Original Abstract
BACKGROUND: Bendopnoea (breathlessness on bending forward) is reported often by patients with pleural effusion, but its prevalence and clinical relevance are unexplored. METHODS: This study prospectively enrolled unselected patients with pleural effusion. Bendopnoea was assessed by time-to-breathlessness when bending patients forward for up to 60 s (60 s-BT). Post-hoc analyses using a 30-second cut-off were also conducted. RESULTS: Two hundred patients (median age=72 years; 61% male) were included; n=88 underwent therapeutic drainage (median=1.50 [Q1-Q3=1.11-2.47] litres). Effusions were commonly malignant and occupied >25% of hemithorax (74%). Most patients had bendopnoea on the 60 s-BT (56%) and reported it "impacted daily activities" (74%). The estimated median time-to-bendopnoea was 43 (95% CI 30-59) seconds. Bendopnoea was more common with larger pleural effusions on chest radiographs (p=0.0332 and p=0.0217 using 60-second and 30-second cut-offs respectively). Patients with bendopnoea on 60 s-BT were more breathless (median: 48 [22-67]30 [5-54] millimetres (mm) on a 100 mm Visual Analog Scale (VAS), p=0.0002) and shorter 6-minute walk distance (6-MWD, median: 200 [128-333]310 [223-371] metres (m), p=0.0013). Similar relevance was found using a 30-second cut-off.The proportion of patients with bendopnoea on 60 s-BT significantly decreased from 62% to 32% post-drainage, p<0.001. Those with bendopnoea (those without) had significantly greater improvement in 6-MWD post-drainage (median 66 [2-101]16 [-40-65] m, p=0.0165). Larger effusion (OR=5.08, 95%CI=1.25-20.66), inverted/flattened hemidiaphragm on ultrasonography (OR=3.93, 95%CI=1.32-11.68 and higher BMI (OR=1.18, 95%CI=1.08-1.28) were associated with bendopnoea (60 s-BT) multivariably. CONCLUSION: Bendopnoea is a simple and worthwhile symptom to recognise in patients with pleural effusion.