Details of investigations of the respiratory and allied systems to determine the cause of cough
| Patient 1 | Patient 2 | Patient 3 | Patient 4 | Patient 5 | |
|---|---|---|---|---|---|
| Chestx ray film | Normal | Normal | Normal | Normal | Normal |
| CT thorax | Normal | — | — | Peribronchial shadowing R upper zone | — |
| Spirometry (observed/expected (n (%))) | |||||
| Vital capacity (l) | 5.4 (104) | 1.9 (89) | 2.4 (114) | 2.9 (104) | 2.8 (117) |
| FEV1 (l) | 4.5 (110) | 1.6 (90) | 1.8 (126) | 2.4 (109) | 2.0 (99) |
| FEV/VC (%) | 83 (108) | 84 (91) | 73 (112) | 83 (98) | 71 (91) |
| Peak expiratory flow rate (l/min) | 710 (114) | 450 (90) | 315 (106) | 475 (117) | 147 (50) |
| Transfer factor (TLCO) (ml/min/mm Hg) | 26 (74) | — | 6.3 (105) | 25 (109) | 15.1 (72) |
| Bronchoscopy | Normal | — | — | Normal | — |
| Nasolaryngoscopy | Small pharyngeal pouch “not functionally significant” | Normal | Normal | Mild rhinitis | Normal |
| Cine-video fluoroscopy | Minimal pooling in valleculae and pyriform fossae. Reduced tongue base contractions | Minimal reduction in tongue base motility | — | Mild reduction in tongue base contractions | — |
| OGD | Small hiatus hernia | Small hiatus hernia | — | Normal | Normal |
| Capsaicin challenge | Increased sensitivity | Increased sensitivity | — | Increased sensitivity | — |
OGD=oesophagogastroduodenoscopy; FEV1=forced expiratory flow in 1 minute; —=not performed; TLCO=transfer coefficient for carbon monoxide.