Nursing Care of Dyspnea: The 6th Vital Sign in Individuals with ...

Nursing Best Practice GuidelineDyspnea: The Principal Symptom of COPDDyspnea is a complex phenomenon, whose genesis from a physiological perspective is associated with anumber of elements involving sensory perception, central processing and motor commands; factorsassociated with respiratory effort or work of breathing, chemoreceptors or chemical factors affectingrespiratory drive and mechanoreceptors or sites of dyspnogenesis (Killian & Campbell, 1996; Killian & Gandevia, 1996).In general, there is consensus in the literature concerning the existing physiological research that suggeststhat the degree of perceived breathlessness is proportional to respiratory effort. That is, the greater theunsuccessful respiratory effort exerted by an individual, the greater the sensation of breathlessnessexperienced (Campbell & Howell, 1963; El-Manshawi, Killian, Summers & Jones, 1986; Jones, 1992; Jones & Wilson, 1996;Killian, 1985; Killian & Gandevia, 1996; Killian, Gandevia, Summer & Campbell, 1984). Whereas the evidence reviewedsuggests a relationship between respiratory effort or work, chemoreceptors and mechanoreceptors, theprecise physical mechanism of dyspnea remains unclear. In order to facilitate the development of effectivestrategies for relief of this distressing symptom in individuals with progressive disease, researcherscontinue to attempt to understand these mechanisms (Killian, 1985).Although the affective contribution to a perception of breathlessness has never been denied, the nature ofits contribution has been elusive (Guz, 1996). Limited research has been conducted to explain whyindividuals with apparently comparable lung disease report varying levels of respiratory distress (Traver,1988). However, the research done in an attempt to understand the psychological aspect of dyspnea doesclearly show a relationship between anxiety and levels of dyspnea (Carrieri-Kolman, Douglas, Murray Gormley &Stulbarg, 1993; Gift & Cahill, 1990; Gift, Plaut, & Jacox, 1986). The affective contribution to a perception of more orless severe breathlessness continues to remain enigmatic. Some researchers would suggest that theinconclusiveness of this research implores that these relationships be examined further, and thatpractitioners should be cautious in their attempt to attribute responsibility for the severity ofbreathlessness to psychological factors (Bailey, 2004). Indeed perhaps the gap in the understanding of thefactors affecting the severity of this perceived symptom is more related to the imperfect understanding ofhow to objectively measure the experience of breathlessness (Killian, 1985; Killian & Gandevia, 1996).Key Points■■■Dyspnea is a subjective symptom of difficult or uncomfortable breathing.Dyspnea must not be confused with changes in rate or depth ofrespiration that may not produce a sense of breathlessness.The affective contribution to a perception of more or lessbreathlessness remains enigmatic.19