Breathlessness in Patients with Chronic Airflow Limitation: The Affective Dimension of Breathlessness
Anxiety or apprehension are almost invariable accompaniments of breathlessness, particularly in patients with advanced disease. Stress and anxiety may of themselves induce breathlessness in CAL or their expression may represent an affective response to the stimulus of perceived inspiratory difficulty. Neuroventilatory dissociation may constitute a specific physiologic stressor; at a cognitive level, NVD may be recognized as a disparity between expectations (whether genetically programmed or learned) and current perceptions of the internal environment. This disparity may elicit patterned psychological and neurohumoral responses that culminate in respiratory distress. generic allegra
Toward a Rational Approach to the Management of Breathlessness
The effective management of breathlessness in CAL awaits a clearer understanding of the neural pathways that subserve respiratory sensation and the mechanisms whereby sensory inputs are processed and modulated at the level of the spinal cord and brain. Current approaches to management are based primarily on our understanding of the pathophysiologic mechanisms of breathlessness. Since breathlessness in CAL is encountered under conditions of increased ventilation, increased impedance to inspiratory muscle action, or functional inspiratory muscle weakness, it follows that any measure that will reduce ventilatory demand or that will unload or strengthen the inspiratory muscles should theoretically ameliorate dyspnea. The neurophysiologic corollary of this is that any intervention that will reduce the amplitude of motor output or enhance neuroventilatory coupling will relieve breathlessness. In addition, the associated anxiety may itself be amenable to treatment.
The study of therapeutic aspects of breathlessness has been greatly facilitated by the recent development of validated instruments that permit us to critically evaluate the impact of an intervention on symptom intensity. Traditionally, therapeutic approaches to breathlessness have focused on measures designed to improve ventilatory capacity or reduce ventilatory demand, ie, increase ventilatory reserve. In patients with advanced disease and relatively fixed pathophysiologic derangements, in general, only modest improvements in ventilatory reserve can be achieved.
Category: Respiratory Symptoms
Tags: breathlessness, chronic airflow limitation, copd, dynamic compression, dynamic hyperinflation, exercise