rates were higher in the HFNC-to-NIV than in NIV-to-HFNC group (81% vs. 35%, p < 0.001). Among HFNC-to-NIV patients, there was no difference in the failure rate between the NIV trial-like and non-NIV trial-like groups (86% vs. 78%, p = 0.575) but the mortality rate was significantly lower in NIV trial-like group (14% vs. 52%, p = 0.02). Among NIV to HFNC patients, NIV failure was lower in the single switch group compared to the multiple switches group (15% vs. 53%, p = 0.039), with a shorter length of stay (5 [2-8] vs. 12 [8-30] days, p = 0.001).

CONCLUSIONS

NIRS combination is used in real life and both switches' strategies, HFNC to NIV and NIV to HFNC, are common in AHRF management. Transitioning from HFNC to NIV is suggested as a therapeutic escalation and in this context performance of a NIV-trial could be beneficial. Conversely, switching from NIV to HFNC is suggested as a de-escalation strategy that is deemed safe if there is no NIRS failure.

Analgo-sedation in Patients on Non-invasive Mechanical Ventilation: Need for Guideline Recommendation

Shrinath V, Marwah V, Jyothis MC. Analgo-sedation in Patients on Non-invasive Mechanical Ventilation: Need for Guideline Recommendation. Indian J Crit Care Med 2024;28(3):309-310.

Nursing Interventions for Client and Family Training in the Proper Use of Noninvasive Ventilation in the Transition from Hospital to Community: A Scoping Review

Noninvasive ventilation is an increasingly disseminated therapeutic option, which is explained by increases in the prevalence of chronic respiratory diseases, life expectancy, and the effectiveness of this type of respiratory support. This literature review observes that upon returning home after hospital discharge, there are difficulties in adhering to and maintaining this therapy. The aim of this study is to identify nursing interventions for client and family training in the proper use of noninvasive ventilation in the transition from hospital to community. A scoping review was carried out by searching MEDLINE, CINAHL, Scopus, and Web of Science. The articles were selected by two independent reviewers by applying the predefined eligibility criteria. Regarding transitional care, the authors opted to include studies about interventions to train clients and families during hospital stay, hospital discharge, transition from hospital to home, and the first 30 days after returning home. The eight included publications allowed for identification of interventions related to masks or interfaces, prevention of complications associated with noninvasive ventilation, leakage control, maintenance and cleaning of ventilators and accessories, respiratory training, ventilator monitoring, communication, and behavioral strategies as transitional care priority interventions to guarantee proper training in the transition from hospital to community.

Are specialist-provided end-of-life scenarios key to initiation of advance care planning in primary care? A mixed-methods study

OBJECTIVES

Specialist-provided end-of-life scenarios (SP-EOLS) may improve advance care planning (ACP) implementation in primary care by helping overcome barriers such as uncertain prognosis and poor interprofessional collaboration. We aimed to explore the current use and potential impact of SP-EOLS on ACP in Dutch primary care.

METHODS

We performed a mixed-methods study. From patients discussed in a hospital-based academic palliative care multidisciplinary team meeting between 2016 and 2019 and died, we collected primary care electronic medical records data on SP-EOLS, actual EOLS, and ACP initiation and applied descriptive and comparative analyses. Subsequently, we interviewed general practitioners (GPs) and thematically analyzed the transcripts.

RESULTS

In 69.7% of 66 reviewed patient files, SP-EOLS were found. In patients whose GP had received SP-EOLS, ACP conversations were more often reported (92.0 vs. 61.0%, p = 0.006). From 11 GP interviews, we identified 4 themes: (1) SP-EOLS guide GPs, patients, and relatives when dealing with an uncertain future perspective; (2) SP-EOLS provide continuity of care between primary and secondary/tertiary care; (3) SP-EOLS should be tailored to the individual patient; and (4) SP-EOLS need to be personalized and uniformly transferred to GPs.

SIGNIFICANCE OF RESULTS

SP-EOLS may facilitate ACP conversations by GPs. They have the potential to help overcome existing barriers to ACP implementation by providing guidance and supporting interprofessional collaboration. Future research should focus on improving SP-EOLS and tailor them to the needs of all end users, focusing on improving their effect on ACP conversations.

Liberation from mechanical ventilation in critically ill patients: Korean Society of Critical Care Medicine Clinical Practice Guidelines

BACKGROUND

Successful liberation from mechanical ventilation is one of the most crucial processes in critical care because it is the first step by which a respiratory failure patient begins to transition out of the intensive care unit and return to their own life. Therefore, when devising appropriate strategies for removing mechanical ventilation, it is essential to consider not only the individual experiences of healthcare professionals, but also scientific and systematic approaches. Recently, numerous studies have investigated methods and tools for identifying when mechanically ventilated patients are ready to breathe on their own. The Korean Society of Critical Care Medicine therefore provides these recommendations to clinicians about liberation from the ventilator.

METHODS

Meta-analyses and comprehensive syntheses were used to thoroughly review, compile, and summarize the complete body of relevant evidence. All studies were meticulously assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method, and the outcomes were presented succinctly as evidence profiles. Those evidence syntheses were discussed by a multidisciplinary committee of experts in mechanical ventilation, who then developed and approved recommendations.

RESULTS

Recommendations for nine PICO (population, intervention, comparator, and outcome) questions about ventilator liberation are presented in this document. This guideline includes seven conditional recommendations, one expert consensus recommendation, and one conditional deferred recommendation.

CONCLUSIONS

We developed these clinical guidelines for mechanical ventilation liberation to provide meaningful recommendations. These guidelines reflect the best treatment for patients seeking liberation from mechanical ventilation.

Non-invasive advanced respiratory support in end-of-life care and symptom management: systematic review

OBJECTIVES

To narrate the canon of knowledge around symptom control at end of life for patients using, or having recently used, non-invasive advanced respiratory support (NARS) at end of life for respiratory failure.

METHODS

A systematic review forming a narrative synthesis from a wide range of sample papers from Medline, Embase, CINAHL, Emcare, Cochrane and OpenGrey databases. A secondary search of grey literature was also performed with hand searching reference lists and author citations. The review was undertaken using the ENTREQ checklist for quality.

RESULTS

In total, 22 studies were included in the synthesis and four themes were generated: NARS as a buoy (NARS can represent hope and relief from the symptoms of respiratory failure), NARS as an anchor (NARS brings significant treatment burden), Impact on Staff (uncertainty over the balance of benefit and burden as well as complex patient care drives distress among staff providing care) and the Process of Withdrawal (withdrawal of therapy felt to be futile exists as discrete event in patient care but is otherwise poorly defined).

CONCLUSION

NARS represents a complex interplay of hope, symptom control, unnaturally prolonged death and treatment burden. The literature captures the breadth of these issues, but further, detailed, research is required in almost every aspect of practice around end-of-life care and NARS-especially how to manage symptoms at the end of life.

Risk factors and prognosis of orotracheal intubation in aquaporin-4-IgG neuromyelitis optica spectrum disorder attacks

BACKGROUND

Aquaporin-4 immunoglobulin G Neuro Myelitis Optica spectrum disorders attacks (NMOSD-AQP4-IgG+ attacks) can cause respiratory failure requiring orotracheal intubation (OTI), but the risk factors and outcomes of OTI during attacks remain unclear. Our primary objective was to identify the clinical and radiological risk factors for OTI in NMOSD-AQP4-IgG+ attacks. As a secondary objective, we aimed to evaluate the prognosis of OTI-attacks.

METHODS

We retrospectively analyzed NMOSD-AQP4-IgG+ attacks at the Pitié-Salpêtrière Hospital (Jan 2010-Jan 2021), excluding isolated optic neuritis. The primary outcome was the need for OTI due to neurological dysfunction an attack (OTI-attack). The secondary outcome was attack's poor recovery after 12 months, defined as a modified Rankin score (mRS) > 2 in patients with an initial mRS ≤ 2, or an increase ≥ 1 point in mRS in other patients. Analyses were performed using a binomial generalized linear mixed model, with a random intercept for the patient ID to account for within-patient correlations.

RESULTS

Seventy-three attacks in 44 patients NMOSD-AQP4-IgG+ were analyzed. Of 73 attacks, 8 (11%) required OTI during the attack, related to acute restrictive respiratory failure (n = 7) and/or severe swallowing disorder (n = 2). None of the OTI-attacks occurred in patients previously treated with active disease-modifying treatment (DMT), while 36 (55.4%) of the non-OTI-attacks occurred in patients who were already on active DMT. On admission, OTI-attacks were more likely to have upper limbs motor paresis of (75.0% versus 29.2%, p = 0.366) and dyspnea (3 [50.0%] versus 4 [6.6%], p = 0.002) compared to non-OTI-attacks. MRI analysis showed that OTI-attacks had edematous lesions in the cervical spinal cord, mainly at levels C1 (75% versus 0% in non-OTI-attacks), C2 (75% versus 1.9%), C3 (62.5% versus 1.9%), and C4 and C5 levels (50% versus to 3.9%). One OTI-attack resulted in the death of one patient. Five patients with OTI-attack had mRS ≤ 2 one year after OTI-attack. Two (25%) OTI-attacks had poor recovery compared to 15 (24.2%) non-OTI-attacks (p = 0.468).

CONCLUSION

OTI-attacks occurred in untreated NMOSD-AQP4-IgG+ patients and were associated with edematous upper cervical lesions. The prognosis of these attacks may be favorable, and warrant maximal medical and supportive treatment. Trial registration This was a retrospective observational monocentric cohort study nested in the NOMADMUS cohort (ClinicalTrials.gov Identifier: NCT02850705).

Supporting patients with hypercapnia

Hypercapnia is commonly encountered by general and specialist respiratory clinicians. Patients at risk of developing hypercapnic respiratory failure include those with chronic obstructive pulmonary disease (COPD), obesity and neuromuscular disease. Such patients may present to clinicians acutely unwell on the acute medical take or during an inpatient deterioration, or be identified in the stable outpatient setting. In this review, we provide a practical guide to develop clinicians' knowledge, skills and confidence in promptly recognising and managing hypercapnic respiratory failure, and to promote national ventilation quality standards to encourage consistent delivery of high-quality care and optimise outcomes for patients.

Risk factors of in-hospital mortality and discriminating capacity of NIVO score in exacerbations of COPD requiring noninvasive ventilation

BACKGROUND

Noninvasive mechanical ventilation (NIV) is recommended as the initial mode of ventilation to treat acute respiratory failure in patients with AECOPD. The Noninvasive Ventilation Outcomes (NIVO) score has been proposed to evaluate the prognosis in patients with AECOPD requiring assisted NIV. However, it is not validated in Chinese patients.

METHODS

We used data from the MAGNET AECOPD Registry study, which is a prospective, noninterventional, multicenter, real-world study conducted between September 2017 and July 2021 in China. Data for the potential risk factors of mortality were collected and the NIVO score was calculated, and the in-hospital mortality was evaluated using the NIVO risk score.

RESULTS

A total of 1164 patients were included in the study, and 57 patients (4.9%) died during their hospital stay. Multiple logistic regression analysis revealed that age ≥75 years, DBP <60 mmHg, Glasgow Coma Scale ≤14, anemia and BUN >7 mmol/L were independent predictors of in-hospital mortality. The in-hospital mortality was associated with an increase in the risk level of NIVO score and the difference was statistically significant (p < .001). The NIVO risk score showed an acceptable accuracy for predicting the in-hospital mortality in AECOPD requiring assisted NIV (AUC: 0.657, 95% CI: 0.584-0.729, p < .001).

CONCLUSION

Our findings identified predictors of mortality in patients with AECOPD receiving NIV, providing useful information to identify severe patients and guide the management of AECOPD. The NIVO score showed an acceptable predictive value for AECOPD receiving NIV in Chinese patients, and additional studies are needed to develop and validate predictive scores based on specific populations.

Extracorporeal carbon dioxide removal for patients with acute respiratory failure: a systematic review and meta-analysis

BACKGROUND

Acute respiratory failure (ARF) is a common clinical critical syndrome with substantial mortality. Extracorporeal carbon dioxide removal (ECCO₂R) has been proposed for the treatment of ARF. However, whether ECCO₂R could provide a survival advantage for patients with ARF is still controversial.

METHODS

Electronic databases (PubMed, Embase, Web of Science, and the Cochrane database) were searched from inception to 30 April 2022. Randomized controlled trials (RCTs) and observational studies that examined the following outcomes were included: mortality, length of hospital and ICU stay, intubation and tracheotomy rate, mechanical ventilation days, ventilator-free days (VFDs), respiratory parameters, and reported adverse events.

RESULTS

Four RCTs and five observational studies including 1173 participants with ARF due to COPD or ARDS were included in this meta-analysis. Pooled analyses of related studies showed no significant difference in overall mortality between ECCO₂R and control group, neither in RCTs targeted ARDS or acute hypoxic respiratory failure patients (RR 1.05, 95% CI 0.83 to 1.32, p = 0.70, I² =0.0%), nor in studies targeted patients with ARF secondary to COPD (RR 0.80, 95% CI 0.58 to 1.11, p = 0.19, I² =0.0%). A shorter duration of ICU stay in the ECCO₂R group was only obtained in observational studies (WMD -4.25, p < 0.01), and ECCO₂R was associated with a longer length of hospital stay (p = 0.02). ECCO₂R was associated with lower intubation rate (p < 0.01) and tracheotomy rate (p = 0.01), and shorter mechanical ventilation days (p < 0.01) in comparison to control group in ARF patients with COPD. In addition, an improvement in pH (p = 0.01), PaO2 (p = 0.01), respiratory rate (p < 0.01), and PaCO2 (p = 0.04) was also observed in patients with COPD exacerbations by ECCO₂R therapy. However, the ECCO₂R-related complication rate was high in six of the included studies.

CONCLUSIONS

Our findings from both RCTs and observational studies did not confirm a significant beneficial effect of ECCO₂R therapy on mortality. A shorter length of ICU stay in the ECCO₂R group was only obtained in observational studies, and ECCO₂R was associated with a longer length of hospital stay. ECCO₂R was associated with lower intubation rate and tracheotomy rate, and shorter mechanical ventilation days in ARF patients with COPD. And an improvement in pH, PaO2, respiratory rate and PaCO2 was observed in the ECCO₂R group. However, outcomes largely relied on data from observational studies targeted patients with ARF secondary to COPD, thus further larger high-quality RCTs are desirable to strengthen the evidence on the efficacy and benefits of ECCO₂R for patients with ARF.Key messagesECCO₂R therapy did not confirm a significant beneficial effect on mortality.ECCO₂R was associated with lower intubation and tracheotomy rate, and shorter mechanical ventilation days in patients with ARF secondary to COPD.An improvement in pH, PaO2, respiratory rate, and PaCO2 was observed in ECCO₂R group in patients with COPD exacerbations.Evidence for the future application of ECCO₂R therapy for patients with ARF. The protocol of this meta-analysis was registered on PROSPERO (CRD42022295174).

Indications and evidence for domiciliary noninvasive ventilation

INTRODUCTION

Home noninvasive ventilation (HNIV) has expanded globally, with a greater evidence base for its use. HNIV improves multiple patient related outcomes in patients with chronic hypercapnic respiratory failure. Obesity hypoventilation syndrome (OHS) is rapidly taking over as the primary indication for HNIV and COPD patients who overlap with obstructive sleep apnea hypoventilation syndromes (OSAHS) and are increasingly recognized but add to the complexity of HNIV prescribing. Optimal settings vary for differing diseases, with higher inspiratory pressures often required in those with OHS and COPD, yet which settings translate into greatest patient benefit remains unknown.

AREAS COVERED

We cover the evidence base underpinning the common indications for HNIV in COPD, OHS, neuromuscular disease (NMD), and chest wall disease (CWD) and highlight common HNIV modes used.

EXPERT OPINION

Active screening for nocturnal hypoventilation in OHS and COPD may be important to guide earlier ventilation. Further research on which HNIV modalities best improve patient related outcomes and the right time for initiation in different patient phenotypes is rapidly needed. Worldwide, clinical research trials should aim to bridge the gap by reporting on patient-related outcomes and cost effectiveness in real-world populations to best understand the true benefit of HNIV amongst heterogenous patient populations.

Identification and Management of Acute Neuromuscular Respiratory Failure in the ICU

Respiratory failure is a common and potentially life-threatening complication of neuromuscular diseases. Prompt recognition and accurate diagnosis of new or worsening chronic neuromuscular disease have important clinical management and prognostic implications. In this article, we present an approach to the acute presentation of undifferentiated neuromuscular respiratory failure in the ICU and guidance for determination and respiratory management of the underlying disorder.

Ventilatory failure in chronic neuromuscular disease

Patients with neuromuscular diseases (NMD) can present to the neurologist with symptoms and signs of respiratory failure, either acutely or as an insidious process in the outpatient setting. Since the advent of non-invasive ventilation, the outcomes of patients with ventilatory failure due to NMD have dramatically improved. However, the natural history of different NMDs requires a nuanced approach to respiratory investigation and management. Respiratory failure dictates the prognosis of many NMDs and timing the most appropriate investigation and referral to ventilation services is crucial in optimising care.

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Long-Term Mortality following Acute Noninvasive Ventilation for Obesity-Related Respiratory Failure: A Retrospective Single-Centre Study

Introduction

Determinants of long-term mortality following acute hypercapnic respiratory failure have been extensively studied in patients with chronic obstructive pulmonary disease. However, respiratory failure due to obesity has not been studied to the same extent. This retrospective survey aims to identify whether admission pH is associated with long-term mortality in patients requiring acute noninvasive ventilation (NIV) for obesity-related respiratory failure (ORRF).

Methods

Records from April 2013 to March 2020 were accessed from a NIV quality database at an acute teaching hospital. Adults with hypercapnic ORRF requiring acute NIV were included. pH data were grouped by threshold (pH≤ and >7.25) and correlated with time from presentation to death; multivariable analysis was performed using Cox proportional hazards.

Results

A total of 277 acute NIV episodes were included. Two-year mortality was similar for patients in both pH categories. Univariable analysis identified pH ≤ 7.25 to increase risk of two-year mortality by 43%. However, multivariable analysis identified that pH was not a significant determinant of long-term mortality, although male sex, older age, and higher admission pCO2 increased the risk of death at two years by 76%, 3% per year of age, and 16% per 1 kPa of pCO2 increase, respectively.

Conclusion

Severity of hypercapnia on admission, male sex, and older age are associated with worse two-year mortality in patients requiring acute NIV for ORRF. There is scope for further analyses including investigating the role of domiciliary NIV in ORRF patients.

Under-The-Nose Versus Over-The-Nose Face Mask to Prevent Facial Pressure Sores During Face Mask-Delivered Noninvasive Ventilation for Acute Hypercapnic Respiratory Failure: A Randomized Controlled Trial

OBJECTIVES

To determine whether an under-the-nose face mask (FM) as the first-line interface strategy reduces the incidence of facial pressure sores with the same clinical improvement as the one obtained by standard over-the-nose face mask-noninvasive ventilation (FM-NIV) in patients with acute hypercapnic respiratory failure (AHRF).

DESIGN

A multicenter, prospective randomized controlled study.

SETTING

Two ICUs from two French tertiary hospitals.

PATIENTS

A total of 108 patients needed NIV for AHRF.

INTERVENTIONS

participants were randomized (1/1) to receive either the under-the-nose FM (intervention group) or the over-the-nose FM (control group). The primary endpoint was the reduction of facial pressure sores. Secondary endpoints included patients outcome, NIV failure (intubation or death), arterial blood gas improvement, and interface failure (the need to switch to a total face mask).

MEASUREMENTS AND MAIN RESULTS

Despite less protective dressings in the intervention group ( n = 4, 5% vs n = 27, 51%; p < 0.001), pressure sores developed less frequently than in the control group ( n = 3, 5% vs n = 39, 74%; p < 0.001). Similar mortality, NIV failure, and arterial blood gas improvement occurred in the two groups. However, under-the-nose FM resulted in a higher interface failure rate than conventional FM ( n = 18, 33% vs n = 5, 9%; p = 0.004), mainly because of excessive unintentional air leaks ( n = 15, 83% vs n = 0, 0%; p < 0.001).

CONCLUSIONS

In patients with AHRF, under-the-nose FM significantly reduced the incidence of facial pressure sores compared to the most commonly used first-line interface, the standard FM. However, with this new mask, excessive unintentional air leaks more often compelled the attending clinician to switch to another interface to pursue NIV.

A pragmatic, open-label, multi-center, randomized controlled clinical trial on the rotational use of interfaces vs standard of care in patients treated with noninvasive positive pressure ventilation for acute hypercapnic respiratory failure: the ROTAtional-USE of interface STUDY (ROTA-USE STUDY)

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.

A New Full-Face Mask for Multifunctional Non-Invasive Ventilation

Background: Noninvasive ventilation (NIV) provides positive pressure through different interfaces. A multifunctional full-face mask prototype was developed to provide NIV from three sources: ICU ventilators, portable ventilators, and high-flow medical gas pipeline systems. This study aimed to evaluate the usability of this prototype mask. Methods: This was a quantitative experimental study, conducted in two phases: the development of a full-face mask prototype NIV interface, and the evaluation of its usability by health professionals (evaluators) using a heuristic approach. The Wolf Mask prototype is a multifunctional full-face mask that makes it possible to deliver positive pressure from three different sources: microprocessor-controlled ICU ventilators, portable ventilators with single-limb circuits, and high-flow medical gas. The evaluation was conducted in three stages: presentation of the prototype to the evaluators; skills testing via simulation in a clinical environment; and a review of skills. Results: The prototype was developed by a multidisciplinary team and patented in Brazil. The evaluators were 10 health professionals specializing in NIV. Seven skills related to handling the prototype were evaluated. Three of the ten evaluators called for (non-urgent) changes to improve recognition of the components of the prototype. Only one evaluator called for (non-urgent) changes to improve recognition of the pieces, assembly, and checking the mask. Conclusions: The newly developed multifunctional full-face mask prototype demonstrated excellent usability for providing noninvasive ventilation from multiple sources. Minor modifications may further improve the design.

Expanded central role of the respiratory physiotherapists in the community setting

The development of community hubs through the Slaintecare initiative will rely on respiratory physiotherapists and clinical nurse specialists for the management of chronic respiratory diseases. The role of the respiratory physiotherapist has evolved dramatically over the last decade. We review the increasing scope of practice of the physiotherapist and the evidence base for same. We pay particular attention to the role of the physiotherapist in areas such as pulmonary rehabilitation, sputum clearance, neuromuscular disease, chronic respiratory failure, ambulatory oxygen assessments and dysfunctional breathing. We give an in depth review of sputum clearance techniques. We also address areas of potential future expansion for the role of the physiotherapist such as prescription and initiation of non-invasive ventilation.

The assessment and management of obstructive sleep apnoea-hypopnoea syndrome and obesity hypoventilation syndrome in obesity

Obesity is associated with respiratory dysfunction. It is a key risk and contributory factor in the sleep related breathing disorders, obstructive sleep apnoea/hypopnoea syndrome (OSAHS) and obesity hypoventilation syndrome (OHS). Weight management is an integral part of the management of these disorders, in addition to continuous positive airways pressure (CPAP) and non-invasive ventilation (NIV). Untreated, these conditions are associated with a high disease burden and as treatment is effective, early recognition and referral is critical. Best practice in on-going care is multidisciplinary.

International Survey of High-Flow Nasal Therapy Use for Respiratory Failure in Adult Patients

(1) Background: High-flow nasal therapy (HFNT) has shown several benefits in addressing respiratory failure. However, the quality of evidence and the guidance for safe practice are lacking. This survey aimed to understand HFNT practice and the needs of the clinical community to support safe practice. (2) Method: A survey questionnaire was developed and distributed to relevant healthcare professionals through national networks in the UK, USA and Canada; responses were collected between October 2020 and April 2021. (3) Results: In the UK and Canada, HFNT was used in 95% of hospitals, with the highest use being in the emergency department. HNFT was widely used outside of a critical care setting. HFNT was mostly used to treat acute type 1 respiratory failure (98%), followed by acute type 2 respiratory failure and chronic respiratory failure. Guideline development was felt to be important (96%) and urgent (81%). Auditing of practice was lacking in 71% of hospitals. In the USA, HFNT was broadly similar to UK and Canadian practice. (4) Conclusions: The survey results reveal several key points: (a) HFNT is used in clinical conditions with limited evidence; (b) there is a lack of auditing; (c) it is used in wards that may not have the appropriate skill mix; and (d) there is a lack of guidance for HFNT use.

Comparison of mathematically arterialised venous blood gas sampling with arterial, capillary, and venous sampling in adult patients with hypercapnic respiratory failure: a single-centre longitudinal cohort study

BACKGROUND

Accurate arterial blood gas (ABG) analysis is essential in the management of patients with hypercapnic respiratory failure, but repeated sampling requires technical expertise and is painful. Missed sampling is common and has a negative impact on patient care. A newer venous to arterial conversion method (v-TAC, Roche) uses mathematical models of acid-base chemistry, a venous blood gas sample and peripheral blood oxygen saturation to calculate arterial acid-base status. It has the potential to replace routine ABG sampling for selected patient cohorts. The aim of this study was to compare v-TAC with ABG, capillary and venous sampling in a patient cohort referred to start non-invasive ventilation (NIV).

METHODS

Recruited patients underwent near simultaneous ABG, capillary blood gas (CBG) and venous blood gas (VBG) sampling at day 0, and up to two further occasions (day 1 NIV and discharge). The primary outcome was the reliability of v-TAC sampling compared with ABG, via Bland-Altman analysis, to identify respiratory failure (via PaCO₂) and to detect changes in PaCO₂ in response to NIV. Secondary outcomes included agreements with pH, sampling success rates and pain.

RESULTS

The agreement between ABG and v-TAC/venous PaCO₂ was assessed for 119 matched sampling episodes and 105 between ABG and CBG. Close agreement was shown for v-TAC (mean difference (SD) 0.01 (0.5) kPa), but not for CBG (-0.75 (0.69) kPa) or VBG (+1.00 (0.90) kPa). Longitudinal data for 32 patients started on NIV showed the closest agreement for ABG and v-TAC (R²=0.61). v-TAC sampling had the highest first-time success rate (88%) and was less painful than arterial (p<0.0001).

CONCLUSION

Mathematical arterialisation of venous samples was easier to obtain and less painful than ABG sampling. Results showed close agreement for PaCO2 and pH and tracked well longitudinally such that the v-TAC method could replace routine ABG testing to recognise and monitor patients with hypercapnic respiratory failure.

TRIAL REGISTRATION NUMBER

NCT04072848; www.

CLINICALTRIALS

gov.

Continuous positive airway pressure in COVID-19-associated respiratory failure: improving patient care with a proforma

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the disease it causes (COVID-19) has proven to be the greatest challenge to modern global health care, infecting more than 450 million people worldwide and responsible for just over 6 million deaths. Over the past 2 years there have been major advances in the treatment of COVID-19, including a significant reduction in the number of individuals developing severe symptoms, since the introduction of COVID-19 vaccines and the advances in pharmacological treatments. However, for those individuals who become infected with COVID-19 and develop acute respiratory failure, the use of continuous positive airway pressure (CPAP) continues to be an essential management strategy that reduces mortality risk and the need for invasive mechanical ventilation. Without any standard regional or national guidelines on CPAP initiation and up-titration during the pandemic, a protocol proforma was devised for use in the author's clinical area. This was particularly useful for staff caring for seriously ill COVID-19 patients who were unfamiliar with providing CPAP. It is hoped that this article will contribute to the knowledge base of nurses and may encourage them to create a similar proforma for use in their clinical area.

Impact of corticosteroids on the duration of ventilatory support during severe acute exacerbations of chronic obstructive pulmonary disease in patients in the intensive care unit: a study protocol for a multicentre, randomized, placebo-controlled, double-blind trial

BACKGROUND

Patients who are admitted to the intensive care unit (ICU) for severe acute exacerbations of chronic obstructive pulmonary disease (COPD) have poor outcomes. Although international clinical practice guidelines cautiously recommend the routine use of systemic corticosteroids for COPD exacerbations, data are scarce and inconclusive regarding their benefit for most severe patients who require mechanical ventilation in the ICU. Furthermore, corticosteroids may be associated with an increased risk of infection, ICU-acquired limb weakness, and metabolic disorders.

METHODS AND ANALYSIS

This study is an investigator-initiated, multicentre, randomized, placebo-controlled, double-blind trial comparing systemic corticosteroids to placebo during severe acute exacerbations of COPD in patients who require mechanical ventilation in French ICUs. A total of 440 patients will be randomized 1:1 to methylprednisolone (1 mg/kg) or placebo for 5 days, and stratified according to initial mechanical ventilation (non-invasive or invasive), pneumonia as triggering factor, and recent use of systemic corticosteroids (< 48 h). The primary outcome is the number of ventilator-free days at day 28, defined as the number of days alive and without mechanical invasive and/or non-invasive ventilation between randomization and day 28. Secondary outcomes include non-invasive ventilation (NIV) failure rate, duration of mechanical ventilation (invasive and/or NIV), circulatory support (vasopressor), outcomes related to corticosteroid adverse events (severe hyperglycaemia, gastrointestinal bleeding, uncontrolled arterial hypertension, ICU-acquired weakness, ICU-acquired infections, and delirium), lengths of ICU and hospital stay, ICU and hospital mortality, day 28 and day 90 mortality, number of new exacerbation(s)/hospitalization(s) between hospital discharge and day 90, and dyspnoea and comfort at randomization, ICU discharge, and day 90. Subgroup analyses for the primary outcome are planned according to stratification criteria at randomization.

Highlights from the Respiratory Failure and Mechanical Ventilation 2022 Conference

The Respiratory Intensive Care Assembly of the European Respiratory Society gathered in Berlin to organise the second Respiratory Failure and Mechanical Ventilation Conference in June 2022. The conference covered several key points of acute and chronic respiratory failure in adults. During the 3-day conference, ventilatory strategies, patient selection, diagnostic approaches, treatment and health-related quality of life topics were addressed by a panel of international experts. Lectures delivered during the event have been summarised by Early Career Members of the Assembly and take-home messages highlighted.

Lessons from COVID-19 in the management of acute respiratory failure

Accumulated evidence supports the efficacy of noninvasive respiratory support therapies in coronavirus disease 2019 (COVID-19)-related acute hypoxaemic respiratory failure, alleviating admissions to intensive care units. Noninvasive respiratory support strategies, including high-flow oxygen therapy, continuous positive airway pressure via mask or helmet and noninvasive ventilation, can be alternatives that may avoid the need for invasive ventilation. Alternating different noninvasive respiratory support therapies and introducing complementary interventions, like self-proning, may improve outcomes. Proper monitoring is warranted to ensure the efficacy of the techniques and to avoid complications while supporting transfer to the intensive care unit. This article reviews the latest evidence on noninvasive respiratory support therapies in COVID-19-related acute hypoxaemic respiratory failure.

How do I wean a patient with acute hypercapnic respiratory failure from noninvasive ventilation?

Noninvasive ventilation (NIV) has been increasingly used for the management of different etiologies of acute hypercapnic respiratory failure (AHRF). Although NIV implementation has been framed well by the guidelines, limited number of studies evaluated the NIV weaning strategies, including a gradual decrease in the level of ventilator support and/or duration of NIV as well as abrupt discontinuation, once respiratory acidosis and distress have resolved. None of the methods have yet been established to be superior to the other in terms of the success rate of weaning and duration of NIV; as well as mortality, length of stay (LOS) in hospital, respiratory ICU (RICU), and ICU.  Patient-derived factors, such as etiology of AHRF, disease severity, history of prior NIV use, and clinical status can help to predict NIV weaning outcome and eventually choose the best method for each individual. In this paper, we have described the strategies for weaning a patient with AHRF from NIV and provided a quick guide for implementation of these data into daily practice based on our experience in and the current scientific evidence.

Noninvasive positive pressure in acute exacerbations of chronic obstructive pulmonary disease

PURPOSE OF REVIEW

Noninvasive positive pressure ventilation (NIV) is standard of care for patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). We review the most current evidence and highlight areas of uncertainty and ongoing research. We highlight key concepts for the clinician caring for patients with AECOPD which require NIV.

RECENT FINDINGS

Implementation of NIV in AECOPD is not uniform in spite of the evidence and guidelines. Initiation of NIV should be done early and following protocols. Low-intensity NIV remains the standard of care, although research and guidelines are evaluating higher intensity NIV. Scores to predict NIV failure continue to be refined to allow early identification and interventions. Several areas of uncertainty remain, among them are interventions to improve tolerance, length of support and titration and nutritional support during NIV.

SUMMARY

The use of NIV in AECOPD is the standard of care as it has demonstrated benefits in several patient-centered outcomes. Current developments and research is related to the implementation and adjustment of NIV.

The effectiveness of pressure support ventilation and T-piece in differing duration among weaning patients: A systematic review and network meta-analysis

BACKGROUND

A spontaneous breathing trial (SBT) is recommended to help patients to liberate themselves from mechanical ventilation as soon as possible in the ICU. The respiratory workload in SBT, which depends on being with or without respiratory support and a specific time, is more accurate to reflect how much support the weaning patients need compared with only considering SBT technologies.

AIM

To compare and rank the effectiveness of different respiratory workloads during SBT via differing technologies (Pressure Support Ventilation and T-piece) and differing duration (30 and 120 min) in SBTs.

STUDY DESIGN

A comprehensive literature search was performed in six English electronic databases to identify eligible randomized controlled trials (RCTs) published before September 2020. The pooled risk ratio (RR) with 95% confidence interval (CI) was calculated by Markov chain Monte Carlo methods. A Bayesian network meta-analysis was conducted using "gemtc" version 0.8.2 of R software. Each intervention's ranking possibilities were calculated using the surface under the cumulative ranking analysis (SUCRA).

RESULTS

A total of nine RCTs including 3115 participants were eligible for this network meta-analysis involving four different commonly used SBT strategies and four outcomes. The only statistically significant difference was between Pressure Support Ventilation (PSV) 30 min and T-piece 120 min in the outcome of the rate of success in SBTs (RR = 0.91; 95% CI, 0.84-0.98). The cumulative rank probability showed that the rate of success in SBT from best to worst was PSV 30 min, PSV 120 min, T-piece 30 min and T-piece 120 min. PSV 30 min and PSV 120 min are more likely to have a higher rate of extubation (SUCRA values of 82.5% for 30 min PSV, 70.7% for 120 min PSV, 36.4% for T-piece 30 min, 10.4% for T-piece 120). Meanwhile, T-piece 120 min (SUCRA, 62.9%) and PSV 120 min (SUCRA, 60.9%) may result in lower reintubation rates, followed by T-piece 30 min (SUCRA, 41.8%) and PSV 30 min (SUCRA, 34.4%).

CONCLUSIONS AND RELEVANCE TO CLINICAL PRACTICE

In comprehensive consideration of four outcomes, regarding SBT strategies, 30-min PSV was superior in simple-to-wean patients. Besides, 120-min T-piece and 120-min PSV are more likely to achieve a lower reintubation rate. Thus, the impact of duration is more significant among patients who have a high risk of reintubation. It is still unclear whether the SBTs affect the outcome of mortality; further studies may need to explore the underlying mechanism.

Improving the delivery of acute NIV at Kings Mill Hospital: A closed loop quality improvement project

BACKGROUND

The British Thoracic Society (BTS) Acute Non-Invasive Ventilation (NIV) standards state all patients who require acute NIV should be initiated on NIV within two hours of hospital admission. The delivery of acute NIV is a time critical intervention as prompt application of acute NIV substantially reduces mortality for patients with acute hypercapnic respiratory failure.

OBJECTIVE

This audit aimed to assess the number of patients for whom there is a delay in the initiation of acute NIV. We also assessed the outcome of admission for patients started on acute NIV.

METHODS

Data was collected on patients admitted to Kings Mill Hospital for acute NIV between 1/2/2019 and 31/3/2019. Awareness and knowledge of acute NIV was highlighted as an area for improvement. E-learning packages on 'Acute NIV' were designed and sent to medical-staff. The audit was repeated for patients admitted for acute NIV between 1/2/2020 and 31/3/2020 and analysed using chi-square tests.

RESULTS

25 patients were included in the initial audit and 30 patients in the re-audit. Prior to intervention 31% of patients had a delay in the initiation of acute NIV, which increased to 77% post-intervention (p < 0.0001). Prior to intervention there was a mortality rate of 17% and a mortality rate of 13% post-intervention (p > 0.05).

CONCLUSION

Further work is required to ensure the sustained delivery of acute NIV to BTS standards, however variable achievements in the targets does not seem to have a significant adverse effect on patient outcomes.

Esophageal Pressure Measurement in Acute Hypercapnic Respiratory Failure Due to Severe COPD Exacerbation Requiring NIV-A Pilot Safety Study

Esophageal pressure (Pes) measurements could optimise ventilator parameters in acute respiratory failure (ARF) patients requiring noninvasive ventilation (NIV). Consequently, the objectives of our study were to evaluate the safety and accuracy of applying a Pes measuring protocol in ARF patients with AECOPD under NIV in our respiratory intermediate care unit (RICU). An observational cohort study was undertaken. The negative inspiratory swing of Pes (ΔPes) was measured: in an upright/supine position in the presence/absence of NIV at D1 (day of admission), D3 (3rd day of NIV), and DoD (day of discharge). A digital filter for artefact removal was developed. We included 15 patients. The maximum values for ∆Pes were recorded at admission (mean ∆Pes 23.2 cm H2O) in the supine position. ∆Pes decreased from D1 to D3 (p < 0.05), the change being BMI-dependent (p < 0.01). The addition of NIV decreased ∆Pes at D1 and D3 (p < 0.01). The reduction of ∆Pes was more significant in the supine position at D1 (8.8 cm H2O, p < 0.01). Under NIV, ∆Pes values remained higher in the supine versus upright position. Therefore, the measurement of Pes in AECOPD patients requiring NIV can be safely done in an RICU. Under NIV, ∆Pes reduction is most significant within the first 24 h of admission.

High-flow nasal cannula versus non-invasive ventilation for acute hypercapnic respiratory failure in adults: a systematic review and meta-analysis of randomized trials

Background

Non-invasive ventilation (NIV) with bi-level positive pressure ventilation is a first-line intervention for selected patients with acute hypercapnic respiratory failure. Compared to conventional oxygen therapy, NIV may reduce endotracheal intubation, death, and intensive care unit length of stay (LOS), but its use is often limited by patient tolerance and treatment failure. High-flow nasal cannula (HFNC) is a potential alternative treatment in this patient population and may be better tolerated.

Research question

For patients presenting with acute hypercapnic respiratory failure, is HFNC an effective alternative to NIV in reducing the need for intubation?

Methods

We searched EMBASE, MEDLINE, and the Cochrane library from database inception through to October 2021 for randomized clinical trials (RCT) of adults with acute hypercapnic respiratory failure assigned to receive HFNC or NIV. The Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias. We calculated pooled relative risks (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with corresponding 95% confidence intervals (CI) using a random-effects model.

Results

We included eight RCTs (n = 528) in the final analysis. The use of HFNC compared to NIV did not reduce the risk of our primary outcome of mortality (RR 0.86, 95% CI 0.48–1.56, low certainty), or our secondary outcomes including endotracheal intubation (RR 0.80, 95% CI 0.46–1.39, low certainty), or hospital LOS (MD − 0.82 days, 95% CI − 1.83–0.20, high certainty). There was no difference in change in partial pressure of carbon dioxide between groups (MD − 1.87 mmHg, 95% CI − 5.34–1.60, moderate certainty).

Interpretation

The current body of evidence is limited in determining whether HFNC may be either superior, inferior, or equivalent to NIV for patients with acute hypercapnic respiratory failure given imprecision and study heterogeneity. Further studies are needed to better understand the effect of HFNC on this population.

Noninvasive Mechanical Ventilation with Average Volume-Assured Pressure Support versus BiPAP S/T in De Novo Hypoxemic Respiratory Failure

Background

Bilevel positive airway pressure in spontaneous/time and average volume-assured pressure support (BiPAP·S/T–AVAPS) could maintain an adequate tidal volume by reducing the patient's inspiratory effort; however, this ventilatory strategy has not been compared with other ventilatory modes, especially the conventional BiPAP S/T mode, when noninvasive mechanical ventilation (NIMV) is used. The primary objective of this study was to determine the rate of success and failure of the use of BiPAP·S/T-AVAPS versus BiPAP·S/T alone in patients with mild-to-moderate “de novo” hypoxemic respiratory failure.

Methods

This was a matched-cohort study. Subjects with mild-to-moderate de novo hypoxemic respiratory failure were divided into two groups according to the ventilatory strategy used. The subjects in the BiPAP·S/T group were paired with those in the BiPAP·S/T-AVAPS group.

Results

A total of 58 subjects were studied. Twenty-nine subjects in the BiPAP·S/T group were paired with 29 subjects in the BiPAP·S/T-AVAPS group. Twenty patients (34.5%) presented with “failure of NIMV,” while 38 (65.5%) patients did not. In addition, 13 (22.4%) patients died, while 45 (77.6%) recovered. No differences were found in the percentage of intubation (P=0.44) and mortality (P=0.1).

Conclusion

The BiPAP S/T-AVAPS ventilator mode was not superior to the BiPAP·S/T mode. A high mortality rate was observed in patients with NIMV failure in both modes. This trial is registered with https://doi.org/10.1186/ISRCTN17904857.

Home Non-Invasive Positive Pressure Ventilation in Chronic Obstructive Pulmonary Disease: Why, Who, and How?

Advanced chronic obstructive pulmonary disease (COPD) might result in chronic hypercapnic ventilatory failure. Similar to neuromuscular and restrictive chest wall diseases, long-term non-invasive positive pressure ventilation (NPPV) is increasingly used in chronic hypercapnic COPD. This review describes the methods, patient selection, ventilatory strategies, and therapeutic effects of long-term Home-NPPV based on randomized controlled clinical trials published since 1985 in English language retrieved from the databases PubMed and Scopus. Long-term NPPV is feasible and effective in stable, non-exacerbated COPD patients with daytime hypercapnia with arterial pressure of carbon dioxide (PaCO2) levels ≥50 mm Hg (6.6 kPa), if the applied ventilatory pressures and application times improve baseline hypercapnia by at least 20%. Patients who survived an acute hypercapnic exacerbation might benefit from long-term NPPV if hypercapnia persists 2-4 weeks after resolution of the exacerbation. Pressure-controlled ventilation or pressure-support ventilation with adequate minimum backup breathing frequencies, in combination with nasal masks or oronasal masks have been successfully used in all larger clinical trials. Ventilatory strategies with mean inspiratory pressures of up to 28 cm H2O are well-tolerated by patients, but limitations exist in patients with impaired cardiac performance. Home-NPPV with a PaCO2-reductive approach might be considered as an additional treatment option in patients with stable chronic hypercapnic COPD.

High-pressure NIV for acute hypercapnic respiratory failure in COPD: improved survival in a retrospective cohort study

Introduction

Updated treatment guidelines for acute hypercapnic respiratory failure (AHRF) in chronic obstructive pulmonary disease (COPD) with non-invasive ventilation (NIV) in 2016 recommended a rapid increase in inspiratory positive airway pressure (IPAP) to 20 cm H₂O with possible further increase for patients not responding. Previous guidelines from 2006 suggested a more conservative algorithm and maximum IPAP of 20 cm H₂O.

Aim

To determine whether updated guidelines recommending higher IPAP during NIV were related with improved outcome in patients with COPD admitted with AHRF, compared with NIV with lower IPAP.

Methods

A retrospective cohort study comparing patients with COPD admitted with AHRF requiring NIV in 2012–2013 and 2017–2018.

Results

101 patients were included in the 2012–2013 cohort with low IPAP regime and 80 patients in the 2017–2018 cohort with high IPAP regime. Baseline characteristics, including age, forced expiratory volume in 1 s (FEV₁), pH and PaCO₂ at initiation of NIV, were comparable. Median IPAP in the 2012–2013 cohort was 12 cm H₂O (IQR 10–14) and 20 cm H₂O (IQR 18-24) in the 2017–2018 cohort (p<0.001). In-hospital mortality was 40.5% in the 2012–2013 cohort and 13.8% in the 2017–2018 cohort (p<0.001). The 30-days and 1-year mortality were significantly lower in the 2017–2018 cohort. With a Cox model 1 year survival analysis, adjusted for age, sex, FEV₁ and pH at NIV initiation, the HR was 0.45 (95% CI 0.27 to 0.74, p=0.002).

Conclusion

Short-term and long-term survival rates were substantially higher in the cohort treated with higher IPAP. Our data support the current strategy of rapid increase and higher pressure.

Impact on staff of providing non-invasive advanced respiratory support during the COVID-19 pandemic: a qualitative study in an acute hospital

OBJECTIVES

To explore the experiences of healthcare workers providing non-invasive advanced respiratory support (NARS) to critically unwell patients with COVID-19.

DESIGN

A qualitative study drawing on a social constructionist perspective using thematic analysis of semistructured interviews.

SETTING

A single acute UK National Health Service Trust across two hospital sites.

PARTICIPANTS

Multidisciplinary team members in acute, respiratory and palliative medicine.

RESULTS

21 nurses, doctors (juniors and consultants) and physiotherapists described the provision of NARS to critically unwell COVID-19 patients as extremely challenging. The main themes were of feeling ill prepared and unsupported, a need to balance complex moral actions and a sense of duty to patients and their families. The impact on staff was profound and findings are discussed via a lens of moral injury. Injurious events included staff feeling they had acted in a way that caused harm, failed to prevent harm or had been let down by seniors or the Trust. Participants identified factors that mitigated adverse impact.

CONCLUSIONS

Although many of the issues described by participants are likely immutable components of healthcare in a pandemic, there were several important protective factors that emerged from the data. Experience, debriefing and breaks from COVID-19 wards were valuable to participants and successfully achieving a peaceful death for the patient was often viewed as compensation for a difficult journey. These protective factors may provide modelling for future education and support services to help prevent moral injury or aide in its recovery.

TRIAL REGISTRATION NUMBER

Registered on the Open Science Framework, DOI 10.17605/OSF.IO/TB5QJ.

ERS statement: a core outcome set for clinical trials evaluating the management of COPD exacerbations

Clinical trials evaluating the management of acute exacerbations of COPD assess heterogeneous outcomes, often omitting those that are clinically relevant or more important to patients. We have developed a core outcome set, a consensus-based minimum set of important outcomes that we recommend are evaluated in all future clinical trials on exacerbations management, to improve their quality and comparability. COPD exacerbations outcomes were identified through methodological systematic reviews and qualitative interviews with 86 patients from 11 countries globally. The most critical outcomes were prioritised for inclusion in the core outcome set through a two-round Delphi survey completed by 1063 participants (256 patients, 488 health professionals and 319 clinical academics) from 88 countries in five continents. Two global, multi-stakeholder, virtual consensus meetings were conducted to 1) finalise the core outcome set and 2) prioritise a single measurement instrument to be used for evaluating each of the prioritised outcomes. Consensus was informed by rigorous methodological systematic reviews. The views of patients with COPD were accounted for at all stages of the project. Survival, treatment success, breathlessness, quality of life, activities of daily living, the need for a higher level of care, arterial blood gases, disease progression, future exacerbations and hospital admissions, treatment safety and adherence were all included in the core outcome set. Focused methodological research was recommended to further validate and optimise some of the selected measurement instruments. The panel did not consider the prioritised set of outcomes and associated measurement instruments to be burdensome for patients and health professionals to use.

A randomised controlled trial of non-invasive ventilation compared with extracorporeal carbon dioxide removal for acute hypercapnic exacerbations of chronic obstructive pulmonary disease

Background

Patients presenting with acute hypercapnic respiratory failure due to exacerbations of chronic obstructive pulmonary disease (AECOPD) are typically managed with non-invasive ventilation (NIV). The impact of low-flow extracorporeal carbon dioxide removal (ECCO₂R) on outcome in these patients has not been explored in randomised trials.

Methods

Open-label randomised trial comparing NIV (NIV arm) with ECCO₂R (ECCO₂R arm) in patients with AECOPD at high risk of NIV failure (pH < 7.30 after ≥ 1 h of NIV). The primary endpoint was time to cessation of NIV. Secondary outcomes included device tolerance and complications, changes in arterial blood gases, hospital survival.

Results

Eighteen patients (median age 67.5, IQR (61.5–71) years; median GOLD stage 3 were enrolled (nine in each arm). Time to NIV discontinuation was shorter with ECCO₂R (7:00 (6:18–8:30) vs 24:30 (18:15–49:45) h, p = 0.004). Arterial pH was higher with ECCO₂R at 4 h post-randomisation (7.35 (7.31–7.37) vs 7.25 (7.21–7.26), p < 0.001). Partial pressure of arterial CO₂ (PaCO₂) was significantly lower with ECCO₂R at 4 h (6.8 (6.2–7.15) vs 8.3 (7.74–9.3) kPa; p = 0.024). Dyspnoea and comfort both rapidly improved with commencement of ECCO₂R. There were no severe or life-threatening complications in the study population. There were no episodes of major bleeding or red blood cell transfusion in either group. ICU and hospital length of stay were longer with ECCO₂R, and there was no difference in 90-day mortality or functional outcomes at follow-up.

Interpretation

There is evidence of benefit associated with ECCO₂R with time to improvement in respiratory acidosis, in respiratory physiology and an immediate improvement in patient comfort and dyspnoea with commencement of ECCO₂R. In addition, there was minimal clinically significant adverse events associated with ECCO₂R use in patients with AECOPD at risk of failing or not tolerating NIV. However, the ICU and hospital lengths of stay were longer in the ECCO₂R for similar outcomes.

Trial registration The trial is prospectively registered on ClinicalTrials.gov: NCT02086084. Registered on 13th March 2014, https://clinicaltrials.gov/ct2/show/NCT02086084?cond=ecco2r&draw=2&rank=8

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01006-8.

Thoracic Society of Australia and New Zealand Position Statement on Acute Oxygen Use in Adults: 'Swimming between the flags'

Oxygen is a life-saving therapy but, when given inappropriately, may also be hazardous. Therefore, in the acute medical setting, oxygen should only be given as treatment for hypoxaemia and requires appropriate prescription, monitoring and review. This update to the Thoracic Society of Australia and New Zealand (TSANZ) guidance on acute oxygen therapy is a brief and practical resource for all healthcare workers involved with administering oxygen therapy to adults in the acute medical setting. It does not apply to intubated or paediatric patients. Recommendations are made in the following six clinical areas: assessment of hypoxaemia (including use of arterial blood gases); prescription of oxygen; peripheral oxygen saturation targets; delivery, including non-invasive ventilation and humidified high-flow nasal cannulae; the significance of high oxygen requirements; and acute hypercapnic respiratory failure. There are three sections which provide (1) a brief summary, (2) recommendations in detail with practice points and (3) a detailed explanation of the reasoning and evidence behind the recommendations. It is anticipated that these recommendations will be disseminated widely in structured programmes across Australia and New Zealand.

Treatment of acute respiratory failure: noninvasive mechanical ventilation

Background: Noninvasive ventilation (NIV) has been an important strategy to support patients with respiratory failure, while preventing complications assorted with invasive mechanical ventilation. Physicians need to be aware of the various roles of NIV and the challenges encountered in clinical practice.Current Concepts: Traditionally, the application of NIV has been well-known to be associated with reduced mortality in patients with chronic obstructive pulmonary disease (COPD) or acute pulmonary edema and those suffering from acute respiratory failure. However, despite some positive results of NIV treatment in patients with de novo hypoxemic respiratory failure such as acute pneumonia or acute respiratory distress syndrome, NIV failure (or delayed intubation) can have deleterious effects on patients outcomes. Besides, the aggravation of lung injury should also be taken into consideration when applied to patients exhibiting high respiratory drive. Nonetheless, NIV has potential for wide applications in various clinical situations such as facilitation of ventilator weaning, post-operative respiratory failure, or palliative treatment.Discussion and Conclusion: In addition to the strong evidence in patients with acute respiratory failure due to COPD or acute pulmonary edema, the NIV treatment can be potentially used for various clinical conditions. However, compared to European countries, the prevalence of NIV use continues to remain lower in South Korea. Nevertheless, when applied in appropriately selected patients in a timely manner, NIV treatment can be associated with improved patient outcomes.