Olfactory performance before and after lung transplantation: quantitative assessment and impact on quality of life

Although olfactory function significantly impacts quality of life (QoL) and factors that potentially interfere with the sense of smell are numerous in solid-organ recipients, no respective data exist for this population. In this study we investigate the olfactory function, QoL, and the accuracy of subjectively perceived olfactory dysfunction.

Olfactory performance was assessed with the aid of a validated test battery (Sniffin' Sticks) in 70 randomly selected lung transplant recipients and 22 patients on the lung transplant waiting list. In addition to assess QoL, the Questions on Life Satisfaction Module (FLZ(M)) and the Hospital Anxiety Depression Scale (HADS) were used.

Waiting list patients and lung transplant recipients did not show differences in terms of demographic data and olfactory performance. Compared with a normative population, patients <55 years of age had a significantly lower olfactory performance both before and after lung transplantation. Scores for general life satisfaction, health life satisfaction, and depression were significantly better in lung transplant recipients. In the multivariate analysis, better olfactory performance was significantly associated with better QoL before and after lung transplantation. Self-estimation of olfactory performance had a sensitivity of 36% and a specificity of 78%, respectively, to detect hyposmia/anosmia in our population.

Although lung transplantation does not seem to have an impact on olfactory performance, sense of smell is significantly below the average in lung transplant recipients and patients on the waiting list. In both groups, olfactory performance is significantly associated with QoL. Furthermore, self-estimation of olfactory function shows inadequately low sensitivity and specificity.