Dyspnoea and clinical outcome in critically ill patients receiving noninvasive support for COVID-19 respiratory failure: post hoc analysis of a randomised clinical trial

Abstract

In non-COVID 19 acute hypoxemic respiratory failure, the entity of dyspnea has been associated with severity of hypoxemia, and represents a factor predicting noninvasive ventilation (NIV) failure, the need for endotracheal intubation and mortality [1].

Association between respiratory distress time and invasive mechanical ventilation in COVID-19 patients: A multicentre regional cohort study

“…This could be particularly relevant in respiratory diseases with a high inflammatory burden, such as severe COVID-19 6 . In parallel with our study, a recent study by Menga et al demonstrated that in hypoxemic COVID-19 patients, moderate-to-severe dyspnoea could be a simple indicator for identifying patients with the highest risk of endotracheal intubation 7 . Regardless of severity, our data showed that the long unresolved duration of respiratory distress before the application of positive pressure ventilation may also represent an earlier marker for invasive MV need.…”

“…In conclusion, supporting the idea that increased work of breathing can lead to worsening of lung injury 6 , 7 , our preliminary and retrospective data demonstrated that DT was independently associated with the progression of respiratory support in patients with SARS-CoV-2 pneumonia. So, specific strategies may be directed towards identifying and managing early symptoms of respiratory distress, regardless of the levels of hypoxemia and the severity of the dyspnoea itself.…”

Gas conditioning during helmet noninvasive ventilation: effect on comfort, gas exchange, inspiratory effort, transpulmonary pressure and patient–ventilator interaction

“…Patient’s comfort appeared essential to prevent dyspnea. Both dyspnea and discomfort are important factors for successful noninvasive ventilation and avoiding the need for endotracheal intubation [ 17 , 18 , 44 – 47 ].…”

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

“…[ 101 ] There are currently no validated scores for predicting helmet NIV failure, although post hoc analyses from a randomized clinical trial identified dyspnea score (assessed with a visual analog scale [VAS]) as predictive of treatment failure with both helmet NIV and HFNO. [ 102 ]…”

“…A post hoc analysis of the HENIVOT trial showed that moderate-to-severe dyspnea, assessed with a VAS, was associated with increased endotracheal intubation rates, fewer respiratory support-free days, longer ICU and hospital stays, and higher in-ICU and in-hospital mortality; it thus constitutes an alarming sign. [ 102 ] Moreover, in the same sample (comparing helmet NIV and HFNO), pretreatment PaCO 2 <35 mmHg or PaO 2 /(FiO 2 × VAS dyspnea) <30 (an index based on oxygenation impairment and dyspnea) identified a clinical phenotype (i.e., those with higher inspiratory effort) in whom helmet NIV produced the greatest clinical benefits. [ 108 ] In other words, PaCO 2 values and the PaO 2 /(FiO 2 × VAS dyspnea) index during low-flow oxygen therapy differentiated patients who would especially benefit from initial treatment with helmet NIV from those in whom HFNO would instead suffice.…”