The Use of Nebulized Opioids in the Management of Dyspnea: Evidence Synthesis

D yspnea is a subjective experience of breathing discomfort that is comprised of qualitatively distinct sensations that vary in intensity. The dyspnea experience derives from interactions among multiple physiologic, psychological, social, and environmental factors and may induce secondary physiologic and behavioral responses (American Thoracic Society [ATS], 1999). This definition stresses the subjective and multifactorial nature of the symptom. Physiologic causes of dyspnea and alternative targets for treatment classified by ATS (1999) are (a) heightened ventilatory demands, (b) increased impedance or resistance to ventilation, (c) abnormalities of the respiratory muscles, and (d) abnormal central perception of dyspnea as a result of increased central respiratory drive. The sensation of dyspnea, like pain, has an affective dimension (Carrieri-Kohlman, Gormley, Douglas, Paul, & Stulbarg, 1996; Wilson & Jones, 1991). The same stimulus, such as walking up stairs, can make patients aware that their breathing has become labored, but patients’ reaction to the breathlessness can vary greatly and make the symptom seem more or less severe. In other words, the affective component of a symptom, in this case dyspnea, can differ greatly and modulate the intensity of the The Use of Nebulized Opioids in the Management of Dyspnea: Evidence Synthesis