Dyspnea in Patients Receiving Invasive Mechanical Ventilation

Dyspnea ranks among the most common and distressing sensations that patients receiving invasive mechanical ventilation may experience during an intensive care unit (ICU) stay. Whereas mechanical ventilation is supposed to alleviate acute respiratory failure, dyspnea affects half of patients receiving invasive mechanical ventilation and is generally rated as intense (50% of a full rating scale). The low tidal volumes delivered to achieve a lung-protective ventilation strategy may contribute to the pathogenesis of dyspnea. Dyspnea is associated with anxiety and with adverse outcomes, such as weaning failure and delayed extubation. In addition, dyspnea is associated with delayed post-traumatic stress disorder. This is true inasmuch as patients receiving invasive mechanical ventilation repeatedly experience dyspnea. Subsequently, the relief of dyspnea should be a major concern for ICU stakeholders whose mission is not only to treat diseases, but also to treat all forms of discomfort. Dyspnea can be alleviated by simple actions. Adjusting ventilator settings significantly improves dyspnea in about one third of patients receiving invasive mechanical ventilation. The detection of dyspnea can be difficult in these patients, who are often unable to communicate and subsequently to self-report dyspnea. As opposed to pain, there are no well-validated observation scales to detect dyspnea in non-communicative patients. For all these reasons, dyspnea is probably underestimated in many patients receiving invasive mechanical ventilation. Implementing a systematic assessment of dyspnea in routine practice, in the same way as for pain, could be the first step in a strategy to improve patient comfort and prevent the disastrous psychological consequences of dyspnea.