tailieunhanh - Chapter 033. Dyspnea and Pulmonary Edema (Part 2)

Integration: Efferent-Reafferent Mismatch A discrepancy or mismatch between the feed-forward message to the ventilatory muscles and the feedback from receptors that monitor the response of the ventilatory pump increases the intensity of dyspnea. This is particularly important when there is a mechanical derangement of the ventilatory pump, such as in asthma or chronic obstructive pulmonary disease (COPD). Anxiety Acute anxiety may increase the severity of dyspnea either by altering the interpretation of sensory data or by leading to patterns of breathing that heighten physiologic abnormalities in the respiratory system. In patients with expiratory flow limitation, for example, the increased respiratory rate that. | Chapter 033. Dyspnea and Pulmonary Edema Part 2 Integration Efferent-Reafferent Mismatch A discrepancy or mismatch between the feed-forward message to the ventilatory muscles and the feedback from receptors that monitor the response of the ventilatory pump increases the intensity of dyspnea. This is particularly important when there is a mechanical derangement of the ventilatory pump such as in asthma or chronic obstructive pulmonary disease COPD . Anxiety Acute anxiety may increase the severity of dyspnea either by altering the interpretation of sensory data or by leading to patterns of breathing that heighten physiologic abnormalities in the respiratory system. In patients with expiratory flow limitation for example the increased respiratory rate that accompanies acute anxiety leads to hyperinflation increased work of breathing a sense of an increased effort to breathe and a sense of an unsatisfying breath. Assessing Dyspnea Quality of Sensation As with pain dyspnea assessment begins with a determination of the quality of the discomfort Table 33-1 . Dyspnea questionnaires or lists of phrases commonly used by patients assist those who have difficulty describing their breathing sensations. Table 33-1 Association of Qualitative Descriptors and Pathophysiologic Mechanisms of Shortness of Breath Descriptor Pathophysiology Chest tightness or constriction Bronchoconstriction interstitial edema asthma myocardial ischemia Increased work or effort of breathing Airway obstruction neuromuscular disease COPD moderate to severe asthma myopathy kyphoscoliosis Air hunger need to breathe urge to breathe Increased drive to breathe CHF pulmonary embolism moderate to severe airflow obstruction Cannot get a deep breath unsatisfying breath Hyperinflation asthma COPD and restricted tidal volume .