The Changing Landscape of Noninvasive Ventilation in the Intensive Care Unit

Comparison between high-flow nasal cannula and noninvasive ventilation in COVID-19 patients: a systematic review and meta-analysis

BACKGROUND

High-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) are important treatment approaches for acute hypoxemic respiratory failure (AHRF) in coronavirus disease 2019 (COVID-19) patients. However, the differential impact of HFNC versus NIV on clinical outcomes of COVID-19 is uncertain.

OBJECTIVES

We assessed the effects of HFNC versus NIV (interface or mode) on clinical outcomes of COVID-19.

METHODS

We searched PubMed, EMBASE, Web of Science, Scopus, MedRxiv, and BioRxiv for randomized controlled trials (RCTs) and observational studies (with a control group) of HFNC and NIV in patients with COVID-19-related AHRF published in English before February 2022. The primary outcome of interest was the mortality rate, and the secondary outcomes were intubation rate, PaO2/FiO2, intensive care unit (ICU) length of stay (LOS), hospital LOS, and days free from invasive mechanical ventilation [ventilator-free day (VFD)].

RESULTS

In all, 23 studies fulfilled the selection criteria, and 5354 patients were included. The mortality rate was higher in the NIV group than the HFNC group [odds ratio (OR) = 0.66, 95% confidence interval (CI): 0.51-0.84, p = 0.0008, I2 = 60%]; however, in this subgroup, no significant difference in mortality was observed in the NIV-helmet group (OR = 1.21, 95% CI: 0.63-2.32, p = 0.57, I2 = 0%) or NIV-continuous positive airway pressure (CPAP) group (OR = 0.77, 95% CI: 0.51-1.17, p = 0.23, I2 = 65%) relative to the HFNC group. There were no differences in intubation rate, PaO2/FiO2, ICU LOS, hospital LOS, or days free from invasive mechanical ventilation (VFD) between the HFNC and NIV groups.

CONCLUSION

Although mortality was lower with HFNC than NIV, there was no difference in mortality between HFNC and NIV on a subgroup of helmet or CPAP group. Future large sample RCTs are necessary to prove our findings.

REGISTRATION

This systematic review and meta-analysis protocol was prospectively registered with PROSPERO (no. CRD42022321997).

ERS Clinical Practice Guidelines: High-flow nasal cannula in acute respiratory failure

BACKGROUND

High-flow nasal cannula (HFNC) has become a frequently used non-invasive form of respiratory support in acute settings, however evidence supporting its use has only recently emerged. These guidelines provide evidence-based recommendations for the use of HFNC alongside other noninvasive forms of respiratory support in adults with acute respiratory failure (ARF).

MATERIALS AND METHODOLOGY

The European Respiratory Society Task Force panel included expert clinicians and methodologists in pulmonology and intensive care medicine. The Task Force used the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) methods to summarize evidence and develop clinical recommendations for the use of HFNC alongside conventional oxygen therapy (COT) and non-invasive ventilation (NIV) for the management of adults in acute settings with ARF.

RESULTS

The Task Force developed 8 conditional recommendations, suggesting using: 1) HFNC over COT in hypoxemic ARF, 2) HFNC over NIV in hypoxemic ARF, 3)HFNC over COT during breaks from NIV, 4) either HFNC or COT in post-operative patients at low risk of pulmonary complications, 5) either HFNC or NIV in post-operative patients at high risk of pulmonary complications, 6) HFNC over COT in non-surgical patients at low risk of extubation failure, 7) NIV over HFNC for patients at high risk of extubation failure unless there are relative or absolute contraindications to NIV, 8) trialling NIV prior to use of HFNC in patients with chronic obstructive pulmonary disease (COPD) and hypercapnic ARF.

CONCLUSIONS

HFNC is a valuable intervention in adults with ARF. These conditional recommendations can assist clinicians in choosing the most appropriate form of non-invasive respiratory support to provide to patients in different acute settings.

Oral Care in Critically Ill Patients Requiring Noninvasive Ventilation: An Evidence-Based Review

TOPIC

Hospital-acquired pneumonia commonly develops after 48 hours of hospitalization and can be divided into non-ventilator-acquired and ventilator-acquired pneumonia. Prevention of non-ventilator-acquired pneumonia requires a multimodal approach. Implementation of oral care bundles can reduce the incidence of ventilator-acquired pneumonia, but the literature on oral care in other populations is limited.

CLINICAL RELEVANCE

Use of noninvasive ventilation is increasing owing to positive outcomes. The incidence of non-ventilator-acquired pneumonia is higher in patients receiving noninvasive ventilation than in the general hospitalized population but remains lower than that of ventilator-acquired pneumonia. Non-ventilator-acquired pneumonia increases mortality risk and hospital length of stay.

PURPOSE

To familiarize nurses with the evidence regarding oral care in critically ill patients requiring noninvasive ventilation.

CONTENT COVERED

No standard of oral care exists for patients requiring noninvasive ventilation owing to variation in study findings, definitions, and methods. Oral care decreases the risk of hospital-acquired pneumonia and improves comfort. Nurses perform oral care less often for nonintubated patients, as it is perceived as primarily a comfort measure. The potential risks of oral care for patients receiving noninvasive ventilation have not been explored. Further research is warranted before this practice can be fully implemented.

CONCLUSION

Oral care is a common preventive measure for non-ventilator-acquired pneumonia and may improve comfort. Adherence to oral care is lower for patients not receiving mechanical ventilation. Further research is needed to identify a standard of care for oral hygiene for patients receiving noninvasive ventilation and assess the risk of adverse events.

Association Between Peripheral Blood Oxygen Saturation (SpO2)/Fraction of Inspired Oxygen (FiO2) Ratio Time at Risk and Hospital Mortality in Mechanically Ventilated Patients

INTRODUCTION

Acute respiratory failure requiring mechanical ventilation is a leading cause of mortality in the intensive care unit. Although single peripheral blood oxygen saturation/fraction of inspired oxygen (SpO2/FiO2) ratios of hypoxemia have been evaluated to risk-stratify patients with acute respiratory distress syndrome, the utility of longitudinal SpO2/FiO2 ratios is unknown.

OBJECTIVE

To assess time-based SpO2/FiO2 ratios ≤ 150-SpO2/FiO2 time at risk (SF-TAR)-for predicting mortality in mechanically ventilated patients.

METHODS

Retrospective, observational cohort study of mechanically ventilated patients at 21 community and 2 academic hospitals. Association between the SF-TAR in the first 24 hours of ventilation and mortality was examined using multivariable logistic regression and compared with the worst recorded isolated partial pressure of arterial oxygen/fraction of inspired oxygen (P/F) ratio.

RESULTS

In 28,758 derivation cohort admissions, every 10% increase in SF-TAR was associated with a 24% increase in adjusted odds of hospital mortality (adjusted odds ratio = 1.24; 95% confidence interval [CI] = 1.23-1.26); a similar association was observed in validation cohorts. Discrimination for mortality modestly improved with SF-TAR (area under the receiver operating characteristic curve [AUROC] = 0.81; 95% CI = 0.81-0.82) vs the worst P/F ratio (AUROC = 0.78; 95% CI = 0.78-0.79) and worst SpO2/FiO2 ratio (AUROC = 0.79; 95% CI = 0.79-0.80). The SF-TAR in the first 6 hours offered comparable discrimination for hospital mortality (AUROC = 0.80; 95% CI = 0.79-0.80) to the 24-hour SF-TAR.

CONCLUSION

The SF-TAR can identify ventilated patients at increased risk of death, offering modest improvements compared with single SpO2/FiO2 and P/F ratios. This longitudinal, noninvasive, and broadly generalizable tool may have particular utility for early phenotyping and risk stratification using electronic health record data in ventilated patients.

Noninvasive ventilation versus oxygen therapy for the treatment of acute respiratory failure

INTRODUCTION

There is an ongoing discussion on whether oxygen therapy or noninvasive ventilation (NIV) should be used in patient with acute respiratory failure. While respiratory acidosis, especially in case of COPD exacerbation, is a clear indication for NIV, data available in patients with acute hypoxemic respiratory failure (AHRF) are ambiguous. In addition, recently the use of nasal high flow (NHF) has been increased. Despite that NHF has been studied as an alternative to NIV, the clinical advantages of NHF need to be confirmed.

AREAS COVERED

The purpose of this review is to enhance our understanding about the management of AHRF in specific settings, focusing on recent papers in which NIV and standard oxygen or NHF have been compared. Expert commentary: The choice of the most appropriate strategy for AHRF treatment should be made based upon patient's clinical status, underlying diseases, level of required respiratory support and patient's tolerance and comfort.

Non-invasive ventilation in immunocompromised patients with acute hypoxemic respiratory failure

The survival rate of immunocompromised patients has improved over the past decades in light of remarkable progress in diagnostic and therapeutic options. Simultaneously, there has been an increase in the number of immunocompromised patients with life threatening complications requiring intensive care unit (ICU) treatment. ICU admission is necessary in up to 15% of patients with acute leukemia and 20% of bone marrow transplantation recipients, and the main reason for ICU referral in this patient population is acute hypoxemic respiratory failure, which is associated with a high mortality rate, particularly in patients requiring endotracheal intubation. The application of non-invasive ventilation (NIV), and thus the avoidance of endotracheal intubation and invasive mechanical ventilation with its side effects, appears therefore of great importance in this patient population. Early trials supported the benefits of NIV in these settings, and the 2011 Canadian guidelines for the use of NIV in critical care settings suggest the use of NIV in immune-compromised patients with a grade 2B recommendation. However, the very encouraging results from initial seminal trials were not confirmed in subsequent observational and randomized clinical studies, questioning the beneficial effect of NIV in immune-compromised patients. Based on these observations, a French group led by Azoulay decided to assess whether early intermittent respiratory support with NIV had a role in reducing the mortality rate of immune-compromised patients with non-hypercapnic hypoxemic respiratory failure developed in less than 72 h, and hence conducted a multicenter randomized controlled trial (RCT) in experienced ICUs in France. This perspective reviews the findings from their RCT in the context of the current critical care landscape, and in light of recent results from other trials focused on the early management of acute hypoxemic respiratory failure.