Non-invasive ventilation for acute hypoxemic respiratory failure, including COVID-19

Knowledge Domain and Emerging Trends in the Treatment of Patients with Chronic Obstructive Pulmonary Disease Combined with Respiratory Failure: A Scientometric Review Based on CiteSpace Analysis

OBJECTIVE

To analyze the status of research on treating chronic obstructive pulmonary disease (COPD) combined with respiratory failure internationally to reveal its development trends through visualization methods and to provide a reference and suggestions for future research directions.

METHODS

Literature on the treatment of COPD combined with respiratory failure published from the year of inception of the Web of Science database to December 31, 2023, was searched. CiteSpace 6.2.R7 software was used to visualize and analyze the published articles. A bibliometric analysis of the publications, keyword co-occurrence analysis, keyword clustering analysis, and keyword emergence analysis were performed to draw a correlation map and analyze the results.

RESULTS

A total of 369 articles were analyzed. An overall increasing trend was observed in the number of publications. The network of researchers was relatively dense, and a core team was clearly observed. The researchers' affiliations were mainly European universities and hospitals, and close cooperation between institutions was observed. The keyword analysis obtained high-frequency keywords such as "noninvasive ventilation", "mechanical ventilation", and "positive pressure ventilation". The keyword clustering analysis revealed 10 clusters, and the keyword emergence analysis yielded 20 keywords.

CONCLUSIONS

The focus of attention internationally has been on respiratory failure classification and types of ventilation support, such as high-flow oxygenation and noninvasive positive pressure ventilation. Future directions should include clinical research on high-flow oxygen administration to improve patient prognosis and the application of extracorporeal carbon dioxide removal technology to enhance patients' quality of life.

Monitoring patients with acute respiratory failure during non-invasive respiratory support to minimize harm and identify treatment failure

Non-invasive respiratory support (NRS), including high flow nasal oxygen therapy, continuous positive airway pressure and non-invasive ventilation, is a cornerstone in the management of critically ill patients who develop acute respiratory failure (ARF). Overall, NRS reduces the work of breathing and relieves dyspnea in many patients with ARF, sometimes avoiding the need for intubation and invasive mechanical ventilation with variable efficacy across diverse clinical scenarios. Nonetheless, prolonged exposure to NRS in the presence of sustained high respiratory drive and effort can result in respiratory muscle fatigue, cardiovascular collapse, and impaired oxygen delivery to vital organs, leading to poor outcomes in patients who ultimately fail NRS and require intubation. Assessment of patients' baseline characteristics before starting NRS, close physiological monitoring to evaluate patients' response to respiratory support, adjustment of device settings and interface, and, most importantly, early identification of failure or of paramount importance to avoid the negative consequences of delayed intubation. This review highlights the role of respiratory monitoring across various modalities of NRS in patients with ARF including dyspnea, general respiratory parameters, measures of drive and effort, and lung imaging. It includes technical specificities related to the target population and emphasizes the importance of clinicians' physiological understanding and tailoring clinical decisions to individual patients' needs.

Comparison of non-invasive ventilation on bilevel pressure mode and CPAP in the treatment of COVID-19 related acute respiratory failure. A propensity score-matched analysis

OBJECTIVE

The purpose of this study was to analyze the differences in the effectiveness and complications of CPAP versus non-invasive ventilation on bilevel positive airway pressure (BiPAP) in the treatment of COVID-19 associated acute respiratory failure (ARF).

DESIGN

Retrospective observational study.

SETTING

ICU.

PATIENTS

All COVID-19 patients, admitted to an ICU between March 2020 and February 2023, who required CPAP or BiPAP were analyzed.

INTERVENTIONS

Use of CPAP or BiPAP in COVID-19 associated ARF.

MAIN VARIABLES OF INTEREST

Initial clinical variables, CPAP and BiPAP failure rate, complications, in-hospital mortality.

RESULTS

429 patients were analyzed, of whom 328 (76.5%) initially received CPAP and 101 (23.5%) BiPAP. Initial respiratory rate was 30 ± 8 in the CPAP group and 34 ± 9 in BiPAP (p < 0.001), while PaO2/FiO2 was 120 ± 26 and 111 ± 24 mmHg (p = 0.001), respectively. The most frequent complication related to the device was claustrophobia/discomfort, 23.2% in CPAP and 25.7% in BiPAP (p = 0.596), while the most frequent complications not related to the device were severe ARDS, 58.6% and 70.1% (p = 0.044), and hyperglycemia, 44.5% and 37.6%, respectively (p = 0.221). After adjusting by propensity score matched analysis, neither failure of the device (OR 1.37, CI 95% 0.72-2.62) nor in-hospital mortality (OR 1.57, CI 95% 0.73-3.42) differed between both groups.

CONCLUSIONS

Either non-invasive ventilatory device failure or mortality rate differed in patients initially treated with CPAP versus BiPAP.

High-Flow Nasal Oxygen in Patients with Acute Hypercapnic Respiratory Failure: A Narrative Review of the Physiological Rationale and Clinical Evidence

Acute hypercapnic respiratory failure is a life-threatening condition caused by alveolar hypoventilation. It is mostly caused by an acute exacerbation of chronic obstructive pulmonary disease or conditions yielding muscle dysfunction. Noninvasive ventilation through a facemask is the cornerstone first-line strategy to support hypercapnic patients with acidemia, and current guidelines strongly recommend this intervention to improve survival and long-term clinical outcomes. Because of its benefits related to carbon dioxide washout from the upper airways and the enhanced comfort, high-flow nasal oxygen has been proposed as a respiratory support strategy in patients with hypercapnic respiratory failure, both as an alternative to and in combination with noninvasive ventilation. When compared to noninvasive ventilation as a first-line intervention, high-flow nasal oxygen shows a higher rate of failure. Hence, if not contraindicated, the use of noninvasive ventilation should be preferred. After the resolution of acidemia with noninvasive ventilation, high-flow nasal oxygen showed promising physiological effects compared to conventional oxygen. During weaning from mechanical ventilation in patients with or at risk of developing hypercapnia, high-flow nasal oxygen showed encouraging results, especially when applied alternating with sessions of noninvasive ventilation. Optimal settings of high-flow nasal oxygen in hypercapnic patients include the use of a smaller-size cannula, flows ranging between 30 and 40 L/min, and FiO2 adjusted to obtain SpO2 between 88% and 92%. Specific interfaces, such as asymmetric cannulas, may further enhance the benefits of a high flow in terms of carbon dioxide clearance. In this narrative review, we provide an updated overview of the physiological rationale and clinical evidence concerning the use of high-flow nasal oxygen in patients with acute hypercapnic respiratory failure.

Pilot Randomized Clinical Trial of a Passive Non-invasive Positive End-Expiratory Pressure (PEEP) Device for Delivering Positive Pressure Therapy Compared to Standard Care in Non-critically Ill Patients With COVID-19

BACKGROUND

During the COVID-19 pandemic, there were reports of a shortage of ventilators and oxygen supply, particularly in resource-limited settings. We report the preliminary evaluation of a non-invasive positive end-expiratory pressure (PEEP) mask in hospitalized non-critically ill patients with COVID-19.

METHODS

We randomly assigned hospitalized adult patients with confirmed COVID-19 infection and requiring greater than 40% supplemental oxygen to either standard care oxygen delivery (control) or via Materialise passive non-invasive PEEP device mask (intervention; Belgium). The primary outcome was a change in mean respiratory rate from baseline over the first three hours after the commencement of the intervention. Secondary outcomes included dyspnea score, need for escalation of respiratory or cardiovascular support, days alive and free of ICU, and day-28 mortality.

RESULTS

Between April 30, 2021, and October 10, 2021, we enrolled 132 (65 control, 67 intervention) patients in the study. The mean respiratory rates at baseline were 23 ± 3 and 23 ± 3 in the control and intervention groups, with no significant differences at three hours (23 ± 2.3 vs. 23 ± 2.1, p=0.14). The control group had a higher mean dyspnea score compared to the intervention group (day 5: 5.4 ± 1.6 vs. 4.7 ± 1.4, p=0.015; day 6: 4.7 ± 1.7 vs. 4.0 ± 0.7, p=0.008). A higher proportion of patients in the control group required escalation of respiratory support (38%), as compared to intervention (12%) (p=0.0004). The two groups had no significant differences across other secondary outcomes or with respect to adverse events (barotrauma, aspiration pneumonia, need for vasopressor support).

CONCLUSIONS

The use of the novel mask compared to standard care in hospitalized non-critically ill patients with COVID-19 was not associated with reductions in the respiratory rate but was associated with a reduction in the need for escalation of respiratory support without an increase in adverse effects. Large-scale clinical trials of this device are warranted.

Application of 24-h respiratory rate and oxygenation index variation to predict the outcome of high-flow nasal cannula therapy in patients with acute hypoxemic respiratory failure in a respiratory intensive care unit

Background: An evaluation system is urgently needed to describe early predictors of the outcome of high-flow nasal cannula (HFNC) oxygen therapy in acute hypoxemic respiratory failure (AHRF) patients. Methods: All consecutive AHRF patients in a Respiratory Intensive Care Unit (RICU) receiving HFNC therapy between January 2019 and December 2021 were enrolled. Results: Of the 106 enrolled AHRF subjects, 57 (53.8%) succeeded in HFNC therapy and 49 (46.2%) failed. Being male (p = 0.006), initial respiratory rate oxygenation (ROX) index (p = 0.011), Acute Physiology and Chronic Health Evaluation II score (p = 0.007) and 24-h ROX index variation rate (p = 0.004) were independent factors of HFNC outcome; among these, 24-h ROX index variation rate (area under the curve = 0.825) was the best evaluation indicator. Conclusion: 24-h ROX index variation rate, introduced by our study, has shown the best potential to predict HFNC outcome in AHRF patients.

Barotrauma during Noninvasive Respiratory Support in COVID-19 Pneumonia Outside ICU: The Ancillary COVIMIX-2 Study

BACKGROUND

Noninvasive respiratory support (NIRS) has been extensively used during the COVID-19 surge for patients with acute respiratory failure. However, little data are available about barotrauma during NIRS in patients treated outside the intensive care unit (ICU) setting.

METHODS

COVIMIX-2 was an ancillary analysis of the previous COVIMIX study, a large multicenter observational work investigating the frequencies of barotrauma (i.e., pneumothorax and pneumomediastinum) in adult patients with COVID-19 interstitial pneumonia. Only patients treated with NIRS outside the ICU were considered. Baseline characteristics, clinical and radiological disease severity, type of ventilatory support used, blood tests and mortality were recorded.

RESULTS

In all, 179 patients were included, 60 of them with barotrauma. They were older and had lower BMI than controls (p < 0.001 and p = 0.045, respectively). Cases had higher respiratory rates and lower PaO₂/FiO₂ (p = 0.009 and p < 0.001). The frequency of barotrauma was 0.3% [0.1-1.3%], with older age being a risk factor for barotrauma (OR 1.06, p = 0.015). Alveolar-arterial gradient (A-a) DO₂ was protective against barotrauma (OR 0.92 [0.87-0.99], p = 0.026). Barotrauma required active treatment, with drainage, in only a minority of cases. The type of NIRS was not explicitly related to the development of barotrauma. Still, an escalation of respiratory support from conventional oxygen therapy, high flow nasal cannula to noninvasive respiratory mask was predictive for in-hospital death (OR 15.51, p = 0.001).

CONCLUSIONS

COVIMIX-2 showed a low frequency for barotrauma, around 0.3%. The type of NIRS used seems not to increase this risk. Patients with barotrauma were older, with more severe systemic disease, and showed increased mortality.