Dyspnea on Exercise Is Associated with Overall Symptom Burden in Patients with Chronic Respiratory Insufficiency

Patients with chronic respiratory insufficiency suffer from many symptoms together with dyspnea. We evaluated the association of dyspnea on exercise with other symptoms in patients with chronic respiratory insufficiency due to chronic obstructive pulmonary disease or interstitial lung disease. This retrospective study included 101 patients in Tampere University Hospital, Finland. Dyspnea on exercise was assessed with modified Medical Research Council (mMRC) dyspnea questionnaire, and other symptoms were assessed with Edmonton Symptom Assessment System (ESAS) and Depression Scale (DEPS). The study was approved by Regional Ethics Committee of Tampere University Hospital, Finland (approval code R15180/December 1, 2015). Patients with mMRC 4 (most severe dyspnea) compared with those with mMRC 0-3 reported higher symptom scores on ESAS in shortness of breath (median 8.0 [IQR 6.0-9.0] vs. 4.0 [2.0-6.0], p < 0.001), dry mouth (7.0 [4.0-8.0] vs. 3.0 [1.0-6.0], p < 0.001), tiredness (6.0 [3.0-7.0] vs. 3.0 [1.0-5.0], p < 0.001), loss of appetite (3.0 [0.0-6.0] vs. 1.0 [0.0-3.0], p = 0.001), insomnia (3.0 [1.0-7.0] vs. 2.0 [0.0-3.0], p = 0.027), anxiety (3.0 [0.0-5.5] vs. 1.0 [0.0-3.0], p = 0.007), and nausea (0.0 [0.0-2.0] vs. 0.0 [0.0-0.3], p = 0.027). Patients with mMRC 4 were more likely to reach the DEPS threshold for depression than those scoring mMRC 0-3 (42.1% vs. 20.8%, p = 0.028). Patients with chronic respiratory insufficiency need comprehensive symptom screening with relevant treatment, as they suffer from broad symptom burden worsening with increased dyspnea on exercise.