Dyspnoea is frequent and often intense in patients receiving noninvasive ventilation (NIV), and is associated with higher short-term and long-term mortality, according to a new study published in the European Respiratory Journal.
Researchers sought to quantify the prevalence, intensity and prognostic impact of dyspnoea in patients receiving noninvasive ventilation (NIV) for acute respiratory failure.
The study comprised a secondary analysis of a prospective observational cohort study in 426 patients who received ventilatory support for acute respiratory failure in 54 intensive care units (ICU) in France and Belgium.
Patients were followed daily in the ICU, at hospital discharge and at 90 days post-ICU discharge. Respiratory rate, intensity of dyspnoea and arterial blood gas values were recorded at ICU admission prior to initiation of ventilatory support, and after the first NIV session.
To assess the intensity of dyspnoea, patients were asked to rate their breathing discomfort on a modified Borg category–ratio (1–10) scale; a dyspnoea intensity of less than four was defined as “mild or no dyspnoea”, while a dyspnoea intensity of four or more was defined as “moderate-to-severe dyspnoea”.
The presence of air leaks and anxiety, and the prescription of analgesics (including opioids) were also recorded, as were the need for invasive mechanical ventilation, ICU and in-hospital length of stay, ICU mortality, in-hospital mortality and day-90 mortality.
The researchers found that the level of dyspnoea was high, and moderate-to-severe dyspnoea after the first NIV session was associated with anxiety.
Moderate-to-severe dyspnoea after the first NIV session was also independently associated with NIV failure and subsequent intubation. Additionally, persistence of moderate-to-severe dyspnoea after the first NIV session was associated with longer length of stay and hospital mortality, but was not associated with post-ICU burden or impaired quality of life.