Dyspnea– difficulty in breathing
Mechanisms of Dyspnea
· Respiratory sensations are the consequence of efferent and afferent input from receptors throughout the body.
· A given disease state may lead to dyspnea by one or more mechanisms.
· Disorders of the ventilatory pump are associated with increased work of breathing or a sense of an increased effort to breathe.
· When the muscles are weak or fatigued, greater effort is required, even though the mechanics of the system are normal.
· Chemoreceptors in the carotid bodies and medulla are activated by hypoxemia, acute hypercapnia, and academia.
· Leads to increase in ventilation, produce a sensation of air hunger.
Occurs in –
· Chest tightness or constriction – in Bronchoconstriction, asthma, myocardial ischemia
· Increased work or effort of breathing – Airway obstruction, neuromuscular disease, kyphoscoliosis
· Air hunger, need to breathe- Increased drive to breathe (CHF, pulmonary embolism, moderate to severe airflow obstruction.
Respiratory System Dyspnea
· Disorders of the airways (e.g., asthma, emphysema, chronic bronchitis, and bronchiectasis) lead to increased airway resistance and work of breathing. Hyperinflation further increases the work of breathing
· Conditions that stiffen the chest wall, such as kyphoscoliosis, or that weaken ventilatory muscles, such as myasthenia gravis or the Guillain-Barre syndrome, are also associated with an increased effort to breathe.
· Pneumonia, pulmonary edema, and aspiration all interfere with gas exchange.
· Pulmonary vascular and interstitial lung disease and pulmonary vascular congestion may produce dyspnea by direct stimulation of pulmonary receptors.
Cardiovascular System Dyspnea
· Mild to moderate anemia is associated with breathing discomfort during exercise
· Hypertension, aortic stenosis, or hypertrophic cardiomyopathy- cause of exercise-induced breathlessness.
· Pericardial disease.
· Diseases of the myocardium resulting from coronary artery disease and non-ischemic cardiomyopathies.
· Correct the underlying problem responsible for the symptom.
· Supplemental O2 administration – oxygen mask , venture mask
· Propped up position.
· Intubation and mechanical ventilation.