Nasal High Flow to Modulate Dyspnea in Orally Intubated Patients

Area of Science:

• Critical Care Medicine
• Respiratory Physiology

Background:

• Acute respiratory failure often necessitates mechanical ventilation, with dyspnea being a primary symptom.
• Nasal high flow (NHF) therapy is increasingly used to manage dyspnea, but its precise mechanisms require further elucidation.
• Understanding NHF's impact on respiratory mechanics and patient-reported outcomes is crucial for optimizing its application.

Purpose of the Study:

• To compare the effects of NHF on dyspnea, airway occlusion pressure (P0.1), and inspiratory work in intubated patients.
• To investigate these effects during both pressure support ventilation (PSV) and spontaneous breathing trials (SBT).

Main Methods:

• Twenty intubated patients with dyspnea (NRS > 3) were studied.
• Measurements included dyspnea scores (NRS, MV-RDOS), P0.1, esophageal pressure, respiratory muscle EMG, and arterial blood gases.
• Patients underwent PSV with varying NHF (0-60 L/min) and SBT with NHF (0 and 50 L/min).

Main Results:

• During PSV, NHF (30 and 50 L/min) significantly reduced dyspnea-NRS scores compared to no NHF (P < 0.05).
• NHF did not alter MV-RDOS scores, P0.1, esophageal pressure, respiratory muscle EMG, or gas exchange during PSV.
• During SBT, NHF (50 L/min) decreased dyspnea-NRS scores and P0.1 (P < 0.01 and P = 0.04, respectively) without changing other measured parameters.

Conclusions:

• NHF therapy is associated with reduced dyspnea and respiratory drive in orally intubated patients.
• These benefits were observed during both PSV and SBT.
• NHF did not significantly affect inspiratory work or respiratory muscle activity in this patient cohort.