A secondary analysis of the WIN-IN-WEAN randomised controlled trial examines the comfort and discomfort associated with three respiratory support strategies used after extubation in critically ill patients without chronic obstructive pulmonary disease (COPD). The study sought to determine whether high-flow nasal cannula oxygen (HFNO), noninvasive ventilation (NIV), or conventional oxygen therapy (COT) differed in terms of patient and nurse perceptions of discomfort during the first 48 hours following extubation.
There is an ongoing debate regarding the tolerability of different noninvasive respiratory supports. Although HFNO is often considered more comfortable than NIV or conventional oxygen therapy, previous systematic reviews have produced conflicting findings. Some studies have suggested that HFNO and NIV provide similar levels of comfort, while others, particularly in COPD populations, have reported superior comfort with HFNO. The authors therefore aimed to assess discomfort specifically in non-COPD patients recovering from mechanical ventilation.
The analysis was based on data from the multicentre WIN-IN-WEAN trial, which originally evaluated strategies for preventing post-extubation respiratory failure. Patients were classified as either high or low risk for extubation failure using the Lung Ultrasound Score (LUS), measured at the end of a successful spontaneous breathing trial. A score of 14 or greater indicated high risk, whereas a score below 14 indicated low risk.
Patients in the intervention arm with high-risk scores received prophylactic HFNO alternating with NIV for 48 hours after extubation, while low-risk patients received conventional oxygen therapy. In the control group, LUS results were concealed from clinicians and patients received conventional oxygen regardless of risk status.
HFNO was delivered using humidified, heated oxygen at flow rates of 50–60 L/min through silicone nasal prongs. NIV was administered through a tightly fitted oro-nasal mask connected to a ventilator delivering pressure support and positive end-expiratory pressure.Conventional oxygen therapy was providedthrough a non-rebreather face mask supplying non-humidified oxygen at 10–15 L/min.
A total of 264 patients receiving conventional oxygen therapy and 42 high-risk patients receiving HFNO and NIV self-reported the discomfort associated with the respiratory interface. Assessments were conducted at 6, 24 and 48 hours after extubation. Patients evaluated the comfort of the specific interface they were using, including the oxygen mask, nasal prongs or NIV face mask. Only alert and cooperative patients with adequate neurological status and minimal sedation were included in these assessments.
In addition to patient self-assessments, nurses evaluated the overall discomfort associated with the respiratory support strategy itself. These assessments included 86 high-risk patients receiving HFNO alternating with NIV and 220 patients receiving conventional oxygen therapy. Nurses were blinded to patients’ LUS classifications to minimise bias.
Clinical characteristics differed between the high-risk and low-risk groups. High-risk patients were generally older, had higher Sequential Organ Failure Assessment (SOFA) scores, lower left ventricular ejection fractions, greater weight gain and a higher prevalence of pleural effusions. These findings confirmed that the high-risk group exhibited more severe underlying physiological impairment.
The principal finding was that NIV was consistently associated with the greatest degree of discomfort. Patients reported significant and persistent discomfort related to the NIV face mask at all measured time points. In contrast, discomfort associated with HFNO nasal prongs and conventional oxygen masks was substantially lower and progressively decreased over time. By 48 hours after extubation, discomfort levels associated with HFNO and conventional oxygen therapy had become minimal and comparable.
Nurse assessments produced similar findings. The respiratory support strategy involving alternating HFNO and NIV was perceived as significantly more uncomfortable than conventional oxygen therapy. Conventional oxygen therapy was rated as the least uncomfortable approach regardless of whether patients were at high or low risk of extubation failure.Importantly, the level of discomfort did not differ significantly between risk groups, suggesting that patient discomfort was more closely related to the respiratory support modality than to the severity of the underlying respiratory condition.
The authors discuss several reasons why NIV may be poorly tolerated. The tightly fitting mask can induce claustrophobia, exert pressure on the face and nose, and contribute to skin injury. NIV also interferes with eating, drinking, communication and secretion clearance, often requiring temporary interruption of treatment. These factors may reduce patient adherence and potentially affect therapeutic effectiveness.
HFNO avoids many of these limitations, although discomfort may arise from excessive flow rates, temperature settings or inadequate humidification. The authors note that comfort with HFNO is influenced by individual patient preferences regarding humidity and temperature. Despite these potential concerns, HFNO produced only limited discomfort in the present study, reinforcing its reputation as a well-tolerated respiratory support modality.
Overall, the study demonstrates that among non-COPD patients recovering from mechanical ventilation, NIV is associated with substantial and persistent discomfort after extubation. HFNO is considerably better tolerated, while conventional oxygen therapy remains the least uncomfortable option. By 48 hours, discomfort associated with HFNO and conventional oxygen therapy is minimal and essentially equivalent. The authors suggest that future research should explore whether differences in comfort influence the overall clinical effectiveness of post-extubation respiratory support strategies.
Source: Critical Care
Image Credit: iStock
