Outcomes of noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease in the United States, 1998-2008

Construction and Validation of an Early Warning Model for Predicting the 28-Day Mortality in Sepsis Patients with Chronic Obstructive Pulmonary Disease

Background

In the intensive care unit (ICU), approximately 45.6% of patients diagnosed with chronic obstructive pulmonary disease (COPD) also presented with sepsis, and this cohort exhibited a significantly higher 28-day mortality rate compared to sepsis patients without COPD (23.6% versus 16.4%). A novel nomogram is necessary to predict the risk of mortality within 28 days for sepsis patients with COPD.

Methods

Clinical data from 501 sepsis patients with COPD were sourced from the MIMIC-IV database. These data were randomly allocated into a training cohort and a validation cohort in a 3:1 ratio. Independent predictors of 28-day mortality were identified through both univariate and multivariate logistic regression analyses. Subsequently, a nomogram model was developed, and its performance was assessed using receiver operating characteristic (ROC) curve analysis, calibration plots, and decision curve analysis.

Results

The 28-day mortality rates in the training and validation cohorts were 32.7% and 27.2%, respectively. Multivariate regression analysis identified age, heart rate (HR), respiratory rate (RR), blood urea nitrogen (BUN), creatinine (Cr), lactate levels, pH, and urine output as independent risk factors for 28-day mortality in sepsis patients with COPD. Furthermore, the nomogram demonstrated superior predictive performance, with an area under the curve (AUC) of 0.784 for the training group and 0.689 for the validation group.

Conclusion

This nomogram integrates laboratory indicators pertinent to the patient's metabolic status, hypoxia status, and organ function, thereby enhancing the accuracy of early prediction of 28-day mortality in sepsis patients with COPD. Additionally, the model's comparative advantage over existing scoring systems (eg, SOFA) would enhance its impact. Our findings hold substantial implications for early prognostic assessment and clinical decision-making in this patient population. Therefore, earlier diagnosis within 24 hours of admission and proper identification of high-risk patients may reduce disease-related mortality by promoting timely treatment.

Use of Noninvasive vs Invasive Ventilation for Patients Hospitalized With Acute Exacerbation of COPD, 2010 to 2019

BACKGROUND

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) contribute to morbidity and mortality. Noninvasive ventilation (NIV), a resource-intensive intervention, decreases mortality and the need for invasive mechanical ventilation.

OBJECTIVE

To study NIV and mechanical ventilation use, NIV failure, and hospital NIV case volumes for inpatients with AECOPD from 2010 to 2019.

METHODS

This retrospective cohort study used the Nationwide Readmissions Database (2010-2019) for adults (≥40 years old) hospitalized for AECOPD. Rates of NIV and mechanical ventilation use and NIV failure were compared per year. Multivariable hierarchical regression models were used. Hospital case volumes of NIV use (overall and for patients with AECOPD) were compared across years.

RESULTS

Patients with AECOPD accounted for 3.35% of admissions in 2010 and 3.20% in 2019. Risk-adjusted rate (95% CI) of mechanical ventilation use decreased from 6.0% (5.6%-6.4%) to 4.5% (4.2%-4.8%); NIV use increased from 6.2% (5.6%-6.9%) to 10.9% (9.9%-12.0%). Noninvasive ventilation failure rate (95% CI) decreased from 7.8% (6.9%-8.7%) to 5.6% (5.0%-6.2%). Mean (SD) hospital case volume for NIV increased overall from 207.3 (237.0) in 2010 to 360.4 (447.4) in 2019 (P < .001); for patients with AECOPD, from 39.5 (37.8) to 79.0 (78.7) (P < .001).

CONCLUSIONS

From 2010 to 2019, mechanical ventilation use and NIV failure decreased; NIV use and hospital NIV case volumes increased. These results indicate greater need for monitored beds, equipment, and trained staff.

Short- and long-term outcomes of pulmonary emphysema patients on mechanical ventilation admitted to the intensive care unit for acute respiratory failure: A retrospective observational study

INTRODUCTION

Acute respiratory failure is a leading cause of admission to the intensive care unit (ICU), with mortality rates remaining stagnant despite advances in resuscitation techniques. Comorbidities, notably chronic obstructive pulmonary disease, significantly impact ICU patient outcomes. Pulmonary emphysema, commonly associated with chronic obstructive pulmonary disease, poses a significant risk, yet its influence on ICU mortality remains understudied.

OBJECTIVES

The aim of this study was to assess the short- and long-term outcomes of ICU patients with pulmonary emphysema requiring mechanical ventilation for acute respiratory failure, evaluating the impact of emphysema severity.

METHODS

A single-centre retrospective cohort study was conducted from 2015 to 2021. Patients with pulmonary emphysema requiring invasive ventilation were included. Emphysema severity was assessed using chest computed tomography scans. Data on mortality, length of stay, and ventilator-free days were collected. Statistical analyses were performed to identify factors associated with outcomes.

RESULTS

Of the 89 included patients, 31.5% died during their ICU stay, with a 39.3% mortality within 12 months postdischarge. Emphysema severity did not significantly correlate with mortality or ventilator-free days. Chronic heart failure emerged as a significant predictor of ICU and in-hospital mortality.

CONCLUSIONS

Emphysema severity does not appear to independently affect mortality in intubated ICU patients with acute respiratory failure. However, mortality rates remain high, warranting further investigation into contributing factors. Our findings underline the complexity of managing critically ill patients with pulmonary emphysema and emphasise the need for comprehensive patient assessment and personalised treatment approaches.

Analyzing Clinical Parameters and Bacterial Profiles to Uncover the COPD Exacerbations: A Focus on Intensive Care Unit Challenges

Background and Objectives: Chronic obstructive pulmonary disease (COPD) poses a significant healthcare challenge worldwide, frequently leading to exacerbations necessitating intensive care unit admissions for potentially life-threatening complications. We aimed to investigate correlations between laboratory parameters, bacteriological agents, ventilation mode, and survival rates among COPD patients admitted to the ICU. Materials and Methods: Data were collected from the Pulmonology Department of Mures Clinical County Hospital, Romania, from 1 January 2022 to 30 October 2023. Eighty-four COPD patients required ICU transfer, except for concurrent SARS-CoV-2 infections. Results: Ventilation modes exhibited a significant correlation with specific bacteriological agents, orotracheal intubation being more prevalent in infections with Acinetobacter baumanii, Staphylococcus aureus, and Streptococcus pneumoniae (p < 0.001). Negative cultures were predominantly found in patients managed with non-invasive ventilation. Laboratory parameters revealed an association between elevated white blood cell counts and bacteriological superinfection, particularly with Escherichia coli (p < 0.001). Different bacteriological agents had different survival rates. Patients infected with Acinetobacter baumanii exhibited the highest mortality rate, while those with Staphylococcus aureus had the lowest (p < 0.01). Conclusions: The importance of prompt evaluation of laboratory parameters and bacteriological findings is underscored by these findings, particularly in ICU settings where ventilation and bacteriological profiles influence patient outcomes. The identification of elevated WBC counts is a marker of bacterial superinfection. The association between specific bacterial agents and ventilation modes highlights the importance of tailored treatment based on microbial profiles. These insights can be applied to refine treatment protocols and enhance survival rates in severe COPD exacerbations that require ICU management.

Diaphragmatic ultrasonographic evaluation as an assessment guide for predicting noninvasive ventilation failure in acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Dynamic hyperinflation in severe acute exacerbation of chronic obstructive pulmonary disease (AECOPD) leads to diaphragmatic fatigue and causes acute respiratory failure. Ultrasound is reliable for evaluating diaphragmatic function. In this study, we aimed to assess the ability of diaphragmatic ultrasound to predict noninvasive ventilation (NIV) failure.

METHODS

This prospective single-center observational cohort study was performed on patients with AECOPD who required NIV in the emergency department between October 1, 2020, and September 30, 2022, at a tertiary healthcare center. The diaphragmatic ultrasound was measured using diaphragmatic excursion (DE) before applying NIV and diaphragmatic thickening fraction (DTF) during NIV use for 2 h. The area under the receiver-operating characteristic (AUROC) curves analysis and multivariable logistic regression was performed to assess the ability of diaphragmatic ultrasound to predict NIV failure in 48 h.

RESULTS

111 patients were included in this study. DTF was an independent variable associated with NIV failure, with an adjusted odds ratio of 0.91 (95 % confidence interval [CI] 0.85-0.98), with a p-value of 0.009. DE and DTF had AUROC of 0.905 (95 % CI 0.835-0.975) and 0.940 (95 % CI 0.894-0.986), respectively, to predict NIV failure within 48 h. The lower DE and DTF increased the probability of NIV failure. The cutoff value of the DTF was 20 %, with a sensitivity of 92.0 % (95 % CI 74.0 % - 99.0 %) and a specificity of 93.0 % (95 % CI 85.4 % - 97.4 %) and the cutoff of the DE was 1.2 cm, with a sensitivity of 88.0 % (95 % CI 68.8 % - 97.5 %) and a specificity of 84.9 % (95 % CI 75.5 % - 91.7 %).

CONCLUSION

Diaphragmatic ultrasound, especially DTF at 2 h during NIV use, is a validated tool for predicting NIV failure in patients with AECOPD. Early detection of diaphragmatic dysfunction with diaphragmatic ultrasound in AECOPD with NIV could help identify high-risk patients and guide clinical decisions. However, further benefits from its implementation in management are required.

Management of Asthma and COPD Exacerbations in Adults in the ICU

Severe, life-threatening asthma and COPD exacerbations are managed commonly in the ICU and are associated with significant morbidity and mortality. It is important to understand the commonalities and differences in the diagnosis and management of these obstructive lung diseases to improve patient outcomes via evidence-based care. In this review, we first outline triggers of acute asthma and COPD exacerbations and an initial diagnostic evaluation and severity assessment. We then review the pathophysiologic features of asthma and COPD exacerbations and create a framework for the management of exacerbations in critically ill adult patients aimed at reducing airway inflammation, reversing bronchospasm, and, in severe cases, supporting patients with mechanical ventilation or advanced therapies until clinical improvement is achieved.

A worldwide assessment of the mechanical ventilation in patients with acute exacerbations of chronic obstructive pulmonary disease. Analysis of the VENTILAGROUP over time. A retrospective, multicenter study

BACKGROUND

The trend over time and across different geographical areas of outcomes and management with noninvasive ventilation or invasive mechanical ventilation in patients admitted for acute exacerbations of chronic obstructive pulmonary disease and treated with ventilatory support is unknown. The purpose of this study was to describe outcomes and identify variables associated with survival for patients admitted to an intensive care unit (ICU) with acute exacerbation of chronic obstructive pulmonary disease [aeCOPD] who received noninvasive or invasive mechanical ventilation worldwide.

METHODS

Retrospective, multi-national, and multicenter studies, including four observational cohort studies, were carried out in 1998, 2004, 2010, and 2016 for the VENTILAGROUP following the same methodology.

RESULTS

A total of 1,848 patients from 1,253 ICUs in 38 countries admitted for aeCOPD and need of ventilatory support were identified in the four study cohorts and included in the study. The overall incidence of aeCOPD as a cause for ventilatory support at ICU admission significantly decreased over time and varied widely according to the gross national income. The mortality of patients admitted to ICU for aeCOPD and ventilatory support significantly decreased over time regardless of the geographical area and gross national income; however, there is a remarkable variability in ICU mortality according to geographical area and gross national income. The use of NPPV as the first attempt at ventilatory support has significantly increased over time, with a parallel reduction of invasive mechanical ventilation regardless of gross national income.

CONCLUSION

In this worldwide observational study, including four sequential cohorts of patients over 18 years from 1998 to 2016, the mortality of patients admitted to ICU for aeCOPD and ventilatory support significantly decreased regardless of the geographical area and gross national income. Future research will need to investigate the reason for the remarkable variability in ICU mortality according to the geographical area, gross national income, and methods to select patients for the appropriate ventilatory support.

Effect of High-Intensity vs Low-Intensity Noninvasive Positive Pressure Ventilation on the Need for Endotracheal Intubation in Patients With an Acute Exacerbation of Chronic Obstructive Pulmonary Disease: The HAPPEN Randomized Clinical Trial

Importance

The effect of high-intensity noninvasive positive pressure ventilation (NPPV) on the need for endotracheal intubation in patients with an acute exacerbation of chronic obstructive pulmonary disease (COPD) is unknown.

Objective

To determine whether the use of high-intensity NPPV vs low-intensity NPPV reduces the need for endotracheal intubation in patients with an acute exacerbation of COPD and hypercapnia.

Design, Setting, and Participants

Randomized clinical trial conducted at 30 general respiratory non-intensive care unit wards of Chinese hospitals from January 3, 2019, to January 31, 2022; the last 90-day follow-up was on April 22, 2022. The included patients had an acute exacerbation of COPD and a Paco2 level greater than 45 mm Hg after receiving 6 hours of low-intensity NPPV.

Interventions

Patients were randomized 1:1 to receive high-intensity NPPV with inspiratory positive airway pressure that was adjusted to obtain a tidal volume 10 mL/kg to 15 mL/kg of predicted body weight (n = 147) or to continue receiving low-intensity NPPV with inspiratory positive airway pressure that was adjusted to obtain a tidal volume of 6 mL/kg to 10 mL/kg of predicted body weight (n = 153). Patients in the low-intensity NPPV group who met the prespecified criteria for the need for endotracheal intubation were allowed to crossover to high-intensity NPPV.

Main Outcomes and Measures

The primary outcome was the need for endotracheal intubation during hospitalization, which was defined by prespecified criteria. There were 15 prespecified secondary outcomes, including endotracheal intubation.

Results

The trial was terminated by the data and safety monitoring board and the trial steering committee after an interim analysis of the first 300 patients. Among the 300 patients who completed the trial (mean age, 73 years [SD, 10 years]; 68% were men), all were included in the analysis. The primary outcome of meeting prespecified criteria for the need for endotracheal intubation occurred in 7 of 147 patients (4.8%) in the high-intensity NPPV group vs 21 of 153 (13.7%) in the low-intensity NPPV group (absolute difference, -9.0% [95% CI, -15.4% to -2.5%], 1-sided P = .004). However, rates of endotracheal intubation did not significantly differ between groups (3.4% [5/147] in the high-intensity NPPV group vs 3.9% [6/153] in the low-intensity NPPV group; absolute difference, -0.5% [95% CI, -4.8% to 3.7%], P = .81). Abdominal distension occurred more frequently in the high-intensity NPPV group (37.4% [55/147]) compared with the low-intensity NPPV group (25.5% [39/153]).

Conclusions and Relevance

Patients with COPD and persistent hypercapnia in the high-intensity NPPV group (vs patients in the low-intensity NPPV group) were significantly less likely to meet criteria for the need for endotracheal intubation; however, patients in the low-intensity NPPV group were allowed to crossover to high-intensity NPPV, and the between-group rate of endotracheal intubation was not significantly different.

Trial Registration

ClinicalTrials.gov Identifier: NCT02985918.

Analysis of pH, electrolytes and non-invasive respiratory support in COPD with elevated CO2

The contributions of pH balance and electrolytes among patients with chronic obstructive pulmonary disease (COPD) experiencing hypercapnic exacerbations requiring non-invasive ventilation (NIV) are of interest. Hence, we used samples from 70 patients admitted in a tertiary care hospital from January to June 2023. The main variable analyzed was arterial blood gas data and serum electrolyte levels. A positive correlation between bicarbonate levels and PCO2 was found, with p < 0.01 and r = 0.74, indicating metabolic compensation for respiratory acidosis. NIV was required in the majority of patients: in 64.3%, values were higher for both PCO2 (52.3 ± 7.1 mmHg vs. 39.6 ± 4.3 mmHg) and bicarbonate levels (32.4 ± 4.8m Eq/L vs. 26.1 ± 3.1 m Eq/L; p < 0.01) in the NIV group. Thus, data highlights the role of monitoring PCO2 and bicarbonate in guiding the use of NIV and in a more secondary role to hypercapnia disturbances in electrolytes.

Noninvasive vs invasive respiratory support for patients with acute hypoxemic respiratory failure

BACKGROUND

Noninvasive respiratory support modalities are common alternatives to mechanical ventilation in acute hypoxemic respiratory failure. However, studies historically compare noninvasive respiratory support to conventional oxygen rather than mechanical ventilation. In this study, we compared outcomes in patients with acute hypoxemic respiratory failure treated initially with noninvasive respiratory support to patients treated initially with invasive mechanical ventilation.

METHODS

This is a retrospective observational cohort study between January 1, 2018 and December 31, 2019 at a large healthcare network in the United States. We used a validated phenotyping algorithm to classify adult patients (≥18 years) with eligible International Classification of Diseases codes into two cohorts: those treated initially with noninvasive respiratory support or those treated invasive mechanical ventilation only. The primary outcome was time-to-in-hospital death analyzed using an inverse probability of treatment weighted Cox model adjusted for potential confounders. Secondary outcomes included time-to-hospital discharge alive. A secondary analysis was conducted to examine potential differences between noninvasive positive pressure ventilation and nasal high flow.

RESULTS

During the study period, 3177 patients met inclusion criteria (40% invasive mechanical ventilation, 60% noninvasive respiratory support). Initial noninvasive respiratory support was not associated with a decreased hazard of in-hospital death (HR: 0.65, 95% CI: 0.35-1.2), but was associated with an increased hazard of discharge alive (HR: 2.26, 95% CI: 1.92-2.67). In-hospital death varied between the nasal high flow (HR 3.27, 95% CI: 1.43-7.45) and noninvasive positive pressure ventilation (HR 0.52, 95% CI 0.25-1.07), but both were associated with increased likelihood of discharge alive (nasal high flow HR 2.12, 95 CI: 1.25-3.57; noninvasive positive pressure ventilation HR 2.29, 95% CI: 1.92-2.74).

CONCLUSIONS

These data show that noninvasive respiratory support is not associated with reduced hazards of in-hospital death but is associated with hospital discharge alive.

Using the ROX Index to Predict Treatment Outcome for High-Flow Nasal Cannula and/or Noninvasive Ventilation in Patients With COPD Exacerbations

BACKGROUND

The ratio of oxygen saturation index (ROX index; or SpO2 /FIO2 /breathing frequency) has been shown to predict risk of intubation after high-flow nasal cannula (HFNC) support among adults with acute hypoxemic respiratory failure primarily due to pneumonia. However, its predictive value for other subtypes of respiratory failure is unknown. This study investigated whether the ROX index predicts liberation from HFNC or noninvasive ventilation (NIV), intubation with mechanical ventilation, or death in adults admitted for respiratory failure due to an exacerbation of COPD.

METHODS

We performed a retrospective study of 260 adults hospitalized with a COPD exacerbation and treated with HFNC and/or NIV (continuous or bi-level). ROX index scores were collected at treatment initiation and predefined time intervals throughout HFNC and/or NIV treatment or until the subject was intubated or died. A ROX index score of ≥ 4.88 was applied to the cohort to determine if the same score would perform similarly in this different cohort. Accuracy of the ROX index was determined by calculating the area under the receiver operator curve.

RESULTS

A total of 47 subjects (18%) required invasive mechanical ventilation or died while on HFNC/NIV. The ROX index at treatment initiation, 1 h, and 6 h demonstrated the best prediction accuracy for avoidance of invasive mechanical ventilation or death (area under the receiver operator curve 0.73 [95% CI 0.66-0.80], 0.72 [95% CI 0.65-0.79], and 0.72 [95% CI 0.63-0.82], respectively). The optimal cutoff value for sensitivity (Sn) and specificity (Sp) was a ROX index score > 6.88 (sensitivity 62%, specificity 57%).

CONCLUSIONS

The ROX index applied to adults with COPD exacerbations treated with HFNC and/or NIV required higher scores to achieve similar prediction of low risk of treatment failure when compared to subjects with hypoxemic respiratory failure/pneumonia. ROX scores < 4.88 did not accurately predict intubation or death.

[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.

Is there still a place for ECCO2R?

The therapeutic target of extracorporeal carbon dioxide removal (ECCO2R) is the elimination of carbon dioxide (CO2) from the blood across a gas exchange membrane without influencing oxygenation to a clinically relevant extent. In acute respiratory distress syndrome (ARDS), ECCO2R has been used to reduce tidal volume, plateau pressure, and driving pressure ("ultraprotective ventilation"). Despite achieving these goals, no benefits in outcome could be shown. Thus, in ARDS, the use of ECCO2R to achieve ultraprotective ventilation can no longer be recommended. Furthermore, ECCO2R has also been used to avoid intubation or facilitate weaning in obstructive lung failure as well as to avoid mechanical ventilation in patients during bridging to lung transplantation. Although these goals can be achieved in many patients, the effects on outcome still remain unclear due to lack of evidence. Despite involving less blood flow, smaller cannulas, and smaller gas exchange membranes compared with extracorporeal membrane oxygenation, ECCO2R bears a comparable risk of complications, especially bleeding. Trials to define indications and analyze the risk-benefit balance are needed prior to implementation of ECCO2R as a standard therapy. Consequently, until then, ECCO2R should be used in clinical studies and experienced centers only. This article is freely available.

Extracorporeal Carbon Dioxide Removal With the Hemolung in Patients With Acute-on-Chronic Respiratory Failure: A Multicenter Retrospective Cohort Study

Extracorporeal carbon dioxide removal (ECCO2R) devices are increasingly used in treating acute-on-chronic respiratory failure caused by chronic lung diseases. There are no large studies that investigated safety, efficacy, and the independent association of prognostic variables to survival that could define the role of ECCO2R devices in such patients. This multicenter, multinational, retrospective study investigated the efficacy, safety of a single ECCO2R device (Hemolung) in patients with acute on chronic respiratory failure and identified variables independently associated with intensive care unit (ICU) survival. The primary outcome was improvement in blood gasses with the use of Hemolung. Secondary outcomes included reduction in tidal volume, respiratory rate, minute ventilation, survival to ICU discharge, and complication profile. Multivariable regression analysis was used to identify variables that are independently associated with ICU survival. A total of 62 patients were included. There was a significant improvement in pH and partial pressure of carbon dioxide in arterial blood (PaCO2) along with a reduction in respiratory rate, tidal volume, and minute ventilation with Hemolung therapy. The complication profile did not differ between survivors and nonsurvivors. Multivariable analysis identified the duration of Hemolung therapy to be independently associated with survival to ICU discharge (adjusted odds ratio = 1.21; 95% confidence interval [CI] = 1.040-1.518; p = 0.01).

Home Noninvasive Ventilation in COPD

Evidence is increasing that long-term noninvasive ventilation (LTNIV) can improve outcomes in individuals with severe, hypercapnic COPD. Although the evidence remains unclear in some aspects, LTNIV seems to be able to improve patient-related and physiologic outcomes like dyspnea, FEV1 and partial pressure of carbon dioxide (Pco2) and also to reduce rehospitalizations and mortality. Efficacy generally is associated with reduction in Pco2. To achieve this, an adequate interface (mask) is essential, as are appropriate ventilation settings that target the specific respiratory physiologic features of COPD. This will ensure comfort, synchrony, and adherence that will result in physiologic improvements. This article briefly reviews the newest evidence and current guidelines on LTNIV in severe COPD. It describes an actual patient who benefitted from the therapy. Finally, it provides strategies for initiating and optimizing this LTNIV in COPD, discussing high-pressure noninvasive ventilation, optimization of triggering, and control of inspiratory time. As demand increases, clinicians will need to be familiar with this therapy to reap its benefits, because inadequately adjusted LTNIV will not be tolerated or effective.

Noninvasive respiratory support in the emergency department: Controversies and state-of-the-art recommendations

Acute respiratory failure is a common reason for emergency department visits and hospital admissions. Diverse underlying physiologic abnormalities lead to unique aspects about the most common causes of acute respiratory failure: acute decompensated heart failure, acute exacerbation of chronic obstructive pulmonary disease, and acute de novo hypoxemic respiratory failure. Noninvasive respiratory support strategies are increasingly used methods to support work of breathing and improve gas exchange abnormalities to improve outcomes relative to conventional oxygen therapy or invasive mechanical ventilation. Noninvasive respiratory support includes noninvasive positive pressure ventilation and nasal high flow, each with unique physiologic mechanisms. This paper will review the physiology of respiratory failure and noninvasive respiratory support modalities and offer data and guideline-driven recommendations in the context of key clinical controversies.

Respiratory Infection Triggering Severe Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Background

Data are scarce on respiratory infections during severe acute exacerbation of chronic obstructive pulmonary disease (COPD). This study aimed to investigate respiratory infection patterns in the intensive care unit (ICU) and identify variables associated with infection type and patient outcome.

Methods

A retrospective, single-centre cohort study. All patients admitted (2015-2021) to our ICU for severe acute exacerbation of COPD were included. Logistic multivariable regression analysis was performed to predict factors associated with infection and assess the association between infection and outcome.

Results

We included 473 patients: 288 (60.9%) had respiratory infection and 139 (29.4%) required invasive mechanical ventilation. Eighty-nine (30.9%) had viral, 81 (28.1%) bacterial, 34 (11.8%) mixed, and 84 (29.2%) undocumented infections. Forty-seven (9.9%) patients died in the ICU and 67 (14.2%) in hospital. Factors associated with respiratory infection were temperature (odds ratio [+1°C]=1.43, P=0.008) and blood neutrophils (1.07, P=0.002). Male sex (2.21, P=0.02) and blood neutrophils were associated with bacterial infection (1.06, P=0.04). In a multivariable analysis, pneumonia (cause-specific hazard=1.75, P=0.005), respiratory rate (1.17, P=0.04), arterial partial pressure of carbon-dioxide (1.08, P=0.04), and lactate (1.14, P=0.02) were associated with the need for invasive MV. Age (1.03, P=0.03), immunodeficiency (1.96, P=0.02), and altered performance status (1.78, P=0.002) were associated with hospital mortality.

Conclusions

Respiratory infections, 39.9% of which were bacterial, were the main cause of severe acute exacerbation of COPD. Body temperature and blood neutrophils were single markers of infection. Pneumonia was associated with the need for invasive mechanical ventilation but not with hospital mortality, as opposed to age, immunodeficiency, and altered performance status.

A Novel Scale to Assess Humidification during Noninvasive Ventilation: A Prospective Observational Study

Objective

To develop a novel scale to assess humidification during noninvasive ventilation (NIV).

Methods

This study was performed in an ICU of a teaching hospital. Three ICU practitioners with more than 10 years of clinical experience developed an oral humidification scale with a range of 1-4 points. Each studied the current literature on humidification and examined 50 images of mouths of NIV patients with different levels of humidification. Then, through discussion, a consensus scale was developed. Next, 10 practitioners and 33 NIV patients were recruited to validate the scale. Finally, the patients rated the dryness of their mouths using the 1-4 visual scale just after the practitioners' assessment. Talking and discussion were forbidden during the assessment, and the scorers were blinded to each other.

Results

We performed 36 assessments in 33 NIV patients. Three patients were assessed twice each more than 2 days apart. The interitem correlation coefficients between the 10 practitioners ranged from 0.748 to 0.917. Fleiss's kappa statistic was 0.516, indicating moderate agreement among practitioners. Of the 33 patients, 5 (15%) were unable to make an assessment using the 1-4 visual scale. Among the remainder, 55.7% provided scores that matched those given by the practitioners; 13.7% of scores were 1 point higher than that rated by the practitioners, and 20.7% were 1 point lower. Only 10% were beyond a 1-point difference. The kappa coefficient was 0.483 between patients and practitioners.

Conclusions

The oral humidification scale showed moderate agreement between practitioners. It was also highly accurate in reflecting the level of humidification assessed by patients.

Noninvasive vs Invasive Respiratory Support for Patients with Acute Hypoxemic Respiratory Failure

Rationale

Noninvasive respiratory support modalities are common alternatives to mechanical ventilation for patients with early acute hypoxemic respiratory failure. These modalities include noninvasive positive pressure ventilation, using either continuous or bilevel positive airway pressure, and nasal high flow using a high flow nasal cannula system. However, outcomes data historically compare noninvasive respiratory support to conventional oxygen rather than to mechanical ventilation.

Objectives

The goal of this study was to compare the outcomes of in-hospital death and alive discharge in patients with acute hypoxemic respiratory failure when treated initially with noninvasive respiratory support compared to patients treated initially with invasive mechanical ventilation.

Methods

We used a validated phenotyping algorithm to classify all patients with eligible International Classification of Diseases codes at a large healthcare network between January 1, 2018 and December 31, 2019 into noninvasive respiratory support and invasive mechanical ventilation cohorts. The primary outcome was time-to-in-hospital death analyzed using an inverse probability of treatment weighted Cox model adjusted for potential confounders, with estimated cumulative incidence curves. Secondary outcomes included time-to-hospital discharge alive. A secondary analysis was conducted to examine potential differences between noninvasive positive pressure ventilation and nasal high flow.

Results

During the study period, 3177 patients met inclusion criteria (40% invasive mechanical ventilation, 60% noninvasive respiratory support). Initial noninvasive respiratory support was not associated with a decreased hazard of in-hospital death (HR: 0.65, 95% CI: 0.35 - 1.2), but was associated with an increased hazard of discharge alive (HR: 2.26, 95% CI: 1.92 - 2.67). In-hospital death varied between the nasal high flow (HR 3.27, 95% CI: 1.43 - 7.45) and noninvasive positive pressure ventilation (HR 0.52, 95% CI 0.25 - 1.07), but both were associated with increased likelihood of discharge alive (nasal high flow HR 2.12, 95 CI: 1.25 - 3.57; noninvasive positive pressure ventilation HR 2.29, 95% CI: 1.92 - 2.74).

Conclusion

These observational data from a large healthcare network show that noninvasive respiratory support is not associated with reduced hazards of in-hospital death but is associated with hospital discharge alive. There are also potential differences between the noninvasive respiratory support modalities.

High-flow nasal cannula may prolong the length of hospital stay in patients with hypercapnic acute COPD exacerbation

BACKGROUND

High-flow nasal cannula (HFNC) is increasingly used in patients with acute exacerbation of COPD (AECOPD). We aimed to confirm whether the baseline bicarbonate is an independent predictor of outcomes in patients with hypercapnic AECOPD receiving HFNC.

METHODS

This was a secondary analysis of a multicentre randomised trial that enrolled 330 patients with non-acidotic hypercapnic AECOPD supported by HFNC or conventional oxygen treatment (COT). We compared the length of stay (LOS) in hospital and the rate of non-invasive positive pressure ventilation (NPPV) use according to baseline bicarbonate levels using the log-rank test or Cox proportional hazard model.

RESULTS

In the high bicarbonate subgroup (n = 165, bicarbonate 35.0[33.3-37.9] mmol/L, partial pressure of arterial carbon dioxide [PaCO2] 56.8[52.0-62.8] mmHg), patients supported by HFNC had a remarkably prolonged LOS in hospital when compared to COT (HR 1.59[1.16-2.17], p = 0.004), whereas patients in the low bicarbonate subgroup (n = 165, bicarbonate 28.8[27.0-30.4] mmol/L, PaCO2 48.0[46.0-50.0] mmHg) had a comparable LOS in hospital regardless of respiratory support modalities. The rate of NPPV use in patients with high baseline bicarbonate level was significantly higher than that in patients with low baseline bicarbonate level (19.4 % vs. 3.0 %, p < 0.0001). Patients with high bicarbonate level in HFNC group had a lower rate of NPPV use compared to COT group (15.4 % vs. 23.0 %, p = 0.217).

CONCLUSIONS

Among patients with non-acidotic hypercapnic AECOPD with high baseline bicarbonate level, HFNC is significantly associated with a prolonged LOS in hospital, which may be due to the reduced escalation of NPPV treatment.

TRIAL REGISTRATION

clinicaltrials.gov (NCT03003559).

Current knowledge gaps in extracorporeal respiratory support

Extracorporeal life support (ECLS) for acute respiratory failure encompasses veno-venous extracorporeal membrane oxygenation (V-V ECMO) and extracorporeal carbon dioxide removal (ECCO2R). V-V ECMO is primarily used to treat severe acute respiratory distress syndrome (ARDS), characterized by life-threatening hypoxemia or ventilatory insufficiency with conventional protective settings. It employs an artificial lung with high blood flows, and allows improvement in gas exchange, correction of hypoxemia, and reduction of the workload on the native lung. On the other hand, ECCO2R focuses on carbon dioxide removal and ventilatory load reduction ("ultra-protective ventilation") in moderate ARDS, or in avoiding pump failure in acute exacerbated chronic obstructive pulmonary disease. Clinical indications for V-V ECLS are tailored to individual patients, as there are no absolute contraindications. However, determining the ideal timing for initiating extracorporeal respiratory support remains uncertain. Current ECLS equipment faces issues like size and durability. Innovations include intravascular lung assist devices (ILADs) and pumpless devices, though they come with their own challenges. Efficient gas exchange relies on modern oxygenators using hollow fiber designs, but research is exploring microfluidic technology to improve oxygenator size, thrombogenicity, and blood flow capacity. Coagulation management during V-V ECLS is crucial due to common bleeding and thrombosis complications; indeed, anticoagulation strategies and monitoring systems require improvement, while surface coatings and new materials show promise. Moreover, pharmacokinetics during ECLS significantly impact antibiotic therapy, necessitating therapeutic drug monitoring for precise dosing. Managing native lung ventilation during V-V ECMO remains complex, requiring a careful balance between benefits and potential risks for spontaneously breathing patients. Moreover, weaning from V-V ECMO is recognized as an area of relevant uncertainty, requiring further research. In the last decade, the concept of Extracorporeal Organ Support (ECOS) for patients with multiple organ dysfunction has emerged, combining ECLS with other organ support therapies to provide a more holistic approach for critically ill patients. In this review, we aim at providing an in-depth overview of V-V ECMO and ECCO2R, addressing various aspects of their use, challenges, and potential future directions in research and development.

The Association between Non-Invasive Ventilation and the Rate of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) has significant effects on patient outcomes, including prolonging the duration of both mechanical ventilation and stay in the intensive care unit (ICU). The aim of this study was to assess the association between non-invasive ventilation/oxygenation (NIVO) prior to intubation and the rate of subsequent VAP. This was a multicenter retrospective cohort study of adult patients who were admitted to the medical ICU from three tertiary care academic centers in three distinct regions. NIVO was defined as continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), or high-flow nasal cannula (HFNC) for any duration during the hospitalization prior to intubation. The primary outcome variable was VAP association with NIVO. A total of 17,302 patients were included. VAP developed in 2.6% of the patients (444/17,302), 2.3% (285/12,518) of patients among those who did not have NIVO, 1.6% (30/1879) of patients who had CPAP, 2.5% (17/690) of patients who had HFNC, 8.1% (16/197) of patients who had BiPAP, and 4.8% (96/2018) of patients who had a combination of NIVO types. Compared to those who did not have NIVO, VAP was more likely to develop among those who had BiPAP (adj OR 3.11, 95% CI 1.80-5.37, p < 0.001) or a combination of NIVO types (adj OR 1.91, 95% CI 1.49-2.44, p < 0.001) after adjusting for patient demographics and comorbidities. The use of BiPAP or a combination of NIVO types significantly increases the odds of developing VAP once receiving IMV.

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.

Modified Respiratory Rate Oxygenation Index: An Early Warning Index for the Need of Intubation in COVID-19 Patients with High-Flow Nasal Cannula Therapy

BACKGROUND

High-flow nasal cannula oxygen therapy (HFNC) is recommended for patients with COVID-19. However, the increasing use of HFNC brings a risk of delayed intubation. The optimal timing of switching from HFNC to invasive mechanical ventilation (IMV) remains unclear. An effective predictor is needed to assist in deciding on the timing of intubation. Respiratory rate and oxygenation (ROX) index, defined as (SpO2/FiO2) / respiratory rate, has already shown good diagnostic accuracy. Modified ROX (mROX) index, defined as (PaO2 /FiO2) / respiratory rate, might be better than the ROX index in predicting HFNC failure.

OBJECTIVE

The aim was to evaluate the predictive value of mROX for HFNC failure in patients with COVID-19.

METHODS

Severe or critical patients with COVID-19 treated with HFNC were enrolled in two clinical centers. Laboratory indicators, respiratory parameters, and mROX index at 0 h and 2 h after initial HFNC were collected. Based on the need for IMV after HFNC initiation, the patients were divided into an HFNC failure group and an HFNC success group. The predictive value of mROX index for IMV was evaluated by the area under the receiver operating characteristic curve (AUROC) and logistic regression analysis. We performed Kaplan-Meier survival analysis using the log-rank test.

RESULTS

Sixty patients with COVID-19 (mean ± SD age, 62.8 ± 14.1 years; 42 patients were male) receiving HFNC were evaluated, including 18 critical and 42 severe cases. A total of 33 patients had hypertension; 14 had diabetes; 17 had chronic cardiac disease; 11 had chronic lung disease; 13 had chronic kidney disease; and 17 had a history of stroke. The AUROC of mROX index at 2 h was superior to that of other respiratory parameters to predict the need for IMV (0.959; p < 0.001). At the mROX index cutoff point of 4.45, predicting HFNC failure reached the optimal threshold, with specificity of 94% and sensitivity of 92%. Logistic regression analysis showed that 2-h mROX index < 4.45 was a protective factor for IMV (odd radio 0.18; 95% CI 0.05-0.64; p = 0.008). In the HFNC failure group, the median time from HFNC to IMV was 22.5 h. The 28-day mortality of the late intubation patients (≥ 22.5 h) was higher than that of the early intubation patients (< 22.5 h) (53.8% vs. 8.3%; p = 0.023).

CONCLUSIONS

mROX at 2 h is a good early warning index of the need for IMV in patients with COVID-19 after HFNC initiation. Early intubation may lead to better survival in patients with 2-h mROX index < 4.45.

Reinforcement Learning Model for Managing Noninvasive Ventilation Switching Policy

Noninvasive ventilation (NIV) has been recognized as a first-line treatment for respiratory failure in patients with chronic obstructive pulmonary disease (COPD) and hypercapnia respiratory failure, which can reduce mortality and burden of intubation. However, during the long-term NIV process, failure to respond to NIV may cause overtreatment or delayed intubation, which is associated with increased mortality or costs. Optimal strategies for switching regime in the course of NIV treatment remain to be explored.For the goal of reducing 28-day mortality of the patients undergoing NIV, Double Dueling Deep Q Network (D3QN) of offline-reinforcement learning algorithm was adopted to develop an optimal regime model for making treatment decisions of discontinuing ventilation, continuing NIV, or intubation. The model was trained and tested using the data from Multi-Parameter Intelligent Monitoring in Intensive Care III (MIMIC-III) and evaluated by the practical strategies. Furthermore, the applicability of the model in majority disease subgroups (Catalogued by International Classification of Diseases, ICD) was investigated. Compared with physician's strategies, the proposed model achieved a higher expected return score (4.25 vs. 2.68) and its recommended treatments reduced the expected mortality from 27.82% to 25.44% in all NIV cases. In particular, for these patients finally received intubation in practice, if the model also supported the regime, it would warn of switching to intubation 13.36 hours earlier than clinicians (8.64 vs. 22 hours after the NIV treatment), granting a 21.7% reduction in estimated mortality. In addition, the model was applicable across various disease groups with distinguished achievement in dealing with respiratory disorders. The proposed model is promising to dynamically provide personalized optimal NIV switching regime for patients undergoing NIV with the potential of improving treatment outcomes.

Predicting Failure of Noninvasive Respiratory Support Using Deep Recurrent Learning

BACKGROUND

Noninvasive respiratory support (NRS) is increasingly used to support patients with acute respiratory failure. However, noninvasive support failure may worsen outcomes compared to primary support with invasive mechanical ventilation. Therefore, there is a need to identify patients where NRS is failing so that treatment can be reassessed and adjusted. The objective of this study was to develop and evaluate 3 recurrent neural network (RNN) models to predict NRS failure.

METHODS

This was a cross-sectional observational study to evaluate the ability of deep RNN models (long short-term memory [LSTM], gated recurrent unit [GRU]), and GRU with trainable decay) to predict failure of NRS. Data were extracted from electronic health records from all adult (≥ 18 y) patient records requiring any type of oxygen therapy or mechanical ventilation between November 1, 2013-September 30, 2020, across 46 ICUs in the Southwest United States in a single health care network. Input variables for each model included serum chloride, creatinine, albumin, breathing frequency, heart rate, SpO2 , FIO2 , arterial oxygen saturation (SaO2 ), and 2 measurements each (point-of-care and laboratory measurement) of PaO2 and partial pressure of arterial oxygen from an arterial blood gas.

RESULTS

Time series data from electronic health records were available for 22,075 subjects. The highest accuracy and area under the receiver operating characteristic curve were for the LSTM model (94.04% and 0.9636, respectively). Accurate predictions were made 12 h after ICU admission, and performance remained high well in advance of NRS failure.

CONCLUSIONS

RNN models using routinely collected time series data can accurately predict NRS failure well before intubation. This lead time may provide an opportunity to intervene to optimize patient outcomes.

Management of Acute Exacerbations of Chronic Obstructive Pulmonary Disease in the ICU: An Observational Study From the OUTCOMEREA Database, 1997-2018

OBJECTIVES

Our aim was to describe changes in the management of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) by ICUs and patient outcomes.

DESIGN

We extracted data from the OutcomeRea database concerning patients admitted for AECOPD between 1997 and 2018. We analyzed trends in the use of ventilatory support, corticosteroid therapy, antibiotic therapy, and patient survival.

SETTING

ICUs at 32 French sites.

PATIENTS

One thousand eight hundred sixteen patients in the database had a diagnosis of AECOPD.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Over time, there was a reduction in the prescription of corticosteroids and antibiotics. In a time-series analysis, these changes in practice were not linked with ICU mortality. The proportion of patients treated with invasive mechanical ventilation (IMV) also gradually declined (from 51% between 1997 and 2002 to 35% between 2013 and 2018) with an association between decrease in IMV use and reduction in ICU mortality in a time series analysis. Rates of noninvasive ventilation (NIV) failure decreased with an increase in NIV use to support weaning from IMV. There was a reduction in the median ICU length of stay (from 8 d in 1997-2002 to 4 d in 2013-2018) and in the median total duration of hospitalization (from 23 d in 1997-2002 to 14 d in 2013-2018). We observed an improvement in prognosis, with decreases in overall hospital mortality (from 24% between 1997 and 2002 to 15% between 2013 and 2018), ICU mortality (from 14% between 1997 and 2002 to 10% between 2013 and 2018), and 90-day mortality (from 41% between 1997 and 2002 to 22% between 2013 and 2018).

CONCLUSIONS

The length of stay and mortality of patients with AECOPD admitted to ICUs has decreased over the last 20 years, with a wider use of NIV and a reduction in antibiotic and corticosteroid prescriptions.

Timing of Treatment Outcomes and Risk Factors for Failure of BPAP in Patients Hospitalized for COPD Exacerbation

BACKGROUND

Patients hospitalized for COPD exacerbation have an increased risk of mortality, particularly among those who fail bi-level positive airway pressure (BPAP) for hypercapnic respiratory failure subsequently requiring invasive mechanical ventilation. Therefore, we sought to investigate the treatment course of BPAP and factors associated with BPAP treatment failure.

METHODS

We performed a retrospective cohort study using real-world evidence to investigate subjects with COPD who were treated with BPAP during a hospitalization for COPD exacerbation. Treatment outcomes were defined within 7 d from BPAP initiation as either failure, persistent, or success. Failure was defined as death or progression to invasive ventilation. Persistent was defined as receiving BPAP during hospital day 7. Success was defined as liberation from BPAP prior to hospital day 7 and not meeting criteria for failure. Unadjusted multinomial logistic regression models were used to examine the association between BPAP treatment outcomes and 17 recipient characteristics.

RESULTS

Among the 427 clinical encounters, 78% were successful, 10% were persistent, and 12% experienced failure. The median time to failure and success was 8 h and 16 h, respectively. Increasing age, body mass index (BMI), bicarbonate level, and creatinine level were significantly associated with either BPAP treatment failure, persistent treatment, or both.

CONCLUSIONS

The first 8 h following initiation of BPAP is a critical time period where patients are at high risk for life-threatening decompensation. Careful consideration should be given to increasing age, BMI, bicarbonate level, and creatinine level as these factors were associated with BPAP treatment failure or persistent treatment.

Factors and Outcomes Associated with Failed Noninvasive Positive Pressure Ventilation in Patients with Acute Respiratory Failure

Background

The decision guild for non-invasive positive pressure ventilation (NPPV) application in acute respiratory failure (ARF) patients still needs to work out.

Methods

Adult patients with acute hypoxemic or hypercapnic respiratory failure were recruited and treated with NPPV or primary invasive mechanical ventilation (IMV). Patients’ characteristic and clinical outcomes were recorded. Logistic regression models were used to estimate the adjusted odds ratio (aOR) and 95% confidence intervals for baseline characteristics and clinical outcomes. Subgroup analyses by reason behind successful NPPV were conducted to ascertain if any difference could influence the outcome.

Results

A total of 4525 ARF patients were recruited in our facility between year 2015 and 2017. After exclusion, 844 IMV patients, 66 patients with failed NPPV, and 74 patients with successful NPPV were enrolled. Statistical analysis showed APACHE II score (aOR = 0.93), time between admission and start NPPV (aOR = 0.92), and P/F ratio (aOR = 1.04) were associated with successful NPPV. When comparing with IMV patients, failed NPPV patients displayed a significantly lower APACHE II score, higher Glasgow Coma Scale, longer length of stay in hospital, longer duration of invasive ventilation, RCW/Home ventilator, and some comorbidities.

Conclusion

APACHE II score, time between admission and start NPPV, and PaO2 can be predictors for successful NPPV. The decision of NPPV application is critical as ARF patients with failed NPPV have various worse outcomes than patients receiving primary IMV.

Predictors of Respiratory Support Use in Emergency Department Patients With COVID-19-Related Respiratory Failure

BACKGROUND

Given the known downstream implications of choice of respiratory support on patient outcomes, all factors influencing these decisions, even those not limited to the patient, warrant close consideration. We examined the effect of emergency department (ED)-specific system factors, such as work load and census, on the use of noninvasive versus invasive respiratory support.

METHODS

We conducted a multi-center retrospective cohort study of all adult subjects with severe COVID-19 requiring an ICU admission from 5 EDs within a single urban health care system. Subject demographics, severity of illness, and the type of respiratory support used were obtained. Using continuous measures of ED census, boarding, and active management, we estimated ED work load for each subjects' ED stay. The subjects were categorized by type(s) of respiratory support used: low-flow oxygen, noninvasive respiratory support (eg, noninvasive ventilation [NIV] and/or high-flow nasal cannula [HFNC]), invasive mechanical ventilation, or invasive mechanical ventilation after trial of NIV/HFNC. We used multivariable logistic regression to examine system factors associated with the type of respiratory support used in the ED.

RESULTS

A total of 634 subjects were included. Of these, 431 (70.0%) were managed on low-flow oxygen alone, 108 (17.0%) on NIV/HFNC, 54 (8.5%) on invasive mechanical ventilation directly, and 41 (6.5%) on NIV/HFNC prior to invasive mechanical ventilation in the ED. Higher severity of illness and underlying lung disease increased the odds of requiring invasive mechanical ventilation compared to low-flow oxygen (odds ratio 1.05 [95% CI 1.03-1.07] and odds ratio 3.47 [95% CI 1.37-8.78], respectively). Older age decreased odds of being on invasive mechanical ventilation compared to low-flow oxygen (odds ratio 0.96 [95% CI 0.94-0.99]). As ED work load increased, the odds for subjects to be managed initially with NIV/HFNC prior to invasive mechanical ventilation increased 6-8-fold.

CONCLUSIONS

High ED work load was associated with higher odds on HFNC/NIV prior to invasive mechanical ventilation.

Physiological effects of high-intensity versus low-intensity noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease: a randomised controlled trial

Background

High-intensity noninvasive positive pressure ventilation (NPPV) is a novel ventilatory approach to maximally decreasing elevated arterial carbon dioxide tension (PaCO₂) toward normocapnia with stepwise up-titration of pressure support. We tested whether high-intensity NPPV is more effective than low-intensity NPPV at decreasing PaCO₂, reducing inspiratory effort, alleviating dyspnoea, improving consciousness, and improving NPPV tolerance in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

In this physiological, randomised controlled trial, we assigned 24 AECOPD patients to undergo either high-intensity NPPV (n = 12) or low-intensity NPPV (n = 12). The primary outcome was PaCO₂ 24 h after randomisation. Secondary outcomes included gas exchange other than PaCO₂ 24 h after randomisation, inspiratory effort, dyspnoea, consciousness, NPPV tolerance, patient–ventilator asynchrony, cardiac function, ventilator-induced lung injury (VILI), and NPPV-related adverse events.

Results

Inspiratory positive airway pressure 24 h after randomisation was significantly higher (28.0 [26.0–28.0] vs. 15.5 [15.0–17.5] cmH₂O; p = 0.000) and NPPV duration within the first 24 h was significantly longer (21.8 ± 2.1 vs. 15.3 ± 4.7 h; p = 0.001) in the high-intensity NPPV group. PaCO₂ 24 h after randomisation decreased to 54.0 ± 11.6 mmHg in the high-intensity NPPV group but only decreased to 67.4 ± 10.6 mmHg in the low-intensity NPPV group (p = 0.008). Inspiratory oesophageal pressure swing, oesophageal pressure–time product (PTPes)/breath, PTPes/min, and PTPes/L were significantly lower in the high-intensity group. Accessory muscle use and dyspnoea score 24 h after randomisation were also significantly lower in that group. No significant between-groups differences were observed in consciousness, NPPV tolerance, patient–ventilator asynchrony, cardiac function, VILI, or NPPV-related adverse events.

Conclusions

High-intensity NPPV is more effective than low-intensity NPPV at decreasing elevated PaCO₂, reducing inspiratory effort, and alleviating dyspnoea in AECOPD patients.

Trial registration: ClinicalTrials.gov (NCT04044625; registered 5 August 2019).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01018-4.

Various Aspects of Non-Invasive Ventilation in COVID-19 Patients: A Narrative Review

Non-invasive ventilation (NIV) is primarily used to treat acute respiratory failure. However, it has broad applications to manage a range of other diseases successfully. The main advantage of NIV lies in its capability to provide the same physiological effects as invasive ventilation while avoiding the placement of an artificial airway and its associated life-threatening complications. The war on the COVID-19 pandemic is far from over. The present narrative review aimed at identifying various aspects of NIV usage, in COVID-19 and other patients, such as the onset time, mode, setting, positioning, sedation, and types of interface. A search for articles published from May 2020 to April 2021 was conducted using MEDLINE, PMC central, Scopus, Web of Science, Cochrane Library, and Embase databases. Of the initially identified 5,450 articles, 73 studies and 24 guidelines on the use of NIV were included. The search was limited to studies involving human cases and English language articles. Despite several reported benefits of NIV, the evidence on the use of NIV in COVID-19 patients does not yet fully support its routine use.

Evidence-based management approaches for patients with severe chronic obstructive pulmonary disease (COPD): A practice review

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) face limited treatment options and inadequate access to palliative care.

AIM

To provide a pragmatic overview of clinical guidelines and produce evidence-based recommendations for severe COPD. Interventions for which there is inconsistent evidence to support their use and areas requiring further research were identified.

DESIGN

Practice review of guidelines supported by scoping review methodology to examine the evidence reporting the use of guideline-recommended interventions.

DATA SOURCES

An electronic search was undertaken in MEDLINE, EMBASE, PsycINFO, CINAHL and The Cochrane Database of Systematic Reviews, complemented by web searching for guidelines and publications providing primary evidence (July 2021). Guidelines published within the last 5 years and evidence in the last 10 years were included.

RESULTS

Severe COPD should be managed using a multidisciplinary approach with a holistic assessment. For stable patients, long-acting beta-agonist/long-acting muscarinic antagonist and pulmonary rehabilitation are recommended. Low dose opioids, self-management, handheld fan and nutritional support may provide small benefits, whereas routine corticosteroids should be avoided. For COPD exacerbations, systematic corticosteroids, non-invasive ventilation and exacerbation action plans are recommended. Short-acting inhaled beta-agonists and antibiotics may be considered but pulmonary rehabilitation should be avoided during hospitalisation. Long term oxygen therapy is only recommended for patients with chronic severe hypoxaemia. Short-acting anticholinergic inhalers, nebulised opioids, oral theophylline or telehealth are not recommended.

CONCLUSIONS

Recommended interventions by guidelines are not always supported by high-quality evidence. Further research is required on efficacy and safety of inhaled corticosteroids, antidepressants, benzodiazepines, mucolytics, relaxation and breathing exercises.

High-flow nasal cannula versus conventional oxygen therapy in acute COPD exacerbation with mild hypercapnia: a multicenter randomized controlled trial

Background

High-flow nasal cannula (HFNC) can improve ventilatory function in patients with acute COPD exacerbation. However, its effect on clinical outcomes remains uncertain.

Methods

This randomized controlled trial was conducted from July 2017 to December 2020 in 16 tertiary hospitals in China. Patients with acute COPD exacerbation with mild hypercapnia (pH ≥ 7.35 and arterial partial pressure of carbon dioxide > 45 mmHg) were randomly assigned to either HFNC or conventional oxygen therapy. The primary outcome was the proportion of patients who met the criteria for intubation during hospitalization. Secondary outcomes included treatment failure (intolerance and need for non-invasive or invasive ventilation), length of hospital stay, hospital cost, mortality, and readmission at day 90.

Results

Among 337 randomized patients (median age, 70.0 years; 280 men [83.1%]; median pH 7.399; arterial partial pressure of carbon dioxide 51 mmHg), 330 completed the trial. 4/158 patients on HFNC and 1/172 patient on conventional oxygen therapy met the criteria for intubation (P = 0.198). Patients progressed to NPPV in both groups were comparable (15 [9.5%] in the HFNC group vs. 22 [12.8%] in the conventional oxygen therapy group; P = 0.343). Compared with conventional oxygen therapy, HFNC yielded a significantly longer median length of hospital stay (9.0 [interquartile range, 7.0–13.0] vs. 8.0 [interquartile range, 7.0–11.0] days) and a higher median hospital cost (approximately $2298 [interquartile range, $1613–$3782] vs. $2005 [interquartile range, $1439–$2968]). There were no significant differences in other secondary outcomes between groups.

Conclusions

In this multi-center randomized controlled study, HFNC compared to conventional oxygen therapy did not reduce need for intubation among acute COPD exacerbation patients with mild hypercapnia. The future studies should focus on patients with acute COPD exacerbation with respiratory acidosis (pH < 7.35). However, because the primary outcome rate was well below expected, the study was underpowered to show a meaningful difference between the two treatment groups.

Trial registration: NCT03003559. Registered on December 28, 2016.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03973-7.

Seznanjenost osebja zdravstvene nege z neinvazivno mehansko ventilacijo

Uvod: Uspešno zdravljenje z neinvazivno mehansko ventilacijo predstavlja velik izziv, saj jo je mogoče učinkovito upravljati v primeru zadostne usposobljenosti vseh članov tima. Namen raziskave je bil oceniti znanje zdravstvenih delavcev, ki se srečujejo s tovrstnim zdravljenjem.Metode: Izvedena je bila kvantitativna presečna opazovalna raziskava. Vanjo je bilo vključenih 68 medicinskih sester, zaposlenih v intenzivnih enotah in na urgenci dveh bolnišnic v severovzhodni Sloveniji. Podatki so bili zbrani s pomočjo vprašalnika ter statistično analizirani in obdelani z uporabo opisne in sklepne statistike.Rezultati: V raziskavi ugotavljamo, da 76,5 % anketirancev meni, da je njihovo znanje o neinvazivni mehanski ventilaciji precej dobro. Znanje o neinvazivni mehanski ventilaciji je 85,3 % anketirancev pridobilo od sodelavcev v službi in 60,3 % od zdravnikov na oddelku. Povprečna vrednost doseženih točk, pridobljena pri vprašanjih o znanju glede uporabe neinvazivne mehanske ventilacije, je bila 23,13 (s = 4.35) od možnih 33. Med delavci, zaposlenimi v urgentnem centru in na oddelkih intenzivne enote, ne obstajajo statistično pomembne razlike v znanju o neinvazivni mehanski ventilaciji (p = 0,456).Diskusija in zaključek: Ugotovili smo, da bi anketiranci potrebovali dodatna usposabljanja s področja neinvazivne mehanske ventilacije. Smiselno bi bilo, da se na državni ravni oziroma ravni posameznih bolnišnic organizirajo izobraževanja s tega področja, na katera se povabi vse zaposlene, ki se srečujejo z neinvazivno mehansko ventilacijo.

Exploring the Patient Experience with Noninvasive Ventilation: A Human-Centered Design Analysis to Inform Planning for Better Tolerance

BACKGROUND

This study brings a human-centered design (HCD) perspective to understanding the patient experience when using noninvasive ventilation (NIV) with the goal of creating better strategies to improve NIV comfort and tolerance.

METHODS

Using an HCD motivational approach, we created a semi-structured interview to uncover the patients' journey while being treated with NIV. We interviewed 16 patients with chronic obstructive pulmonary disease (COPD) treated with NIV while hospitalized. Patients' experiences were captured in a stepwise narrative creating a journey map as a framework describing the overall experience and highlighting the key processes, tensions, and flows. We broke the journey into phases, steps, emotions, and themes to get a clear picture of the overall experience levers for patients.

RESULTS

The following themes promoted NIV tolerance: trust in the providers, the favorable impression of the facility and staff, understanding why the mask was needed, how NIV works and how long it will be needed, immediate relief of the threatening suffocating sensation, familiarity with similar treatments, use of meditation and mindfulness, and the realization that treatment was useful. The following themes deterred NIV tolerance: physical and psychological discomfort with the mask, impaired control, feeling of loss of control, and being misinformed.

CONCLUSIONS

Understanding the reality of patients with COPD treated with NIV will help refine strategies that can improve their experience and tolerance with NIV. Future research should test ideas with the best potential and generate prototypes and design iterations to be tested with patients.

Extracorporeal carbon dioxide removal for treatment of exacerbated chronic obstructive pulmonary disease (ORION): study protocol for a randomised controlled trial

Background

Hypercapnic exacerbations are severe complications of chronic obstructive pulmonary disease (COPD), characterized by negative impact on prognosis, quality of life and healthcare costs. The present standard of care for acute exacerbations of COPD is non-invasive ventilation; when it fails, the use of invasive mechanical ventilation is inevitable, but is associated with extremely poor prognosis. Extracorporeal circuits designed to remove CO₂ (ECCO₂R) may enhance the efficacy of NIV to remove CO₂ and avoid the worsening of respiratory acidosis, which inevitably leads to failure of non-invasive ventilation. Although the use of ECCO₂R for acute exacerbations of COPD is steadily increasing, solid evidence on its efficacy and safety is scarce, thus the need for a randomized controlled trial.

Methods

multicenter randomized controlled unblinded clinical trial including 284 (142 per arm) patients with acute hypercapnic respiratory failure caused by exacerbation of COPD, requiring respiratory support with NIV. The primary outcome is event free survival at 28 days, a composite outcome defined by survival in absence of prolonged mechanical ventilation, severe hypoxemia, septic shock and second episode of COPD exacerbation. Secondary outcomes are incidence of endotracheal intubation and tracheostomy, intensive care and hospital length-of-stay and 90-day mortality.

Discussion

Acute exacerbations of COPD represent a significant burden in terms of prognosis, quality of life and healthcare costs. Lack definite evidence despite increasing use of ECCO₂R justifies a randomized trial to evaluate whether patients with acute hypercapnic acidosis not responsive to NIV should undergo invasive mechanical ventilation (with all serious related risks) or be treated with ECCO₂R to avoid invasive ventilation but be exposed to possible adverse events of ECCO₂R. Owing to its pragmatic nature, sample size and composite primary outcome, this trial aims at providing valuable answers to relevant questions for clinical treatment of acute exacerbations of COPD.

Trial registration

ClinicalTrials.gov, NCT04582799. Registered 12 October 2020, .

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05692-w.

The Coexistence of Chronic Obstructive Pulmonary Disease and Heart Failure

Chronic obstructive pulmonary disease (COPD) is a chronic illness that is widely prevalent within the United States and has been frequently associated with heart failure (HF). COPD is associated with progressive damage and inflammation of the airways leading to airflow obstruction and inadequate gas exchange. HF represents a decline in the normal functioning of the heart resulting in insufficient pumping of blood through the circulatory system. COPD and HF present with similar signs and symptoms with some variation.

There are many specific diagnostic tests and treatment modalities which we use to diagnose COPD and HF, but it becomes an issue when you come across a patient who has both conditions simultaneously. For example, attempting to use an X-ray to diagnose HF in a COPD patient is next to impossible because the results are manipulated by the COPD disease process. This is the case with many other diagnostic tests such as an electrocardiogram (ECG), chest radiography (X-ray), B-type natriuretic peptide (BNP), echocardiogram, cardiac magnetic resonance imaging (CMR), pulmonary function test (PFT), arterial blood gas (ABG), and exercise stress testing.

When a patient has both COPD and HF, it becomes more difficult to treat. Many treatments for HF have negative impacts on COPD patients and vice-versa, whereas some have also shown positive clinical outcomes in both diseases. It is agreeable that treatment has to be patient-centered and it can vary from case to case depending on the severity of the disease. Ultimately, in this review, we discuss COPD and HF and how they interplay in their diagnostic and treatment modalities to gain a better understanding of how to effectively manage patients who have been diagnosed with both conditions.

[Factors predicting the need for invasive mechanical ventilation in patients with chronic obstructive pulmonary disease (COPD)]

Introduction

the use of invasive mechanical ventilation (IMV) in acute exacerbations of chronic obstructive pulmonary disease (AECOPD) constitutes a negative turning point in the progression of the disease. The purpose of this study is to determine factors predicting the need for IMV in AECOPD.

Methods

we conducted a retrospective study by reviewing the medical records of patients with AECOPD hospitalized in our Department over a 18-year period (2000-2017). We compared 2 groups: G1: patients with AECOPD undergoing at least one IMV and G2: patients who had never undergone IMV following AECOPD.

Results

the study included 1152 patients with COPD: 133 in the G1 group (11.5%), and 1019 in the G2 group (88.5%). G1 patients were more symptomatic (p < 0.001), with more severe bronchial obstruction (p < 0.001). G1 patients had more exacerbations (p < 0.001), more hospitalizations and a higher need for non-invasive ventilation (NIV) (p < 0.001). Similarly, G1 patients more often developed chronic respiratory failure (p < 0.001) and had significantly lower survival rates. Independent risk factors associated with IMV were hypercapnia and decreased pH (in patients with severe AECOPD), a history of NIV, and chronic respiratory failure (CRF).

Conclusion

respiratory function impairment, the severity of exacerbation and the need for NIV in a previous episode are factors predicting the need for IMV and poor outcomes.

Dynamic prediction of late noninvasive ventilation failure in intensive care unit using a time adaptive machine model

BACKGROUND

Noninvasive ventilation (NIV) failure is strongly associated with poor prognosis. Nowadays, plenty of mature studies have been proposed to predict early NIV failure (within 48 hours of NIV), however, the prediction for late NIV failure (after 48 hours of NIV) lacks sufficient research. Late NIV failure delays intubation resulting in the increasing mortality of the patients. Therefore, it is of great significance to expeditiously predict the late NIV failure. In order to dynamically predict late NIV failure, we proposed a Time Updated Light Gradient Boosting Machine (TULightGBM) model.

MATERIAL AND METHODS

In this work, 5653 patients undergoing NIV over 48 hours were extracted from the database of Medical Information Mart for Intensive Care Ⅲ (MIMIC-Ⅲ) for model construction. The TULightGBM model consists of a series of sub-models which learn clinical information from updating data within 48 hours of NIV and integrates the outputs of the sub-models by the dynamic attention mechanism to predict late NIV failure. The performance of the proposed TULightGBM model was assessed by comparison with common models of logistic regression (LR), random forest (RF), LightGBM, eXtreme gradient boosting (XGBoost), artificial neural network (ANN), and long short-term memory (LSTM).

RESULTS

The TULightGBM model yielded prediction results at 8, 16, 24, 36, and 48 hours after the start of the NIV with dynamic AUC values of 0.8323, 0.8435, 0.8576, 0.8886, and 0.9123, respectively. Furthermore, the sensitivity, specificity, and accuracy of the TULightGBM model were 0.8207, 0.8164, and 0.8184, respectively. The proposed model achieved superior performance over other tested models.

CONCLUSIONS

The TULightGBM model is able to dynamically predict the late NIV failure with high accuracy and offer potential decision support for clinical practice.

Duration of noninvasive ventilation is not a predictor of clinical outcomes in patients with acute exacerbation of COPD and respiratory failure

Purpose

Acute exacerbation of chronic obstructive pulmonary disease (COPD) is a major cause of mortality and morbidity. Noninvasive ventilation (NIV) is proven to be effective in the majority of patients with acute exacerbation COPD (AECOPD) complicated with respiratory failure. NIV could be lifesaving but also can delay mechanical ventilation if its efficacy is not assessed in a timely manner. In this study, we analyzed potential predictors of NIV failure in AECOPD in a tertiary medical intensive care unit (MICU). In particular, we wondered whether duration of NIV among those who eventually failed was associated with poor outcomes.

Methods

A retrospective review of consecutive patients with a primary diagnosis of AECOPD requiring NIV admitted to the MICU was conducted for the period between 2012 and 2017. Baseline data included demographics, APACHE III score, albumin level, blood lactate, and blood gas elements. Additional chart review was performed to collect NIV setting parameters on presentation to the MICU. Clinical outcome variables collected included outcome and duration of NIV, duration of invasive mechanical ventilation, MICU length of stay, hospital length of stay, and in-hospital mortality. Multivariate regression analysis was performed to determine independent variables associated with clinical outcomes.

Results

There were 370 patients who met the inclusion criteria; 53.2% were male. Mean age was 64.7 ± 11.2 years old. Mean baseline FEV₁ was 34 ±17% of predicted. Patients had mean pH of 7.20 ± 0.54 and P_aCO₂ of 70.3 ± 28.7 on presentation; 323 patients (87.3%) were successfully weaned off NIV; 47 patients (12.7%) failed NIV and required invasive mechanical ventilation. APACHE III score was higher among patients who failed NIV (68.3±18.9 versus 48.8± 15.2, P < 0.001). In the subset of 47 patients who failed NIV requiring intubation, duration of NIV was 25.0 ± 58.8 h. Multivariate regression analysis yielded a model consisting of APACHE III score and body mass index as predictive variables for NIV failure (C-statistic = 0.809). Duration of NIV was not associated with worse clinical outcomes among patients who failed NIV.

Conclusions

NIV is successful in preventing invasive mechanical ventilation in majority of patients with acute respiratory failure due to COPD. Patients with worse clinical status at presentation are more likely to fail NIV and require mechanical ventilation. In the subgroup of patients who failed NIV, duration of NIV prior to intubation was not associated with poor clinical outcomes.

The Neutrophil/Lymphocyte Ratio Could Predict Noninvasive Mechanical Ventilation Failure in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Retrospective Observational Study

Purpose

To determine the effectiveness of neutrophil/lymphocyte ratio (NLR), compared to traditional inflammatory markers, for predicting noninvasive mechanical ventilation (NIMV) failure in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients.

Patients and Methods

We conducted this retrospective observational study including 212 AECOPD patients who required NIMV during hospitalization from January 2015 to December 2020 in the department of respiratory and critical care medicine of Beijing Chao-Yang Hospital (west campus). We reviewed the medical record to determine if NIMV succeeded or failed for each patient, and compared NLR with traditional markers (leukocyte, C-reactive protein [CRP] and procalcitonin [PCT]) between NIMV failure and NIMV success group. Receiver-operating characteristic (ROC) curve and multivariate logistic regression analysis were used to assess the accuracy of these markers for predicting NIMV failure.

Results

A total of 38 (17.9%) patients experienced NIMV failure. NLR was a more sensitive biomarker to predict NIMV failure (AUC, 0.858; 95% CI 0.785-0.931) than leukocyte counts (AUC, 0.723; 95% CI 0.623-0.823), CRP (AUC, 0.670; 95% CI 0.567-0.773) and PCT (AUC, 0.719; 95% CI 0.615-0.823). There was statistically positive correlation between NLR and leukocytes count (r=0.35, p<0.001), between NLR and CRP (r=0.258, p<0.001), between NLR and PCT (r=0.306, p<0.001). The cutoff value of NLR to predict NIMV failure was 8.9 with sensitivity 0.688, specificity 0.886 and diagnostic accuracy 0.868. NLR>8.9 (odds ratio, 10.783; 95% CI, 2.069-56.194; P=0.05) was an independent predictor of NIMV failure in the multivariate logistic regression model.

Conclusion

NLR may be an effective marker for predicting NIMV failure in AECOPD patients, and the patients with NLR>8.9 should be handled with caution since they are at higher risk of NIMV failure and require intubation. Further study with a larger sample size and with more data is necessary to confirm our study.