Nasal high-flow oxygen versus noninvasive ventilation in acute exacerbation of COPD: protocol for a randomised noninferiority clinical trial

Nasal high flow or noninvasive ventilation? navigating hypercapnic COPD exacerbation treatment: A randomized noninferiority clinical trial

BACKGROUND

Noninvasive ventilation (NIV) has been the cornerstone for managing acute exacerbations of COPD (AECOPD) with hypercapnic respiratory failure. Nasal high flow (NHF) oxygen therapy has emerged as a potential alternative, offering a more tolerable modality with promising outcomes. The aim of the present study was to evaluate whether NHF respiratory support is noninferior to NIV with respect to treatment failure, in patients with mild-to-moderate hypercapnic AECOPD.

METHODS

In this multi-center, randomized, noninferiority trial, 105 patients with AECOPD and respiratory failure type II were enrolled. Participants were randomly assigned to receive either NHF therapy or NIV. The primary endpoint was the frequency of treatment failure, defined as the need for intubation and invasive mechanical ventilation or a switch to the alternative treatment group. Secondary endpoints included changes in respiratory parameters, patient comfort indicators, and the occurrence of complications.

RESULTS

The findings revealed no significant difference in the primary outcome between the groups, with a treatment failure rate of 19.6 % (10 out of 51) in the NHF group and 14.8 % (8 out of 54) in the NIV group. Interestingly, NHF users reported significantly lower levels of dyspnea and discomfort at multiple follow-up points. Despite the differences in patient comfort, respiratory parameters such as respiratory rate, arterial blood gases, and use of accessory muscles of respiration showed no significant disparities between the groups throughout the study period.

CONCLUSIONS

NHF therapy was similar to NIV in preventing treatment failure among patients with hypercapnic AECOPD, offering a viable alternative with enhanced comfort.

TRIAL REGISTRATION

The study was prospectively registered in ClinicalTrials.gov (Identifier: NCT03466385) on March 15, 2018.

Assessing Treatment Success or Failure as an Outcome in Randomised Clinical Trials of COPD Exacerbations. A Meta-Epidemiological Study

A recently published ERS core outcome set recommends that all trials of COPD exacerbation management should assess the treatment success (or “cure” of the exacerbation), defined as a dichotomous measure of the overall outcome of an exacerbation. This methodological systematic review describes and compares the instruments that were used to assess treatment success or failure in 54 such RCTs, published between 2006–2020. Twenty-three RCTs used composite measures consisting of several undesirable outcomes of an exacerbation, together defining an overall unfavourable outcome, to define treatment failure. Thirty-four RCTs used descriptive instruments that used qualitative or semi-quantitative descriptions to define cure, marked improvement, improvement of the exacerbation, or treatment failure. Treatment success and failure rates among patients receiving guidelines-directed treatments at different settings and timepoints are described and could be used to inform power calculations in future trials. Descriptive instruments appeared more sensitive to treatment effects compared to composite instruments. Further methodological studies are needed to optimise the evaluation of treatment success/failure. In the meantime, based on the findings of this systematic review, the ERS core outcome set recommends that cure should be defined as sufficient improvement of the signs and symptoms of the exacerbation such that no additional systemic treatments are required.

Nasal high flow oxygen therapy during acute admissions or periods of worsening symptoms

PURPOSE OF REVIEW

Nasal high flow therapy (NHF) is increasingly used in acute care settings. In this review, we consider recent advances in the utilization of NHF in chronic obstructive pulmonary disease (COPD), terminal cancer and symptom management. Considerations around NHF use during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic are also discussed.

RECENT FINDINGS

NHF enables humidification and high flows to be provided together with titrated, supplemental oxygen therapy. Compared to conventional oxygen therapy, NHF improves respiratory physiology by reducing workload, enhancing muco-ciliary clearance and improving dead space washout. Some studies suggest that early use of NHF in people being cared for in the emergency department leads to lower rates of invasive ventilation and noninvasive ventilation. There is also emerging evidence for NHF use in people with COPD and chronic respiratory failure, and in palliative care. NHF is comfortable, well-tolerated and safe for use in the management of breathlessness in people with cancer. NHF can be delivered by face mask to patients with SARS-CoV-2 infection, to ease the burden on critical care resources.

SUMMARY

The evidence base for NHF is rapidly growing and offers promise in relieving troublesome symptoms and for people receiving palliative care.