Results of the patients’ investigations and final diagnosis
| Patient no. (no. in fig1) | PEF variation? | Beta agonist response | FEV1/FVC (%) | sGaw | Arterial blood gas tensions | Histamine PC20 (mg/ml) | Bronchoscopy and biopsy | Hyperventilation test | Sleep study |
|---|---|---|---|---|---|---|---|---|---|
| 1 (1) | Yes | None | 92 | No | Normal | >16 | Normal | Positive | ND |
| 2 (2) | Yes | None | 74 | Normal | Inc Pao 2, dec Paco 2 | >16 | ND | Positive | ND |
| 3 (3&4) | No | <10% | 78 | ND | Dec Paco 2 | 6 | Normal | Normal | ND |
| 4 (5) | Yes | >20% | 67 | Normal | Dec Paco 2 | ND | ND | Positive | ND |
| 5 (6) | Yes | <10% | 60 | ND | Normal | 0.5 | ND | ND | ND |
| 6 (7) | Yes | None | 69 | ND | Dec Pao 2once | ND | ND | ND | ND |
| 7 (8) | Yes | None | 76 | Normal | Inc Pao 2 | 0.49 | ND | Normal | Abnormal |
| 8 (9) | Yes | None | 83 | Normal | Dec Pao 2 | Poor effort | ND | ND | Abnormal |
| 9 | Yes | ND | ND | ND | Dec Paco 2 | ND | Normal | ND | ND |
| 10 (10) | Yes | None | 71 | ND | Dec Pao 2 | ND | ND | Positive | ND |
| 11 | Yes | >20% | 68 | Normal | Dec Paco 2 | ND | ND | Positive | ND |
| 12 | Yes | ND | 66 | Normal | Dec Pao 2 once | ND | ND | ND | ND |
| 13 (11) | Yes | <10% | 87 | Normal | Inc Paco 2 | ND | ND | ND | ND |
| 14 (12) | Yes | None | 85 | ND | Dec Paco 2 | ND | ND | Positive | Indeterminate |
| Mean | 13/14 | 2/12 | 75.1 |
| Oesophageal pH monitoring | Psychiatric assessment | ENT appraisal | Eventual diagnosis |
|---|---|---|---|
| Positive | ND | Abnormal | Reflux, vocal cord dysfunction |
| Positive | ND | ND | Hyperventilation, reflux |
| Positive | ND | ND | Hyperventilation, reflux, possible mild asthma |
| ND | Abnormal | ND | Hyperventilation, psychiatric disorder, ?asthma |
| ND | Abnormal | ND | Personality disorder, possibly asthma or Munchausen’s syndrome |
| ND | Abnormal | ND | Personality disorder, ?asthma |
| ND | ND | Abnormal | Obstructive sleep apnoea, obesity |
| ND | Yes | ND | Obstructive sleep apnoea |
| ND | Yes | ND | Hyperventilation |
| ND | Yes | ND | ?Hyperventilation, ?COPD, but some sputum eosinophilia |
| ND | ND | ND | Hyperventilation, sputum eosinophilia, normal sGaw, eosinophilic syndrome? |
| ND | Yes | ND | Smoking related airway obstruction |
| ND | ND | ND | Not asthma as normal sGaw, elevated CO2 and no salbutamol response |
| ND | Abnormal | ND | Hyperventilation, possible obstructive sleep apnoea |
Pao2, Paco2 = arterial oxygen and carbon dioxide tensions; sGaw = specific airway conductance; ND = not determined.