Table 2

Results of the patients’ investigations and final diagnosis

Patient no. (no. in fig1)PEF variation?Beta agonist responseFEV1/FVC (%)sGawArterial blood gas tensionsHistamine PC20 (mg/ml)Bronchoscopy and biopsyHyperventilation testSleep study
1 (1)YesNone92NoNormal>16NormalPositiveND
2 (2)YesNone74Normal Inc Pao 2, dec Paco 2 >16NDPositiveND
3 (3&4)No<10%78NDDec Paco 2 6NormalNormalND
4 (5)Yes>20%67NormalDec Paco 2 NDNDPositiveND
5 (6)

6 (7)YesNone69NDDec Pao 2onceNDNDNDND
7 (8)YesNone76NormalInc Pao 2 0.49NDNormalAbnormal
8 (9)YesNone83NormalDec Pao 2 Poor effortNDNDAbnormal
9YesNDNDNDDec Paco 2 NDNormalNDND
10 (10)

YesNone71NDDec Pao 2 NDNDPositiveND

Yes>20%68NormalDec Paco 2 NDNDPositiveND
12YesND66NormalDec Pao 2 onceNDNDNDND
13 (11)

Yes<10%87NormalInc Paco 2 NDNDNDND
14 (12)

YesNone85NDDec Paco 2 NDNDPositiveIndeterminate
Oesophageal pH monitoringPsychiatric assessmentENT appraisalEventual diagnosis
PositiveNDAbnormalReflux, vocal cord dysfunction
PositiveNDNDHyperventilation, reflux
PositiveNDNDHyperventilation, reflux, possible mild asthma
NDAbnormalNDHyperventilation, psychiatric disorder, ?asthma
NDAbnormalNDPersonality disorder, possibly asthma or Munchausen’s syndrome
NDAbnormalNDPersonality disorder, ?asthma
NDNDAbnormalObstructive sleep apnoea, obesity
NDYesNDObstructive sleep apnoea
NDYesND?Hyperventilation, ?COPD, but some sputum eosinophilia
NDNDNDHyperventilation, sputum eosinophilia, normal sGaw, eosinophilic syndrome?
NDYesNDSmoking related airway obstruction
NDNDNDNot asthma as normal sGaw, elevated CO2 and no salbutamol response
NDAbnormalNDHyperventilation, possible obstructive sleep apnoea
  • Pao2, Paco2 = arterial oxygen and carbon dioxide tensions; sGaw = specific airway conductance; ND = not determined.