Sensory interventions to relieve dyspnea in critically ill mechanically ventilated patients.

RATIONALE:In critically ill patients receiving mechanical ventilation (MV), dyspnea is frequent, severe, and associated with an increased risk of neuropsychological sequelae. We evaluated the efficacy of sensory interventions targeting the brain rather than the respiratory system to relieve dyspnea in MV patients. METHODS:Patients receiving MV for ≥48 h and reporting dyspnea (unidimensional dyspnea visual analogue scale [Dyspnea-VAS]) first underwent increased pressure support, and then, in random order, auditory stimulation (relaxing music versus pink noise) and air flux stimulation (facial versus lower limb). Treatment responses were assessed using Dyspnea-VAS, the Multidimensional Dyspnea Profile, and measures of the neural drive to breathe (P0.1; electromyogram of inspiratory muscles). MAIN RESULTS:We included 46 patients (tracheotomy or intubation n=37, non-invasive ventilation n=9). Increasing pressure support decreased Dyspnea-VAS by median 40 mm (p<0.001). Exposure to music decreased Dyspnea-VAS compared exposure to pink noise by 40 mm (p<0.001). Exposure to facial air flux decreased Dyspnea-VAS compared to limb air flux by 30 mm (p<0.001). Increasing pressure support, but not music exposure and facial air flux, reduced P0.1 (by 3.3 cmH2O; p<0.001). CONCLUSIONS:In MV patients, sensory interventions can modulate the processing of respiratory signals by the brain irrespective of the intensity of the neural drive to breathe. It should therefore be possible to alleviate dyspnea without resorting to pharmacological interventions or having to infringe the constraints of MV lung protection strategies by increasing ventilatory support.