Study of the relationship of dyspnea with depression and functional status in patients with interstitial lung disease

Background: Interstitial lung disease (ILD) is a chronic progressive disease resulting in substantial morbidity and mortality. The cardinal symptom of ILD is dyspnea; however, other pulmonary and extra-pulmonary symptoms are often present. Depression is a common comorbidity of many chronic diseases and directly impacts quality of life. Aim of work: To determine the relationship of dyspnea with selected clinical and psychiatric variables including functional status and depression in patients with ILD. Patients and methods: The work included thirty five clinically and radiologically known cases of ILD and ten healthy controls, they were subdivided into Group I: Twenty patients without pulmonary hypertension. Group II: Fifteen patients with pulmonary hypertension. Group III: Ten healthy controls. All cases subjected to medical history, clinical examination, plain X-ray chest, HRCT, 6-minute walk test, arterial blood gases, Flow/volume loop , echocardiography, Other investigations e.g., collagen profile and depression, anxiety, pain, sleep and dyspnea questionnaire. Results: Among ILD groups: Dyspnea score showed a statistically significant positive correlation with psychiatric disorders (depression score, anxiety score, sleep disorders and pain score) while a statistically significant negative correlation with 6MWD, spirometric variables (FEV1 % and FVC %) and ABG variables (PaO2 and SO2 %). Dyspnea score, clinical variables (6MWD, RVSP, spirometric and ABG variables) and psychiatric disorders were statistically significantly more affected in ILD group with PHTN than in ILD group without PHTN. There was no statistically significant correlation between psychiatric disorders and both sex and smoking history among ILD groups. Conclusion: Dyspnea is common in ILD and is strongly correlated with functional status and psychiatric disorders. Dyspnea score, functional status and psychiatric disorders are more affected in ILD with PHTN than in ILD without PHTN. Accordingly, routine screening for mental disorders is recommended for patients with ILD, and should be accompanied by accurate assessment of patient’s symptoms, particularly in patients with high levels of functional impairment